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7974362afd
gecko-dev/modules/libpref/Preferences.cpp
Nicholas Nethercote 7974362afd Bug 1567329 - Append _AtStartup to once static pref getters. r=erahm 
Currently it's completely unclear at use sites that the getters for `once`
static prefs return the pref value from startup, rather than the current pref
value. (Bugs have been caused by this.) This commit improves things by changing
the getter name to make it clear that the pref value obtained is from startup.

This required changing things within libpref so it distinguishes between the
"base id" (`foo_bar`) and the "full id" (`foo_bar` or
`foo_bar_DoNotUseDirectly` or `foo_bar_AtStartup` or
`foo_bar_AtStartup_DoNotUseDirectly`; the name used depends on the `mirror` and
`do_not_use_directly` values in the YAML definition.) The "full id" is used in
most places, while the "base id" is used for the `GetPrefName_*` and
`GetPrefDefault_*` functions.

(This is a nice demonstration of the benefits of the YAML file, BTW. Making
this change with the old code would have involved adding an entry to every
single pref in StaticPrefList.h.)

The patch also rejigs the comment at the top of StaticPrefList.yaml, to clarify
some things.

Differential Revision: https://phabricator.services.mozilla.com/D38604

--HG--
extra : moz-landing-system : lando
2019-07-22 02:10:14 +00:00

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "SharedPrefMap.h"
#include "base/basictypes.h"
#include "GeckoProfiler.h"
#include "MainThreadUtils.h"
#include "mozilla/ArenaAllocatorExtensions.h"
#include "mozilla/ArenaAllocator.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/Components.h"
#include "mozilla/dom/PContent.h"
#include "mozilla/HashFunctions.h"
#include "mozilla/HashTable.h"
#include "mozilla/Logging.h"
#include "mozilla/Maybe.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Omnijar.h"
#include "mozilla/Preferences.h"
#include "mozilla/ResultExtensions.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/Services.h"
#include "mozilla/ServoStyleSet.h"
#include "mozilla/StaticMutex.h"
#include "mozilla/StaticPrefs.h"
#include "mozilla/StaticPrefs_accessibility.h"
#include "mozilla/SyncRunnable.h"
#include "mozilla/SystemGroup.h"
#include "mozilla/Telemetry.h"
#include "mozilla/UniquePtrExtensions.h"
#include "mozilla/URLPreloader.h"
#include "mozilla/Variant.h"
#include "mozilla/Vector.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsAutoPtr.h"
#include "nsCategoryManagerUtils.h"
#include "nsClassHashtable.h"
#include "nsCOMArray.h"
#include "nsCOMPtr.h"
#include "nsCRT.h"
#include "nsDataHashtable.h"
#include "nsDirectoryServiceDefs.h"
#include "nsHashKeys.h"
#include "nsICategoryManager.h"
#include "nsIConsoleService.h"
#include "nsIDirectoryService.h"
#include "nsIFile.h"
#include "nsIInputStream.h"
#include "nsIMemoryReporter.h"
#include "nsIObserver.h"
#include "nsIObserverService.h"
#include "nsIOutputStream.h"
#include "nsIPrefBranch.h"
#include "nsIPrefLocalizedString.h"
#include "nsIRelativeFilePref.h"
#include "nsISafeOutputStream.h"
#include "nsISimpleEnumerator.h"
#include "nsIStringBundle.h"
#include "nsIStringEnumerator.h"
#include "nsISupportsImpl.h"
#include "nsISupportsPrimitives.h"
#include "nsIZipReader.h"
#include "nsNetUtil.h"
#include "nsPrintfCString.h"
#include "nsQuickSort.h"
#include "nsReadableUtils.h"
#include "nsRefPtrHashtable.h"
#include "nsRelativeFilePref.h"
#include "nsString.h"
#include "nsTArray.h"
#include "nsThreadUtils.h"
#include "nsUTF8Utils.h"
#include "nsWeakReference.h"
#include "nsXPCOMCID.h"
#include "nsXPCOM.h"
#include "nsXULAppAPI.h"
#include "nsZipArchive.h"
#include "plbase64.h"
#include "PLDHashTable.h"
#include "plstr.h"
#include "prlink.h"
#include "xpcpublic.h"
#ifdef DEBUG
# include <map>
#endif
#ifdef MOZ_MEMORY
# include "mozmemory.h"
#endif
#ifdef XP_WIN
# include "windows.h"
#endif
using namespace mozilla;
using ipc::FileDescriptor;
#ifdef DEBUG
# define ENSURE_PARENT_PROCESS(func, pref) \
do { \
if (MOZ_UNLIKELY(!XRE_IsParentProcess())) { \
nsPrintfCString msg( \
"ENSURE_PARENT_PROCESS: called %s on %s in a non-parent process", \
func, pref); \
NS_ERROR(msg.get()); \
return NS_ERROR_NOT_AVAILABLE; \
} \
} while (0)
#else // DEBUG
# define ENSURE_PARENT_PROCESS(func, pref) \
if (MOZ_UNLIKELY(!XRE_IsParentProcess())) { \
return NS_ERROR_NOT_AVAILABLE; \
}
#endif // DEBUG
//===========================================================================
// Low-level types and operations
//===========================================================================
typedef nsTArray<nsCString> PrefSaveData;
// 1 MB should be enough for everyone.
static const uint32_t MAX_PREF_LENGTH = 1 * 1024 * 1024;
// Actually, 4kb should be enough for everyone.
static const uint32_t MAX_ADVISABLE_PREF_LENGTH = 4 * 1024;
// This is used for pref names and string pref values. We encode the string
// length, then a '/', then the string chars. This encoding means there are no
// special chars that are forbidden or require escaping.
static void SerializeAndAppendString(const char* aChars, nsCString& aStr) {
aStr.AppendInt(uint32_t(strlen(aChars)));
aStr.Append('/');
aStr.Append(aChars);
}
static char* DeserializeString(char* aChars, nsCString& aStr) {
char* p = aChars;
uint32_t length = strtol(p, &p, 10);
MOZ_ASSERT(p[0] == '/');
p++; // move past the '/'
aStr.Assign(p, length);
p += length; // move past the string itself
return p;
}
// Keep this in sync with PrefValue in prefs_parser/src/lib.rs.
union PrefValue {
const char* mStringVal;
int32_t mIntVal;
bool mBoolVal;
PrefValue() = default;
explicit PrefValue(bool aVal) : mBoolVal(aVal) {}
explicit PrefValue(int32_t aVal) : mIntVal(aVal) {}
explicit PrefValue(const char* aVal) : mStringVal(aVal) {}
bool Equals(PrefType aType, PrefValue aValue) {
switch (aType) {
case PrefType::String: {
if (mStringVal && aValue.mStringVal) {
return strcmp(mStringVal, aValue.mStringVal) == 0;
}
if (!mStringVal && !aValue.mStringVal) {
return true;
}
return false;
}
case PrefType::Int:
return mIntVal == aValue.mIntVal;
case PrefType::Bool:
return mBoolVal == aValue.mBoolVal;
default:
MOZ_CRASH("Unhandled enum value");
}
}
template <typename T>
T Get() const;
void Init(PrefType aNewType, PrefValue aNewValue) {
if (aNewType == PrefType::String) {
MOZ_ASSERT(aNewValue.mStringVal);
aNewValue.mStringVal = moz_xstrdup(aNewValue.mStringVal);
}
*this = aNewValue;
}
void Clear(PrefType aType) {
if (aType == PrefType::String) {
free(const_cast<char*>(mStringVal));
}
// Zero the entire value (regardless of type) via mStringVal.
mStringVal = nullptr;
}
void Replace(bool aHasValue, PrefType aOldType, PrefType aNewType,
PrefValue aNewValue) {
if (aHasValue) {
Clear(aOldType);
}
Init(aNewType, aNewValue);
}
void ToDomPrefValue(PrefType aType, dom::PrefValue* aDomValue) {
switch (aType) {
case PrefType::String:
*aDomValue = nsDependentCString(mStringVal);
return;
case PrefType::Int:
*aDomValue = mIntVal;
return;
case PrefType::Bool:
*aDomValue = mBoolVal;
return;
default:
MOZ_CRASH();
}
}
PrefType FromDomPrefValue(const dom::PrefValue& aDomValue) {
switch (aDomValue.type()) {
case dom::PrefValue::TnsCString:
mStringVal = aDomValue.get_nsCString().get();
return PrefType::String;
case dom::PrefValue::Tint32_t:
mIntVal = aDomValue.get_int32_t();
return PrefType::Int;
case dom::PrefValue::Tbool:
mBoolVal = aDomValue.get_bool();
return PrefType::Bool;
default:
MOZ_CRASH();
}
}
void SerializeAndAppend(PrefType aType, nsCString& aStr) {
switch (aType) {
case PrefType::Bool:
aStr.Append(mBoolVal ? 'T' : 'F');
break;
case PrefType::Int:
aStr.AppendInt(mIntVal);
break;
case PrefType::String: {
SerializeAndAppendString(mStringVal, aStr);
break;
}
case PrefType::None:
default:
MOZ_CRASH();
}
}
static char* Deserialize(PrefType aType, char* aStr,
Maybe<dom::PrefValue>* aDomValue) {
char* p = aStr;
switch (aType) {
case PrefType::Bool:
if (*p == 'T') {
*aDomValue = Some(true);
} else if (*p == 'F') {
*aDomValue = Some(false);
} else {
*aDomValue = Some(false);
NS_ERROR("bad bool pref value");
}
p++;
return p;
case PrefType::Int: {
*aDomValue = Some(int32_t(strtol(p, &p, 10)));
return p;
}
case PrefType::String: {
nsCString str;
p = DeserializeString(p, str);
*aDomValue = Some(str);
return p;
}
default:
MOZ_CRASH();
}
}
};
template <>
bool PrefValue::Get() const {
return mBoolVal;
}
template <>
int32_t PrefValue::Get() const {
return mIntVal;
}
template <>
nsDependentCString PrefValue::Get() const {
return nsDependentCString(mStringVal);
}
#ifdef DEBUG
const char* PrefTypeToString(PrefType aType) {
switch (aType) {
case PrefType::None:
return "none";
case PrefType::String:
return "string";
case PrefType::Int:
return "int";
case PrefType::Bool:
return "bool";
default:
MOZ_CRASH("Unhandled enum value");
}
}
#endif
// Assign to aResult a quoted, escaped copy of aOriginal.
static void StrEscape(const char* aOriginal, nsCString& aResult) {
if (aOriginal == nullptr) {
aResult.AssignLiteral("\"\"");
return;
}
// JavaScript does not allow quotes, slashes, or line terminators inside
// strings so we must escape them. ECMAScript defines four line terminators,
// but we're only worrying about \r and \n here. We currently feed our pref
// script to the JS interpreter as Latin-1 so we won't encounter \u2028
// (line separator) or \u2029 (paragraph separator).
//
// WARNING: There are hints that we may be moving to storing prefs as utf8.
// If we ever feed them to the JS compiler as UTF8 then we'll have to worry
// about the multibyte sequences that would be interpreted as \u2028 and
// \u2029.
const char* p;
aResult.Assign('"');
// Paranoid worst case all slashes will free quickly.
for (p = aOriginal; *p; ++p) {
switch (*p) {
case '\n':
aResult.AppendLiteral("\\n");
break;
case '\r':
aResult.AppendLiteral("\\r");
break;
case '\\':
aResult.AppendLiteral("\\\\");
break;
case '\"':
aResult.AppendLiteral("\\\"");
break;
default:
aResult.Append(*p);
break;
}
}
aResult.Append('"');
}
namespace mozilla {
struct PrefsSizes {
PrefsSizes()
: mHashTable(0),
mPrefValues(0),
mStringValues(0),
mCacheData(0),
mRootBranches(0),
mPrefNameArena(0),
mCallbacksObjects(0),
mCallbacksDomains(0),
mMisc(0) {}
size_t mHashTable;
size_t mPrefValues;
size_t mStringValues;
size_t mCacheData;
size_t mRootBranches;
size_t mPrefNameArena;
size_t mCallbacksObjects;
size_t mCallbacksDomains;
size_t mMisc;
};
} // namespace mozilla
static StaticRefPtr<SharedPrefMap> gSharedMap;
static ArenaAllocator<4096, 1> gPrefNameArena;
class PrefWrapper;
class Pref {
public:
explicit Pref(const char* aName)
: mName(ArenaStrdup(aName, gPrefNameArena)),
mType(static_cast<uint32_t>(PrefType::None)),
mIsSticky(false),
mIsLocked(false),
mDefaultChanged(false),
mHasDefaultValue(false),
mHasUserValue(false),
mIsSkippedByIteration(false),
mDefaultValue(),
mUserValue() {}
~Pref() {
// There's no need to free mName because it's allocated in memory owned by
// gPrefNameArena.
mDefaultValue.Clear(Type());
mUserValue.Clear(Type());
}
const char* Name() const { return mName; }
nsDependentCString NameString() const { return nsDependentCString(mName); }
// Types.
PrefType Type() const { return static_cast<PrefType>(mType); }
void SetType(PrefType aType) { mType = static_cast<uint32_t>(aType); }
bool IsType(PrefType aType) const { return Type() == aType; }
bool IsTypeNone() const { return IsType(PrefType::None); }
bool IsTypeString() const { return IsType(PrefType::String); }
bool IsTypeInt() const { return IsType(PrefType::Int); }
bool IsTypeBool() const { return IsType(PrefType::Bool); }
// Other properties.
bool IsLocked() const { return mIsLocked; }
void SetIsLocked(bool aValue) { mIsLocked = aValue; }
bool IsSkippedByIteration() const { return mIsSkippedByIteration; }
void SetIsSkippedByIteration(bool aValue) { mIsSkippedByIteration = aValue; }
bool DefaultChanged() const { return mDefaultChanged; }
bool IsSticky() const { return mIsSticky; }
bool HasDefaultValue() const { return mHasDefaultValue; }
bool HasUserValue() const { return mHasUserValue; }
template <typename T>
void AddToMap(SharedPrefMapBuilder& aMap) {
aMap.Add(Name(),
{HasDefaultValue(), HasUserValue(), IsSticky(), IsLocked(),
DefaultChanged(), IsSkippedByIteration()},
HasDefaultValue() ? mDefaultValue.Get<T>() : T(),
HasUserValue() ? mUserValue.Get<T>() : T());
}
void AddToMap(SharedPrefMapBuilder& aMap) {
if (IsTypeBool()) {
AddToMap<bool>(aMap);
} else if (IsTypeInt()) {
AddToMap<int32_t>(aMap);
} else if (IsTypeString()) {
AddToMap<nsDependentCString>(aMap);
} else {
MOZ_ASSERT_UNREACHABLE("Unexpected preference type");
}
}
// Other operations.
bool GetBoolValue(PrefValueKind aKind = PrefValueKind::User) const {
MOZ_ASSERT(IsTypeBool());
MOZ_ASSERT(aKind == PrefValueKind::Default ? HasDefaultValue()
: HasUserValue());
return aKind == PrefValueKind::Default ? mDefaultValue.mBoolVal
: mUserValue.mBoolVal;
}
int32_t GetIntValue(PrefValueKind aKind = PrefValueKind::User) const {
MOZ_ASSERT(IsTypeInt());
MOZ_ASSERT(aKind == PrefValueKind::Default ? HasDefaultValue()
: HasUserValue());
return aKind == PrefValueKind::Default ? mDefaultValue.mIntVal
: mUserValue.mIntVal;
}
const char* GetBareStringValue(
PrefValueKind aKind = PrefValueKind::User) const {
MOZ_ASSERT(IsTypeString());
MOZ_ASSERT(aKind == PrefValueKind::Default ? HasDefaultValue()
: HasUserValue());
return aKind == PrefValueKind::Default ? mDefaultValue.mStringVal
: mUserValue.mStringVal;
}
nsDependentCString GetStringValue(
PrefValueKind aKind = PrefValueKind::User) const {
return nsDependentCString(GetBareStringValue(aKind));
}
void ToDomPref(dom::Pref* aDomPref) {
MOZ_ASSERT(XRE_IsParentProcess());
aDomPref->name() = mName;
aDomPref->isLocked() = mIsLocked;
if (mHasDefaultValue) {
aDomPref->defaultValue() = Some(dom::PrefValue());
mDefaultValue.ToDomPrefValue(Type(), &aDomPref->defaultValue().ref());
} else {
aDomPref->defaultValue() = Nothing();
}
if (mHasUserValue) {
aDomPref->userValue() = Some(dom::PrefValue());
mUserValue.ToDomPrefValue(Type(), &aDomPref->userValue().ref());
} else {
aDomPref->userValue() = Nothing();
}
MOZ_ASSERT(aDomPref->defaultValue().isNothing() ||
aDomPref->userValue().isNothing() ||
(aDomPref->defaultValue().ref().type() ==
aDomPref->userValue().ref().type()));
}
void FromDomPref(const dom::Pref& aDomPref, bool* aValueChanged) {
MOZ_ASSERT(!XRE_IsParentProcess());
MOZ_ASSERT(strcmp(mName, aDomPref.name().get()) == 0);
mIsLocked = aDomPref.isLocked();
const Maybe<dom::PrefValue>& defaultValue = aDomPref.defaultValue();
bool defaultValueChanged = false;
if (defaultValue.isSome()) {
PrefValue value;
PrefType type = value.FromDomPrefValue(defaultValue.ref());
if (!ValueMatches(PrefValueKind::Default, type, value)) {
// Type() is PrefType::None if it's a newly added pref. This is ok.
mDefaultValue.Replace(mHasDefaultValue, Type(), type, value);
SetType(type);
mHasDefaultValue = true;
defaultValueChanged = true;
}
}
// Note: we never clear a default value.
const Maybe<dom::PrefValue>& userValue = aDomPref.userValue();
bool userValueChanged = false;
if (userValue.isSome()) {
PrefValue value;
PrefType type = value.FromDomPrefValue(userValue.ref());
if (!ValueMatches(PrefValueKind::User, type, value)) {
// Type() is PrefType::None if it's a newly added pref. This is ok.
mUserValue.Replace(mHasUserValue, Type(), type, value);
SetType(type);
mHasUserValue = true;
userValueChanged = true;
}
} else if (mHasUserValue) {
ClearUserValue();
userValueChanged = true;
}
if (userValueChanged || (defaultValueChanged && !mHasUserValue)) {
*aValueChanged = true;
}
}
void FromWrapper(PrefWrapper& aWrapper);
bool HasAdvisablySizedValues() {
MOZ_ASSERT(XRE_IsParentProcess());
if (!IsTypeString()) {
return true;
}
const char* stringVal;
if (mHasDefaultValue) {
stringVal = mDefaultValue.mStringVal;
if (strlen(stringVal) > MAX_ADVISABLE_PREF_LENGTH) {
return false;
}
}
if (mHasUserValue) {
stringVal = mUserValue.mStringVal;
if (strlen(stringVal) > MAX_ADVISABLE_PREF_LENGTH) {
return false;
}
}
return true;
}
private:
bool ValueMatches(PrefValueKind aKind, PrefType aType, PrefValue aValue) {
return IsType(aType) &&
(aKind == PrefValueKind::Default
? mHasDefaultValue && mDefaultValue.Equals(aType, aValue)
: mHasUserValue && mUserValue.Equals(aType, aValue));
}
public:
void ClearUserValue() {
mUserValue.Clear(Type());
mHasUserValue = false;
}
nsresult SetDefaultValue(PrefType aType, PrefValue aValue, bool aIsSticky,
bool aIsLocked, bool* aValueChanged) {
// Types must always match when setting the default value.
if (!IsType(aType)) {
return NS_ERROR_UNEXPECTED;
}
// Should we set the default value? Only if the pref is not locked, and
// doing so would change the default value.
if (!IsLocked()) {
if (aIsLocked) {
SetIsLocked(true);
}
if (!ValueMatches(PrefValueKind::Default, aType, aValue)) {
mDefaultValue.Replace(mHasDefaultValue, Type(), aType, aValue);
if (mHasDefaultValue) {
mDefaultChanged = true;
}
mHasDefaultValue = true;
if (aIsSticky) {
mIsSticky = true;
}
if (!mHasUserValue) {
*aValueChanged = true;
}
// What if we change the default to be the same as the user value?
// Should we clear the user value? Currently we don't.
}
}
return NS_OK;
}
nsresult SetUserValue(PrefType aType, PrefValue aValue, bool aFromInit,
bool* aValueChanged) {
// If we have a default value, types must match when setting the user
// value.
if (mHasDefaultValue && !IsType(aType)) {
return NS_ERROR_UNEXPECTED;
}
// Should we clear the user value, if present? Only if the new user value
// matches the default value, and the pref isn't sticky, and we aren't
// force-setting it during initialization.
if (ValueMatches(PrefValueKind::Default, aType, aValue) && !mIsSticky &&
!aFromInit) {
if (mHasUserValue) {
ClearUserValue();
if (!IsLocked()) {
*aValueChanged = true;
}
}
// Otherwise, should we set the user value? Only if doing so would
// change the user value.
} else if (!ValueMatches(PrefValueKind::User, aType, aValue)) {
mUserValue.Replace(mHasUserValue, Type(), aType, aValue);
SetType(aType); // needed because we may have changed the type
mHasUserValue = true;
if (!IsLocked()) {
*aValueChanged = true;
}
}
return NS_OK;
}
// Prefs are serialized in a manner that mirrors dom::Pref. The two should be
// kept in sync. E.g. if something is added to one it should also be added to
// the other. (It would be nice to be able to use the code generated from
// IPDL for serializing dom::Pref here instead of writing by hand this
// serialization/deserialization. Unfortunately, that generated code is
// difficult to use directly, outside of the IPDL IPC code.)
//
// The grammar for the serialized prefs has the following form.
//
// <pref> = <type> <locked> ':' <name> ':' <value>? ':' <value>? '\n'
// <type> = 'B' | 'I' | 'S'
// <locked> = 'L' | '-'
// <name> = <string-value>
// <value> = <bool-value> | <int-value> | <string-value>
// <bool-value> = 'T' | 'F'
// <int-value> = an integer literal accepted by strtol()
// <string-value> = <int-value> '/' <chars>
// <chars> = any char sequence of length dictated by the preceding
// <int-value>.
//
// No whitespace is tolerated between tokens. <type> must match the types of
// the values.
//
// The serialization is text-based, rather than binary, for the following
// reasons.
//
// - The size difference wouldn't be much different between text-based and
// binary. Most of the space is for strings (pref names and string pref
// values), which would be the same in both styles. And other differences
// would be minimal, e.g. small integers are shorter in text but long
// integers are longer in text.
//
// - Likewise, speed differences should be negligible.
//
// - It's much easier to debug a text-based serialization. E.g. you can
// print it and inspect it easily in a debugger.
//
// Examples of unlocked boolean prefs:
// - "B-:8/my.bool1:F:T\n"
// - "B-:8/my.bool2:F:\n"
// - "B-:8/my.bool3::T\n"
//
// Examples of locked integer prefs:
// - "IL:7/my.int1:0:1\n"
// - "IL:7/my.int2:123:\n"
// - "IL:7/my.int3::-99\n"
//
// Examples of unlocked string prefs:
// - "S-:10/my.string1:3/abc:4/wxyz\n"
// - "S-:10/my.string2:5/1.234:\n"
// - "S-:10/my.string3::7/string!\n"
void SerializeAndAppend(nsCString& aStr) {
switch (Type()) {
case PrefType::Bool:
aStr.Append('B');
break;
case PrefType::Int:
aStr.Append('I');
break;
case PrefType::String: {
aStr.Append('S');
break;
}
case PrefType::None:
default:
MOZ_CRASH();
}
aStr.Append(mIsLocked ? 'L' : '-');
aStr.Append(':');
SerializeAndAppendString(mName, aStr);
aStr.Append(':');
if (mHasDefaultValue) {
mDefaultValue.SerializeAndAppend(Type(), aStr);
}
aStr.Append(':');
if (mHasUserValue) {
mUserValue.SerializeAndAppend(Type(), aStr);
}
aStr.Append('\n');
}
static char* Deserialize(char* aStr, dom::Pref* aDomPref) {
char* p = aStr;
// The type.
PrefType type;
if (*p == 'B') {
type = PrefType::Bool;
} else if (*p == 'I') {
type = PrefType::Int;
} else if (*p == 'S') {
type = PrefType::String;
} else {
NS_ERROR("bad pref type");
type = PrefType::None;
}
p++; // move past the type char
// Locked?
bool isLocked;
if (*p == 'L') {
isLocked = true;
} else if (*p == '-') {
isLocked = false;
} else {
NS_ERROR("bad pref locked status");
isLocked = false;
}
p++; // move past the isLocked char
MOZ_ASSERT(*p == ':');
p++; // move past the ':'
// The pref name.
nsCString name;
p = DeserializeString(p, name);
MOZ_ASSERT(*p == ':');
p++; // move past the ':' preceding the default value
Maybe<dom::PrefValue> maybeDefaultValue;
if (*p != ':') {
dom::PrefValue defaultValue;
p = PrefValue::Deserialize(type, p, &maybeDefaultValue);
}
MOZ_ASSERT(*p == ':');
p++; // move past the ':' between the default and user values
Maybe<dom::PrefValue> maybeUserValue;
if (*p != '\n') {
dom::PrefValue userValue;
p = PrefValue::Deserialize(type, p, &maybeUserValue);
}
MOZ_ASSERT(*p == '\n');
p++; // move past the '\n' following the user value
*aDomPref = dom::Pref(name, isLocked, maybeDefaultValue, maybeUserValue);
return p;
}
void AddSizeOfIncludingThis(MallocSizeOf aMallocSizeOf, PrefsSizes& aSizes) {
// Note: mName is allocated in gPrefNameArena, measured elsewhere.
aSizes.mPrefValues += aMallocSizeOf(this);
if (IsTypeString()) {
if (mHasDefaultValue) {
aSizes.mStringValues += aMallocSizeOf(mDefaultValue.mStringVal);
}
if (mHasUserValue) {
aSizes.mStringValues += aMallocSizeOf(mUserValue.mStringVal);
}
}
}
private:
const char* mName; // allocated in gPrefNameArena
uint32_t mType : 2;
uint32_t mIsSticky : 1;
uint32_t mIsLocked : 1;
uint32_t mDefaultChanged : 1;
uint32_t mHasDefaultValue : 1;
uint32_t mHasUserValue : 1;
uint32_t mIsSkippedByIteration : 1;
PrefValue mDefaultValue;
PrefValue mUserValue;
};
struct PrefHasher {
using Key = UniquePtr<Pref>;
using Lookup = const char*;
static HashNumber hash(const Lookup& aLookup) { return HashString(aLookup); }
static bool match(const Key& aKey, const Lookup& aLookup) {
if (!aLookup || !aKey->Name()) {
return false;
}
return strcmp(aLookup, aKey->Name()) == 0;
}
};
using PrefWrapperBase = Variant<Pref*, SharedPrefMap::Pref>;
class MOZ_STACK_CLASS PrefWrapper : public PrefWrapperBase {
using SharedPref = const SharedPrefMap::Pref;
public:
MOZ_IMPLICIT PrefWrapper(Pref* aPref) : PrefWrapperBase(AsVariant(aPref)) {}
MOZ_IMPLICIT PrefWrapper(const SharedPrefMap::Pref& aPref)
: PrefWrapperBase(AsVariant(aPref)) {}
// Types.
bool IsType(PrefType aType) const { return Type() == aType; }
bool IsTypeNone() const { return IsType(PrefType::None); }
bool IsTypeString() const { return IsType(PrefType::String); }
bool IsTypeInt() const { return IsType(PrefType::Int); }
bool IsTypeBool() const { return IsType(PrefType::Bool); }
#define FORWARD(retType, method) \
retType method() const { \
struct Matcher { \
retType operator()(const Pref* aPref) { return aPref->method(); } \
retType operator()(SharedPref& aPref) { return aPref.method(); } \
}; \
return match(Matcher()); \
}
FORWARD(bool, DefaultChanged)
FORWARD(bool, IsLocked)
FORWARD(bool, IsSticky)
FORWARD(bool, HasDefaultValue)
FORWARD(bool, HasUserValue)
FORWARD(const char*, Name)
FORWARD(nsCString, NameString)
FORWARD(PrefType, Type)
#undef FORWARD
#define FORWARD(retType, method) \
retType method(PrefValueKind aKind = PrefValueKind::User) const { \
struct Matcher { \
PrefValueKind mKind; \
\
retType operator()(const Pref* aPref) { return aPref->method(mKind); } \
retType operator()(SharedPref& aPref) { return aPref.method(mKind); } \
}; \
return match(Matcher{aKind}); \
}
FORWARD(bool, GetBoolValue)
FORWARD(int32_t, GetIntValue)
FORWARD(nsCString, GetStringValue)
FORWARD(const char*, GetBareStringValue)
#undef FORWARD
PrefValue GetValue(PrefValueKind aKind = PrefValueKind::User) const {
switch (Type()) {
case PrefType::Bool:
return PrefValue{GetBoolValue(aKind)};
case PrefType::Int:
return PrefValue{GetIntValue(aKind)};
case PrefType::String:
return PrefValue{GetBareStringValue(aKind)};
default:
MOZ_ASSERT_UNREACHABLE("Unexpected pref type");
return PrefValue{};
}
}
Result<PrefValueKind, nsresult> WantValueKind(PrefType aType,
PrefValueKind aKind) const {
if (Type() != aType) {
return Err(NS_ERROR_UNEXPECTED);
}
if (aKind == PrefValueKind::Default || IsLocked() || !HasUserValue()) {
if (!HasDefaultValue()) {
return Err(NS_ERROR_UNEXPECTED);
}
return PrefValueKind::Default;
}
return PrefValueKind::User;
}
nsresult GetValue(PrefValueKind aKind, bool* aResult) const {
PrefValueKind kind;
MOZ_TRY_VAR(kind, WantValueKind(PrefType::Bool, aKind));
*aResult = GetBoolValue(kind);
return NS_OK;
}
nsresult GetValue(PrefValueKind aKind, int32_t* aResult) const {
PrefValueKind kind;
MOZ_TRY_VAR(kind, WantValueKind(PrefType::Int, aKind));
*aResult = GetIntValue(kind);
return NS_OK;
}
nsresult GetValue(PrefValueKind aKind, uint32_t* aResult) const {
return GetValue(aKind, reinterpret_cast<int32_t*>(aResult));
}
nsresult GetValue(PrefValueKind aKind, float* aResult) const {
nsAutoCString result;
nsresult rv = GetValue(aKind, result);
if (NS_SUCCEEDED(rv)) {
// ToFloat() does a locale-independent conversion.
*aResult = result.ToFloat(&rv);
}
return rv;
}
nsresult GetValue(PrefValueKind aKind, nsACString& aResult) const {
PrefValueKind kind;
MOZ_TRY_VAR(kind, WantValueKind(PrefType::String, aKind));
aResult = GetStringValue(kind);
return NS_OK;
}
// Returns false if this pref doesn't have a user value worth saving.
bool UserValueToStringForSaving(nsCString& aStr) {
// Should we save the user value, if present? Only if it does not match the
// default value, or it is sticky.
if (HasUserValue() &&
(!ValueMatches(PrefValueKind::Default, Type(), GetValue()) ||
IsSticky())) {
if (IsTypeString()) {
StrEscape(GetStringValue().get(), aStr);
} else if (IsTypeInt()) {
aStr.AppendInt(GetIntValue());
} else if (IsTypeBool()) {
aStr = GetBoolValue() ? "true" : "false";
}
return true;
}
// Do not save default prefs that haven't changed.
return false;
}
bool Matches(PrefType aType, PrefValueKind aKind, PrefValue& aValue,
bool aIsSticky, bool aIsLocked) const {
return (ValueMatches(aKind, aType, aValue) && aIsSticky == IsSticky() &&
aIsLocked == IsLocked());
}
bool ValueMatches(PrefValueKind aKind, PrefType aType,
const PrefValue& aValue) const {
if (!IsType(aType)) {
return false;
}
if (!(aKind == PrefValueKind::Default ? HasDefaultValue()
: HasUserValue())) {
return false;
}
switch (aType) {
case PrefType::Bool:
return GetBoolValue(aKind) == aValue.mBoolVal;
case PrefType::Int:
return GetIntValue(aKind) == aValue.mIntVal;
case PrefType::String:
return strcmp(GetBareStringValue(aKind), aValue.mStringVal) == 0;
default:
MOZ_ASSERT_UNREACHABLE("Unexpected preference type");
return false;
}
}
};
void Pref::FromWrapper(PrefWrapper& aWrapper) {
MOZ_ASSERT(aWrapper.is<SharedPrefMap::Pref>());
auto pref = aWrapper.as<SharedPrefMap::Pref>();
MOZ_ASSERT(IsTypeNone());
MOZ_ASSERT(strcmp(mName, pref.Name()) == 0);
mType = uint32_t(pref.Type());
mIsLocked = pref.IsLocked();
mIsSticky = pref.IsSticky();
mHasDefaultValue = pref.HasDefaultValue();
mHasUserValue = pref.HasUserValue();
if (mHasDefaultValue) {
mDefaultValue.Init(Type(), aWrapper.GetValue(PrefValueKind::Default));
}
if (mHasUserValue) {
mUserValue.Init(Type(), aWrapper.GetValue(PrefValueKind::User));
}
}
class CallbackNode {
public:
CallbackNode(const nsACString& aDomain, PrefChangedFunc aFunc, void* aData,
Preferences::MatchKind aMatchKind)
: mDomain(AsVariant(nsCString(aDomain))),
mFunc(aFunc),
mData(aData),
mNextAndMatchKind(aMatchKind) {}
CallbackNode(const char** aDomains, PrefChangedFunc aFunc, void* aData,
Preferences::MatchKind aMatchKind)
: mDomain(AsVariant(aDomains)),
mFunc(aFunc),
mData(aData),
mNextAndMatchKind(aMatchKind) {}
// mDomain is a UniquePtr<>, so any uses of Domain() should only be temporary
// borrows.
const Variant<nsCString, const char**>& Domain() const { return mDomain; }
PrefChangedFunc Func() const { return mFunc; }
void ClearFunc() { mFunc = nullptr; }
void* Data() const { return mData; }
Preferences::MatchKind MatchKind() const {
return static_cast<Preferences::MatchKind>(mNextAndMatchKind &
kMatchKindMask);
}
bool DomainIs(const nsACString& aDomain) const {
return mDomain.is<nsCString>() && mDomain.as<nsCString>() == aDomain;
}
bool DomainIs(const char** aPrefs) const {
return mDomain == AsVariant(aPrefs);
}
bool Matches(const nsACString& aPrefName) const {
auto match = [&](const nsACString& aStr) {
return MatchKind() == Preferences::ExactMatch
? aPrefName == aStr
: StringBeginsWith(aPrefName, aStr);
};
if (mDomain.is<nsCString>()) {
return match(mDomain.as<nsCString>());
}
for (const char** ptr = mDomain.as<const char**>(); *ptr; ptr++) {
if (match(nsDependentCString(*ptr))) {
return true;
}
}
return false;
}
CallbackNode* Next() const {
return reinterpret_cast<CallbackNode*>(mNextAndMatchKind & kNextMask);
}
void SetNext(CallbackNode* aNext) {
uintptr_t matchKind = mNextAndMatchKind & kMatchKindMask;
mNextAndMatchKind = reinterpret_cast<uintptr_t>(aNext);
MOZ_ASSERT((mNextAndMatchKind & kMatchKindMask) == 0);
mNextAndMatchKind |= matchKind;
}
void AddSizeOfIncludingThis(MallocSizeOf aMallocSizeOf, PrefsSizes& aSizes) {
aSizes.mCallbacksObjects += aMallocSizeOf(this);
if (mDomain.is<nsCString>()) {
aSizes.mCallbacksDomains +=
mDomain.as<nsCString>().SizeOfExcludingThisIfUnshared(aMallocSizeOf);
}
}
private:
static const uintptr_t kMatchKindMask = uintptr_t(0x1);
static const uintptr_t kNextMask = ~kMatchKindMask;
Variant<nsCString, const char**> mDomain;
// If someone attempts to remove the node from the callback list while
// NotifyCallbacks() is running, |func| is set to nullptr. Such nodes will
// be removed at the end of NotifyCallbacks().
PrefChangedFunc mFunc;
void* mData;
// Conceptually this is two fields:
// - CallbackNode* mNext;
// - Preferences::MatchKind mMatchKind;
// They are combined into a tagged pointer to save memory.
uintptr_t mNextAndMatchKind;
};
using PrefsHashTable = HashSet<UniquePtr<Pref>, PrefHasher>;
static PrefsHashTable* gHashTable;
#ifdef DEBUG
// This defines the datatype used to store our `Once` StaticPrefs checker.
// We can't use HashMap for now due to alignment restrictions when dealing with
// std::function<void()> (see bug 1557617).
typedef std::function<void()> AntiFootgunCallback;
struct CompareStr {
bool operator()(char const* a, char const* b) const {
return std::strcmp(a, b) < 0;
}
};
typedef std::map<const char*, AntiFootgunCallback, CompareStr> AntiFootgunMap;
static AntiFootgunMap* gOnceStaticPrefsAntiFootgun;
#endif
// The callback list contains all the priority callbacks followed by the
// non-priority callbacks. gLastPriorityNode records where the first part ends.
static CallbackNode* gFirstCallback = nullptr;
static CallbackNode* gLastPriorityNode = nullptr;
#ifdef DEBUG
# define ACCESS_COUNTS
#endif
#ifdef ACCESS_COUNTS
using AccessCountsHashTable = nsDataHashtable<nsCStringHashKey, uint32_t>;
static AccessCountsHashTable* gAccessCounts;
static void AddAccessCount(const nsACString& aPrefName) {
// FIXME: Servo reads preferences from background threads in unsafe ways (bug
// 1474789), and triggers assertions here if we try to add usage count entries
// from background threads.
if (NS_IsMainThread()) {
uint32_t& count = gAccessCounts->GetOrInsert(aPrefName);
count++;
}
}
static void AddAccessCount(const char* aPrefName) {
AddAccessCount(nsDependentCString(aPrefName));
}
#else
static void MOZ_MAYBE_UNUSED AddAccessCount(const nsACString& aPrefName) {}
static void AddAccessCount(const char* aPrefName) {}
#endif
// These are only used during the call to NotifyCallbacks().
static bool gCallbacksInProgress = false;
static bool gShouldCleanupDeadNodes = false;
class PrefsHashIter {
using Iterator = decltype(gHashTable->modIter());
using ElemType = Pref*;
Iterator mIter;
public:
explicit PrefsHashIter(PrefsHashTable* aTable) : mIter(aTable->modIter()) {}
class Elem {
friend class PrefsHashIter;
PrefsHashIter& mParent;
bool mDone;
Elem(PrefsHashIter& aIter, bool aDone) : mParent(aIter), mDone(aDone) {}
Iterator& Iter() { return mParent.mIter; }
public:
Elem& operator*() { return *this; }
ElemType get() {
if (mDone) {
return nullptr;
}
return Iter().get().get();
}
ElemType get() const { return const_cast<Elem*>(this)->get(); }
ElemType operator->() { return get(); }
ElemType operator->() const { return get(); }
operator ElemType() { return get(); }
void Remove() { Iter().remove(); }
Elem& operator++() {
MOZ_ASSERT(!mDone);
Iter().next();
mDone = Iter().done();
return *this;
}
bool operator!=(Elem& other) {
return mDone != other.mDone || this->get() != other.get();
}
};
Elem begin() { return Elem(*this, mIter.done()); }
Elem end() { return Elem(*this, true); }
};
class PrefsIter {
using Iterator = decltype(gHashTable->iter());
using ElemType = PrefWrapper;
using HashElem = PrefsHashIter::Elem;
using SharedElem = SharedPrefMap::Pref;
using ElemTypeVariant = Variant<HashElem, SharedElem>;
SharedPrefMap* mSharedMap;
PrefsHashTable* mHashTable;
PrefsHashIter mIter;
ElemTypeVariant mPos;
ElemTypeVariant mEnd;
Maybe<PrefWrapper> mEntry;
public:
PrefsIter(PrefsHashTable* aHashTable, SharedPrefMap* aSharedMap)
: mSharedMap(aSharedMap),
mHashTable(aHashTable),
mIter(aHashTable),
mPos(AsVariant(mIter.begin())),
mEnd(AsVariant(mIter.end())) {
if (Done()) {
NextIterator();
}
}
private:
#define MATCH(type, ...) \
do { \
struct Matcher { \
PrefsIter& mIter; \
type operator()(HashElem& pos) { \
HashElem& end MOZ_MAYBE_UNUSED = mIter.mEnd.as<HashElem>(); \
__VA_ARGS__; \
} \
type operator()(SharedElem& pos) { \
SharedElem& end MOZ_MAYBE_UNUSED = mIter.mEnd.as<SharedElem>(); \
__VA_ARGS__; \
} \
}; \
return mPos.match(Matcher{*this}); \
} while (0);
bool Done() { MATCH(bool, return pos == end); }
PrefWrapper MakeEntry() { MATCH(PrefWrapper, return PrefWrapper(pos)); }
void NextEntry() {
mEntry.reset();
MATCH(void, ++pos);
}
#undef MATCH
bool Next() {
NextEntry();
return !Done() || NextIterator();
}
bool NextIterator() {
if (mPos.is<HashElem>() && mSharedMap) {
mPos = AsVariant(mSharedMap->begin());
mEnd = AsVariant(mSharedMap->end());
return !Done();
}
return false;
}
bool IteratingBase() { return mPos.is<SharedElem>(); }
PrefWrapper& Entry() {
MOZ_ASSERT(!Done());
if (!mEntry.isSome()) {
mEntry.emplace(MakeEntry());
}
return mEntry.ref();
}
public:
class Elem {
friend class PrefsIter;
PrefsIter& mParent;
bool mDone;
Elem(PrefsIter& aIter, bool aDone) : mParent(aIter), mDone(aDone) {
SkipDuplicates();
}
void Next() { mDone = !mParent.Next(); }
void SkipDuplicates() {
while (!mDone &&
(mParent.IteratingBase() ? mParent.mHashTable->has(ref().Name())
: ref().IsTypeNone())) {
Next();
}
}
public:
Elem& operator*() { return *this; }
ElemType& ref() { return mParent.Entry(); }
const ElemType& ref() const { return const_cast<Elem*>(this)->ref(); }
ElemType* operator->() { return &ref(); }
const ElemType* operator->() const { return &ref(); }
operator ElemType() { return ref(); }
void Remove() {
MOZ_ASSERT(!mParent.IteratingBase());
mParent.mPos.as<HashElem>().Remove();
}
Elem& operator++() {
MOZ_ASSERT(!mDone);
Next();
SkipDuplicates();
return *this;
}
bool operator!=(Elem& other) {
if (mDone != other.mDone) {
return true;
}
if (mDone) {
return false;
}
return &this->ref() != &other.ref();
}
};
Elem begin() { return {*this, Done()}; }
Elem end() { return {*this, true}; }
};
static Pref* pref_HashTableLookup(const char* aPrefName);
static void NotifyCallbacks(const char* aPrefName,
const PrefWrapper* aPref = nullptr);
static void NotifyCallbacks(const char* aPrefName, const PrefWrapper& aPref) {
NotifyCallbacks(aPrefName, &aPref);
}
// The approximate number of preferences in the dynamic hashtable for the parent
// and content processes, respectively. These numbers are used to determine the
// initial size of the dynamic preference hashtables, and should be chosen to
// avoid rehashing during normal usage. The actual number of preferences will,
// or course, change over time, but these numbers only need to be within a
// binary order of magnitude of the actual values to remain effective.
//
// The number for the parent process should reflect the total number of
// preferences in the database, since the parent process needs to initially
// build a dynamic hashtable of the entire preference database. The number for
// the child process should reflect the number of preferences which are likely
// to change after the startup of the first content process, since content
// processes only store changed preferences on top of a snapshot of the database
// created at startup.
//
// Note: The capacity of a hashtable doubles when its length reaches an exact
// power of two. A table with an initial length of 64 is twice as large as one
// with an initial length of 63. This is important in content processes, where
// lookup speed is less critical and we pay the price of the additional overhead
// for each content process. So the initial content length should generally be
// *under* the next power-of-two larger than its expected length.
constexpr size_t kHashTableInitialLengthParent = 3000;
constexpr size_t kHashTableInitialLengthContent = 64;
static PrefSaveData pref_savePrefs() {
MOZ_ASSERT(NS_IsMainThread());
PrefSaveData savedPrefs(gHashTable->count());
for (auto& pref : PrefsIter(gHashTable, gSharedMap)) {
nsAutoCString prefValueStr;
if (!pref->UserValueToStringForSaving(prefValueStr)) {
continue;
}
nsAutoCString prefNameStr;
StrEscape(pref->Name(), prefNameStr);
nsPrintfCString str("user_pref(%s, %s);", prefNameStr.get(),
prefValueStr.get());
savedPrefs.AppendElement(str);
}
return savedPrefs;
}
#ifdef DEBUG
// Note that this never changes in the parent process, and is only read in
// content processes.
static bool gContentProcessPrefsAreInited = false;
#endif // DEBUG
static Pref* pref_HashTableLookup(const char* aPrefName) {
MOZ_ASSERT(NS_IsMainThread() || ServoStyleSet::IsInServoTraversal());
MOZ_ASSERT_IF(!XRE_IsParentProcess(), gContentProcessPrefsAreInited);
// We use readonlyThreadsafeLookup() because we often have concurrent lookups
// from multiple Stylo threads. This is safe because those threads cannot
// modify gHashTable, and the main thread is blocked while Stylo threads are
// doing these lookups.
auto p = gHashTable->readonlyThreadsafeLookup(aPrefName);
return p ? p->get() : nullptr;
}
// While notifying preference callbacks, this holds the wrapper for the
// preference being notified, in order to optimize lookups.
//
// Note: Callbacks and lookups only happen on the main thread, so this is safe
// to use without locking.
static const PrefWrapper* gCallbackPref;
Maybe<PrefWrapper> pref_SharedLookup(const char* aPrefName) {
MOZ_DIAGNOSTIC_ASSERT(gSharedMap, "gSharedMap must be initialized");
if (Maybe<SharedPrefMap::Pref> pref = gSharedMap->Get(aPrefName)) {
return Some(*pref);
}
return Nothing();
}
Maybe<PrefWrapper> pref_Lookup(const char* aPrefName,
bool aIncludeTypeNone = false) {
MOZ_ASSERT(NS_IsMainThread() || ServoStyleSet::IsInServoTraversal());
AddAccessCount(aPrefName);
if (gCallbackPref && strcmp(aPrefName, gCallbackPref->Name()) == 0) {
return Some(*gCallbackPref);
}
if (Pref* pref = pref_HashTableLookup(aPrefName)) {
if (aIncludeTypeNone || !pref->IsTypeNone()) {
return Some(pref);
}
} else if (gSharedMap) {
return pref_SharedLookup(aPrefName);
}
return Nothing();
}
static Result<Pref*, nsresult> pref_LookupForModify(
const char* aPrefName,
const std::function<bool(const PrefWrapper&)>& aCheckFn) {
Maybe<PrefWrapper> wrapper =
pref_Lookup(aPrefName, /* includeTypeNone */ true);
if (wrapper.isNothing()) {
return Err(NS_ERROR_INVALID_ARG);
}
if (!aCheckFn(*wrapper)) {
return nullptr;
}
if (wrapper->is<Pref*>()) {
return wrapper->as<Pref*>();
}
Pref* pref = new Pref(aPrefName);
if (!gHashTable->putNew(aPrefName, pref)) {
delete pref;
return Err(NS_ERROR_OUT_OF_MEMORY);
}
pref->FromWrapper(*wrapper);
return pref;
}
static nsresult pref_SetPref(const char* aPrefName, PrefType aType,
PrefValueKind aKind, PrefValue aValue,
bool aIsSticky, bool aIsLocked, bool aFromInit) {
MOZ_ASSERT(NS_IsMainThread());
if (!gHashTable) {
return NS_ERROR_OUT_OF_MEMORY;
}
Pref* pref = nullptr;
if (gSharedMap) {
auto result =
pref_LookupForModify(aPrefName, [&](const PrefWrapper& aWrapper) {
return !aWrapper.Matches(aType, aKind, aValue, aIsSticky, aIsLocked);
});
if (result.isOk() && !(pref = result.unwrap())) {
// No changes required.
return NS_OK;
}
}
if (!pref) {
auto p = gHashTable->lookupForAdd(aPrefName);
if (!p) {
pref = new Pref(aPrefName);
pref->SetType(aType);
if (!gHashTable->add(p, pref)) {
delete pref;
return NS_ERROR_OUT_OF_MEMORY;
}
} else {
pref = p->get();
}
}
bool valueChanged = false;
nsresult rv;
if (aKind == PrefValueKind::Default) {
rv = pref->SetDefaultValue(aType, aValue, aIsSticky, aIsLocked,
&valueChanged);
} else {
MOZ_ASSERT(!aIsLocked); // `locked` is disallowed in user pref files
rv = pref->SetUserValue(aType, aValue, aFromInit, &valueChanged);
}
if (NS_FAILED(rv)) {
NS_WARNING(
nsPrintfCString("Rejected attempt to change type of pref %s's %s value "
"from %s to %s",
aPrefName,
(aKind == PrefValueKind::Default) ? "default" : "user",
PrefTypeToString(pref->Type()), PrefTypeToString(aType))
.get());
return rv;
}
if (valueChanged) {
if (aKind == PrefValueKind::User && XRE_IsParentProcess()) {
Preferences::HandleDirty();
}
NotifyCallbacks(aPrefName, PrefWrapper(pref));
}
return NS_OK;
}
// Removes |node| from callback list. Returns the node after the deleted one.
static CallbackNode* pref_RemoveCallbackNode(CallbackNode* aNode,
CallbackNode* aPrevNode) {
MOZ_ASSERT(!aPrevNode || aPrevNode->Next() == aNode);
MOZ_ASSERT(aPrevNode || gFirstCallback == aNode);
MOZ_ASSERT(!gCallbacksInProgress);
CallbackNode* next_node = aNode->Next();
if (aPrevNode) {
aPrevNode->SetNext(next_node);
} else {
gFirstCallback = next_node;
}
if (gLastPriorityNode == aNode) {
gLastPriorityNode = aPrevNode;
}
delete aNode;
return next_node;
}
static void NotifyCallbacks(const char* aPrefName, const PrefWrapper* aPref) {
bool reentered = gCallbacksInProgress;
gCallbackPref = aPref;
auto cleanup = MakeScopeExit([]() { gCallbackPref = nullptr; });
// Nodes must not be deleted while gCallbacksInProgress is true.
// Nodes that need to be deleted are marked for deletion by nulling
// out the |func| pointer. We release them at the end of this function
// if we haven't reentered.
gCallbacksInProgress = true;
nsDependentCString prefName(aPrefName);
for (CallbackNode* node = gFirstCallback; node; node = node->Next()) {
if (node->Func()) {
if (node->Matches(prefName)) {
(node->Func())(aPrefName, node->Data());
}
}
}
gCallbacksInProgress = reentered;
if (gShouldCleanupDeadNodes && !gCallbacksInProgress) {
CallbackNode* prev_node = nullptr;
CallbackNode* node = gFirstCallback;
while (node) {
if (!node->Func()) {
node = pref_RemoveCallbackNode(node, prev_node);
} else {
prev_node = node;
node = node->Next();
}
}
gShouldCleanupDeadNodes = false;
}
#ifdef DEBUG
if (XRE_IsParentProcess() &&
!StaticPrefs::preferences_force_disable_check_once_policy() &&
(StaticPrefs::preferences_check_once_policy() || xpc::IsInAutomation())) {
// Check that we aren't modifying a `Once` pref using that prefName.
// We have about 100 `Once` StaticPrefs defined. std::map performs a search
// in O(log n), so this is fast enough for our case.
MOZ_ASSERT(gOnceStaticPrefsAntiFootgun);
auto search = gOnceStaticPrefsAntiFootgun->find(aPrefName);
if (search != gOnceStaticPrefsAntiFootgun->end()) {
// Run the callback.
(search->second)();
}
}
#endif
}
//===========================================================================
// Prefs parsing
//===========================================================================
struct TelemetryLoadData {
uint32_t mFileLoadSize_B;
uint32_t mFileLoadNumPrefs;
uint32_t mFileLoadTime_us;
};
static nsDataHashtable<nsCStringHashKey, TelemetryLoadData>* gTelemetryLoadData;
extern "C" {
// Keep this in sync with PrefFn in prefs_parser/src/lib.rs.
typedef void (*PrefsParserPrefFn)(const char* aPrefName, PrefType aType,
PrefValueKind aKind, PrefValue aValue,
bool aIsSticky, bool aIsLocked);
// Keep this in sync with ErrorFn in prefs_parser/src/lib.rs.
//
// `aMsg` is just a borrow of the string, and must be copied if it is used
// outside the lifetime of the prefs_parser_parse() call.
typedef void (*PrefsParserErrorFn)(const char* aMsg);
// Keep this in sync with prefs_parser_parse() in prefs_parser/src/lib.rs.
bool prefs_parser_parse(const char* aPath, PrefValueKind aKind,
const char* aBuf, size_t aLen,
PrefsParserPrefFn aPrefFn, PrefsParserErrorFn aErrorFn);
}
class Parser {
public:
Parser() = default;
~Parser() = default;
bool Parse(const nsCString& aName, PrefValueKind aKind, const char* aPath,
const TimeStamp& aStartTime, const nsCString& aBuf) {
sNumPrefs = 0;
bool ok = prefs_parser_parse(aPath, aKind, aBuf.get(), aBuf.Length(),
HandlePref, HandleError);
if (!ok) {
return false;
}
uint32_t loadTime_us = (TimeStamp::Now() - aStartTime).ToMicroseconds();
// Most prefs files are read before telemetry initializes, so we have to
// save these measurements now and send them to telemetry later.
TelemetryLoadData loadData = {uint32_t(aBuf.Length()), sNumPrefs,
loadTime_us};
gTelemetryLoadData->Put(aName, loadData);
return true;
}
private:
static void HandlePref(const char* aPrefName, PrefType aType,
PrefValueKind aKind, PrefValue aValue, bool aIsSticky,
bool aIsLocked) {
sNumPrefs++;
pref_SetPref(aPrefName, aType, aKind, aValue, aIsSticky, aIsLocked,
/* fromInit */ true);
}
static void HandleError(const char* aMsg) {
nsresult rv;
nsCOMPtr<nsIConsoleService> console =
do_GetService("@mozilla.org/consoleservice;1", &rv);
if (NS_SUCCEEDED(rv)) {
console->LogStringMessage(NS_ConvertUTF8toUTF16(aMsg).get());
}
#ifdef DEBUG
NS_ERROR(aMsg);
#else
printf_stderr("%s\n", aMsg);
#endif
}
// This is static so that HandlePref() can increment it easily. This is ok
// because prefs files are read one at a time.
static uint32_t sNumPrefs;
};
uint32_t Parser::sNumPrefs = 0;
// The following code is test code for the gtest.
static void TestParseErrorHandlePref(const char* aPrefName, PrefType aType,
PrefValueKind aKind, PrefValue aValue,
bool aIsSticky, bool aIsLocked) {}
static nsCString gTestParseErrorMsgs;
static void TestParseErrorHandleError(const char* aMsg) {
gTestParseErrorMsgs.Append(aMsg);
gTestParseErrorMsgs.Append('\n');
}
// Keep this in sync with the declaration in test/gtest/Parser.cpp.
void TestParseError(PrefValueKind aKind, const char* aText,
nsCString& aErrorMsg) {
prefs_parser_parse("test", aKind, aText, strlen(aText),
TestParseErrorHandlePref, TestParseErrorHandleError);
// Copy the error messages into the outparam, then clear them from
// gTestParseErrorMsgs.
aErrorMsg.Assign(gTestParseErrorMsgs);
gTestParseErrorMsgs.Truncate();
}
void SendTelemetryLoadData() {
for (auto iter = gTelemetryLoadData->Iter(); !iter.Done(); iter.Next()) {
const nsCString& filename = PromiseFlatCString(iter.Key());
const TelemetryLoadData& data = iter.Data();
Telemetry::Accumulate(Telemetry::PREFERENCES_FILE_LOAD_SIZE_B, filename,
data.mFileLoadSize_B);
Telemetry::Accumulate(Telemetry::PREFERENCES_FILE_LOAD_NUM_PREFS, filename,
data.mFileLoadNumPrefs);
Telemetry::Accumulate(Telemetry::PREFERENCES_FILE_LOAD_TIME_US, filename,
data.mFileLoadTime_us);
}
gTelemetryLoadData->Clear();
}
//===========================================================================
// nsPrefBranch et al.
//===========================================================================
namespace mozilla {
class PreferenceServiceReporter;
} // namespace mozilla
class PrefCallback : public PLDHashEntryHdr {
friend class mozilla::PreferenceServiceReporter;
public:
typedef PrefCallback* KeyType;
typedef const PrefCallback* KeyTypePointer;
static const PrefCallback* KeyToPointer(PrefCallback* aKey) { return aKey; }
static PLDHashNumber HashKey(const PrefCallback* aKey) {
uint32_t hash = HashString(aKey->mDomain);
return AddToHash(hash, aKey->mCanonical);
}
public:
// Create a PrefCallback with a strong reference to its observer.
PrefCallback(const nsACString& aDomain, nsIObserver* aObserver,
nsPrefBranch* aBranch)
: mDomain(aDomain),
mBranch(aBranch),
mWeakRef(nullptr),
mStrongRef(aObserver) {
MOZ_COUNT_CTOR(PrefCallback);
nsCOMPtr<nsISupports> canonical = do_QueryInterface(aObserver);
mCanonical = canonical;
}
// Create a PrefCallback with a weak reference to its observer.
PrefCallback(const nsACString& aDomain, nsISupportsWeakReference* aObserver,
nsPrefBranch* aBranch)
: mDomain(aDomain),
mBranch(aBranch),
mWeakRef(do_GetWeakReference(aObserver)),
mStrongRef(nullptr) {
MOZ_COUNT_CTOR(PrefCallback);
nsCOMPtr<nsISupports> canonical = do_QueryInterface(aObserver);
mCanonical = canonical;
}
// This is explicitly not a copy constructor.
explicit PrefCallback(const PrefCallback*& aCopy)
: mDomain(aCopy->mDomain),
mBranch(aCopy->mBranch),
mWeakRef(aCopy->mWeakRef),
mStrongRef(aCopy->mStrongRef),
mCanonical(aCopy->mCanonical) {
MOZ_COUNT_CTOR(PrefCallback);
}
PrefCallback(const PrefCallback&) = delete;
PrefCallback(PrefCallback&&) = default;
~PrefCallback() { MOZ_COUNT_DTOR(PrefCallback); }
bool KeyEquals(const PrefCallback* aKey) const {
// We want to be able to look up a weakly-referencing PrefCallback after
// its observer has died so we can remove it from the table. Once the
// callback's observer dies, its canonical pointer is stale -- in
// particular, we may have allocated a new observer in the same spot in
// memory! So we can't just compare canonical pointers to determine whether
// aKey refers to the same observer as this.
//
// Our workaround is based on the way we use this hashtable: When we ask
// the hashtable to remove a PrefCallback whose weak reference has expired,
// we use as the key for removal the same object as was inserted into the
// hashtable. Thus we can say that if one of the keys' weak references has
// expired, the two keys are equal iff they're the same object.
if (IsExpired() || aKey->IsExpired()) {
return this == aKey;
}
if (mCanonical != aKey->mCanonical) {
return false;
}
return mDomain.Equals(aKey->mDomain);
}
PrefCallback* GetKey() const { return const_cast<PrefCallback*>(this); }
// Get a reference to the callback's observer, or null if the observer was
// weakly referenced and has been destroyed.
already_AddRefed<nsIObserver> GetObserver() const {
if (!IsWeak()) {
nsCOMPtr<nsIObserver> copy = mStrongRef;
return copy.forget();
}
nsCOMPtr<nsIObserver> observer = do_QueryReferent(mWeakRef);
return observer.forget();
}
const nsCString& GetDomain() const { return mDomain; }
nsPrefBranch* GetPrefBranch() const { return mBranch; }
// Has this callback's weak reference died?
bool IsExpired() const {
if (!IsWeak()) return false;
nsCOMPtr<nsIObserver> observer(do_QueryReferent(mWeakRef));
return !observer;
}
size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
size_t n = aMallocSizeOf(this);
n += mDomain.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
// All the other fields are non-owning pointers, so we don't measure them.
return n;
}
enum { ALLOW_MEMMOVE = true };
private:
nsCString mDomain;
nsPrefBranch* mBranch;
// Exactly one of mWeakRef and mStrongRef should be non-null.
nsWeakPtr mWeakRef;
nsCOMPtr<nsIObserver> mStrongRef;
// We need a canonical nsISupports pointer, per bug 578392.
nsISupports* mCanonical;
bool IsWeak() const { return !!mWeakRef; }
};
class nsPrefBranch final : public nsIPrefBranch,
public nsIObserver,
public nsSupportsWeakReference {
friend class mozilla::PreferenceServiceReporter;
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIPREFBRANCH
NS_DECL_NSIOBSERVER
nsPrefBranch(const char* aPrefRoot, PrefValueKind aKind);
nsPrefBranch() = delete;
static void NotifyObserver(const char* aNewpref, void* aData);
size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
private:
// Helper class for either returning a raw cstring or nsCString.
typedef Variant<const char*, const nsCString> PrefNameBase;
class PrefName : public PrefNameBase {
public:
explicit PrefName(const char* aName) : PrefNameBase(aName) {}
explicit PrefName(const nsCString& aName) : PrefNameBase(aName) {}
// Use default move constructors, disallow copy constructors.
PrefName(PrefName&& aOther) = default;
PrefName& operator=(PrefName&& aOther) = default;
PrefName(const PrefName&) = delete;
PrefName& operator=(const PrefName&) = delete;
struct PtrMatcher {
const char* operator()(const char* aVal) { return aVal; }
const char* operator()(const nsCString& aVal) { return aVal.get(); }
};
struct CStringMatcher {
// Note: This is a reference, not an instance. It's used to pass our outer
// method argument through to our matcher methods.
nsACString& mStr;
void operator()(const char* aVal) { mStr.Assign(aVal); }
void operator()(const nsCString& aVal) { mStr.Assign(aVal); }
};
struct LenMatcher {
size_t operator()(const char* aVal) { return strlen(aVal); }
size_t operator()(const nsCString& aVal) { return aVal.Length(); }
};
const char* get() const { return match(PtrMatcher{}); }
void get(nsACString& aStr) const { match(CStringMatcher{aStr}); }
size_t Length() const { return match(LenMatcher{}); }
};
virtual ~nsPrefBranch();
int32_t GetRootLength() const { return mPrefRoot.Length(); }
nsresult GetDefaultFromPropertiesFile(const char* aPrefName,
nsAString& aReturn);
// As SetCharPref, but without any check on the length of |aValue|.
nsresult SetCharPrefNoLengthCheck(const char* aPrefName,
const nsACString& aValue);
// Reject strings that are more than 1Mb, warn if strings are more than 16kb.
nsresult CheckSanityOfStringLength(const char* aPrefName,
const nsAString& aValue);
nsresult CheckSanityOfStringLength(const char* aPrefName,
const nsACString& aValue);
nsresult CheckSanityOfStringLength(const char* aPrefName,
const uint32_t aLength);
void RemoveExpiredCallback(PrefCallback* aCallback);
PrefName GetPrefName(const char* aPrefName) const {
return GetPrefName(nsDependentCString(aPrefName));
}
PrefName GetPrefName(const nsACString& aPrefName) const;
void FreeObserverList(void);
const nsCString mPrefRoot;
PrefValueKind mKind;
bool mFreeingObserverList;
nsClassHashtable<PrefCallback, PrefCallback> mObservers;
};
class nsPrefLocalizedString final : public nsIPrefLocalizedString {
public:
nsPrefLocalizedString();
NS_DECL_ISUPPORTS
NS_FORWARD_NSISUPPORTSPRIMITIVE(mUnicodeString->)
NS_FORWARD_NSISUPPORTSSTRING(mUnicodeString->)
nsresult Init();
private:
virtual ~nsPrefLocalizedString();
nsCOMPtr<nsISupportsString> mUnicodeString;
};
//----------------------------------------------------------------------------
// nsPrefBranch
//----------------------------------------------------------------------------
nsPrefBranch::nsPrefBranch(const char* aPrefRoot, PrefValueKind aKind)
: mPrefRoot(aPrefRoot),
mKind(aKind),
mFreeingObserverList(false),
mObservers() {
nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
if (observerService) {
++mRefCnt; // must be > 0 when we call this, or we'll get deleted!
// Add weakly so we don't have to clean up at shutdown.
observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, true);
--mRefCnt;
}
}
nsPrefBranch::~nsPrefBranch() { FreeObserverList(); }
NS_IMPL_ISUPPORTS(nsPrefBranch, nsIPrefBranch, nsIObserver,
nsISupportsWeakReference)
NS_IMETHODIMP
nsPrefBranch::GetRoot(nsACString& aRoot) {
aRoot = mPrefRoot;
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::GetPrefType(const char* aPrefName, int32_t* aRetVal) {
NS_ENSURE_ARG(aPrefName);
const PrefName& prefName = GetPrefName(aPrefName);
*aRetVal = Preferences::GetType(prefName.get());
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::GetBoolPrefWithDefault(const char* aPrefName, bool aDefaultValue,
uint8_t aArgc, bool* aRetVal) {
nsresult rv = GetBoolPref(aPrefName, aRetVal);
if (NS_FAILED(rv) && aArgc == 1) {
*aRetVal = aDefaultValue;
return NS_OK;
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::GetBoolPref(const char* aPrefName, bool* aRetVal) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::GetBool(pref.get(), aRetVal, mKind);
}
NS_IMETHODIMP
nsPrefBranch::SetBoolPref(const char* aPrefName, bool aValue) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::SetBool(pref.get(), aValue, mKind);
}
NS_IMETHODIMP
nsPrefBranch::GetFloatPrefWithDefault(const char* aPrefName,
float aDefaultValue, uint8_t aArgc,
float* aRetVal) {
nsresult rv = GetFloatPref(aPrefName, aRetVal);
if (NS_FAILED(rv) && aArgc == 1) {
*aRetVal = aDefaultValue;
return NS_OK;
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::GetFloatPref(const char* aPrefName, float* aRetVal) {
NS_ENSURE_ARG(aPrefName);
nsAutoCString stringVal;
nsresult rv = GetCharPref(aPrefName, stringVal);
if (NS_SUCCEEDED(rv)) {
// ToFloat() does a locale-independent conversion.
*aRetVal = stringVal.ToFloat(&rv);
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::GetCharPrefWithDefault(const char* aPrefName,
const nsACString& aDefaultValue,
uint8_t aArgc, nsACString& aRetVal) {
nsresult rv = GetCharPref(aPrefName, aRetVal);
if (NS_FAILED(rv) && aArgc == 1) {
aRetVal = aDefaultValue;
return NS_OK;
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::GetCharPref(const char* aPrefName, nsACString& aRetVal) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::GetCString(pref.get(), aRetVal, mKind);
}
NS_IMETHODIMP
nsPrefBranch::SetCharPref(const char* aPrefName, const nsACString& aValue) {
nsresult rv = CheckSanityOfStringLength(aPrefName, aValue);
if (NS_FAILED(rv)) {
return rv;
}
return SetCharPrefNoLengthCheck(aPrefName, aValue);
}
nsresult nsPrefBranch::SetCharPrefNoLengthCheck(const char* aPrefName,
const nsACString& aValue) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::SetCString(pref.get(), aValue, mKind);
}
NS_IMETHODIMP
nsPrefBranch::GetStringPref(const char* aPrefName,
const nsACString& aDefaultValue, uint8_t aArgc,
nsACString& aRetVal) {
nsCString utf8String;
nsresult rv = GetCharPref(aPrefName, utf8String);
if (NS_SUCCEEDED(rv)) {
aRetVal = utf8String;
return rv;
}
if (aArgc == 1) {
aRetVal = aDefaultValue;
return NS_OK;
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::SetStringPref(const char* aPrefName, const nsACString& aValue) {
nsresult rv = CheckSanityOfStringLength(aPrefName, aValue);
if (NS_FAILED(rv)) {
return rv;
}
return SetCharPrefNoLengthCheck(aPrefName, aValue);
}
NS_IMETHODIMP
nsPrefBranch::GetIntPrefWithDefault(const char* aPrefName,
int32_t aDefaultValue, uint8_t aArgc,
int32_t* aRetVal) {
nsresult rv = GetIntPref(aPrefName, aRetVal);
if (NS_FAILED(rv) && aArgc == 1) {
*aRetVal = aDefaultValue;
return NS_OK;
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::GetIntPref(const char* aPrefName, int32_t* aRetVal) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::GetInt(pref.get(), aRetVal, mKind);
}
NS_IMETHODIMP
nsPrefBranch::SetIntPref(const char* aPrefName, int32_t aValue) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::SetInt(pref.get(), aValue, mKind);
}
NS_IMETHODIMP
nsPrefBranch::GetComplexValue(const char* aPrefName, const nsIID& aType,
void** aRetVal) {
NS_ENSURE_ARG(aPrefName);
nsresult rv;
nsAutoCString utf8String;
// We have to do this one first because it's different to all the rest.
if (aType.Equals(NS_GET_IID(nsIPrefLocalizedString))) {
nsCOMPtr<nsIPrefLocalizedString> theString(
do_CreateInstance(NS_PREFLOCALIZEDSTRING_CONTRACTID, &rv));
if (NS_FAILED(rv)) {
return rv;
}
const PrefName& pref = GetPrefName(aPrefName);
bool bNeedDefault = false;
if (mKind == PrefValueKind::Default) {
bNeedDefault = true;
} else {
// if there is no user (or locked) value
if (!Preferences::HasUserValue(pref.get()) &&
!Preferences::IsLocked(pref.get())) {
bNeedDefault = true;
}
}
// if we need to fetch the default value, do that instead, otherwise use the
// value we pulled in at the top of this function
if (bNeedDefault) {
nsAutoString utf16String;
rv = GetDefaultFromPropertiesFile(pref.get(), utf16String);
if (NS_SUCCEEDED(rv)) {
theString->SetData(utf16String);
}
} else {
rv = GetCharPref(aPrefName, utf8String);
if (NS_SUCCEEDED(rv)) {
theString->SetData(NS_ConvertUTF8toUTF16(utf8String));
}
}
if (NS_SUCCEEDED(rv)) {
theString.forget(reinterpret_cast<nsIPrefLocalizedString**>(aRetVal));
}
return rv;
}
// if we can't get the pref, there's no point in being here
rv = GetCharPref(aPrefName, utf8String);
if (NS_FAILED(rv)) {
return rv;
}
if (aType.Equals(NS_GET_IID(nsIFile))) {
ENSURE_PARENT_PROCESS("GetComplexValue(nsIFile)", aPrefName);
nsCOMPtr<nsIFile> file(do_CreateInstance(NS_LOCAL_FILE_CONTRACTID, &rv));
if (NS_SUCCEEDED(rv)) {
rv = file->SetPersistentDescriptor(utf8String);
if (NS_SUCCEEDED(rv)) {
file.forget(reinterpret_cast<nsIFile**>(aRetVal));
return NS_OK;
}
}
return rv;
}
if (aType.Equals(NS_GET_IID(nsIRelativeFilePref))) {
ENSURE_PARENT_PROCESS("GetComplexValue(nsIRelativeFilePref)", aPrefName);
nsACString::const_iterator keyBegin, strEnd;
utf8String.BeginReading(keyBegin);
utf8String.EndReading(strEnd);
// The pref has the format: [fromKey]a/b/c
if (*keyBegin++ != '[') {
return NS_ERROR_FAILURE;
}
nsACString::const_iterator keyEnd(keyBegin);
if (!FindCharInReadable(']', keyEnd, strEnd)) {
return NS_ERROR_FAILURE;
}
nsAutoCString key(Substring(keyBegin, keyEnd));
nsCOMPtr<nsIFile> fromFile;
nsCOMPtr<nsIProperties> directoryService(
do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
if (NS_FAILED(rv)) {
return rv;
}
rv = directoryService->Get(key.get(), NS_GET_IID(nsIFile),
getter_AddRefs(fromFile));
if (NS_FAILED(rv)) {
return rv;
}
nsCOMPtr<nsIFile> theFile;
rv = NS_NewNativeLocalFile(EmptyCString(), true, getter_AddRefs(theFile));
if (NS_FAILED(rv)) {
return rv;
}
rv = theFile->SetRelativeDescriptor(fromFile, Substring(++keyEnd, strEnd));
if (NS_FAILED(rv)) {
return rv;
}
nsCOMPtr<nsIRelativeFilePref> relativePref = new nsRelativeFilePref();
Unused << relativePref->SetFile(theFile);
Unused << relativePref->SetRelativeToKey(key);
relativePref.forget(reinterpret_cast<nsIRelativeFilePref**>(aRetVal));
return NS_OK;
}
NS_WARNING("nsPrefBranch::GetComplexValue - Unsupported interface type");
return NS_NOINTERFACE;
}
nsresult nsPrefBranch::CheckSanityOfStringLength(const char* aPrefName,
const nsAString& aValue) {
return CheckSanityOfStringLength(aPrefName, aValue.Length());
}
nsresult nsPrefBranch::CheckSanityOfStringLength(const char* aPrefName,
const nsACString& aValue) {
return CheckSanityOfStringLength(aPrefName, aValue.Length());
}
nsresult nsPrefBranch::CheckSanityOfStringLength(const char* aPrefName,
const uint32_t aLength) {
if (aLength > MAX_PREF_LENGTH) {
return NS_ERROR_ILLEGAL_VALUE;
}
if (aLength <= MAX_ADVISABLE_PREF_LENGTH) {
return NS_OK;
}
nsresult rv;
nsCOMPtr<nsIConsoleService> console =
do_GetService("@mozilla.org/consoleservice;1", &rv);
if (NS_FAILED(rv)) {
return rv;
}
nsAutoCString message(nsPrintfCString(
"Warning: attempting to write %d bytes to preference %s. This is bad "
"for general performance and memory usage. Such an amount of data "
"should rather be written to an external file. This preference will "
"not be sent to any content processes.",
aLength, GetPrefName(aPrefName).get()));
rv = console->LogStringMessage(NS_ConvertUTF8toUTF16(message).get());
if (NS_FAILED(rv)) {
return rv;
}
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::SetComplexValue(const char* aPrefName, const nsIID& aType,
nsISupports* aValue) {
ENSURE_PARENT_PROCESS("SetComplexValue", aPrefName);
NS_ENSURE_ARG(aPrefName);
nsresult rv = NS_NOINTERFACE;
if (aType.Equals(NS_GET_IID(nsIFile))) {
nsCOMPtr<nsIFile> file = do_QueryInterface(aValue);
if (!file) {
return NS_NOINTERFACE;
}
nsAutoCString descriptorString;
rv = file->GetPersistentDescriptor(descriptorString);
if (NS_SUCCEEDED(rv)) {
rv = SetCharPrefNoLengthCheck(aPrefName, descriptorString);
}
return rv;
}
if (aType.Equals(NS_GET_IID(nsIRelativeFilePref))) {
nsCOMPtr<nsIRelativeFilePref> relFilePref = do_QueryInterface(aValue);
if (!relFilePref) {
return NS_NOINTERFACE;
}
nsCOMPtr<nsIFile> file;
relFilePref->GetFile(getter_AddRefs(file));
if (!file) {
return NS_NOINTERFACE;
}
nsAutoCString relativeToKey;
(void)relFilePref->GetRelativeToKey(relativeToKey);
nsCOMPtr<nsIFile> relativeToFile;
nsCOMPtr<nsIProperties> directoryService(
do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
if (NS_FAILED(rv)) {
return rv;
}
rv = directoryService->Get(relativeToKey.get(), NS_GET_IID(nsIFile),
getter_AddRefs(relativeToFile));
if (NS_FAILED(rv)) {
return rv;
}
nsAutoCString relDescriptor;
rv = file->GetRelativeDescriptor(relativeToFile, relDescriptor);
if (NS_FAILED(rv)) {
return rv;
}
nsAutoCString descriptorString;
descriptorString.Append('[');
descriptorString.Append(relativeToKey);
descriptorString.Append(']');
descriptorString.Append(relDescriptor);
return SetCharPrefNoLengthCheck(aPrefName, descriptorString);
}
if (aType.Equals(NS_GET_IID(nsIPrefLocalizedString))) {
nsCOMPtr<nsISupportsString> theString = do_QueryInterface(aValue);
if (theString) {
nsString wideString;
rv = theString->GetData(wideString);
if (NS_SUCCEEDED(rv)) {
// Check sanity of string length before any lengthy conversion
rv = CheckSanityOfStringLength(aPrefName, wideString);
if (NS_FAILED(rv)) {
return rv;
}
rv = SetCharPrefNoLengthCheck(aPrefName,
NS_ConvertUTF16toUTF8(wideString));
}
}
return rv;
}
NS_WARNING("nsPrefBranch::SetComplexValue - Unsupported interface type");
return NS_NOINTERFACE;
}
NS_IMETHODIMP
nsPrefBranch::ClearUserPref(const char* aPrefName) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::ClearUser(pref.get());
}
NS_IMETHODIMP
nsPrefBranch::PrefHasUserValue(const char* aPrefName, bool* aRetVal) {
NS_ENSURE_ARG_POINTER(aRetVal);
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
*aRetVal = Preferences::HasUserValue(pref.get());
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::LockPref(const char* aPrefName) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::Lock(pref.get());
}
NS_IMETHODIMP
nsPrefBranch::PrefIsLocked(const char* aPrefName, bool* aRetVal) {
NS_ENSURE_ARG_POINTER(aRetVal);
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
*aRetVal = Preferences::IsLocked(pref.get());
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::UnlockPref(const char* aPrefName) {
NS_ENSURE_ARG(aPrefName);
const PrefName& pref = GetPrefName(aPrefName);
return Preferences::Unlock(pref.get());
}
NS_IMETHODIMP
nsPrefBranch::ResetBranch(const char* aStartingAt) {
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsPrefBranch::DeleteBranch(const char* aStartingAt) {
ENSURE_PARENT_PROCESS("DeleteBranch", aStartingAt);
NS_ENSURE_ARG(aStartingAt);
MOZ_ASSERT(NS_IsMainThread());
if (!gHashTable) {
return NS_ERROR_NOT_INITIALIZED;
}
const PrefName& pref = GetPrefName(aStartingAt);
nsAutoCString branchName(pref.get());
// Add a trailing '.' if it doesn't already have one.
if (branchName.Length() > 1 &&
!StringEndsWith(branchName, NS_LITERAL_CSTRING("."))) {
branchName += '.';
}
const nsACString& branchNameNoDot =
Substring(branchName, 0, branchName.Length() - 1);
for (auto iter = gHashTable->modIter(); !iter.done(); iter.next()) {
// The first disjunct matches branches: e.g. a branch name "foo.bar."
// matches a name "foo.bar.baz" (but it won't match "foo.barrel.baz").
// The second disjunct matches leaf nodes: e.g. a branch name "foo.bar."
// matches a name "foo.bar" (by ignoring the trailing '.').
nsDependentCString name(iter.get()->Name());
if (StringBeginsWith(name, branchName) || name.Equals(branchNameNoDot)) {
iter.remove();
// The saved callback pref may be invalid now.
gCallbackPref = nullptr;
}
}
Preferences::HandleDirty();
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::GetChildList(const char* aStartingAt,
nsTArray<nsCString>& aChildArray) {
NS_ENSURE_ARG(aStartingAt);
MOZ_ASSERT(NS_IsMainThread());
// This will contain a list of all the pref name strings. Allocated on the
// stack for speed.
AutoTArray<nsCString, 32> prefArray;
const PrefName& parent = GetPrefName(aStartingAt);
size_t parentLen = parent.Length();
for (auto& pref : PrefsIter(gHashTable, gSharedMap)) {
if (strncmp(pref->Name(), parent.get(), parentLen) == 0) {
prefArray.AppendElement(pref->NameString());
}
}
// Now that we've built up the list, run the callback on all the matching
// elements.
aChildArray.SetCapacity(prefArray.Length());
for (auto& element : prefArray) {
// we need to lop off mPrefRoot in case the user is planning to pass this
// back to us because if they do we are going to add mPrefRoot again.
aChildArray.AppendElement(Substring(element, mPrefRoot.Length()));
}
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::AddObserverImpl(const nsACString& aDomain, nsIObserver* aObserver,
bool aHoldWeak) {
PrefCallback* pCallback;
NS_ENSURE_ARG(aObserver);
nsCString prefName;
GetPrefName(aDomain).get(prefName);
// Hold a weak reference to the observer if so requested.
if (aHoldWeak) {
nsCOMPtr<nsISupportsWeakReference> weakRefFactory =
do_QueryInterface(aObserver);
if (!weakRefFactory) {
// The caller didn't give us a object that supports weak reference...
// tell them.
return NS_ERROR_INVALID_ARG;
}
// Construct a PrefCallback with a weak reference to the observer.
pCallback = new PrefCallback(prefName, weakRefFactory, this);
} else {
// Construct a PrefCallback with a strong reference to the observer.
pCallback = new PrefCallback(prefName, aObserver, this);
}
auto p = mObservers.LookupForAdd(pCallback);
if (p) {
NS_WARNING("Ignoring duplicate observer.");
delete pCallback;
return NS_OK;
}
p.OrInsert([&pCallback]() { return pCallback; });
// We must pass a fully qualified preference name to the callback
// aDomain == nullptr is the only possible failure, and we trapped it with
// NS_ENSURE_ARG above.
Preferences::RegisterCallback(NotifyObserver, prefName, pCallback,
Preferences::PrefixMatch,
/* isPriority */ false);
return NS_OK;
}
NS_IMETHODIMP
nsPrefBranch::RemoveObserverImpl(const nsACString& aDomain,
nsIObserver* aObserver) {
NS_ENSURE_ARG(aObserver);
nsresult rv = NS_OK;
// If we're in the middle of a call to FreeObserverList, don't process this
// RemoveObserver call -- the observer in question will be removed soon, if
// it hasn't been already.
//
// It's important that we don't touch mObservers in any way -- even a Get()
// which returns null might cause the hashtable to resize itself, which will
// break the iteration in FreeObserverList.
if (mFreeingObserverList) {
return NS_OK;
}
// Remove the relevant PrefCallback from mObservers and get an owning pointer
// to it. Unregister the callback first, and then let the owning pointer go
// out of scope and destroy the callback.
nsCString prefName;
GetPrefName(aDomain).get(prefName);
PrefCallback key(prefName, aObserver, this);
nsAutoPtr<PrefCallback> pCallback;
mObservers.Remove(&key, &pCallback);
if (pCallback) {
rv = Preferences::UnregisterCallback(NotifyObserver, prefName, pCallback,
Preferences::PrefixMatch);
}
return rv;
}
NS_IMETHODIMP
nsPrefBranch::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aData) {
// Watch for xpcom shutdown and free our observers to eliminate any cyclic
// references.
if (!nsCRT::strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
FreeObserverList();
}
return NS_OK;
}
/* static */
void nsPrefBranch::NotifyObserver(const char* aNewPref, void* aData) {
PrefCallback* pCallback = (PrefCallback*)aData;
nsCOMPtr<nsIObserver> observer = pCallback->GetObserver();
if (!observer) {
// The observer has expired. Let's remove this callback.
pCallback->GetPrefBranch()->RemoveExpiredCallback(pCallback);
return;
}
// Remove any root this string may contain so as to not confuse the observer
// by passing them something other than what they passed us as a topic.
uint32_t len = pCallback->GetPrefBranch()->GetRootLength();
nsDependentCString suffix(aNewPref + len);
observer->Observe(static_cast<nsIPrefBranch*>(pCallback->GetPrefBranch()),
NS_PREFBRANCH_PREFCHANGE_TOPIC_ID,
NS_ConvertASCIItoUTF16(suffix).get());
}
size_t nsPrefBranch::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
size_t n = aMallocSizeOf(this);
n += mPrefRoot.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
n += mObservers.ShallowSizeOfExcludingThis(aMallocSizeOf);
for (auto iter = mObservers.ConstIter(); !iter.Done(); iter.Next()) {
const PrefCallback* data = iter.UserData();
n += data->SizeOfIncludingThis(aMallocSizeOf);
}
return n;
}
void nsPrefBranch::FreeObserverList() {
// We need to prevent anyone from modifying mObservers while we're iterating
// over it. In particular, some clients will call RemoveObserver() when
// they're removed and destructed via the iterator; we set
// mFreeingObserverList to keep those calls from touching mObservers.
mFreeingObserverList = true;
for (auto iter = mObservers.Iter(); !iter.Done(); iter.Next()) {
nsAutoPtr<PrefCallback>& callback = iter.Data();
Preferences::UnregisterCallback(nsPrefBranch::NotifyObserver,
callback->GetDomain(), callback,
Preferences::PrefixMatch);
iter.Remove();
}
nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
if (observerService) {
observerService->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
}
mFreeingObserverList = false;
}
void nsPrefBranch::RemoveExpiredCallback(PrefCallback* aCallback) {
MOZ_ASSERT(aCallback->IsExpired());
mObservers.Remove(aCallback);
}
nsresult nsPrefBranch::GetDefaultFromPropertiesFile(const char* aPrefName,
nsAString& aReturn) {
// The default value contains a URL to a .properties file.
nsAutoCString propertyFileURL;
nsresult rv = Preferences::GetCString(aPrefName, propertyFileURL,
PrefValueKind::Default);
if (NS_FAILED(rv)) {
return rv;
}
nsCOMPtr<nsIStringBundleService> bundleService =
services::GetStringBundleService();
if (!bundleService) {
return NS_ERROR_FAILURE;
}
nsCOMPtr<nsIStringBundle> bundle;
rv = bundleService->CreateBundle(propertyFileURL.get(),
getter_AddRefs(bundle));
if (NS_FAILED(rv)) {
return rv;
}
return bundle->GetStringFromName(aPrefName, aReturn);
}
nsPrefBranch::PrefName nsPrefBranch::GetPrefName(
const nsACString& aPrefName) const {
if (mPrefRoot.IsEmpty()) {
return PrefName(PromiseFlatCString(aPrefName));
}
return PrefName(mPrefRoot + aPrefName);
}
//----------------------------------------------------------------------------
// nsPrefLocalizedString
//----------------------------------------------------------------------------
nsPrefLocalizedString::nsPrefLocalizedString() = default;
nsPrefLocalizedString::~nsPrefLocalizedString() = default;
NS_IMPL_ISUPPORTS(nsPrefLocalizedString, nsIPrefLocalizedString,
nsISupportsString)
nsresult nsPrefLocalizedString::Init() {
nsresult rv;
mUnicodeString = do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID, &rv);
return rv;
}
//----------------------------------------------------------------------------
// nsRelativeFilePref
//----------------------------------------------------------------------------
NS_IMPL_ISUPPORTS(nsRelativeFilePref, nsIRelativeFilePref)
nsRelativeFilePref::nsRelativeFilePref() = default;
nsRelativeFilePref::~nsRelativeFilePref() = default;
NS_IMETHODIMP
nsRelativeFilePref::GetFile(nsIFile** aFile) {
NS_ENSURE_ARG_POINTER(aFile);
*aFile = mFile;
NS_IF_ADDREF(*aFile);
return NS_OK;
}
NS_IMETHODIMP
nsRelativeFilePref::SetFile(nsIFile* aFile) {
mFile = aFile;
return NS_OK;
}
NS_IMETHODIMP
nsRelativeFilePref::GetRelativeToKey(nsACString& aRelativeToKey) {
aRelativeToKey.Assign(mRelativeToKey);
return NS_OK;
}
NS_IMETHODIMP
nsRelativeFilePref::SetRelativeToKey(const nsACString& aRelativeToKey) {
mRelativeToKey.Assign(aRelativeToKey);
return NS_OK;
}
//===========================================================================
// class Preferences and related things
//===========================================================================
namespace mozilla {
#define INITIAL_PREF_FILES 10
static NS_DEFINE_CID(kZipReaderCID, NS_ZIPREADER_CID);
void Preferences::HandleDirty() {
MOZ_ASSERT(XRE_IsParentProcess());
if (!gHashTable || !sPreferences) {
return;
}
if (sPreferences->mProfileShutdown) {
NS_WARNING("Setting user pref after profile shutdown.");
return;
}
if (!sPreferences->mDirty) {
sPreferences->mDirty = true;
if (sPreferences->mCurrentFile && sPreferences->AllowOffMainThreadSave() &&
!sPreferences->mSavePending) {
sPreferences->mSavePending = true;
static const int PREF_DELAY_MS = 500;
NS_DelayedDispatchToCurrentThread(
NewRunnableMethod("Preferences::SavePrefFileAsynchronous",
sPreferences.get(),
&Preferences::SavePrefFileAsynchronous),
PREF_DELAY_MS);
}
}
}
static nsresult openPrefFile(nsIFile* aFile, PrefValueKind aKind);
static nsresult parsePrefData(const nsCString& aData, PrefValueKind aKind);
// clang-format off
static const char kPrefFileHeader[] =
"// Mozilla User Preferences"
NS_LINEBREAK
NS_LINEBREAK
"// DO NOT EDIT THIS FILE."
NS_LINEBREAK
"//"
NS_LINEBREAK
"// If you make changes to this file while the application is running,"
NS_LINEBREAK
"// the changes will be overwritten when the application exits."
NS_LINEBREAK
"//"
NS_LINEBREAK
"// To change a preference value, you can either:"
NS_LINEBREAK
"// - modify it via the UI (e.g. via about:config in the browser); or"
NS_LINEBREAK
"// - set it within a user.js file in your profile."
NS_LINEBREAK
NS_LINEBREAK;
// clang-format on
// Note: if sShutdown is true, sPreferences will be nullptr.
StaticRefPtr<Preferences> Preferences::sPreferences;
bool Preferences::sShutdown = false;
// This globally enables or disables OMT pref writing, both sync and async.
static int32_t sAllowOMTPrefWrite = -1;
// Write the preference data to a file.
class PreferencesWriter final {
public:
PreferencesWriter() = default;
static nsresult Write(nsIFile* aFile, PrefSaveData& aPrefs) {
nsCOMPtr<nsIOutputStream> outStreamSink;
nsCOMPtr<nsIOutputStream> outStream;
uint32_t writeAmount;
nsresult rv;
// Execute a "safe" save by saving through a tempfile.
rv = NS_NewSafeLocalFileOutputStream(getter_AddRefs(outStreamSink), aFile,
-1, 0600);
if (NS_FAILED(rv)) {
return rv;
}
rv = NS_NewBufferedOutputStream(getter_AddRefs(outStream),
outStreamSink.forget(), 4096);
if (NS_FAILED(rv)) {
return rv;
}
struct CharComparator {
bool LessThan(const nsCString& aA, const nsCString& aB) const {
return aA < aB;
}
bool Equals(const nsCString& aA, const nsCString& aB) const {
return aA == aB;
}
};
// Sort the preferences to make a readable file on disk.
aPrefs.Sort(CharComparator());
// Write out the file header.
outStream->Write(kPrefFileHeader, sizeof(kPrefFileHeader) - 1,
&writeAmount);
for (nsCString& pref : aPrefs) {
outStream->Write(pref.get(), pref.Length(), &writeAmount);
outStream->Write(NS_LINEBREAK, NS_LINEBREAK_LEN, &writeAmount);
}
// Tell the safe output stream to overwrite the real prefs file.
// (It'll abort if there were any errors during writing.)
nsCOMPtr<nsISafeOutputStream> safeStream = do_QueryInterface(outStream);
MOZ_ASSERT(safeStream, "expected a safe output stream!");
if (safeStream) {
rv = safeStream->Finish();
}
#ifdef DEBUG
if (NS_FAILED(rv)) {
NS_WARNING("failed to save prefs file! possible data loss");
}
#endif
return rv;
}
static void Flush() {
// This can be further optimized; instead of waiting for all of the writer
// thread to be available, we just have to wait for all the pending writes
// to be done.
if (!sPendingWriteData.compareExchange(nullptr, nullptr)) {
nsresult rv = NS_OK;
nsCOMPtr<nsIEventTarget> target =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
if (NS_SUCCEEDED(rv)) {
target->Dispatch(NS_NewRunnableFunction("Preferences_dummy", [] {}),
nsIEventTarget::DISPATCH_SYNC);
}
}
}
// This is the data that all of the runnables (see below) will attempt
// to write. It will always have the most up to date version, or be
// null, if the up to date information has already been written out.
static Atomic<PrefSaveData*> sPendingWriteData;
};
Atomic<PrefSaveData*> PreferencesWriter::sPendingWriteData(nullptr);
class PWRunnable : public Runnable {
public:
explicit PWRunnable(nsIFile* aFile) : Runnable("PWRunnable"), mFile(aFile) {}
NS_IMETHOD Run() override {
// If we get a nullptr on the exchange, it means that somebody
// else has already processed the request, and we can just return.
UniquePtr<PrefSaveData> prefs(
PreferencesWriter::sPendingWriteData.exchange(nullptr));
nsresult rv = NS_OK;
if (prefs) {
rv = PreferencesWriter::Write(mFile, *prefs);
// Make a copy of these so we can have them in runnable lambda.
// nsIFile is only there so that we would never release the
// ref counted pointer off main thread.
nsresult rvCopy = rv;
nsCOMPtr<nsIFile> fileCopy(mFile);
SystemGroup::Dispatch(
TaskCategory::Other,
NS_NewRunnableFunction("Preferences::WriterRunnable",
[fileCopy, rvCopy] {
MOZ_RELEASE_ASSERT(NS_IsMainThread());
if (NS_FAILED(rvCopy)) {
Preferences::HandleDirty();
}
}));
}
return rv;
}
protected:
nsCOMPtr<nsIFile> mFile;
};
struct CacheData {
CacheData(void* aCacheLocation, bool aValue)
: mCacheLocation(aCacheLocation), mDefaultValueBool(aValue) {}
CacheData(void* aCacheLocation, int32_t aValue)
: mCacheLocation(aCacheLocation), mDefaultValueInt(aValue) {}
CacheData(void* aCacheLocation, uint32_t aValue)
: mCacheLocation(aCacheLocation), mDefaultValueUint(aValue) {}
CacheData(void* aCacheLocation, float aValue)
: mCacheLocation(aCacheLocation), mDefaultValueFloat(aValue) {}
template <typename T>
T GetDefault() const;
void* const mCacheLocation;
private:
union {
const bool mDefaultValueBool;
const int32_t mDefaultValueInt;
const uint32_t mDefaultValueUint;
const float mDefaultValueFloat;
};
};
// We specialise the CacheData::GetDefault() here, as somehow you can't do it
// inline within CacheData definition.
template <>
bool CacheData::GetDefault() const {
return mDefaultValueBool;
}
template <>
int32_t CacheData::GetDefault() const {
return mDefaultValueInt;
}
template <>
uint32_t CacheData::GetDefault() const {
return mDefaultValueUint;
}
template <>
float CacheData::GetDefault() const {
return mDefaultValueFloat;
}
// gCacheDataDesc holds information about prefs startup. It's being used for
// diagnosing prefs startup problems in bug 1276488.
static const char* gCacheDataDesc = "untouched";
// gCacheData holds the CacheData objects used for VarCache prefs. It owns
// those objects, and also is used to detect if multiple VarCaches get tied to
// a single global variable.
static nsTArray<nsAutoPtr<CacheData>>* gCacheData = nullptr;
#ifdef DEBUG
static bool HaveExistingCacheFor(void* aPtr) {
MOZ_ASSERT(NS_IsMainThread());
if (gCacheData) {
for (size_t i = 0, count = gCacheData->Length(); i < count; ++i) {
if ((*gCacheData)[i]->mCacheLocation == aPtr) {
return true;
}
}
}
return false;
}
#endif
static void AssertNotAlreadyCached(const char* aPrefType, const char* aPref,
void* aPtr) {
#ifdef DEBUG
MOZ_ASSERT(aPtr);
if (HaveExistingCacheFor(aPtr)) {
fprintf_stderr(
stderr,
"Attempt to add a %s pref cache for preference '%s' at address '%p'"
"was made. However, a pref was already cached at this address.\n",
aPrefType, aPref, aPtr);
MOZ_ASSERT(false,
"Should not have an existing pref cache for this address");
}
#endif
}
static void AssertNotAlreadyCached(const char* aPrefType,
const nsACString& aPref, void* aPtr) {
AssertNotAlreadyCached(aPrefType, PromiseFlatCString(aPref).get(), aPtr);
}
// Although this is a member of Preferences, it measures sPreferences and
// several other global structures.
/* static */
void Preferences::AddSizeOfIncludingThis(MallocSizeOf aMallocSizeOf,
PrefsSizes& aSizes) {
if (!sPreferences) {
return;
}
aSizes.mMisc += aMallocSizeOf(sPreferences.get());
aSizes.mRootBranches +=
static_cast<nsPrefBranch*>(sPreferences->mRootBranch.get())
->SizeOfIncludingThis(aMallocSizeOf) +
static_cast<nsPrefBranch*>(sPreferences->mDefaultRootBranch.get())
->SizeOfIncludingThis(aMallocSizeOf);
}
class PreferenceServiceReporter final : public nsIMemoryReporter {
~PreferenceServiceReporter() {}
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIMEMORYREPORTER
protected:
static const uint32_t kSuspectReferentCount = 1000;
};
NS_IMPL_ISUPPORTS(PreferenceServiceReporter, nsIMemoryReporter)
MOZ_DEFINE_MALLOC_SIZE_OF(PreferenceServiceMallocSizeOf)
NS_IMETHODIMP
PreferenceServiceReporter::CollectReports(
nsIHandleReportCallback* aHandleReport, nsISupports* aData,
bool aAnonymize) {
MOZ_ASSERT(NS_IsMainThread());
MallocSizeOf mallocSizeOf = PreferenceServiceMallocSizeOf;
PrefsSizes sizes;
Preferences::AddSizeOfIncludingThis(mallocSizeOf, sizes);
if (gHashTable) {
sizes.mHashTable += gHashTable->shallowSizeOfIncludingThis(mallocSizeOf);
for (auto iter = gHashTable->iter(); !iter.done(); iter.next()) {
iter.get()->AddSizeOfIncludingThis(mallocSizeOf, sizes);
}
}
if (gCacheData) {
sizes.mCacheData += gCacheData->ShallowSizeOfIncludingThis(mallocSizeOf);
for (uint32_t i = 0, count = gCacheData->Length(); i < count; ++i) {
sizes.mCacheData += mallocSizeOf((*gCacheData)[i]);
}
}
sizes.mPrefNameArena += gPrefNameArena.SizeOfExcludingThis(mallocSizeOf);
for (CallbackNode* node = gFirstCallback; node; node = node->Next()) {
node->AddSizeOfIncludingThis(mallocSizeOf, sizes);
}
if (gSharedMap) {
sizes.mMisc += mallocSizeOf(gSharedMap);
}
MOZ_COLLECT_REPORT("explicit/preferences/hash-table", KIND_HEAP, UNITS_BYTES,
sizes.mHashTable, "Memory used by libpref's hash table.");
MOZ_COLLECT_REPORT("explicit/preferences/pref-values", KIND_HEAP, UNITS_BYTES,
sizes.mPrefValues,
"Memory used by PrefValues hanging off the hash table.");
MOZ_COLLECT_REPORT("explicit/preferences/string-values", KIND_HEAP,
UNITS_BYTES, sizes.mStringValues,
"Memory used by libpref's string pref values.");
MOZ_COLLECT_REPORT("explicit/preferences/cache-data", KIND_HEAP, UNITS_BYTES,
sizes.mCacheData, "Memory used by libpref's VarCaches.");
MOZ_COLLECT_REPORT("explicit/preferences/root-branches", KIND_HEAP,
UNITS_BYTES, sizes.mRootBranches,
"Memory used by libpref's root branches.");
MOZ_COLLECT_REPORT("explicit/preferences/pref-name-arena", KIND_HEAP,
UNITS_BYTES, sizes.mPrefNameArena,
"Memory used by libpref's arena for pref names.");
MOZ_COLLECT_REPORT("explicit/preferences/callbacks/objects", KIND_HEAP,
UNITS_BYTES, sizes.mCallbacksObjects,
"Memory used by pref callback objects.");
MOZ_COLLECT_REPORT("explicit/preferences/callbacks/domains", KIND_HEAP,
UNITS_BYTES, sizes.mCallbacksDomains,
"Memory used by pref callback domains (pref names and "
"prefixes).");
MOZ_COLLECT_REPORT("explicit/preferences/misc", KIND_HEAP, UNITS_BYTES,
sizes.mMisc, "Miscellaneous memory used by libpref.");
if (gSharedMap) {
if (XRE_IsParentProcess()) {
MOZ_COLLECT_REPORT("explicit/preferences/shared-memory-map", KIND_NONHEAP,
UNITS_BYTES, gSharedMap->MapSize(),
"The shared memory mapping used to share a "
"snapshot of preference values across processes.");
}
}
nsPrefBranch* rootBranch =
static_cast<nsPrefBranch*>(Preferences::GetRootBranch());
if (!rootBranch) {
return NS_OK;
}
size_t numStrong = 0;
size_t numWeakAlive = 0;
size_t numWeakDead = 0;
nsTArray<nsCString> suspectPreferences;
// Count of the number of referents for each preference.
nsDataHashtable<nsCStringHashKey, uint32_t> prefCounter;
for (auto iter = rootBranch->mObservers.Iter(); !iter.Done(); iter.Next()) {
nsAutoPtr<PrefCallback>& callback = iter.Data();
if (callback->IsWeak()) {
nsCOMPtr<nsIObserver> callbackRef = do_QueryReferent(callback->mWeakRef);
if (callbackRef) {
numWeakAlive++;
} else {
numWeakDead++;
}
} else {
numStrong++;
}
uint32_t oldCount = 0;
prefCounter.Get(callback->GetDomain(), &oldCount);
uint32_t currentCount = oldCount + 1;
prefCounter.Put(callback->GetDomain(), currentCount);
// Keep track of preferences that have a suspiciously large number of
// referents (a symptom of a leak).
if (currentCount == kSuspectReferentCount) {
suspectPreferences.AppendElement(callback->GetDomain());
}
}
for (uint32_t i = 0; i < suspectPreferences.Length(); i++) {
nsCString& suspect = suspectPreferences[i];
uint32_t totalReferentCount = 0;
prefCounter.Get(suspect, &totalReferentCount);
nsPrintfCString suspectPath(
"preference-service-suspect/"
"referent(pref=%s)",
suspect.get());
aHandleReport->Callback(
/* process = */ EmptyCString(), suspectPath, KIND_OTHER, UNITS_COUNT,
totalReferentCount,
NS_LITERAL_CSTRING("A preference with a suspiciously large number "
"referents (symptom of a "
"leak)."),
aData);
}
MOZ_COLLECT_REPORT(
"preference-service/referent/strong", KIND_OTHER, UNITS_COUNT, numStrong,
"The number of strong referents held by the preference service.");
MOZ_COLLECT_REPORT(
"preference-service/referent/weak/alive", KIND_OTHER, UNITS_COUNT,
numWeakAlive,
"The number of weak referents held by the preference service that are "
"still alive.");
MOZ_COLLECT_REPORT(
"preference-service/referent/weak/dead", KIND_OTHER, UNITS_COUNT,
numWeakDead,
"The number of weak referents held by the preference service that are "
"dead.");
return NS_OK;
}
namespace {
class AddPreferencesMemoryReporterRunnable : public Runnable {
public:
AddPreferencesMemoryReporterRunnable()
: Runnable("AddPreferencesMemoryReporterRunnable") {}
NS_IMETHOD Run() override {
return RegisterStrongMemoryReporter(new PreferenceServiceReporter());
}
};
} // namespace
// A list of changed prefs sent from the parent via shared memory.
static nsTArray<dom::Pref>* gChangedDomPrefs;
static const char kTelemetryPref[] = "toolkit.telemetry.enabled";
static const char kChannelPref[] = "app.update.channel";
#ifdef MOZ_WIDGET_ANDROID
static Maybe<bool> TelemetryPrefValue() {
// Leave it unchanged if it's already set.
// XXX: how could it already be set?
if (Preferences::GetType(kTelemetryPref) != nsIPrefBranch::PREF_INVALID) {
return Nothing();
}
// Determine the correct default for toolkit.telemetry.enabled. If this
// build has MOZ_TELEMETRY_ON_BY_DEFAULT *or* we're on the beta channel,
// telemetry is on by default, otherwise not. This is necessary so that
// beta users who are testing final release builds don't flipflop defaults.
# ifdef MOZ_TELEMETRY_ON_BY_DEFAULT
return Some(true);
# else
nsAutoCString channelPrefValue;
Unused << Preferences::GetCString(kChannelPref, channelPrefValue,
PrefValueKind::Default);
return Some(channelPrefValue.EqualsLiteral("beta"));
# endif
}
/* static */
void Preferences::SetupTelemetryPref() {
MOZ_ASSERT(XRE_IsParentProcess());
Maybe<bool> telemetryPrefValue = TelemetryPrefValue();
if (telemetryPrefValue.isSome()) {
Preferences::SetBool(kTelemetryPref, *telemetryPrefValue,
PrefValueKind::Default);
}
}
#else // !MOZ_WIDGET_ANDROID
static bool TelemetryPrefValue() {
// For platforms with Unified Telemetry (here meaning not-Android),
// toolkit.telemetry.enabled determines whether we send "extended" data.
// We only want extended data from pre-release channels due to size.
NS_NAMED_LITERAL_CSTRING(channel, NS_STRINGIFY(MOZ_UPDATE_CHANNEL));
// Easy cases: Nightly, Aurora, Beta.
if (channel.EqualsLiteral("nightly") || channel.EqualsLiteral("aurora") ||
channel.EqualsLiteral("beta")) {
return true;
}
# ifndef MOZILLA_OFFICIAL
// Local developer builds: non-official builds on the "default" channel.
if (channel.EqualsLiteral("default")) {
return true;
}
# endif
// Release Candidate builds: builds that think they are release builds, but
// are shipped to beta users.
if (channel.EqualsLiteral("release")) {
nsAutoCString channelPrefValue;
Unused << Preferences::GetCString(kChannelPref, channelPrefValue,
PrefValueKind::Default);
if (channelPrefValue.EqualsLiteral("beta")) {
return true;
}
}
return false;
}
/* static */
void Preferences::SetupTelemetryPref() {
MOZ_ASSERT(XRE_IsParentProcess());
Preferences::SetBool(kTelemetryPref, TelemetryPrefValue(),
PrefValueKind::Default);
Preferences::Lock(kTelemetryPref);
}
static void CheckTelemetryPref() {
MOZ_ASSERT(!XRE_IsParentProcess());
// Make sure the children got passed the right telemetry pref details.
DebugOnly<bool> value;
MOZ_ASSERT(NS_SUCCEEDED(Preferences::GetBool(kTelemetryPref, &value)) &&
value == TelemetryPrefValue());
MOZ_ASSERT(Preferences::IsLocked(kTelemetryPref));
}
#endif // MOZ_WIDGET_ANDROID
/* static */
already_AddRefed<Preferences> Preferences::GetInstanceForService() {
if (sPreferences) {
return do_AddRef(sPreferences);
}
if (sShutdown) {
gCacheDataDesc = "shutting down in GetInstanceForService()";
return nullptr;
}
sPreferences = new Preferences();
MOZ_ASSERT(!gHashTable);
gHashTable = new PrefsHashTable(XRE_IsParentProcess()
? kHashTableInitialLengthParent
: kHashTableInitialLengthContent);
gTelemetryLoadData =
new nsDataHashtable<nsCStringHashKey, TelemetryLoadData>();
#ifdef DEBUG
gOnceStaticPrefsAntiFootgun = new AntiFootgunMap();
#endif
#ifdef ACCESS_COUNTS
MOZ_ASSERT(!gAccessCounts);
gAccessCounts = new AccessCountsHashTable();
#endif
gCacheData = new nsTArray<nsAutoPtr<CacheData>>();
gCacheDataDesc = "set by GetInstanceForService() (1)";
Result<Ok, const char*> res = InitInitialObjects(/* isStartup */ true);
if (res.isErr()) {
sPreferences = nullptr;
gCacheDataDesc = res.unwrapErr();
return nullptr;
}
if (!XRE_IsParentProcess()) {
MOZ_ASSERT(gChangedDomPrefs);
for (unsigned int i = 0; i < gChangedDomPrefs->Length(); i++) {
Preferences::SetPreference(gChangedDomPrefs->ElementAt(i));
}
delete gChangedDomPrefs;
gChangedDomPrefs = nullptr;
#ifndef MOZ_WIDGET_ANDROID
CheckTelemetryPref();
#endif
} else {
// Check if there is a deployment configuration file. If so, set up the
// pref config machinery, which will actually read the file.
nsAutoCString lockFileName;
nsresult rv = Preferences::GetCString("general.config.filename",
lockFileName, PrefValueKind::User);
if (NS_SUCCEEDED(rv)) {
NS_CreateServicesFromCategory(
"pref-config-startup",
static_cast<nsISupports*>(static_cast<void*>(sPreferences)),
"pref-config-startup");
}
nsCOMPtr<nsIObserverService> observerService =
services::GetObserverService();
if (!observerService) {
sPreferences = nullptr;
gCacheDataDesc = "GetObserverService() failed (1)";
return nullptr;
}
observerService->AddObserver(sPreferences,
"profile-before-change-telemetry", true);
rv = observerService->AddObserver(sPreferences, "profile-before-change",
true);
observerService->AddObserver(sPreferences, "suspend_process_notification",
true);
if (NS_FAILED(rv)) {
sPreferences = nullptr;
gCacheDataDesc = "AddObserver(\"profile-before-change\") failed";
return nullptr;
}
}
const char* defaultPrefs = getenv("MOZ_DEFAULT_PREFS");
if (defaultPrefs) {
parsePrefData(nsCString(defaultPrefs), PrefValueKind::Default);
}
gCacheDataDesc = "set by GetInstanceForService() (2)";
// Preferences::GetInstanceForService() can be called from GetService(), and
// RegisterStrongMemoryReporter calls GetService(nsIMemoryReporter). To
// avoid a potential recursive GetService() call, we can't register the
// memory reporter here; instead, do it off a runnable.
RefPtr<AddPreferencesMemoryReporterRunnable> runnable =
new AddPreferencesMemoryReporterRunnable();
NS_DispatchToMainThread(runnable);
return do_AddRef(sPreferences);
}
/* static */
bool Preferences::IsServiceAvailable() { return !!sPreferences; }
/* static */
bool Preferences::InitStaticMembers() {
MOZ_ASSERT(NS_IsMainThread() || ServoStyleSet::IsInServoTraversal());
if (MOZ_LIKELY(sPreferences)) {
return true;
}
if (!sShutdown) {
MOZ_ASSERT(NS_IsMainThread());
nsCOMPtr<nsIPrefService> prefService =
do_GetService(NS_PREFSERVICE_CONTRACTID);
}
return sPreferences != nullptr;
}
/* static */
void Preferences::Shutdown() {
if (!sShutdown) {
sShutdown = true; // Don't create the singleton instance after here.
sPreferences = nullptr;
}
}
Preferences::Preferences()
: mRootBranch(new nsPrefBranch("", PrefValueKind::User)),
mDefaultRootBranch(new nsPrefBranch("", PrefValueKind::Default)) {}
Preferences::~Preferences() {
MOZ_ASSERT(!sPreferences);
delete gCacheData;
gCacheData = nullptr;
MOZ_ASSERT(!gCallbacksInProgress);
CallbackNode* node = gFirstCallback;
while (node) {
CallbackNode* next_node = node->Next();
delete node;
node = next_node;
}
gLastPriorityNode = gFirstCallback = nullptr;
delete gHashTable;
gHashTable = nullptr;
delete gTelemetryLoadData;
gTelemetryLoadData = nullptr;
#ifdef DEBUG
delete gOnceStaticPrefsAntiFootgun;
gOnceStaticPrefsAntiFootgun = nullptr;
#endif
#ifdef ACCESS_COUNTS
delete gAccessCounts;
#endif
gSharedMap = nullptr;
gPrefNameArena.Clear();
}
NS_IMPL_ISUPPORTS(Preferences, nsIPrefService, nsIObserver, nsIPrefBranch,
nsISupportsWeakReference)
/* static */
void Preferences::SerializePreferences(nsCString& aStr) {
MOZ_RELEASE_ASSERT(InitStaticMembers());
aStr.Truncate();
for (auto iter = gHashTable->iter(); !iter.done(); iter.next()) {
Pref* pref = iter.get().get();
if (!pref->IsTypeNone() && pref->HasAdvisablySizedValues()) {
pref->SerializeAndAppend(aStr);
}
}
aStr.Append('\0');
}
/* static */
void Preferences::DeserializePreferences(char* aStr, size_t aPrefsLen) {
MOZ_ASSERT(!XRE_IsParentProcess());
MOZ_ASSERT(!gChangedDomPrefs);
gChangedDomPrefs = new nsTArray<dom::Pref>();
char* p = aStr;
while (*p != '\0') {
dom::Pref pref;
p = Pref::Deserialize(p, &pref);
gChangedDomPrefs->AppendElement(pref);
}
// We finished parsing on a '\0'. That should be the last char in the shared
// memory. (aPrefsLen includes the '\0'.)
MOZ_ASSERT(p == aStr + aPrefsLen - 1);
#ifdef DEBUG
MOZ_ASSERT(!gContentProcessPrefsAreInited);
gContentProcessPrefsAreInited = true;
#endif
}
// Forward declarations.
namespace StaticPrefs {
static void InitAll(bool aIsStartup);
static void InitOncePrefs();
static void InitStaticPrefsFromShared();
static void RegisterOncePrefs(SharedPrefMapBuilder& aBuilder);
} // namespace StaticPrefs
/* static */
FileDescriptor Preferences::EnsureSnapshot(size_t* aSize) {
MOZ_ASSERT(XRE_IsParentProcess());
if (!gSharedMap) {
SharedPrefMapBuilder builder;
for (auto iter = gHashTable->iter(); !iter.done(); iter.next()) {
iter.get()->AddToMap(builder);
}
// Store the current value of Once StaticPrefs. Following this those
// StaticPrefs will become immutable.
StaticPrefs::RegisterOncePrefs(builder);
gSharedMap = new SharedPrefMap(std::move(builder));
// Once we've built a snapshot of the database, there's no need to continue
// storing dynamic copies of the preferences it contains. Once we reset the
// hashtable, preference lookups will fall back to the snapshot for any
// preferences not in the dynamic hashtable.
//
// And since the majority of the database is now contained in the snapshot,
// we can initialize the hashtable with the expected number of per-session
// changed preferences, rather than the expected total number of
// preferences.
gHashTable->clearAndCompact();
Unused << gHashTable->reserve(kHashTableInitialLengthContent);
gPrefNameArena.Clear();
}
*aSize = gSharedMap->MapSize();
return gSharedMap->CloneFileDescriptor();
}
/* static */
void Preferences::InitSnapshot(const FileDescriptor& aHandle, size_t aSize) {
MOZ_ASSERT(!XRE_IsParentProcess());
MOZ_ASSERT(!gSharedMap);
gSharedMap = new SharedPrefMap(aHandle, aSize);
StaticPrefs::InitStaticPrefsFromShared();
}
/* static */
void Preferences::InitializeUserPrefs() {
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(!sPreferences->mCurrentFile, "Should only initialize prefs once");
// Prefs which are set before we initialize the profile are silently
// discarded. This is stupid, but there are various tests which depend on
// this behavior.
sPreferences->ResetUserPrefs();
nsCOMPtr<nsIFile> prefsFile = sPreferences->ReadSavedPrefs();
sPreferences->ReadUserOverridePrefs();
sPreferences->mDirty = false;
// Don't set mCurrentFile until we're done so that dirty flags work properly.
sPreferences->mCurrentFile = prefsFile.forget();
sPreferences->NotifyServiceObservers(NS_PREFSERVICE_READ_TOPIC_ID);
// At this point all the prefs files have been read and telemetry has been
// initialized. Send all the file load measurements to telemetry.
SendTelemetryLoadData();
}
NS_IMETHODIMP
Preferences::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* someData) {
if (MOZ_UNLIKELY(!XRE_IsParentProcess())) {
return NS_ERROR_NOT_AVAILABLE;
}
nsresult rv = NS_OK;
if (!nsCRT::strcmp(aTopic, "profile-before-change")) {
// Normally prefs aren't written after this point, and so we kick off
// an asynchronous pref save so that I/O can be done in parallel with
// other shutdown.
if (AllowOffMainThreadSave()) {
SavePrefFile(nullptr);
}
} else if (!nsCRT::strcmp(aTopic, "profile-before-change-telemetry")) {
// It's possible that a profile-before-change observer after ours
// set a pref. A blocking save here re-saves if necessary and also waits
// for any pending saves to complete.
SavePrefFileBlocking();
MOZ_ASSERT(!mDirty, "Preferences should not be dirty");
mProfileShutdown = true;
} else if (!nsCRT::strcmp(aTopic, "reload-default-prefs")) {
// Reload the default prefs from file.
Unused << InitInitialObjects(/* isStartup */ false);
} else if (!nsCRT::strcmp(aTopic, "suspend_process_notification")) {
// Our process is being suspended. The OS may wake our process later,
// or it may kill the process. In case our process is going to be killed
// from the suspended state, we save preferences before suspending.
rv = SavePrefFileBlocking();
}
return rv;
}
NS_IMETHODIMP
Preferences::ReadDefaultPrefsFromFile(nsIFile* aFile) {
ENSURE_PARENT_PROCESS("Preferences::ReadDefaultPrefsFromFile", "all prefs");
if (!aFile) {
NS_ERROR("ReadDefaultPrefsFromFile requires a parameter");
return NS_ERROR_INVALID_ARG;
}
return openPrefFile(aFile, PrefValueKind::Default);
}
NS_IMETHODIMP
Preferences::ReadUserPrefsFromFile(nsIFile* aFile) {
ENSURE_PARENT_PROCESS("Preferences::ReadUserPrefsFromFile", "all prefs");
if (!aFile) {
NS_ERROR("ReadUserPrefsFromFile requires a parameter");
return NS_ERROR_INVALID_ARG;
}
return openPrefFile(aFile, PrefValueKind::User);
}
NS_IMETHODIMP
Preferences::ResetPrefs() {
ENSURE_PARENT_PROCESS("Preferences::ResetPrefs", "all prefs");
if (gSharedMap) {
return NS_ERROR_NOT_AVAILABLE;
}
gHashTable->clearAndCompact();
Unused << gHashTable->reserve(kHashTableInitialLengthParent);
gPrefNameArena.Clear();
return InitInitialObjects(/* isStartup */ false).isOk() ? NS_OK
: NS_ERROR_FAILURE;
}
NS_IMETHODIMP
Preferences::ResetUserPrefs() {
ENSURE_PARENT_PROCESS("Preferences::ResetUserPrefs", "all prefs");
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
MOZ_ASSERT(NS_IsMainThread());
Vector<const char*> prefNames;
for (auto iter = gHashTable->modIter(); !iter.done(); iter.next()) {
Pref* pref = iter.get().get();
if (pref->HasUserValue()) {
if (!prefNames.append(pref->Name())) {
return NS_ERROR_OUT_OF_MEMORY;
}
pref->ClearUserValue();
if (!pref->HasDefaultValue()) {
iter.remove();
}
}
}
for (const char* prefName : prefNames) {
NotifyCallbacks(prefName);
}
Preferences::HandleDirty();
return NS_OK;
}
bool Preferences::AllowOffMainThreadSave() {
// Put in a preference that allows us to disable off main thread preference
// file save.
if (sAllowOMTPrefWrite < 0) {
bool value = false;
Preferences::GetBool("preferences.allow.omt-write", &value);
sAllowOMTPrefWrite = value ? 1 : 0;
}
return !!sAllowOMTPrefWrite;
}
nsresult Preferences::SavePrefFileBlocking() {
if (mDirty) {
return SavePrefFileInternal(nullptr, SaveMethod::Blocking);
}
// If we weren't dirty to start, SavePrefFileInternal will early exit so
// there is no guarantee that we don't have oustanding async saves in the
// pipe. Since the contract of SavePrefFileOnMainThread is that the file on
// disk matches the preferences, we have to make sure those requests are
// completed.
if (AllowOffMainThreadSave()) {
PreferencesWriter::Flush();
}
return NS_OK;
}
nsresult Preferences::SavePrefFileAsynchronous() {
return SavePrefFileInternal(nullptr, SaveMethod::Asynchronous);
}
NS_IMETHODIMP
Preferences::SavePrefFile(nsIFile* aFile) {
// This is the method accessible from service API. Make it off main thread.
return SavePrefFileInternal(aFile, SaveMethod::Asynchronous);
}
/* static */
void Preferences::SetPreference(const dom::Pref& aDomPref) {
MOZ_ASSERT(!XRE_IsParentProcess());
NS_ENSURE_TRUE(InitStaticMembers(), (void)0);
const char* prefName = aDomPref.name().get();
Pref* pref;
auto p = gHashTable->lookupForAdd(prefName);
if (!p) {
pref = new Pref(prefName);
if (!gHashTable->add(p, pref)) {
delete pref;
return;
}
} else {
pref = p->get();
}
bool valueChanged = false;
pref->FromDomPref(aDomPref, &valueChanged);
// When the parent process clears a pref's user value we get a DomPref here
// with no default value and no user value. There are two possibilities.
//
// - There was an existing pref with only a user value. FromDomPref() will
// have just cleared that user value, so the pref can be removed.
//
// - There was no existing pref. FromDomPref() will have done nothing, and
// `pref` will be valueless. We will end up adding and removing the value
// needlessly, but that's ok because this case is rare.
//
if (!pref->HasDefaultValue() && !pref->HasUserValue()) {
// If the preference exists in the shared map, we need to keep the dynamic
// entry around to mask it.
if (gSharedMap->Has(pref->Name())) {
pref->SetType(PrefType::None);
} else {
gHashTable->remove(prefName);
}
pref = nullptr;
}
// Note: we don't have to worry about HandleDirty() because we are setting
// prefs in the content process that have come from the parent process.
if (valueChanged) {
if (pref) {
NotifyCallbacks(prefName, PrefWrapper(pref));
} else {
NotifyCallbacks(prefName);
}
}
}
/* static */
void Preferences::GetPreference(dom::Pref* aDomPref) {
MOZ_ASSERT(XRE_IsParentProcess());
Pref* pref = pref_HashTableLookup(aDomPref->name().get());
if (pref && pref->HasAdvisablySizedValues()) {
pref->ToDomPref(aDomPref);
}
}
#ifdef DEBUG
bool Preferences::ArePrefsInitedInContentProcess() {
MOZ_ASSERT(!XRE_IsParentProcess());
return gContentProcessPrefsAreInited;
}
#endif
NS_IMETHODIMP
Preferences::GetBranch(const char* aPrefRoot, nsIPrefBranch** aRetVal) {
if ((nullptr != aPrefRoot) && (*aPrefRoot != '\0')) {
// TODO: Cache this stuff and allow consumers to share branches (hold weak
// references, I think).
RefPtr<nsPrefBranch> prefBranch =
new nsPrefBranch(aPrefRoot, PrefValueKind::User);
prefBranch.forget(aRetVal);
} else {
// Special case: caching the default root.
nsCOMPtr<nsIPrefBranch> root(sPreferences->mRootBranch);
root.forget(aRetVal);
}
return NS_OK;
}
NS_IMETHODIMP
Preferences::GetDefaultBranch(const char* aPrefRoot, nsIPrefBranch** aRetVal) {
if (!aPrefRoot || !aPrefRoot[0]) {
nsCOMPtr<nsIPrefBranch> root(sPreferences->mDefaultRootBranch);
root.forget(aRetVal);
return NS_OK;
}
// TODO: Cache this stuff and allow consumers to share branches (hold weak
// references, I think).
RefPtr<nsPrefBranch> prefBranch =
new nsPrefBranch(aPrefRoot, PrefValueKind::Default);
if (!prefBranch) {
return NS_ERROR_OUT_OF_MEMORY;
}
prefBranch.forget(aRetVal);
return NS_OK;
}
NS_IMETHODIMP
Preferences::ReadStats(nsIPrefStatsCallback* aCallback) {
#ifdef ACCESS_COUNTS
for (auto iter = gAccessCounts->Iter(); !iter.Done(); iter.Next()) {
aCallback->Visit(iter.Key(), iter.Data());
}
return NS_OK;
#else
return NS_ERROR_NOT_IMPLEMENTED;
#endif
}
NS_IMETHODIMP
Preferences::ResetStats() {
#ifdef ACCESS_COUNTS
gAccessCounts->Clear();
return NS_OK;
#else
return NS_ERROR_NOT_IMPLEMENTED;
#endif
}
NS_IMETHODIMP
Preferences::GetDirty(bool* aRetVal) {
*aRetVal = mDirty;
return NS_OK;
}
nsresult Preferences::NotifyServiceObservers(const char* aTopic) {
nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
if (!observerService) {
return NS_ERROR_FAILURE;
}
auto subject = static_cast<nsIPrefService*>(this);
observerService->NotifyObservers(subject, aTopic, nullptr);
return NS_OK;
}
already_AddRefed<nsIFile> Preferences::ReadSavedPrefs() {
nsCOMPtr<nsIFile> file;
nsresult rv =
NS_GetSpecialDirectory(NS_APP_PREFS_50_FILE, getter_AddRefs(file));
if (NS_WARN_IF(NS_FAILED(rv))) {
return nullptr;
}
rv = openPrefFile(file, PrefValueKind::User);
if (rv == NS_ERROR_FILE_NOT_FOUND) {
// This is a normal case for new users.
Telemetry::ScalarSet(
Telemetry::ScalarID::PREFERENCES_CREATED_NEW_USER_PREFS_FILE, true);
rv = NS_OK;
} else if (NS_FAILED(rv)) {
// Save a backup copy of the current (invalid) prefs file, since all prefs
// from the error line to the end of the file will be lost (bug 361102).
// TODO we should notify the user about it (bug 523725).
Telemetry::ScalarSet(
Telemetry::ScalarID::PREFERENCES_PREFS_FILE_WAS_INVALID, true);
MakeBackupPrefFile(file);
}
return file.forget();
}
void Preferences::ReadUserOverridePrefs() {
nsCOMPtr<nsIFile> aFile;
nsresult rv =
NS_GetSpecialDirectory(NS_APP_PREFS_50_DIR, getter_AddRefs(aFile));
if (NS_WARN_IF(NS_FAILED(rv))) {
return;
}
aFile->AppendNative(NS_LITERAL_CSTRING("user.js"));
rv = openPrefFile(aFile, PrefValueKind::User);
if (rv != NS_ERROR_FILE_NOT_FOUND) {
// If the file exists and was at least partially read, record that in
// telemetry as it may be a sign of pref injection.
Telemetry::ScalarSet(Telemetry::ScalarID::PREFERENCES_READ_USER_JS, true);
}
}
nsresult Preferences::MakeBackupPrefFile(nsIFile* aFile) {
// Example: this copies "prefs.js" to "Invalidprefs.js" in the same directory.
// "Invalidprefs.js" is removed if it exists, prior to making the copy.
nsAutoString newFilename;
nsresult rv = aFile->GetLeafName(newFilename);
NS_ENSURE_SUCCESS(rv, rv);
newFilename.InsertLiteral(u"Invalid", 0);
nsCOMPtr<nsIFile> newFile;
rv = aFile->GetParent(getter_AddRefs(newFile));
NS_ENSURE_SUCCESS(rv, rv);
rv = newFile->Append(newFilename);
NS_ENSURE_SUCCESS(rv, rv);
bool exists = false;
newFile->Exists(&exists);
if (exists) {
rv = newFile->Remove(false);
NS_ENSURE_SUCCESS(rv, rv);
}
rv = aFile->CopyTo(nullptr, newFilename);
NS_ENSURE_SUCCESS(rv, rv);
return rv;
}
nsresult Preferences::SavePrefFileInternal(nsIFile* aFile,
SaveMethod aSaveMethod) {
ENSURE_PARENT_PROCESS("Preferences::SavePrefFileInternal", "all prefs");
// We allow different behavior here when aFile argument is not null, but it
// happens to be the same as the current file. It is not clear that we
// should, but it does give us a "force" save on the unmodified pref file
// (see the original bug 160377 when we added this.)
if (nullptr == aFile) {
mSavePending = false;
// Off main thread writing only if allowed.
if (!AllowOffMainThreadSave()) {
aSaveMethod = SaveMethod::Blocking;
}
// The mDirty flag tells us if we should write to mCurrentFile. We only
// check this flag when the caller wants to write to the default.
if (!mDirty) {
return NS_OK;
}
// Check for profile shutdown after mDirty because the runnables from
// HandleDirty() can still be pending.
if (mProfileShutdown) {
NS_WARNING("Cannot save pref file after profile shutdown.");
return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
}
// It's possible that we never got a prefs file.
nsresult rv = NS_OK;
if (mCurrentFile) {
rv = WritePrefFile(mCurrentFile, aSaveMethod);
}
// If we succeeded writing to mCurrentFile, reset the dirty flag.
if (NS_SUCCEEDED(rv)) {
mDirty = false;
}
return rv;
} else {
// We only allow off main thread writes on mCurrentFile.
return WritePrefFile(aFile, SaveMethod::Blocking);
}
}
nsresult Preferences::WritePrefFile(nsIFile* aFile, SaveMethod aSaveMethod) {
MOZ_ASSERT(XRE_IsParentProcess());
if (!gHashTable) {
return NS_ERROR_NOT_INITIALIZED;
}
AUTO_PROFILER_LABEL("Preferences::WritePrefFile", OTHER);
if (AllowOffMainThreadSave()) {
nsresult rv = NS_OK;
UniquePtr<PrefSaveData> prefs = MakeUnique<PrefSaveData>(pref_savePrefs());
// Put the newly constructed preference data into sPendingWriteData
// for the next request to pick up
prefs.reset(PreferencesWriter::sPendingWriteData.exchange(prefs.release()));
if (prefs) {
// There was a previous request that hasn't been processed,
// and this is the data it had.
return rv;
}
// There were no previous requests. Dispatch one since sPendingWriteData has
// the up to date information.
nsCOMPtr<nsIEventTarget> target =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
if (NS_SUCCEEDED(rv)) {
bool async = aSaveMethod == SaveMethod::Asynchronous;
if (async) {
rv = target->Dispatch(new PWRunnable(aFile),
nsIEventTarget::DISPATCH_NORMAL);
} else {
// Note that we don't get the nsresult return value here.
SyncRunnable::DispatchToThread(target, new PWRunnable(aFile), true);
}
return rv;
}
// If we can't get the thread for writing, for whatever reason, do the main
// thread write after making some noise.
MOZ_ASSERT(false, "failed to get the target thread for OMT pref write");
}
// This will do a main thread write. It is safe to do it this way because
// AllowOffMainThreadSave() returns a consistent value for the lifetime of
// the parent process.
PrefSaveData prefsData = pref_savePrefs();
return PreferencesWriter::Write(aFile, prefsData);
}
static nsresult openPrefFile(nsIFile* aFile, PrefValueKind aKind) {
TimeStamp startTime = TimeStamp::Now();
nsCString data;
MOZ_TRY_VAR(data, URLPreloader::ReadFile(aFile));
nsAutoString filenameUtf16;
aFile->GetLeafName(filenameUtf16);
NS_ConvertUTF16toUTF8 filename(filenameUtf16);
nsAutoString path;
aFile->GetPath(path);
Parser parser;
if (!parser.Parse(filename, aKind, NS_ConvertUTF16toUTF8(path).get(),
startTime, data)) {
return NS_ERROR_FILE_CORRUPTED;
}
return NS_OK;
}
static nsresult parsePrefData(const nsCString& aData, PrefValueKind aKind) {
TimeStamp startTime = TimeStamp::Now();
const nsCString path = NS_LITERAL_CSTRING("$MOZ_DEFAULT_PREFS");
Parser parser;
if (!parser.Parse(path, aKind, path.get(), startTime, aData)) {
return NS_ERROR_FILE_CORRUPTED;
}
return NS_OK;
}
static int pref_CompareFileNames(nsIFile* aFile1, nsIFile* aFile2,
void* /* unused */) {
nsAutoCString filename1, filename2;
aFile1->GetNativeLeafName(filename1);
aFile2->GetNativeLeafName(filename2);
return Compare(filename2, filename1);
}
// Load default pref files from a directory. The files in the directory are
// sorted reverse-alphabetically; a set of "special file names" may be
// specified which are loaded after all the others.
static nsresult pref_LoadPrefsInDir(nsIFile* aDir,
char const* const* aSpecialFiles,
uint32_t aSpecialFilesCount) {
nsresult rv, rv2;
nsCOMPtr<nsIDirectoryEnumerator> dirIterator;
// This may fail in some normal cases, such as embedders who do not use a
// GRE.
rv = aDir->GetDirectoryEntries(getter_AddRefs(dirIterator));
if (NS_FAILED(rv)) {
// If the directory doesn't exist, then we have no reason to complain. We
// loaded everything (and nothing) successfully.
if (rv == NS_ERROR_FILE_NOT_FOUND ||
rv == NS_ERROR_FILE_TARGET_DOES_NOT_EXIST) {
rv = NS_OK;
}
return rv;
}
nsCOMArray<nsIFile> prefFiles(INITIAL_PREF_FILES);
nsCOMArray<nsIFile> specialFiles(aSpecialFilesCount);
nsCOMPtr<nsIFile> prefFile;
while (NS_SUCCEEDED(dirIterator->GetNextFile(getter_AddRefs(prefFile))) &&
prefFile) {
nsAutoCString leafName;
prefFile->GetNativeLeafName(leafName);
MOZ_ASSERT(
!leafName.IsEmpty(),
"Failure in default prefs: directory enumerator returned empty file?");
// Skip non-js files.
if (StringEndsWith(leafName, NS_LITERAL_CSTRING(".js"),
nsCaseInsensitiveCStringComparator())) {
bool shouldParse = true;
// Separate out special files.
for (uint32_t i = 0; i < aSpecialFilesCount; ++i) {
if (leafName.Equals(nsDependentCString(aSpecialFiles[i]))) {
shouldParse = false;
// Special files should be processed in order. We put them into the
// array by index, which can make the array sparse.
specialFiles.ReplaceObjectAt(prefFile, i);
}
}
if (shouldParse) {
prefFiles.AppendObject(prefFile);
}
}
}
if (prefFiles.Count() + specialFiles.Count() == 0) {
NS_WARNING("No default pref files found.");
if (NS_SUCCEEDED(rv)) {
rv = NS_SUCCESS_FILE_DIRECTORY_EMPTY;
}
return rv;
}
prefFiles.Sort(pref_CompareFileNames, nullptr);
uint32_t arrayCount = prefFiles.Count();
uint32_t i;
for (i = 0; i < arrayCount; ++i) {
rv2 = openPrefFile(prefFiles[i], PrefValueKind::Default);
if (NS_FAILED(rv2)) {
NS_ERROR("Default pref file not parsed successfully.");
rv = rv2;
}
}
arrayCount = specialFiles.Count();
for (i = 0; i < arrayCount; ++i) {
// This may be a sparse array; test before parsing.
nsIFile* file = specialFiles[i];
if (file) {
rv2 = openPrefFile(file, PrefValueKind::Default);
if (NS_FAILED(rv2)) {
NS_ERROR("Special default pref file not parsed successfully.");
rv = rv2;
}
}
}
return rv;
}
static nsresult pref_ReadPrefFromJar(nsZipArchive* aJarReader,
const char* aName) {
TimeStamp startTime = TimeStamp::Now();
nsCString manifest;
MOZ_TRY_VAR(manifest,
URLPreloader::ReadZip(aJarReader, nsDependentCString(aName)));
Parser parser;
if (!parser.Parse(nsDependentCString(aName), PrefValueKind::Default, aName,
startTime, manifest)) {
return NS_ERROR_FILE_CORRUPTED;
}
return NS_OK;
}
static nsresult pref_ReadDefaultPrefs(const RefPtr<nsZipArchive> jarReader,
const char* path) {
nsZipFind* findPtr;
nsAutoPtr<nsZipFind> find;
nsTArray<nsCString> prefEntries;
const char* entryName;
uint16_t entryNameLen;
nsresult rv = jarReader->FindInit(path, &findPtr);
NS_ENSURE_SUCCESS(rv, rv);
find = findPtr;
while (NS_SUCCEEDED(find->FindNext(&entryName, &entryNameLen))) {
prefEntries.AppendElement(Substring(entryName, entryNameLen));
}
prefEntries.Sort();
for (uint32_t i = prefEntries.Length(); i--;) {
rv = pref_ReadPrefFromJar(jarReader, prefEntries[i].get());
if (NS_FAILED(rv)) {
NS_WARNING("Error parsing preferences.");
}
}
return NS_OK;
}
// These preference getter wrappers allow us to look up the value for static
// preferences based on their native types, rather than manually mapping them to
// the appropriate Preferences::Get* functions.
// We define these methods in a struct which is made friend of Preferences in
// order to access private members.
struct PreferencesInternalMethods {
template <typename T>
static nsresult GetPrefValue(const char* aPrefName, T&& aResult,
PrefValueKind aKind) {
NS_ENSURE_TRUE(Preferences::InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
if (Maybe<PrefWrapper> pref = pref_Lookup(aPrefName)) {
return pref->GetValue(aKind, std::forward<T>(aResult));
}
return NS_ERROR_UNEXPECTED;
}
template <typename T>
static nsresult GetSharedPrefValue(const char* aName, T* aResult) {
if (Maybe<PrefWrapper> pref = pref_SharedLookup(aName)) {
return pref->GetValue(PrefValueKind::User, aResult);
}
return NS_ERROR_UNEXPECTED;
}
template <typename T>
static T GetPref(const char* aPrefName, T aFallback,
PrefValueKind aKind = PrefValueKind::User) {
T result = aFallback;
GetPrefValue(aPrefName, &result, aKind);
return result;
}
template <typename T>
static void VarChanged(const char* aPref, void* aClosure) {
CacheData* cache = static_cast<CacheData*>(aClosure);
*static_cast<T*>(cache->mCacheLocation) =
GetPref(aPref, cache->GetDefault<StripAtomic<T>>());
}
template <typename T>
static nsresult RegisterCallback(CacheData* aCacheData,
const nsACString& aPref) {
return Preferences::RegisterCallback(VarChanged<T>, aPref, aCacheData,
Preferences::ExactMatch,
/* isPriority */ true);
}
};
// Initialize default preference JavaScript buffers from appropriate TEXT
// resources.
/* static */
Result<Ok, const char*> Preferences::InitInitialObjects(bool aIsStartup) {
// Initialize static prefs before prefs from data files so that the latter
// will override the former.
StaticPrefs::InitAll(aIsStartup);
if (!XRE_IsParentProcess()) {
MOZ_DIAGNOSTIC_ASSERT(gSharedMap);
#ifdef DEBUG
// For a VarCache pref like this:
//
// VARCACHE_PREF($POLICY, "my.pref", my_pref, my_pref, int32_t, 99)
//
// we generate checking code like this:
//
// MOZ_ASSERT(PreferencesInternalMethods::GetPref<int32_t>(name, value) ==
// StaticPrefs::my_pref(),
// "Incorrect cached value for my.pref");
//
// This checks that all VarCache preferences match their current values.
// This can currently fail if the default value of a static VarCache
// preference is changed in a preference file or at runtime, rather than in
// StaticPrefList*.h.
//
# define PREF(name, cpp_type, value)
# define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, value) \
MOZ_ASSERT(PreferencesInternalMethods::GetPref<StripAtomic<cpp_type>>( \
name, value) == StaticPrefs::full_id(), \
"Incorrect cached value for " name);
# include "mozilla/StaticPrefListAll.h"
# undef PREF
# undef VARCACHE_PREF
#endif
return Ok();
}
// In the omni.jar case, we load the following prefs:
// - jar:$gre/omni.jar!/greprefs.js
// - jar:$gre/omni.jar!/defaults/pref/*.js
//
// In the non-omni.jar case, we load:
// - $gre/greprefs.js
//
// In both cases, we also load:
// - $gre/defaults/pref/*.js
//
// This is kept for bug 591866 (channel-prefs.js should not be in omni.jar)
// in the `$app == $gre` case; we load all files instead of channel-prefs.js
// only to have the same behaviour as `$app != $gre`, where this is required
// as a supported location for GRE preferences.
//
// When `$app != $gre`, we additionally load, in the omni.jar case:
// - jar:$app/omni.jar!/defaults/preferences/*.js
// - $app/defaults/preferences/*.js
//
// and in the non-omni.jar case:
// - $app/defaults/preferences/*.js
//
// When `$app == $gre`, we additionally load, in the omni.jar case:
// - jar:$gre/omni.jar!/defaults/preferences/*.js
//
// Thus, in the omni.jar case, we always load app-specific default
// preferences from omni.jar, whether or not `$app == $gre`.
nsresult rv = NS_ERROR_FAILURE;
nsZipFind* findPtr;
nsAutoPtr<nsZipFind> find;
nsTArray<nsCString> prefEntries;
const char* entryName;
uint16_t entryNameLen;
RefPtr<nsZipArchive> jarReader = Omnijar::GetReader(Omnijar::GRE);
if (jarReader) {
#ifdef MOZ_WIDGET_ANDROID
// Try to load an architecture-specific greprefs.js first. This will be
// present in FAT AAR builds of GeckoView on Android.
const char* abi = getenv("MOZ_ANDROID_CPU_ABI");
if (abi) {
nsAutoCString path;
path.AppendPrintf("%s/greprefs.js", abi);
rv = pref_ReadPrefFromJar(jarReader, path.get());
}
if (NS_FAILED(rv)) {
// Fallback to toplevel greprefs.js if arch-specific load fails.
rv = pref_ReadPrefFromJar(jarReader, "greprefs.js");
}
#else
// Load jar:$gre/omni.jar!/greprefs.js.
rv = pref_ReadPrefFromJar(jarReader, "greprefs.js");
#endif
NS_ENSURE_SUCCESS(rv, Err("pref_ReadPrefFromJar() failed"));
// Load jar:$gre/omni.jar!/defaults/pref/*.js.
rv = pref_ReadDefaultPrefs(jarReader, "defaults/pref/*.js$");
NS_ENSURE_SUCCESS(rv, Err("pref_ReadDefaultPrefs() failed"));
#ifdef MOZ_WIDGET_ANDROID
// Load jar:$gre/omni.jar!/defaults/pref/$MOZ_ANDROID_CPU_ABI/*.js.
nsAutoCString path;
path.AppendPrintf("jar:$gre/omni.jar!/defaults/pref/%s/*.js$", abi);
pref_ReadDefaultPrefs(jarReader, path.get());
NS_ENSURE_SUCCESS(
rv, Err("architecture-specific pref_ReadDefaultPrefs() failed"));
#endif
} else {
// Load $gre/greprefs.js.
nsCOMPtr<nsIFile> greprefsFile;
rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(greprefsFile));
NS_ENSURE_SUCCESS(rv, Err("NS_GetSpecialDirectory(NS_GRE_DIR) failed"));
rv = greprefsFile->AppendNative(NS_LITERAL_CSTRING("greprefs.js"));
NS_ENSURE_SUCCESS(rv, Err("greprefsFile->AppendNative() failed"));
rv = openPrefFile(greprefsFile, PrefValueKind::Default);
if (NS_FAILED(rv)) {
NS_WARNING(
"Error parsing GRE default preferences. Is this an old-style "
"embedding app?");
}
}
// Load $gre/defaults/pref/*.js.
nsCOMPtr<nsIFile> defaultPrefDir;
rv = NS_GetSpecialDirectory(NS_APP_PREF_DEFAULTS_50_DIR,
getter_AddRefs(defaultPrefDir));
NS_ENSURE_SUCCESS(
rv, Err("NS_GetSpecialDirectory(NS_APP_PREF_DEFAULTS_50_DIR) failed"));
// These pref file names should not be used: we process them after all other
// application pref files for backwards compatibility.
static const char* specialFiles[] = {
#if defined(XP_MACOSX)
"macprefs.js"
#elif defined(XP_WIN)
"winpref.js"
#elif defined(XP_UNIX)
"unix.js"
# if defined(_AIX)
,
"aix.js"
# endif
#elif defined(XP_BEOS)
"beos.js"
#endif
};
rv = pref_LoadPrefsInDir(defaultPrefDir, specialFiles,
ArrayLength(specialFiles));
if (NS_FAILED(rv)) {
NS_WARNING("Error parsing application default preferences.");
}
// Load jar:$app/omni.jar!/defaults/preferences/*.js
// or jar:$gre/omni.jar!/defaults/preferences/*.js.
RefPtr<nsZipArchive> appJarReader = Omnijar::GetReader(Omnijar::APP);
// GetReader(Omnijar::APP) returns null when `$app == $gre`, in
// which case we look for app-specific default preferences in $gre.
if (!appJarReader) {
appJarReader = Omnijar::GetReader(Omnijar::GRE);
}
if (appJarReader) {
rv = appJarReader->FindInit("defaults/preferences/*.js$", &findPtr);
NS_ENSURE_SUCCESS(rv, Err("appJarReader->FindInit() failed"));
find = findPtr;
prefEntries.Clear();
while (NS_SUCCEEDED(find->FindNext(&entryName, &entryNameLen))) {
prefEntries.AppendElement(Substring(entryName, entryNameLen));
}
prefEntries.Sort();
for (uint32_t i = prefEntries.Length(); i--;) {
rv = pref_ReadPrefFromJar(appJarReader, prefEntries[i].get());
if (NS_FAILED(rv)) {
NS_WARNING("Error parsing preferences.");
}
}
}
nsCOMPtr<nsIProperties> dirSvc(
do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
NS_ENSURE_SUCCESS(
rv, Err("do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID) failed"));
nsCOMPtr<nsISimpleEnumerator> list;
dirSvc->Get(NS_APP_PREFS_DEFAULTS_DIR_LIST, NS_GET_IID(nsISimpleEnumerator),
getter_AddRefs(list));
if (list) {
bool hasMore;
while (NS_SUCCEEDED(list->HasMoreElements(&hasMore)) && hasMore) {
nsCOMPtr<nsISupports> elem;
list->GetNext(getter_AddRefs(elem));
if (!elem) {
continue;
}
nsCOMPtr<nsIFile> path = do_QueryInterface(elem);
if (!path) {
continue;
}
// Do we care if a file provided by this process fails to load?
pref_LoadPrefsInDir(path, nullptr, 0);
}
}
if (XRE_IsParentProcess()) {
SetupTelemetryPref();
}
NS_CreateServicesFromCategory(NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID, nullptr,
NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID);
nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
NS_ENSURE_SUCCESS(rv, Err("GetObserverService() failed (2)"));
observerService->NotifyObservers(nullptr, NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID,
nullptr);
return Ok();
}
/* static */
nsresult Preferences::GetBool(const char* aPrefName, bool* aResult,
PrefValueKind aKind) {
MOZ_ASSERT(aResult);
return PreferencesInternalMethods::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetInt(const char* aPrefName, int32_t* aResult,
PrefValueKind aKind) {
MOZ_ASSERT(aResult);
return PreferencesInternalMethods::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetFloat(const char* aPrefName, float* aResult,
PrefValueKind aKind) {
MOZ_ASSERT(aResult);
return PreferencesInternalMethods::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetCString(const char* aPrefName, nsACString& aResult,
PrefValueKind aKind) {
aResult.SetIsVoid(true);
return PreferencesInternalMethods::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetString(const char* aPrefName, nsAString& aResult,
PrefValueKind aKind) {
nsAutoCString result;
nsresult rv = Preferences::GetCString(aPrefName, result, aKind);
if (NS_SUCCEEDED(rv)) {
CopyUTF8toUTF16(result, aResult);
}
return rv;
}
/* static */
nsresult Preferences::GetLocalizedCString(const char* aPrefName,
nsACString& aResult,
PrefValueKind aKind) {
nsAutoString result;
nsresult rv = GetLocalizedString(aPrefName, result, aKind);
if (NS_SUCCEEDED(rv)) {
CopyUTF16toUTF8(result, aResult);
}
return rv;
}
/* static */
nsresult Preferences::GetLocalizedString(const char* aPrefName,
nsAString& aResult,
PrefValueKind aKind) {
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
nsCOMPtr<nsIPrefLocalizedString> prefLocalString;
nsresult rv = GetRootBranch(aKind)->GetComplexValue(
aPrefName, NS_GET_IID(nsIPrefLocalizedString),
getter_AddRefs(prefLocalString));
if (NS_SUCCEEDED(rv)) {
MOZ_ASSERT(prefLocalString, "Succeeded but the result is NULL");
prefLocalString->GetData(aResult);
}
return rv;
}
/* static */
nsresult Preferences::GetComplex(const char* aPrefName, const nsIID& aType,
void** aResult, PrefValueKind aKind) {
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
return GetRootBranch(aKind)->GetComplexValue(aPrefName, aType, aResult);
}
/* static */
bool Preferences::GetBool(const char* aPrefName, bool aFallback,
PrefValueKind aKind) {
return PreferencesInternalMethods::GetPref(aPrefName, aFallback, aKind);
}
/* static */
int32_t Preferences::GetInt(const char* aPrefName, int32_t aFallback,
PrefValueKind aKind) {
return PreferencesInternalMethods::GetPref(aPrefName, aFallback, aKind);
}
/* static */
uint32_t Preferences::GetUint(const char* aPrefName, uint32_t aFallback,
PrefValueKind aKind) {
return PreferencesInternalMethods::GetPref(aPrefName, aFallback, aKind);
}
/* static */
float Preferences::GetFloat(const char* aPrefName, float aFallback,
PrefValueKind aKind) {
return PreferencesInternalMethods::GetPref(aPrefName, aFallback, aKind);
}
/* static */
nsresult Preferences::SetCString(const char* aPrefName,
const nsACString& aValue,
PrefValueKind aKind) {
ENSURE_PARENT_PROCESS("SetCString", aPrefName);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
if (aValue.Length() > MAX_PREF_LENGTH) {
return NS_ERROR_ILLEGAL_VALUE;
}
// It's ok to stash a pointer to the temporary PromiseFlatCString's chars in
// pref because pref_SetPref() duplicates those chars.
PrefValue prefValue;
const nsCString& flat = PromiseFlatCString(aValue);
prefValue.mStringVal = flat.get();
return pref_SetPref(aPrefName, PrefType::String, aKind, prefValue,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ false);
}
/* static */
nsresult Preferences::SetBool(const char* aPrefName, bool aValue,
PrefValueKind aKind) {
ENSURE_PARENT_PROCESS("SetBool", aPrefName);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
PrefValue prefValue;
prefValue.mBoolVal = aValue;
return pref_SetPref(aPrefName, PrefType::Bool, aKind, prefValue,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ false);
}
/* static */
nsresult Preferences::SetInt(const char* aPrefName, int32_t aValue,
PrefValueKind aKind) {
ENSURE_PARENT_PROCESS("SetInt", aPrefName);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
PrefValue prefValue;
prefValue.mIntVal = aValue;
return pref_SetPref(aPrefName, PrefType::Int, aKind, prefValue,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ false);
}
/* static */
nsresult Preferences::SetComplex(const char* aPrefName, const nsIID& aType,
nsISupports* aValue, PrefValueKind aKind) {
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
return GetRootBranch(aKind)->SetComplexValue(aPrefName, aType, aValue);
}
/* static */
nsresult Preferences::Lock(const char* aPrefName) {
ENSURE_PARENT_PROCESS("Lock", aPrefName);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
Pref* pref;
MOZ_TRY_VAR(pref,
pref_LookupForModify(aPrefName, [](const PrefWrapper& aPref) {
return !aPref.IsLocked();
}));
if (pref) {
pref->SetIsLocked(true);
NotifyCallbacks(aPrefName, PrefWrapper(pref));
}
return NS_OK;
}
/* static */
nsresult Preferences::Unlock(const char* aPrefName) {
ENSURE_PARENT_PROCESS("Unlock", aPrefName);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
Pref* pref;
MOZ_TRY_VAR(pref,
pref_LookupForModify(aPrefName, [](const PrefWrapper& aPref) {
return aPref.IsLocked();
}));
if (pref) {
pref->SetIsLocked(false);
NotifyCallbacks(aPrefName, PrefWrapper(pref));
}
return NS_OK;
}
/* static */
bool Preferences::IsLocked(const char* aPrefName) {
NS_ENSURE_TRUE(InitStaticMembers(), false);
Maybe<PrefWrapper> pref = pref_Lookup(aPrefName);
return pref.isSome() && pref->IsLocked();
}
/* static */
nsresult Preferences::ClearUser(const char* aPrefName) {
ENSURE_PARENT_PROCESS("ClearUser", aPrefName);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
auto result = pref_LookupForModify(
aPrefName, [](const PrefWrapper& aPref) { return aPref.HasUserValue(); });
if (result.isErr()) {
return NS_OK;
}
if (Pref* pref = result.unwrap()) {
pref->ClearUserValue();
if (!pref->HasDefaultValue()) {
if (!gSharedMap || !gSharedMap->Has(pref->Name())) {
gHashTable->remove(aPrefName);
} else {
pref->SetType(PrefType::None);
}
NotifyCallbacks(aPrefName);
} else {
NotifyCallbacks(aPrefName, PrefWrapper(pref));
}
Preferences::HandleDirty();
}
return NS_OK;
}
/* static */
bool Preferences::HasUserValue(const char* aPrefName) {
NS_ENSURE_TRUE(InitStaticMembers(), false);
Maybe<PrefWrapper> pref = pref_Lookup(aPrefName);
return pref.isSome() && pref->HasUserValue();
}
/* static */
int32_t Preferences::GetType(const char* aPrefName) {
NS_ENSURE_TRUE(InitStaticMembers(), nsIPrefBranch::PREF_INVALID);
if (!gHashTable) {
return PREF_INVALID;
}
Maybe<PrefWrapper> pref = pref_Lookup(aPrefName);
if (!pref.isSome()) {
return PREF_INVALID;
}
switch (pref->Type()) {
case PrefType::String:
return PREF_STRING;
case PrefType::Int:
return PREF_INT;
case PrefType::Bool:
return PREF_BOOL;
default:
MOZ_CRASH();
}
}
/* static */
nsresult Preferences::AddStrongObserver(nsIObserver* aObserver,
const nsACString& aPref) {
MOZ_ASSERT(aObserver);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
return sPreferences->mRootBranch->AddObserver(aPref, aObserver, false);
}
/* static */
nsresult Preferences::AddWeakObserver(nsIObserver* aObserver,
const nsACString& aPref) {
MOZ_ASSERT(aObserver);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
return sPreferences->mRootBranch->AddObserver(aPref, aObserver, true);
}
/* static */
nsresult Preferences::RemoveObserver(nsIObserver* aObserver,
const nsACString& aPref) {
MOZ_ASSERT(aObserver);
if (sShutdown) {
MOZ_ASSERT(!sPreferences);
return NS_OK; // Observers have been released automatically.
}
NS_ENSURE_TRUE(sPreferences, NS_ERROR_NOT_AVAILABLE);
return sPreferences->mRootBranch->RemoveObserver(aPref, aObserver);
}
template <typename T>
static void AssertNotMallocAllocated(T* aPtr) {
#if defined(DEBUG) && defined(MOZ_MEMORY)
jemalloc_ptr_info_t info;
jemalloc_ptr_info((void*)aPtr, &info);
MOZ_ASSERT(info.tag == TagUnknown);
#endif
}
/* static */
nsresult Preferences::AddStrongObservers(nsIObserver* aObserver,
const char** aPrefs) {
MOZ_ASSERT(aObserver);
for (uint32_t i = 0; aPrefs[i]; i++) {
AssertNotMallocAllocated(aPrefs[i]);
nsCString pref;
pref.AssignLiteral(aPrefs[i], strlen(aPrefs[i]));
nsresult rv = AddStrongObserver(aObserver, pref);
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
/* static */
nsresult Preferences::AddWeakObservers(nsIObserver* aObserver,
const char** aPrefs) {
MOZ_ASSERT(aObserver);
for (uint32_t i = 0; aPrefs[i]; i++) {
AssertNotMallocAllocated(aPrefs[i]);
nsCString pref;
pref.AssignLiteral(aPrefs[i], strlen(aPrefs[i]));
nsresult rv = AddWeakObserver(aObserver, pref);
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
/* static */
nsresult Preferences::RemoveObservers(nsIObserver* aObserver,
const char** aPrefs) {
MOZ_ASSERT(aObserver);
if (sShutdown) {
MOZ_ASSERT(!sPreferences);
return NS_OK; // Observers have been released automatically.
}
NS_ENSURE_TRUE(sPreferences, NS_ERROR_NOT_AVAILABLE);
for (uint32_t i = 0; aPrefs[i]; i++) {
nsresult rv = RemoveObserver(aObserver, nsDependentCString(aPrefs[i]));
NS_ENSURE_SUCCESS(rv, rv);
}
return NS_OK;
}
template <typename T>
/* static */
nsresult Preferences::RegisterCallbackImpl(PrefChangedFunc aCallback,
T& aPrefNode, void* aData,
MatchKind aMatchKind,
bool aIsPriority) {
NS_ENSURE_ARG(aCallback);
NS_ENSURE_TRUE(InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
auto node = new CallbackNode(aPrefNode, aCallback, aData, aMatchKind);
if (aIsPriority) {
// Add to the start of the list.
node->SetNext(gFirstCallback);
gFirstCallback = node;
if (!gLastPriorityNode) {
gLastPriorityNode = node;
}
} else {
// Add to the start of the non-priority part of the list.
if (gLastPriorityNode) {
node->SetNext(gLastPriorityNode->Next());
gLastPriorityNode->SetNext(node);
} else {
node->SetNext(gFirstCallback);
gFirstCallback = node;
}
}
return NS_OK;
}
/* static */
nsresult Preferences::RegisterCallback(PrefChangedFunc aCallback,
const nsACString& aPrefNode, void* aData,
MatchKind aMatchKind, bool aIsPriority) {
return RegisterCallbackImpl(aCallback, aPrefNode, aData, aMatchKind,
aIsPriority);
}
/* static */
nsresult Preferences::RegisterCallbacks(PrefChangedFunc aCallback,
const char** aPrefs, void* aData,
MatchKind aMatchKind) {
return RegisterCallbackImpl(aCallback, aPrefs, aData, aMatchKind);
}
/* static */
nsresult Preferences::RegisterCallbackAndCall(PrefChangedFunc aCallback,
const nsACString& aPref,
void* aClosure,
MatchKind aMatchKind) {
MOZ_ASSERT(aCallback);
nsresult rv = RegisterCallback(aCallback, aPref, aClosure, aMatchKind);
if (NS_SUCCEEDED(rv)) {
(*aCallback)(PromiseFlatCString(aPref).get(), aClosure);
}
return rv;
}
/* static */
nsresult Preferences::RegisterCallbacksAndCall(PrefChangedFunc aCallback,
const char** aPrefs,
void* aClosure) {
MOZ_ASSERT(aCallback);
nsresult rv =
RegisterCallbacks(aCallback, aPrefs, aClosure, MatchKind::ExactMatch);
if (NS_SUCCEEDED(rv)) {
for (const char** ptr = aPrefs; *ptr; ptr++) {
(*aCallback)(*ptr, aClosure);
}
}
return rv;
}
template <typename T>
/* static */
nsresult Preferences::UnregisterCallbackImpl(PrefChangedFunc aCallback,
T& aPrefNode, void* aData,
MatchKind aMatchKind) {
MOZ_ASSERT(aCallback);
if (sShutdown) {
MOZ_ASSERT(!sPreferences);
return NS_OK; // Observers have been released automatically.
}
NS_ENSURE_TRUE(sPreferences, NS_ERROR_NOT_AVAILABLE);
nsresult rv = NS_ERROR_FAILURE;
CallbackNode* node = gFirstCallback;
CallbackNode* prev_node = nullptr;
while (node) {
if (node->Func() == aCallback && node->Data() == aData &&
node->MatchKind() == aMatchKind && node->DomainIs(aPrefNode)) {
if (gCallbacksInProgress) {
// Postpone the node removal until after callbacks enumeration is
// finished.
node->ClearFunc();
gShouldCleanupDeadNodes = true;
prev_node = node;
node = node->Next();
} else {
node = pref_RemoveCallbackNode(node, prev_node);
}
rv = NS_OK;
} else {
prev_node = node;
node = node->Next();
}
}
return rv;
}
/* static */
nsresult Preferences::UnregisterCallback(PrefChangedFunc aCallback,
const nsACString& aPrefNode,
void* aData, MatchKind aMatchKind) {
return UnregisterCallbackImpl<const nsACString&>(aCallback, aPrefNode, aData,
aMatchKind);
}
/* static */
nsresult Preferences::UnregisterCallbacks(PrefChangedFunc aCallback,
const char** aPrefs, void* aData,
MatchKind aMatchKind) {
return UnregisterCallbackImpl(aCallback, aPrefs, aData, aMatchKind);
}
static void CacheDataAppendElement(CacheData* aData) {
if (!gCacheData) {
MOZ_CRASH_UNSAFE_PRINTF("!gCacheData: %s", gCacheDataDesc);
}
gCacheData->AppendElement(aData);
}
template <typename T>
static nsresult AddVarCache(T* aCache, const nsACString& aPref,
StripAtomic<T> aDefault, bool aSkipAssignment) {
if (!aSkipAssignment) {
*aCache = PreferencesInternalMethods::GetPref(
PromiseFlatCString(aPref).get(), aDefault);
}
CacheData* data = new CacheData(aCache, aDefault);
CacheDataAppendElement(data);
PreferencesInternalMethods::RegisterCallback<T>(data, aPref);
return NS_OK;
}
/* static */
nsresult Preferences::AddBoolVarCache(bool* aCache, const nsACString& aPref,
bool aDefault, bool aSkipAssignment) {
AssertNotAlreadyCached("bool", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
template <MemoryOrdering Order>
/* static */
nsresult Preferences::AddAtomicBoolVarCache(Atomic<bool, Order>* aCache,
const nsACString& aPref,
bool aDefault,
bool aSkipAssignment) {
AssertNotAlreadyCached("bool", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
/* static */
nsresult Preferences::AddIntVarCache(int32_t* aCache, const nsACString& aPref,
int32_t aDefault, bool aSkipAssignment) {
AssertNotAlreadyCached("int", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
template <MemoryOrdering Order>
/* static */
nsresult Preferences::AddAtomicIntVarCache(Atomic<int32_t, Order>* aCache,
const nsACString& aPref,
int32_t aDefault,
bool aSkipAssignment) {
AssertNotAlreadyCached("int", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
/* static */
nsresult Preferences::AddUintVarCache(uint32_t* aCache, const nsACString& aPref,
uint32_t aDefault, bool aSkipAssignment) {
AssertNotAlreadyCached("uint", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
template <MemoryOrdering Order>
/* static */
nsresult Preferences::AddAtomicUintVarCache(Atomic<uint32_t, Order>* aCache,
const nsACString& aPref,
uint32_t aDefault,
bool aSkipAssignment) {
AssertNotAlreadyCached("uint", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
// Since the definition of template functions is not in a header file, we
// need to explicitly specify the instantiations that are required. Currently
// limited orders are needed and therefore implemented.
template nsresult Preferences::AddAtomicBoolVarCache(Atomic<bool, Relaxed>*,
const nsACString&, bool,
bool);
template nsresult Preferences::AddAtomicBoolVarCache(
Atomic<bool, ReleaseAcquire>*, const nsACString&, bool, bool);
template nsresult Preferences::AddAtomicBoolVarCache(
Atomic<bool, SequentiallyConsistent>*, const nsACString&, bool, bool);
template nsresult Preferences::AddAtomicIntVarCache(Atomic<int32_t, Relaxed>*,
const nsACString&, int32_t,
bool);
template nsresult Preferences::AddAtomicUintVarCache(Atomic<uint32_t, Relaxed>*,
const nsACString&,
uint32_t, bool);
template nsresult Preferences::AddAtomicUintVarCache(
Atomic<uint32_t, ReleaseAcquire>*, const nsACString&, uint32_t, bool);
template nsresult Preferences::AddAtomicUintVarCache(
Atomic<uint32_t, SequentiallyConsistent>*, const nsACString&, uint32_t,
bool);
/* static */
nsresult Preferences::AddFloatVarCache(float* aCache, const nsACString& aPref,
float aDefault, bool aSkipAssignment) {
AssertNotAlreadyCached("float", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
/* static */
nsresult Preferences::AddAtomicFloatVarCache(std::atomic<float>* aCache,
const nsACString& aPref,
float aDefault,
bool aSkipAssignment) {
AssertNotAlreadyCached("float", aPref, aCache);
return AddVarCache(aCache, aPref, aDefault, aSkipAssignment);
}
// The SetPref_*() functions below end in a `_<type>` suffix because they are
// used by the PREF macro definition in InitAll() below.
static void SetPref_bool(const char* aName, bool aDefaultValue) {
PrefValue value;
value.mBoolVal = aDefaultValue;
pref_SetPref(aName, PrefType::Bool, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void SetPref_int32_t(const char* aName, int32_t aDefaultValue) {
PrefValue value;
value.mIntVal = aDefaultValue;
pref_SetPref(aName, PrefType::Int, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void SetPref_float(const char* aName, float aDefaultValue) {
PrefValue value;
// Convert the value in a locale-independent way.
nsAutoCString defaultValue;
defaultValue.AppendFloat(aDefaultValue);
value.mStringVal = defaultValue.get();
pref_SetPref(aName, PrefType::String, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
// XXX: this will eventually become used
MOZ_MAYBE_UNUSED static void SetPref_String(const char* aName,
const char* aDefaultValue) {
PrefValue value;
value.mStringVal = aDefaultValue;
pref_SetPref(aName, PrefType::String, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void SetPref(const char* aName, bool aDefaultValue) {
SetPref_bool(aName, aDefaultValue);
}
static void SetPref(const char* aName, int32_t aDefaultValue) {
SetPref_int32_t(aName, aDefaultValue);
}
static void SetPref(const char* aName, uint32_t aDefaultValue) {
SetPref_int32_t(aName, int32_t(aDefaultValue));
}
static void SetPref(const char* aName, float aDefaultValue) {
SetPref_float(aName, aDefaultValue);
}
MOZ_MAYBE_UNUSED static void SetPref(const char* aName,
const char* aDefaultValue) {
SetPref_String(aName, aDefaultValue);
}
template <typename T>
static void InitVarCachePref(StaticPrefs::UpdatePolicy aPolicy,
const nsACString& aName, T* aCache,
StripAtomic<T> aDefaultValue, bool aIsStartup,
bool aSetValue) {
// aSetValue is set when we are running in the parent process.
// aIsStartup will be true when we first initialize the StaticPrefs and false
// when we want to reset the Preferences/StaticPrefs to their default value.
// InitVarCachePref is called under the following scenarios:
// aSetValue | aIsStartup | Action
// true | true | Set underlying preference and StaticPrefs to
// | | their default value, set callback for Live pref.
// true | false | reset underlying preference and StaticPref to
// | | default value.
// false | true | set callback for Live pref.
// false | false | none.
//
// We only set *aCache if the policy is Live as:
// 1- On startup, `Once` prefs will be initialized lazily in InitOncePrefs(),
// 2- After that, `Once` prefs are immutable.
if (aSetValue) {
SetPref(PromiseFlatCString(aName).get(), aDefaultValue);
if (MOZ_LIKELY(aPolicy == StaticPrefs::UpdatePolicy::Live)) {
*aCache = aDefaultValue;
}
}
if (MOZ_LIKELY(aPolicy == StaticPrefs::UpdatePolicy::Live) &&
MOZ_LIKELY(aIsStartup)) {
AddVarCache(aCache, aName, aDefaultValue, true);
}
}
static Atomic<bool> sOncePrefRead(false);
static StaticMutex sOncePrefMutex;
namespace StaticPrefs {
void MaybeInitOncePrefs() {
if (MOZ_LIKELY(sOncePrefRead)) {
// `Once` StaticPrefs have already been initialized to their default value.
return;
}
StaticMutexAutoLock lock(sOncePrefMutex);
if (NS_IsMainThread()) {
InitOncePrefs();
} else {
RefPtr<Runnable> runnable = NS_NewRunnableFunction(
"Preferences::MaybeInitOncePrefs", [&]() { InitOncePrefs(); });
// This logic needs to run on the main thread
SyncRunnable::DispatchToThread(
SystemGroup::EventTargetFor(TaskCategory::Other), runnable);
}
sOncePrefRead = true;
}
// For a pref like this:
//
// VARCACHE_PREF($POLICY, "my.pref", my_pref, my_pref, int32_t, 99)
//
// we generate a variable definition like this:
//
// int32_t sVarCache_my_pref(99);
//
#define PREF(name, cpp_type, value)
#define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, default_value) \
cpp_type sVarCache_##full_id(default_value);
#include "mozilla/StaticPrefListAll.h"
#undef PREF
#undef VARCACHE_PREF
static void InitAll(bool aIsStartup) {
bool isParent = XRE_IsParentProcess();
// For prefs like these:
//
// PREF("foo.bar.baz", bool, true)
// VARCACHE_PREF($POLICY, "my.pref", my_pref, my_pref, int32_t, 99)
//
// we generate registration calls like this:
//
// if (isParent) {
// SetPref_bool("foo.bar.baz", true);
// }
// InitVarCachePref(UpdatePolicy::Live, "my.pref", &sVarCache_my_pref,
// 99, aIsStartup, isParent);
//
// The SetPref_*() functions have a type suffix to avoid ambiguity between
// prefs having int32_t and float default values. That suffix is not needed
// for the InitVarCachePref() functions because they take a pointer parameter,
// which prevents automatic int-to-float coercion.
//
// In content processes, we rely on the parent to send us the correct initial
// values via shared memory, so we do not re-initialize them here.
#define PREF(name, cpp_type, value) \
if (isParent) { \
SetPref_##cpp_type(name, value); \
}
#define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, value) \
InitVarCachePref(UpdatePolicy::policy, NS_LITERAL_CSTRING(name), \
&sVarCache_##full_id, value, aIsStartup, isParent);
#include "mozilla/StaticPrefListAll.h"
#undef PREF
#undef VARCACHE_PREF
}
static void InitOncePrefs() {
// For a pref like this:
//
// VARCACHE_PREF($POLICY, "my.pref", my_pref, my_pref, int32_t, 99)
//
// we generate an initialization (in a non-DEBUG build) like this:
//
// if (UpdatePolicy::$POLICY == UpdatePolicy::Once) {
// sVarCache_my_pref = PreferencesInternalMethods::GetPref("my.pref", 99);
// }
//
// This is done to get the potentially updated Preference value as we didn't
// register a callback method for the `Once` policy.
//
// On debug build, we also install a mechanism that allows to check if the
// original Preference is being modified once `Once` StaticPrefs have been
// initialized as this would indicate a likely misuse of `Once` StaticPrefs
// and that maybe instead they should have been made `Live`.
//
#define PREF(name, cpp_type, value)
#ifdef DEBUG
# define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, value) \
if (UpdatePolicy::policy == UpdatePolicy::Once) { \
MOZ_ASSERT(gOnceStaticPrefsAntiFootgun); \
sVarCache_##full_id = PreferencesInternalMethods::GetPref( \
name, StripAtomic<cpp_type>(value)); \
auto checkPref = [&]() { \
MOZ_ASSERT(sOncePrefRead); \
StripAtomic<cpp_type> staticPrefValue = full_id(); \
StripAtomic<cpp_type> preferenceValue = \
PreferencesInternalMethods::GetPref(GetPrefName_##base_id(), \
StripAtomic<cpp_type>(value)); \
MOZ_ASSERT(staticPrefValue == preferenceValue, \
"Preference '" name \
"' got modified since StaticPrefs::" #full_id \
" was initialized. Consider using an `always` mirror kind " \
"instead"); \
}; \
gOnceStaticPrefsAntiFootgun->insert( \
std::pair<const char*, AntiFootgunCallback>(GetPrefName_##base_id(), \
std::move(checkPref))); \
}
#else
# define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, value) \
if (UpdatePolicy::policy == UpdatePolicy::Once) { \
sVarCache_##full_id = PreferencesInternalMethods::GetPref( \
name, StripAtomic<cpp_type>(value)); \
}
#endif
#include "mozilla/StaticPrefListAll.h"
#undef PREF
#undef VARCACHE_PREF
}
} // namespace StaticPrefs
static MOZ_MAYBE_UNUSED void SaveOncePrefToSharedMap(
SharedPrefMapBuilder& aBuilder, const char* aName, bool aValue) {
auto oncePref = MakeUnique<Pref>(aName);
oncePref->SetType(PrefType::Bool);
oncePref->SetIsSkippedByIteration(true);
bool valueChanged = false;
MOZ_ALWAYS_SUCCEEDS(
oncePref->SetDefaultValue(PrefType::Bool, PrefValue(aValue),
/* isSticky */ true,
/* isLocked */ true, &valueChanged));
oncePref->AddToMap(aBuilder);
}
static MOZ_MAYBE_UNUSED void SaveOncePrefToSharedMap(
SharedPrefMapBuilder& aBuilder, const char* aName, int32_t aValue) {
auto oncePref = MakeUnique<Pref>(aName);
oncePref->SetType(PrefType::Int);
oncePref->SetIsSkippedByIteration(true);
bool valueChanged = false;
MOZ_ALWAYS_SUCCEEDS(
oncePref->SetDefaultValue(PrefType::Int, PrefValue(aValue),
/* isSticky */ true,
/* isLocked */ true, &valueChanged));
oncePref->AddToMap(aBuilder);
}
static MOZ_MAYBE_UNUSED void SaveOncePrefToSharedMap(
SharedPrefMapBuilder& aBuilder, const char* aName, uint32_t aValue) {
SaveOncePrefToSharedMap(aBuilder, aName, int32_t(aValue));
}
static MOZ_MAYBE_UNUSED void SaveOncePrefToSharedMap(
SharedPrefMapBuilder& aBuilder, const char* aName, float aValue) {
auto oncePref = MakeUnique<Pref>(aName);
oncePref->SetType(PrefType::String);
oncePref->SetIsSkippedByIteration(true);
nsAutoCString value;
value.AppendFloat(aValue);
bool valueChanged = false;
// It's ok to stash a pointer to the temporary PromiseFlatCString's chars in
// pref because pref_SetPref() duplicates those chars.
const nsCString& flat = PromiseFlatCString(value);
MOZ_ALWAYS_SUCCEEDS(
oncePref->SetDefaultValue(PrefType::String, PrefValue(flat.get()),
/* isSticky */ true,
/* isLocked */ true, &valueChanged));
oncePref->AddToMap(aBuilder);
}
#define ONCE_PREF_NAME(name) ("$$$" name "$$$")
namespace StaticPrefs {
static void RegisterOncePrefs(SharedPrefMapBuilder& aBuilder) {
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_DIAGNOSTIC_ASSERT(!gSharedMap,
"Must be called before gSharedMap has been created");
MaybeInitOncePrefs();
// For a pref like this:
//
// VARCACHE_PREF($POLICY, "my.pref", my_pref, my_pref, int32_t, 99)
//
// we generate a save call like this:
//
// if (UpdatePolicy::$POLICY == UpdatePolicy::Once) {
// SaveOncePrefToSharedMap(aBuilder, ONCE_PREF_NAME(my.pref),
// sVarCache_my_pref);
// }
//
// `Once` StaticPrefs values will be stored in a hidden and locked preferences
// in the global SharedPreferenceMap. In order for those preferences to be
// hidden and not appear in about:config nor ever be stored to disk, we add
// the "$$$" prefix and suffix to the preference name and set the IsVisible
// flag to false.
//
#define PREF(name, cpp_type, value)
#define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, value) \
if (UpdatePolicy::policy == UpdatePolicy::Once) { \
SaveOncePrefToSharedMap(aBuilder, ONCE_PREF_NAME(name), \
StripAtomic<cpp_type>(sVarCache_##full_id)); \
}
#include "mozilla/StaticPrefListAll.h"
#undef PREF
#undef VARCACHE_PREF
}
static void InitStaticPrefsFromShared() {
MOZ_ASSERT(!XRE_IsParentProcess());
MOZ_DIAGNOSTIC_ASSERT(gSharedMap,
"Must be called once gSharedMap has been created");
// For a prefs like this:
//
// VARCACHE_PREF($POLICY, "my.pref", my_pref, my_pref, int32_t, 99)
//
// we generate an initialization like this:
//
// {
// int32_t val;
// nsresult rv;
// if (UpdatePolicy::$POLICY == UpdatePolicy::Once) {
// rv = PreferencesInternalMethods::GetSharedPrefValue(
// "$$$my.pref$$$", &val);
// } else if (UpdatePolicy::Once == UpdatePolicy::Live) {
// rv = PreferencesInternalMethods::GetSharedPrefValue("my.pref", &val);
// }
// MOZ_DIAGNOSTIC_ALWAYS_TRUE(NS_SUCCEEDED(rv));
// sVarCache_my_pref = val;
// }
//
#define PREF(name, cpp_type, value)
#define VARCACHE_PREF(policy, name, base_id, full_id, cpp_type, value) \
{ \
StripAtomic<cpp_type> val; \
nsresult rv; \
if (UpdatePolicy::policy == UpdatePolicy::Once) { \
rv = PreferencesInternalMethods::GetSharedPrefValue( \
ONCE_PREF_NAME(name), &val); \
} else { \
rv = PreferencesInternalMethods::GetSharedPrefValue(name, &val); \
} \
MOZ_DIAGNOSTIC_ALWAYS_TRUE(NS_SUCCEEDED(rv)); \
StaticPrefs::sVarCache_##full_id = val; \
}
#include "mozilla/StaticPrefListAll.h"
#undef PREF
#undef VARCACHE_PREF
// `Once` StaticPrefs have been set to their value in the step above and
// outside the parent process they are immutable. So we set sOncePrefRead
// so that we can directly skip any lazy initializations.
sOncePrefRead = true;
}
} // namespace StaticPrefs
} // namespace mozilla
#undef ENSURE_PARENT_PROCESS
//===========================================================================
// Module and factory stuff
//===========================================================================
NS_IMPL_COMPONENT_FACTORY(nsPrefLocalizedString) {
auto str = MakeRefPtr<nsPrefLocalizedString>();
if (NS_SUCCEEDED(str->Init())) {
return str.forget().downcast<nsISupports>();
}
return nullptr;
}
namespace mozilla {
void UnloadPrefsModule() { Preferences::Shutdown(); }
} // namespace mozilla
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