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gecko-dev/modules/libpref/Preferences.cpp

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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/. */
// Documentation for libpref is in modules/libpref/docs/index.rst.
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "SharedPrefMap.h"
#include "base/basictypes.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/ProfilerLabels.h"
#include "mozilla/ProfilerMarkers.h"
#include "mozilla/ResultExtensions.h"
#include "mozilla/SchedulerGroup.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/ServoStyleSet.h"
#include "mozilla/SpinEventLoopUntil.h"
#include "mozilla/StaticMutex.h"
#include "mozilla/StaticPrefsAll.h"
#include "mozilla/SyncRunnable.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 "nsCategoryManagerUtils.h"
#include "nsClassHashtable.h"
#include "nsCOMArray.h"
#include "nsCOMPtr.h"
#include "nsComponentManagerUtils.h"
#include "nsCRT.h"
#include "nsTHashMap.h"
#include "nsDirectoryServiceDefs.h"
#include "nsIConsoleService.h"
#include "nsIFile.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 "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 MOZ_BACKGROUNDTASKS
# include "mozilla/BackgroundTasks.h"
#endif
#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 nsCString& aChars, nsCString& aStr) {
aStr.AppendInt(aChars.Length());
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 parser/src/lib.rs.
union PrefValue {
// PrefValues within Pref objects own their chars. PrefValues passed around
// as arguments don't own their chars.
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(nsDependentCString(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),
mRootBranches(0),
mPrefNameArena(0),
mCallbacksObjects(0),
mCallbacksDomains(0),
mMisc(0) {}
size_t mHashTable;
size_t mPrefValues;
size_t mStringValues;
size_t mRootBranches;
size_t mPrefNameArena;
size_t mCallbacksObjects;
size_t mCallbacksDomains;
size_t mMisc;
};
} // namespace mozilla
static StaticRefPtr<SharedPrefMap> gSharedMap;
// Arena for Pref names. Inside a function so we can assert it's only accessed
// on the main thread.
static inline ArenaAllocator<4096, 1>& PrefNameArena() {
MOZ_ASSERT(NS_IsMainThread());
static ArenaAllocator<4096, 1> sPrefNameArena;
return sPrefNameArena;
}
class PrefWrapper;
class Pref {
public:
explicit Pref(const nsACString& aName)
: mName(ArenaStrdup(aName, PrefNameArena()), aName.Length()),
mType(static_cast<uint32_t>(PrefType::None)),
mIsSticky(false),
mIsLocked(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
// sPrefNameArena.
mDefaultValue.Clear(Type());
mUserValue.Clear(Type());
}
const char* Name() const { return mName.get(); }
const nsDependentCString& NameString() const { return 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 IsSticky() const { return mIsSticky; }
bool HasDefaultValue() const { return mHasDefaultValue; }
bool HasUserValue() const { return mHasUserValue; }
template <typename T>
void AddToMap(SharedPrefMapBuilder& aMap) {
aMap.Add(NameString(),
{HasDefaultValue(), HasUserValue(), IsSticky(), IsLocked(),
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(mName == aDomPref.name());
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;
}
if (mHasDefaultValue &&
strlen(mDefaultValue.mStringVal) > MAX_ADVISABLE_PREF_LENGTH) {
return false;
}
if (mHasUserValue &&
strlen(mUserValue.mStringVal) > 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);
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 sPrefNameArena, measured elsewhere.
aSizes.mPrefValues += aMallocSizeOf(this);
if (IsTypeString()) {
if (mHasDefaultValue) {
aSizes.mStringValues += aMallocSizeOf(mDefaultValue.mStringVal);
}
if (mHasUserValue) {
aSizes.mStringValues += aMallocSizeOf(mUserValue.mStringVal);
}
}
}
private:
const nsDependentCString mName; // allocated in sPrefNameArena
uint32_t mType : 2;
uint32_t mIsSticky : 1;
uint32_t mIsLocked : 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, 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(mName == pref.NameString());
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>;
// The main prefs hash table. Inside a function so we can assert it's only
// accessed on the main thread. (That assertion can be avoided but only do so
// with great care!)
static inline PrefsHashTable*& HashTable(bool aOffMainThread = false) {
MOZ_ASSERT(NS_IsMainThread() || ServoStyleSet::IsInServoTraversal());
static PrefsHashTable* sHashTable = nullptr;
return sHashTable;
}
#ifdef DEBUG
// This defines the type used to store our `once` mirrors 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 = nsTHashMap<nsCStringHashKey, uint32_t>;
static AccessCountsHashTable* gAccessCounts = nullptr;
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->LookupOrInsert(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(HashTable()->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(HashTable()->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(); }
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 nsCString& aPrefName,
const PrefWrapper* aPref = nullptr);
static void NotifyCallbacks(const nsCString& 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(HashTable()->count());
for (auto& pref : PrefsIter(HashTable(), 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 sHashTable, and the main thread is blocked while Stylo threads are
// doing these lookups.
auto p = HashTable()->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 nsCString& aPrefName,
const std::function<bool(const PrefWrapper&)>& aCheckFn) {
Maybe<PrefWrapper> wrapper =
pref_Lookup(aPrefName.get(), /* 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 (!HashTable()->putNew(aPrefName.get(), pref)) {
delete pref;
return Err(NS_ERROR_OUT_OF_MEMORY);
}
pref->FromWrapper(*wrapper);
return pref;
}
static nsresult pref_SetPref(const nsCString& aPrefName, PrefType aType,
PrefValueKind aKind, PrefValue aValue,
bool aIsSticky, bool aIsLocked, bool aFromInit) {
MOZ_ASSERT(XRE_IsParentProcess());
MOZ_ASSERT(NS_IsMainThread());
if (!HashTable()) {
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 = HashTable()->lookupForAdd(aPrefName.get());
if (!p) {
pref = new Pref(aPrefName);
pref->SetType(aType);
if (!HashTable()->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.get(),
(aKind == PrefValueKind::Default) ? "default" : "user",
PrefTypeToString(pref->Type()), PrefTypeToString(aType))
.get());
return rv;
}
if (valueChanged) {
if (aKind == PrefValueKind::User) {
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 nsCString& 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;
for (CallbackNode* node = gFirstCallback; node; node = node->Next()) {
if (node->Func()) {
if (node->Matches(aPrefName)) {
(node->Func())(aPrefName.get(), 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`-mirrored pref using that pref
// name. We have about 100 `once`-mirrored prefs. std::map performs a
// search in O(log n), so this is fast enough.
MOZ_ASSERT(gOnceStaticPrefsAntiFootgun);
auto search = gOnceStaticPrefsAntiFootgun->find(aPrefName.get());
if (search != gOnceStaticPrefsAntiFootgun->end()) {
// Run the callback.
(search->second)();
}
}
#endif
}
//===========================================================================
// Prefs parsing
//===========================================================================
extern "C" {
// Keep this in sync with PrefFn in 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 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 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(PrefValueKind aKind, const char* aPath, const nsCString& aBuf) {
MOZ_ASSERT(XRE_IsParentProcess());
return prefs_parser_parse(aPath, aKind, aBuf.get(), aBuf.Length(),
HandlePref, HandleError);
}
private:
static void HandlePref(const char* aPrefName, PrefType aType,
PrefValueKind aKind, PrefValue aValue, bool aIsSticky,
bool aIsLocked) {
MOZ_ASSERT(XRE_IsParentProcess());
pref_SetPref(nsDependentCString(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
}
};
// 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();
}
//===========================================================================
// 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;
MOZ_COUNTED_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:
using PrefName = nsCString;
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(""_ns, 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 (!HashTable()) {
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)) {
branchName += '.';
}
const nsACString& branchNameNoDot =
Substring(branchName, 0, branchName.Length() - 1);
for (auto iter = HashTable()->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(HashTable(), 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) {
UniquePtr<PrefCallback> pCallback;
NS_ENSURE_ARG(aObserver);
const nsCString& prefName = GetPrefName(aDomain);
// 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 = MakeUnique<PrefCallback>(prefName, weakRefFactory, this);
} else {
// Construct a PrefCallback with a strong reference to the observer.
pCallback = MakeUnique<PrefCallback>(prefName, aObserver, this);
}
mObservers.WithEntryHandle(pCallback.get(), [&](auto&& p) {
if (p) {
NS_WARNING("Ignoring duplicate observer.");
} else {
// 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.get(),
Preferences::PrefixMatch,
/* isPriority */ false);
p.Insert(std::move(pCallback));
}
});
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.
const nsCString& prefName = GetPrefName(aDomain);
PrefCallback key(prefName, aObserver, this);
mozilla::UniquePtr<PrefCallback> pCallback;
mObservers.Remove(&key, &pCallback);
if (pCallback) {
rv = Preferences::UnregisterCallback(
NotifyObserver, prefName, pCallback.get(), 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 (const auto& entry : mObservers) {
const PrefCallback* data = entry.GetWeak();
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()) {
auto callback = iter.UserData();
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 =
components::StringBundle::Service();
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 (!HashTable() || !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() {
MOZ_DIAGNOSTIC_ASSERT(sPendingWriteCount >= 0);
// SpinEventLoopUntil is unfortunate, but ultimately it's the best thing
// we can do here given the constraint that we need to ensure that
// the preferences on disk match what we have in memory. We could
// easily perform the write here ourselves by doing exactly what
// happens in PWRunnable::Run. This would be the right thing to do
// if we're stuck here because other unrelated runnables are taking
// a long time, and the wrong thing to do if PreferencesWriter::Write
// is what takes a long time, as we would be trading a SpinEventLoopUntil
// for a synchronous disk write, wherein we could not even spin the
// event loop. Given that PWRunnable generally runs on a thread pool,
// if we're stuck here, it's likely because of PreferencesWriter::Write
// and not some other runnable. Thus, spin away.
mozilla::SpinEventLoopUntil([]() { return sPendingWriteCount <= 0; });
}
// 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;
// This is the number of writes via PWRunnables which have been dispatched
// but not yet completed. This is intended to be used by Flush to ensure
// that there are no outstanding writes left incomplete, and thus our prefs
// on disk are in sync with what we have in memory.
static Atomic<int> sPendingWriteCount;
// See PWRunnable::Run for details on why we need this lock.
static StaticMutex sWritingToFile;
};
Atomic<PrefSaveData*> PreferencesWriter::sPendingWriteData(nullptr);
Atomic<int> PreferencesWriter::sPendingWriteCount(0);
StaticMutex PreferencesWriter::sWritingToFile;
class PWRunnable : public Runnable {
public:
explicit PWRunnable(nsIFile* aFile) : Runnable("PWRunnable"), mFile(aFile) {}
NS_IMETHOD Run() override {
// Preference writes are handled a bit strangely, in that a "newer"
// write is generally regarded as always better. For this reason,
// sPendingWriteData can be overwritten multiple times before anyone
// gets around to actually using it, minimizing writes. However,
// once we've acquired sPendingWriteData we've reached a
// "point of no return" and have to complete the write.
//
// Unfortunately, this design allows the following behaviour:
//
// 1. write1 is queued up
// 2. thread1 acquires write1
// 3. write2 is queued up
// 4. thread2 acquires write2
// 5. thread1 and thread2 concurrently clobber each other
//
// To avoid this, we use this lock to ensure that only one thread
// at a time is trying to acquire the write, and when it does,
// all other threads are prevented from acquiring writes until it
// completes the write. New writes are still allowed to be queued
// up in this time.
//
// Although it's atomic, the acquire needs to be guarded by the mutex
// to avoid reordering of writes -- we don't want an older write to
// run after a newer one. To avoid this causing too much waiting, we check
// if sPendingWriteData is already null before acquiring the mutex. If it
// is, then there's definitely no work to be done (or someone is in the
// middle of doing it for us).
//
// Note that every time a new write is queued up, a new write task is
// is also queued up, so there will always be a task that can see the newest
// write.
//
// Ideally this lock wouldn't be necessary, and the PreferencesWriter
// would be used more carefully, but it's hard to untangle all that.
nsresult rv = NS_OK;
if (PreferencesWriter::sPendingWriteData) {
StaticMutexAutoLock lock(PreferencesWriter::sWritingToFile);
// 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));
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);
SchedulerGroup::Dispatch(
TaskCategory::Other,
NS_NewRunnableFunction("Preferences::WriterRunnable",
[fileCopy, rvCopy] {
MOZ_RELEASE_ASSERT(NS_IsMainThread());
if (NS_FAILED(rvCopy)) {
Preferences::HandleDirty();
}
}));
}
}
// We've completed the write to the best of our abilities, whether
// we had prefs to write or another runnable got to them first. If
// PreferencesWriter::Write failed, this is still correct as the
// write is no longer outstanding, and the above HandleDirty call
// will just start the cycle again.
PreferencesWriter::sPendingWriteCount--;
return rv;
}
protected:
nsCOMPtr<nsIFile> mFile;
};
// 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 (HashTable()) {
sizes.mHashTable += HashTable()->shallowSizeOfIncludingThis(mallocSizeOf);
for (auto iter = HashTable()->iter(); !iter.done(); iter.next()) {
iter.get()->AddSizeOfIncludingThis(mallocSizeOf, sizes);
}
}
sizes.mPrefNameArena += PrefNameArena().SizeOfExcludingThis(mallocSizeOf);
for (CallbackNode* node = gFirstCallback; node; node = node->Next()) {
node->AddSizeOfIncludingThis(mallocSizeOf, sizes);
}
if (gSharedMap) {
sizes.mMisc += mallocSizeOf(gSharedMap);
}
#ifdef ACCESS_COUNTS
if (gAccessCounts) {
sizes.mMisc += gAccessCounts->ShallowSizeOfIncludingThis(mallocSizeOf);
}
#endif
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/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.
nsTHashMap<nsCStringHashKey, uint32_t> prefCounter;
for (const auto& entry : rootBranch->mObservers) {
auto* callback = entry.GetWeak();
if (callback->IsWeak()) {
nsCOMPtr<nsIObserver> callbackRef = do_QueryReferent(callback->mWeakRef);
if (callbackRef) {
numWeakAlive++;
} else {
numWeakDead++;
}
} else {
numStrong++;
}
const uint32_t currentCount = prefCounter.Get(callback->GetDomain()) + 1;
prefCounter.InsertOrUpdate(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];
const uint32_t totalReferentCount = prefCounter.Get(suspect);
nsPrintfCString suspectPath(
"preference-service-suspect/"
"referent(pref=%s)",
suspect.get());
aHandleReport->Callback(
/* process = */ ""_ns, suspectPath, KIND_OTHER, UNITS_COUNT,
totalReferentCount,
"A preference with a suspiciously large number "
"referents (symptom of a leak)."_ns,
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.
constexpr auto channel = MOZ_STRINGIFY(MOZ_UPDATE_CHANNEL) ""_ns;
// 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) {
return nullptr;
}
sPreferences = new Preferences();
MOZ_ASSERT(!HashTable());
HashTable() = new PrefsHashTable(XRE_IsParentProcess()
? kHashTableInitialLengthParent
: kHashTableInitialLengthContent);
#ifdef DEBUG
gOnceStaticPrefsAntiFootgun = new AntiFootgunMap();
#endif
#ifdef ACCESS_COUNTS
MOZ_ASSERT(!gAccessCounts);
gAccessCounts = new AccessCountsHashTable();
#endif
nsresult rv = InitInitialObjects(/* isStartup */ true);
if (NS_FAILED(rv)) {
sPreferences = nullptr;
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;
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;
return nullptr;
}
}
const char* defaultPrefs = getenv("MOZ_DEFAULT_PREFS");
if (defaultPrefs) {
parsePrefData(nsCString(defaultPrefs), PrefValueKind::Default);
}
// 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);
MOZ_ASSERT(!gCallbacksInProgress);
CallbackNode* node = gFirstCallback;
while (node) {
CallbackNode* next_node = node->Next();
delete node;
node = next_node;
}
gLastPriorityNode = gFirstCallback = nullptr;
delete HashTable();
HashTable() = nullptr;
#ifdef DEBUG
delete gOnceStaticPrefsAntiFootgun;
gOnceStaticPrefsAntiFootgun = nullptr;
#endif
#ifdef ACCESS_COUNTS
delete gAccessCounts;
#endif
gSharedMap = nullptr;
PrefNameArena().Clear();
}
NS_IMPL_ISUPPORTS(Preferences, nsIPrefService, nsIObserver, nsIPrefBranch,
nsISupportsWeakReference)
/* static */
void Preferences::SerializePreferences(nsCString& aStr) {
MOZ_RELEASE_ASSERT(InitStaticMembers());
aStr.Truncate();
for (auto iter = HashTable()->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();
static void StartObservingAlwaysPrefs();
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 = HashTable()->iter(); !iter.done(); iter.next()) {
iter.get()->AddToMap(builder);
}
// Store the current value of `once`-mirrored prefs. After this point they
// will be 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.
HashTable()->clearAndCompact();
Unused << HashTable()->reserve(kHashTableInitialLengthContent);
PrefNameArena().Clear();
gCallbackPref = nullptr;
}
*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 = std::move(prefsFile);
}
/* static */
void Preferences::FinishInitializingUserPrefs() {
sPreferences->NotifyServiceObservers(NS_PREFSERVICE_READ_TOPIC_ID);
}
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;
}
HashTable()->clearAndCompact();
Unused << HashTable()->reserve(kHashTableInitialLengthParent);
PrefNameArena().Clear();
return InitInitialObjects(/* isStartup */ false);
}
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 = HashTable()->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(nsDependentCString(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 nsCString& prefName = aDomPref.name();
Pref* pref;
auto p = HashTable()->lookupForAdd(prefName.get());
if (!p) {
pref = new Pref(prefName);
if (!HashTable()->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 {
HashTable()->remove(prefName.get());
}
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 (const auto& entry : *gAccessCounts) {
aCallback->Visit(entry.GetKey(), entry.GetData());
}
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
}
// We would much prefer to use C++ lambdas, but we cannot convert
// lambdas that capture (here, the underlying observer) to C pointer
// to functions. So, here we are, with icky C callbacks. Be aware
// that nothing is thread-safe here because there's a single global
// `nsIPrefObserver` instance. Use this from the main thread only.
nsIPrefObserver* PrefObserver = nullptr;
void HandlePref(const char* aPrefName, PrefType aType, PrefValueKind aKind,
PrefValue aValue, bool aIsSticky, bool aIsLocked) {
MOZ_ASSERT(NS_IsMainThread());
if (!PrefObserver) {
return;
}
const char* kind = aKind == PrefValueKind::Default ? "Default" : "User";
switch (aType) {
case PrefType::String:
PrefObserver->OnStringPref(kind, aPrefName, aValue.mStringVal, aIsSticky,
aIsLocked);
break;
case PrefType::Int:
PrefObserver->OnIntPref(kind, aPrefName, aValue.mIntVal, aIsSticky,
aIsLocked);
break;
case PrefType::Bool:
PrefObserver->OnBoolPref(kind, aPrefName, aValue.mBoolVal, aIsSticky,
aIsLocked);
break;
default:
PrefObserver->OnError("Unexpected pref type.");
}
}
void HandleError(const char* aMsg) {
MOZ_ASSERT(NS_IsMainThread());
if (!PrefObserver) {
return;
}
PrefObserver->OnError(aMsg);
}
NS_IMETHODIMP
Preferences::ParsePrefsFromBuffer(const nsTArray<uint8_t>& aBytes,
nsIPrefObserver* aObserver,
const char* aPathLabel) {
MOZ_ASSERT(NS_IsMainThread());
// We need a null-terminated buffer.
nsTArray<uint8_t> data = aBytes.Clone();
data.AppendElement(0);
// Parsing as default handles both `pref` and `user_pref`.
PrefObserver = aObserver;
prefs_parser_parse(aPathLabel ? aPathLabel : "<ParsePrefsFromBuffer data>",
PrefValueKind::Default, (const char*)data.Elements(),
data.Length() - 1, HandlePref, HandleError);
PrefObserver = nullptr;
return NS_OK;
}
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("user.js"_ns);
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 (!HashTable()) {
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;
// Increment sPendingWriteCount, even though it's redundant to track this
// in the case of a sync runnable; it just makes it easier to simply
// decrement this inside PWRunnable. We could alternatively increment
// sPendingWriteCount in PWRunnable's constructor, but if for any reason
// in future code we create a PWRunnable without dispatching it, we would
// get stuck in an infinite SpinEventLoopUntil inside
// PreferencesWriter::Flush. Better that in future code we miss an
// increment of sPendingWriteCount and cause a simple crash due to it
// ending up negative.
PreferencesWriter::sPendingWriteCount++;
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) {
MOZ_ASSERT(XRE_IsParentProcess());
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(aKind, NS_ConvertUTF16toUTF8(path).get(), data)) {
return NS_ERROR_FILE_CORRUPTED;
}
return NS_OK;
}
static nsresult parsePrefData(const nsCString& aData, PrefValueKind aKind) {
const nsCString path = "$MOZ_DEFAULT_PREFS"_ns;
Parser parser;
if (!parser.Parse(aKind, path.get(), 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) {
MOZ_ASSERT(XRE_IsParentProcess());
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, ".js"_ns,
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) {
nsCString manifest;
MOZ_TRY_VAR(manifest,
URLPreloader::ReadZip(aJarReader, nsDependentCString(aName)));
Parser parser;
if (!parser.Parse(PrefValueKind::Default, aName, manifest)) {
return NS_ERROR_FILE_CORRUPTED;
}
return NS_OK;
}
static nsresult pref_ReadDefaultPrefs(const RefPtr<nsZipArchive> jarReader,
const char* path) {
UniquePtr<nsZipFind> find;
nsTArray<nsCString> prefEntries;
const char* entryName;
uint16_t entryNameLen;
nsresult rv = jarReader->FindInit(path, getter_Transfers(find));
NS_ENSURE_SUCCESS(rv, rv);
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;
}
static nsCString PrefValueToString(const bool* b) {
return nsCString(*b ? "true" : "false");
}
static nsCString PrefValueToString(const int* i) {
return nsPrintfCString("%d", *i);
}
static nsCString PrefValueToString(const uint32_t* u) {
return nsPrintfCString("%d", *u);
}
static nsCString PrefValueToString(const float* f) {
return nsPrintfCString("%f", *f);
}
static nsCString PrefValueToString(const nsACString& s) { return nsCString(s); }
// 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 Internals {
struct PreferenceReadMarker {
static constexpr Span<const char> MarkerTypeName() {
return MakeStringSpan("PreferenceRead");
}
static void StreamJSONMarkerData(
baseprofiler::SpliceableJSONWriter& aWriter,
const ProfilerString8View& aPrefName,
const Maybe<PrefValueKind>& aPrefKind, PrefType aPrefType,
const ProfilerString8View& aPrefValue) {
aWriter.StringProperty("prefName", aPrefName);
aWriter.StringProperty("prefKind", PrefValueKindToString(aPrefKind));
aWriter.StringProperty("prefType", PrefTypeToString(aPrefType));
aWriter.StringProperty("prefValue", aPrefValue);
}
static MarkerSchema MarkerTypeDisplay() {
using MS = MarkerSchema;
MS schema{MS::Location::markerChart, MS::Location::markerTable};
schema.AddKeyLabelFormat("prefName", "Name", MS::Format::string);
schema.AddKeyLabelFormat("prefKind", "Kind", MS::Format::string);
schema.AddKeyLabelFormat("prefType", "Type", MS::Format::string);
schema.AddKeyLabelFormat("prefValue", "Value", MS::Format::string);
return schema;
}
private:
static Span<const char> PrefValueKindToString(
const Maybe<PrefValueKind>& aKind) {
if (aKind) {
return *aKind == PrefValueKind::Default ? MakeStringSpan("Default")
: MakeStringSpan("User");
}
return "Shared";
}
static Span<const char> PrefTypeToString(PrefType type) {
switch (type) {
case PrefType::None:
return "None";
case PrefType::Int:
return "Int";
case PrefType::Bool:
return "Bool";
case PrefType::String:
return "String";
default:
MOZ_ASSERT_UNREACHABLE("Unknown preference type.");
return "Unknown";
}
}
};
template <typename T>
static nsresult GetPrefValue(const char* aPrefName, T&& aResult,
PrefValueKind aKind) {
nsresult rv = NS_ERROR_UNEXPECTED;
NS_ENSURE_TRUE(Preferences::InitStaticMembers(), NS_ERROR_NOT_AVAILABLE);
if (Maybe<PrefWrapper> pref = pref_Lookup(aPrefName)) {
rv = pref->GetValue(aKind, std::forward<T>(aResult));
if (profiler_feature_active(ProfilerFeature::PreferenceReads)) {
profiler_add_marker(
"PreferenceRead", baseprofiler::category::OTHER_PreferenceRead, {},
PreferenceReadMarker{},
ProfilerString8View::WrapNullTerminatedString(aPrefName),
Some(aKind), pref->Type(), PrefValueToString(aResult));
}
}
return rv;
}
template <typename T>
static nsresult GetSharedPrefValue(const char* aName, T* aResult) {
nsresult rv = NS_ERROR_UNEXPECTED;
if (Maybe<PrefWrapper> pref = pref_SharedLookup(aName)) {
rv = pref->GetValue(PrefValueKind::User, aResult);
if (profiler_feature_active(ProfilerFeature::PreferenceReads)) {
profiler_add_marker(
"PreferenceRead", baseprofiler::category::OTHER_PreferenceRead, {},
PreferenceReadMarker{},
ProfilerString8View::WrapNullTerminatedString(aName),
Nothing() /* indicates Shared */, pref->Type(),
PrefValueToString(aResult));
}
}
return rv;
}
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 UpdateMirror(const char* aPref, void* aMirror) {
StripAtomic<T> value;
nsresult rv = GetPrefValue(aPref, &value, PrefValueKind::User);
if (NS_SUCCEEDED(rv)) {
*static_cast<T*>(aMirror) = value;
} else {
// GetPrefValue() can fail if the update is caused by the pref being
// deleted or if it fails to make a cast. This assertion is the only place
// where we safeguard these. In this case the mirror variable will be
// untouched, thus keeping the value it had prior to the change.
// (Note that this case won't happen for a deletion via DeleteBranch()
// unless bug 343600 is fixed, but it will happen for a deletion via
// ClearUserPref().)
NS_WARNING(nsPrintfCString("Pref changed failure: %s\n", aPref).get());
MOZ_ASSERT(false);
}
}
template <typename T>
static nsresult RegisterCallback(void* aMirror, const nsACString& aPref) {
return Preferences::RegisterCallback(UpdateMirror<T>, aPref, aMirror,
Preferences::ExactMatch,
/* isPriority */ true);
}
};
// Initialize default preference JavaScript buffers from appropriate TEXT
// resources.
/* static */
nsresult Preferences::InitInitialObjects(bool aIsStartup) {
MOZ_ASSERT(NS_IsMainThread());
if (!XRE_IsParentProcess()) {
MOZ_DIAGNOSTIC_ASSERT(gSharedMap);
if (aIsStartup) {
StaticPrefs::StartObservingAlwaysPrefs();
}
return NS_OK;
}
// Initialize static prefs before prefs from data files so that the latter
// will override the former.
StaticPrefs::InitAll();
// 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 == $gre`.
nsresult rv = NS_ERROR_FAILURE;
UniquePtr<nsZipFind> find;
nsTArray<nsCString> prefEntries;
const char* entryName;
uint16_t entryNameLen;
RefPtr<nsZipArchive> jarReader = Omnijar::GetReader(Omnijar::GRE);
if (jarReader) {
#ifdef MOZ_WIDGET_ANDROID
// Try to load an architecture-specific greprefs.js first. This will be
// present in FAT AAR builds of GeckoView on Android.
const char* abi = getenv("MOZ_ANDROID_CPU_ABI");
if (abi) {
nsAutoCString path;
path.AppendPrintf("%s/greprefs.js", abi);
rv = pref_ReadPrefFromJar(jarReader, path.get());
}
if (NS_FAILED(rv)) {
// Fallback to toplevel greprefs.js if arch-specific load fails.
rv = pref_ReadPrefFromJar(jarReader, "greprefs.js");
}
#else
// Load jar:$gre/omni.jar!/greprefs.js.
rv = pref_ReadPrefFromJar(jarReader, "greprefs.js");
#endif
NS_ENSURE_SUCCESS(rv, rv);
// Load jar:$gre/omni.jar!/defaults/pref/*.js.
rv = pref_ReadDefaultPrefs(jarReader, "defaults/pref/*.js$");
NS_ENSURE_SUCCESS(rv, rv);
#ifdef MOZ_BACKGROUNDTASKS
if (BackgroundTasks::IsBackgroundTaskMode()) {
rv = pref_ReadDefaultPrefs(jarReader, "defaults/backgroundtasks/*.js$");
NS_ENSURE_SUCCESS(rv, rv);
}
#endif
#ifdef MOZ_WIDGET_ANDROID
// Load jar:$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, rv);
#endif
} else {
// Load $gre/greprefs.js.
nsCOMPtr<nsIFile> greprefsFile;
rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(greprefsFile));
NS_ENSURE_SUCCESS(rv, rv);
rv = greprefsFile->AppendNative("greprefs.js"_ns);
NS_ENSURE_SUCCESS(rv, rv);
rv = openPrefFile(greprefsFile, PrefValueKind::Default);
if (NS_FAILED(rv)) {
NS_WARNING(
"Error parsing GRE default preferences. Is this an old-style "
"embedding app?");
}
}
// Load $gre/defaults/pref/*.js.
nsCOMPtr<nsIFile> defaultPrefDir;
rv = NS_GetSpecialDirectory(NS_APP_PREF_DEFAULTS_50_DIR,
getter_AddRefs(defaultPrefDir));
NS_ENSURE_SUCCESS(rv, rv);
// These pref file names should not be used: we process them after all other
// application pref files for backwards compatibility.
static const char* specialFiles[] = {
#if defined(XP_MACOSX)
"macprefs.js"
#elif defined(XP_WIN)
"winpref.js"
#elif defined(XP_UNIX)
"unix.js"
# if defined(_AIX)
,
"aix.js"
# endif
#elif defined(XP_BEOS)
"beos.js"
#endif
};
rv = pref_LoadPrefsInDir(defaultPrefDir, specialFiles,
ArrayLength(specialFiles));
if (NS_FAILED(rv)) {
NS_WARNING("Error parsing application default preferences.");
}
// Load jar:$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 $gre.
if (!appJarReader) {
appJarReader = Omnijar::GetReader(Omnijar::GRE);
}
if (appJarReader) {
rv = appJarReader->FindInit("defaults/preferences/*.js$",
getter_Transfers(find));
NS_ENSURE_SUCCESS(rv, rv);
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.");
}
}
#ifdef MOZ_BACKGROUNDTASKS
if (BackgroundTasks::IsBackgroundTaskMode()) {
rv = appJarReader->FindInit("defaults/backgroundtasks/*.js$",
getter_Transfers(find));
NS_ENSURE_SUCCESS(rv, rv);
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.");
}
}
}
#endif
}
nsCOMPtr<nsIProperties> dirSvc(
do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
NS_ENSURE_SUCCESS(rv, rv);
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();
}
if (aIsStartup) {
// Now that all prefs have their initial values, install the callbacks for
// `always`-mirrored static prefs. We do this now rather than in
// StaticPrefs::InitAll() so that the callbacks don't need to be traversed
// while we load prefs from data files.
StaticPrefs::StartObservingAlwaysPrefs();
}
NS_CreateServicesFromCategory(NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID, nullptr,
NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID);
nsCOMPtr<nsIObserverService> observerService = services::GetObserverService();
NS_ENSURE_SUCCESS(rv, rv);
observerService->NotifyObservers(nullptr, NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID,
nullptr);
return NS_OK;
}
/* static */
nsresult Preferences::GetBool(const char* aPrefName, bool* aResult,
PrefValueKind aKind) {
MOZ_ASSERT(aResult);
return Internals::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetInt(const char* aPrefName, int32_t* aResult,
PrefValueKind aKind) {
MOZ_ASSERT(aResult);
return Internals::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetFloat(const char* aPrefName, float* aResult,
PrefValueKind aKind) {
MOZ_ASSERT(aResult);
return Internals::GetPrefValue(aPrefName, aResult, aKind);
}
/* static */
nsresult Preferences::GetCString(const char* aPrefName, nsACString& aResult,
PrefValueKind aKind) {
aResult.SetIsVoid(true);
return Internals::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 Internals::GetPref(aPrefName, aFallback, aKind);
}
/* static */
int32_t Preferences::GetInt(const char* aPrefName, int32_t aFallback,
PrefValueKind aKind) {
return Internals::GetPref(aPrefName, aFallback, aKind);
}
/* static */
uint32_t Preferences::GetUint(const char* aPrefName, uint32_t aFallback,
PrefValueKind aKind) {
return Internals::GetPref(aPrefName, aFallback, aKind);
}
/* static */
float Preferences::GetFloat(const char* aPrefName, float aFallback,
PrefValueKind aKind) {
return Internals::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(nsDependentCString(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(nsDependentCString(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(nsDependentCString(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);
const auto& prefName = nsDependentCString(aPrefName);
Pref* pref;
MOZ_TRY_VAR(pref,
pref_LookupForModify(prefName, [](const PrefWrapper& aPref) {
return !aPref.IsLocked();
}));
if (pref) {
pref->SetIsLocked(true);
NotifyCallbacks(prefName, 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);
const auto& prefName = nsDependentCString(aPrefName);
Pref* pref;
MOZ_TRY_VAR(pref,
pref_LookupForModify(prefName, [](const PrefWrapper& aPref) {
return aPref.IsLocked();
}));
if (pref) {
pref->SetIsLocked(false);
NotifyCallbacks(prefName, 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);
const auto& prefName = nsDependentCString{aPrefName};
auto result = pref_LookupForModify(
prefName, [](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())) {
HashTable()->remove(aPrefName);
} else {
pref->SetType(PrefType::None);
}
NotifyCallbacks(prefName);
} else {
NotifyCallbacks(prefName, 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 (!HashTable()) {
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);
}
template <typename T>
static void AddMirrorCallback(T* aMirror, const nsACString& aPref) {
MOZ_ASSERT(NS_IsMainThread());
Internals::RegisterCallback<T>(aMirror, aPref);
}
// Don't inline because it explodes compile times.
template <typename T>
static MOZ_NEVER_INLINE void AddMirror(T* aMirror, const nsACString& aPref,
StripAtomic<T> aDefault) {
*aMirror = Internals::GetPref(PromiseFlatCString(aPref).get(), aDefault);
AddMirrorCallback(aMirror, aPref);
}
// The InitPref_*() functions below end in a `_<type>` suffix because they are
// used by the PREF macro definition in InitAll() below.
static void InitPref_bool(const nsCString& aName, bool aDefaultValue) {
MOZ_ASSERT(XRE_IsParentProcess());
PrefValue value;
value.mBoolVal = aDefaultValue;
pref_SetPref(aName, PrefType::Bool, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void InitPref_int32_t(const nsCString& aName, int32_t aDefaultValue) {
MOZ_ASSERT(XRE_IsParentProcess());
PrefValue value;
value.mIntVal = aDefaultValue;
pref_SetPref(aName, PrefType::Int, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void InitPref_uint32_t(const nsCString& aName, uint32_t aDefaultValue) {
InitPref_int32_t(aName, int32_t(aDefaultValue));
}
static void InitPref_float(const nsCString& aName, float aDefaultValue) {
MOZ_ASSERT(XRE_IsParentProcess());
PrefValue value;
// Convert the value in a locale-independent way, including a trailing ".0"
// if necessary to distinguish floating-point from integer prefs when viewing
// them in about:config.
nsAutoCString defaultValue;
defaultValue.AppendFloat(aDefaultValue);
if (!defaultValue.Contains('.') && !defaultValue.Contains('e')) {
defaultValue.AppendLiteral(".0");
}
value.mStringVal = defaultValue.get();
pref_SetPref(aName, PrefType::String, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void InitPref_String(const nsCString& aName, const char* aDefaultValue) {
MOZ_ASSERT(XRE_IsParentProcess());
PrefValue value;
value.mStringVal = aDefaultValue;
pref_SetPref(aName, PrefType::String, PrefValueKind::Default, value,
/* isSticky */ false,
/* isLocked */ false,
/* fromInit */ true);
}
static void InitPref(const nsCString& aName, bool aDefaultValue) {
InitPref_bool(aName, aDefaultValue);
}
static void InitPref(const nsCString& aName, int32_t aDefaultValue) {
InitPref_int32_t(aName, aDefaultValue);
}
static void InitPref(const nsCString& aName, uint32_t aDefaultValue) {
InitPref_uint32_t(aName, aDefaultValue);
}
static void InitPref(const nsCString& aName, float aDefaultValue) {
InitPref_float(aName, aDefaultValue);
}
template <typename T>
static void InitAlwaysPref(const nsCString& aName, T* aCache,
StripAtomic<T> aDefaultValue) {
// Only called in the parent process. Set/reset the pref value and the
// `always` mirror to the default value.
// `once` mirrors will be initialized lazily in InitOncePrefs().
InitPref(aName, aDefaultValue);
*aCache = aDefaultValue;
}
static Atomic<bool> sOncePrefRead(false);
static StaticMutex sOncePrefMutex;
namespace StaticPrefs {
void MaybeInitOncePrefs() {
if (MOZ_LIKELY(sOncePrefRead)) {
// `once`-mirrored prefs 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(GetMainThreadSerialEventTarget(), runnable);
}
sOncePrefRead = true;
}
// For mirrored prefs we generate a variable definition.
#define NEVER_PREF(name, cpp_type, value)
#define ALWAYS_PREF(name, base_id, full_id, cpp_type, default_value) \
cpp_type sMirror_##full_id(default_value);
#define ONCE_PREF(name, base_id, full_id, cpp_type, default_value) \
cpp_type sMirror_##full_id(default_value);
#include "mozilla/StaticPrefListAll.h"
#undef NEVER_PREF
#undef ALWAYS_PREF
#undef ONCE_PREF
static void InitAll() {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(XRE_IsParentProcess());
// For all prefs we generate some initialization code.
//
// The InitPref_*() functions have a type suffix to avoid ambiguity between
// prefs having int32_t and float default values. That suffix is not needed
// for the InitAlwaysPref() functions because they take a pointer parameter,
// which prevents automatic int-to-float coercion.
#define NEVER_PREF(name, cpp_type, value) \
InitPref_##cpp_type(name ""_ns, value);
#define ALWAYS_PREF(name, base_id, full_id, cpp_type, value) \
InitAlwaysPref(name ""_ns, &sMirror_##full_id, value);
#define ONCE_PREF(name, base_id, full_id, cpp_type, value) \
InitPref_##cpp_type(name ""_ns, value);
#include "mozilla/StaticPrefListAll.h"
#undef NEVER_PREF
#undef ALWAYS_PREF
#undef ONCE_PREF
}
static void StartObservingAlwaysPrefs() {
MOZ_ASSERT(NS_IsMainThread());
// Call AddMirror so that our mirrors for `always` prefs will stay updated.
// The call to AddMirror re-reads the current pref value into the mirror, so
// our mirror will now be up-to-date even if some of the prefs have changed
// since the call to InitAll().
#define NEVER_PREF(name, cpp_type, value)
#define ALWAYS_PREF(name, base_id, full_id, cpp_type, value) \
AddMirror(&sMirror_##full_id, name ""_ns, sMirror_##full_id);
#define ONCE_PREF(name, base_id, full_id, cpp_type, value)
#include "mozilla/StaticPrefListAll.h"
#undef NEVER_PREF
#undef ALWAYS_PREF
#undef ONCE_PREF
}
static void InitOncePrefs() {
// For `once`-mirrored prefs we generate some initialization code. This is
// done in case the pref value was updated when reading pref data files. It's
// necessary because we don't have callbacks registered for `once`-mirrored
// prefs.
//
// In debug builds, we also install a mechanism that can check if the
// preference value is modified after `once`-mirrored prefs are initialized.
// In tests this would indicate a likely misuse of a `once`-mirrored pref and
// suggest that it should instead be `always`-mirrored.
#define NEVER_PREF(name, cpp_type, value)
#define ALWAYS_PREF(name, base_id, full_id, cpp_type, value)
#ifdef DEBUG
# define ONCE_PREF(name, base_id, full_id, cpp_type, value) \
{ \
MOZ_ASSERT(gOnceStaticPrefsAntiFootgun); \
sMirror_##full_id = Internals::GetPref(name, cpp_type(value)); \
auto checkPref = [&]() { \
MOZ_ASSERT(sOncePrefRead); \
cpp_type staticPrefValue = full_id(); \
cpp_type preferenceValue = \
Internals::GetPref(GetPrefName_##base_id(), 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 ONCE_PREF(name, base_id, full_id, cpp_type, value) \
sMirror_##full_id = Internals::GetPref(name, cpp_type(value));
#endif
#include "mozilla/StaticPrefListAll.h"
#undef NEVER_PREF
#undef ALWAYS_PREF
#undef ONCE_PREF
}
} // namespace StaticPrefs
static MOZ_MAYBE_UNUSED void SaveOncePrefToSharedMap(
SharedPrefMapBuilder& aBuilder, const nsACString& 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 nsACString& 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 nsACString& aName, uint32_t aValue) {
SaveOncePrefToSharedMap(aBuilder, aName, int32_t(aValue));
}
static MOZ_MAYBE_UNUSED void SaveOncePrefToSharedMap(
SharedPrefMapBuilder& aBuilder, const nsACString& 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 `once`-mirrored prefs we generate a save call, which saves the value
// as it was at parent startup. It is stored in a special (hidden and locked)
// entry in the global SharedPreferenceMap. In order for the entry to be
// hidden and not appear in about:config nor ever be stored to disk, we set
// its IsSkippedByIteration flag to true. We also distinguish it by adding a
// "$$$" prefix and suffix to the preference name.
#define NEVER_PREF(name, cpp_type, value)
#define ALWAYS_PREF(name, base_id, full_id, cpp_type, value)
#define ONCE_PREF(name, base_id, full_id, cpp_type, value) \
SaveOncePrefToSharedMap(aBuilder, ONCE_PREF_NAME(name) ""_ns, \
cpp_type(sMirror_##full_id));
#include "mozilla/StaticPrefListAll.h"
#undef NEVER_PREF
#undef ALWAYS_PREF
#undef ONCE_PREF
}
static void InitStaticPrefsFromShared() {
MOZ_ASSERT(!XRE_IsParentProcess());
MOZ_DIAGNOSTIC_ASSERT(gSharedMap,
"Must be called once gSharedMap has been created");
// For mirrored static prefs we generate some initialization code. Each
// mirror variable is already initialized in the binary with the default
// value. If the pref value hasn't changed from the default in the main
// process (the common case) then the overwriting here won't change the
// mirror variable's value.
//
// Note that the MOZ_ASSERT calls below can fail in one obscure case: when a
// Firefox update occurs and we get a main process from the old binary (with
// static prefs {A,B,C,D}) plus a new content process from the new binary
// (with static prefs {A,B,C,D,E}). The content process' call to
// GetSharedPrefValue() for pref E will fail because the shared pref map was
// created by the main process, which doesn't have pref E.
//
// This silent failure is safe. The mirror variable for pref E is already
// initialized to the default value in the content process, and the main
// process cannot have changed pref E because it doesn't know about it!
//
// Nonetheless, it's useful to have the MOZ_ASSERT here for testing of debug
// builds, where this scenario involving inconsistent binaries should not
// occur.
#define NEVER_PREF(name, cpp_type, value)
#define ALWAYS_PREF(name, base_id, full_id, cpp_type, value) \
{ \
StripAtomic<cpp_type> val; \
DebugOnly<nsresult> rv = Internals::GetSharedPrefValue(name, &val); \
MOZ_ASSERT(NS_SUCCEEDED(rv)); \
StaticPrefs::sMirror_##full_id = val; \
}
#define ONCE_PREF(name, base_id, full_id, cpp_type, value) \
{ \
cpp_type val; \
DebugOnly<nsresult> rv = \
Internals::GetSharedPrefValue(ONCE_PREF_NAME(name), &val); \
MOZ_ASSERT(NS_SUCCEEDED(rv)); \
StaticPrefs::sMirror_##full_id = val; \
}
#include "mozilla/StaticPrefListAll.h"
#undef NEVER_PREF
#undef ALWAYS_PREF
#undef ONCE_PREF
// `once`-mirrored prefs have been set to their value in the step above and
// outside the parent process they are immutable. 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
// This file contains the C wrappers for the C++ static pref getters, as used
// by Rust code.
#include "init/StaticPrefsCGetters.cpp"
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