gecko-dev/xpcom/components/nsCategoryManager.cpp
Eric Rahm 478755933a Bug 1351732 - Part 2: Replace use of PLArena with ArenaAllocator in xpcom. r=froydnj
This swaps xpcom's plarena usage to ArenaAllocator. The new ArenaStrdup
extensions are used as well.

MozReview-Commit-ID: DHDfl6IkGJL
2017-03-30 16:46:58 -07:00

819 lines
19 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsICategoryManager.h"
#include "nsCategoryManager.h"
#include "prio.h"
#include "prlock.h"
#include "nsCOMPtr.h"
#include "nsTHashtable.h"
#include "nsClassHashtable.h"
#include "nsIFactory.h"
#include "nsIStringEnumerator.h"
#include "nsSupportsPrimitives.h"
#include "nsComponentManagerUtils.h"
#include "nsServiceManagerUtils.h"
#include "nsIObserver.h"
#include "nsIObserverService.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"
#include "nsQuickSort.h"
#include "nsEnumeratorUtils.h"
#include "nsThreadUtils.h"
#include "mozilla/ArenaAllocatorExtensions.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Services.h"
#include "ManifestParser.h"
#include "nsISimpleEnumerator.h"
using namespace mozilla;
class nsIComponentLoaderManager;
/*
CategoryDatabase
contains 0 or more 1-1 mappings of string to Category
each Category contains 0 or more 1-1 mappings of string keys to string values
In other words, the CategoryDatabase is a tree, whose root is a hashtable.
Internal nodes (or Categories) are hashtables. Leaf nodes are strings.
The leaf strings are allocated in an arena, because we assume they're not
going to change much ;)
*/
//
// BaseStringEnumerator is subclassed by EntryEnumerator and
// CategoryEnumerator
//
class BaseStringEnumerator
: public nsISimpleEnumerator
, private nsIUTF8StringEnumerator
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSISIMPLEENUMERATOR
NS_DECL_NSIUTF8STRINGENUMERATOR
protected:
// Callback function for NS_QuickSort to sort mArray
static int SortCallback(const void*, const void*, void*);
BaseStringEnumerator()
: mArray(nullptr)
, mCount(0)
, mSimpleCurItem(0)
, mStringCurItem(0)
{
}
// A virtual destructor is needed here because subclasses of
// BaseStringEnumerator do not implement their own Release() method.
virtual ~BaseStringEnumerator()
{
delete [] mArray;
}
void Sort();
const char** mArray;
uint32_t mCount;
uint32_t mSimpleCurItem;
uint32_t mStringCurItem;
};
NS_IMPL_ISUPPORTS(BaseStringEnumerator, nsISimpleEnumerator,
nsIUTF8StringEnumerator)
NS_IMETHODIMP
BaseStringEnumerator::HasMoreElements(bool* aResult)
{
*aResult = (mSimpleCurItem < mCount);
return NS_OK;
}
NS_IMETHODIMP
BaseStringEnumerator::GetNext(nsISupports** aResult)
{
if (mSimpleCurItem >= mCount) {
return NS_ERROR_FAILURE;
}
auto* str = new nsSupportsDependentCString(mArray[mSimpleCurItem++]);
if (!str) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aResult = str;
NS_ADDREF(*aResult);
return NS_OK;
}
NS_IMETHODIMP
BaseStringEnumerator::HasMore(bool* aResult)
{
*aResult = (mStringCurItem < mCount);
return NS_OK;
}
NS_IMETHODIMP
BaseStringEnumerator::GetNext(nsACString& aResult)
{
if (mStringCurItem >= mCount) {
return NS_ERROR_FAILURE;
}
aResult = nsDependentCString(mArray[mStringCurItem++]);
return NS_OK;
}
int
BaseStringEnumerator::SortCallback(const void* aE1, const void* aE2,
void* /*unused*/)
{
char const* const* s1 = reinterpret_cast<char const* const*>(aE1);
char const* const* s2 = reinterpret_cast<char const* const*>(aE2);
return strcmp(*s1, *s2);
}
void
BaseStringEnumerator::Sort()
{
NS_QuickSort(mArray, mCount, sizeof(mArray[0]), SortCallback, nullptr);
}
//
// EntryEnumerator is the wrapper that allows nsICategoryManager::EnumerateCategory
//
class EntryEnumerator
: public BaseStringEnumerator
{
public:
static EntryEnumerator* Create(nsTHashtable<CategoryLeaf>& aTable);
};
EntryEnumerator*
EntryEnumerator::Create(nsTHashtable<CategoryLeaf>& aTable)
{
auto* enumObj = new EntryEnumerator();
if (!enumObj) {
return nullptr;
}
enumObj->mArray = new char const* [aTable.Count()];
if (!enumObj->mArray) {
delete enumObj;
return nullptr;
}
for (auto iter = aTable.Iter(); !iter.Done(); iter.Next()) {
CategoryLeaf* leaf = iter.Get();
if (leaf->value) {
enumObj->mArray[enumObj->mCount++] = leaf->GetKey();
}
}
enumObj->Sort();
return enumObj;
}
//
// CategoryNode implementations
//
CategoryNode*
CategoryNode::Create(CategoryAllocator* aArena)
{
return new (aArena) CategoryNode();
}
CategoryNode::~CategoryNode() = default;
void*
CategoryNode::operator new(size_t aSize, CategoryAllocator* aArena)
{
return aArena->Allocate(aSize, mozilla::fallible);
}
nsresult
CategoryNode::GetLeaf(const char* aEntryName,
char** aResult)
{
MutexAutoLock lock(mLock);
nsresult rv = NS_ERROR_NOT_AVAILABLE;
CategoryLeaf* ent = mTable.GetEntry(aEntryName);
if (ent && ent->value) {
*aResult = NS_strdup(ent->value);
if (*aResult) {
rv = NS_OK;
}
}
return rv;
}
nsresult
CategoryNode::AddLeaf(const char* aEntryName,
const char* aValue,
bool aReplace,
char** aResult,
CategoryAllocator* aArena)
{
if (aResult) {
*aResult = nullptr;
}
MutexAutoLock lock(mLock);
CategoryLeaf* leaf = mTable.GetEntry(aEntryName);
if (!leaf) {
const char* arenaEntryName = ArenaStrdup(aEntryName, *aArena);
if (!arenaEntryName) {
return NS_ERROR_OUT_OF_MEMORY;
}
leaf = mTable.PutEntry(arenaEntryName);
if (!leaf) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
if (leaf->value && !aReplace) {
return NS_ERROR_INVALID_ARG;
}
const char* arenaValue = ArenaStrdup(aValue, *aArena);
if (!arenaValue) {
return NS_ERROR_OUT_OF_MEMORY;
}
if (aResult && leaf->value) {
*aResult = ToNewCString(nsDependentCString(leaf->value));
if (!*aResult) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
leaf->value = arenaValue;
return NS_OK;
}
void
CategoryNode::DeleteLeaf(const char* aEntryName)
{
// we don't throw any errors, because it normally doesn't matter
// and it makes JS a lot cleaner
MutexAutoLock lock(mLock);
// we can just remove the entire hash entry without introspection
mTable.RemoveEntry(aEntryName);
}
nsresult
CategoryNode::Enumerate(nsISimpleEnumerator** aResult)
{
if (NS_WARN_IF(!aResult)) {
return NS_ERROR_INVALID_ARG;
}
MutexAutoLock lock(mLock);
EntryEnumerator* enumObj = EntryEnumerator::Create(mTable);
if (!enumObj) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aResult = enumObj;
NS_ADDREF(*aResult);
return NS_OK;
}
size_t
CategoryNode::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf)
{
// We don't measure the strings pointed to by the entries because the
// pointers are non-owning.
return mTable.ShallowSizeOfExcludingThis(aMallocSizeOf);
}
//
// CategoryEnumerator class
//
class CategoryEnumerator
: public BaseStringEnumerator
{
public:
static CategoryEnumerator* Create(nsClassHashtable<nsDepCharHashKey,
CategoryNode>& aTable);
};
CategoryEnumerator*
CategoryEnumerator::Create(nsClassHashtable<nsDepCharHashKey, CategoryNode>&
aTable)
{
auto* enumObj = new CategoryEnumerator();
if (!enumObj) {
return nullptr;
}
enumObj->mArray = new const char* [aTable.Count()];
if (!enumObj->mArray) {
delete enumObj;
return nullptr;
}
for (auto iter = aTable.Iter(); !iter.Done(); iter.Next()) {
// if a category has no entries, we pretend it doesn't exist
CategoryNode* aNode = iter.UserData();
if (aNode->Count()) {
const char* str = iter.Key();
enumObj->mArray[enumObj->mCount++] = str;
}
}
return enumObj;
}
//
// nsCategoryManager implementations
//
NS_IMPL_QUERY_INTERFACE(nsCategoryManager, nsICategoryManager, nsIMemoryReporter)
NS_IMETHODIMP_(MozExternalRefCountType)
nsCategoryManager::AddRef()
{
return 2;
}
NS_IMETHODIMP_(MozExternalRefCountType)
nsCategoryManager::Release()
{
return 1;
}
nsCategoryManager* nsCategoryManager::gCategoryManager;
/* static */ nsCategoryManager*
nsCategoryManager::GetSingleton()
{
if (!gCategoryManager) {
gCategoryManager = new nsCategoryManager();
}
return gCategoryManager;
}
/* static */ void
nsCategoryManager::Destroy()
{
// The nsMemoryReporterManager gets destroyed before the nsCategoryManager,
// so we don't need to unregister the nsCategoryManager as a memory reporter.
// In debug builds we assert that unregistering fails, as a way (imperfect
// but better than nothing) of testing the "destroyed before" part.
MOZ_ASSERT(NS_FAILED(UnregisterWeakMemoryReporter(gCategoryManager)));
delete gCategoryManager;
gCategoryManager = nullptr;
}
nsresult
nsCategoryManager::Create(nsISupports* aOuter, REFNSIID aIID, void** aResult)
{
if (aOuter) {
return NS_ERROR_NO_AGGREGATION;
}
return GetSingleton()->QueryInterface(aIID, aResult);
}
nsCategoryManager::nsCategoryManager()
: mArena()
, mTable()
, mLock("nsCategoryManager")
, mSuppressNotifications(false)
{
}
void
nsCategoryManager::InitMemoryReporter()
{
RegisterWeakMemoryReporter(this);
}
nsCategoryManager::~nsCategoryManager()
{
// the hashtable contains entries that must be deleted before the arena is
// destroyed, or else you will have PRLocks undestroyed and other Really
// Bad Stuff (TM)
mTable.Clear();
}
inline CategoryNode*
nsCategoryManager::get_category(const char* aName)
{
CategoryNode* node;
if (!mTable.Get(aName, &node)) {
return nullptr;
}
return node;
}
MOZ_DEFINE_MALLOC_SIZE_OF(CategoryManagerMallocSizeOf)
NS_IMETHODIMP
nsCategoryManager::CollectReports(nsIHandleReportCallback* aHandleReport,
nsISupports* aData, bool aAnonymize)
{
MOZ_COLLECT_REPORT(
"explicit/xpcom/category-manager", KIND_HEAP, UNITS_BYTES,
SizeOfIncludingThis(CategoryManagerMallocSizeOf),
"Memory used for the XPCOM category manager.");
return NS_OK;
}
size_t
nsCategoryManager::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
{
size_t n = aMallocSizeOf(this);
n += mArena.SizeOfExcludingThis(aMallocSizeOf);
n += mTable.ShallowSizeOfExcludingThis(aMallocSizeOf);
for (auto iter = mTable.ConstIter(); !iter.Done(); iter.Next()) {
// We don't measure the key string because it's a non-owning pointer.
n += iter.Data()->SizeOfExcludingThis(aMallocSizeOf);
}
return n;
}
namespace {
class CategoryNotificationRunnable : public Runnable
{
public:
CategoryNotificationRunnable(nsISupports* aSubject,
const char* aTopic,
const char* aData)
: Runnable("CategoryNotificationRunnable")
, mSubject(aSubject)
, mTopic(aTopic)
, mData(aData)
{
}
NS_DECL_NSIRUNNABLE
private:
nsCOMPtr<nsISupports> mSubject;
const char* mTopic;
NS_ConvertUTF8toUTF16 mData;
};
NS_IMETHODIMP
CategoryNotificationRunnable::Run()
{
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
if (observerService) {
observerService->NotifyObservers(mSubject, mTopic, mData.get());
}
return NS_OK;
}
} // namespace
void
nsCategoryManager::NotifyObservers(const char* aTopic,
const char* aCategoryName,
const char* aEntryName)
{
if (mSuppressNotifications) {
return;
}
RefPtr<CategoryNotificationRunnable> r;
if (aEntryName) {
nsCOMPtr<nsISupportsCString> entry =
do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID);
if (!entry) {
return;
}
nsresult rv = entry->SetData(nsDependentCString(aEntryName));
if (NS_FAILED(rv)) {
return;
}
r = new CategoryNotificationRunnable(entry, aTopic, aCategoryName);
} else {
r = new CategoryNotificationRunnable(NS_ISUPPORTS_CAST(nsICategoryManager*,
this),
aTopic, aCategoryName);
}
NS_DispatchToMainThread(r);
}
NS_IMETHODIMP
nsCategoryManager::GetCategoryEntry(const char* aCategoryName,
const char* aEntryName,
char** aResult)
{
if (NS_WARN_IF(!aCategoryName) ||
NS_WARN_IF(!aEntryName) ||
NS_WARN_IF(!aResult)) {
return NS_ERROR_INVALID_ARG;
}
nsresult status = NS_ERROR_NOT_AVAILABLE;
CategoryNode* category;
{
MutexAutoLock lock(mLock);
category = get_category(aCategoryName);
}
if (category) {
status = category->GetLeaf(aEntryName, aResult);
}
return status;
}
NS_IMETHODIMP
nsCategoryManager::AddCategoryEntry(const char* aCategoryName,
const char* aEntryName,
const char* aValue,
bool aPersist,
bool aReplace,
char** aResult)
{
if (aPersist) {
NS_ERROR("Category manager doesn't support persistence.");
return NS_ERROR_INVALID_ARG;
}
AddCategoryEntry(aCategoryName, aEntryName, aValue, aReplace, aResult);
return NS_OK;
}
void
nsCategoryManager::AddCategoryEntry(const char* aCategoryName,
const char* aEntryName,
const char* aValue,
bool aReplace,
char** aOldValue)
{
if (aOldValue) {
*aOldValue = nullptr;
}
// Before we can insert a new entry, we'll need to
// find the |CategoryNode| to put it in...
CategoryNode* category;
{
MutexAutoLock lock(mLock);
category = get_category(aCategoryName);
if (!category) {
// That category doesn't exist yet; let's make it.
category = CategoryNode::Create(&mArena);
char* categoryName = ArenaStrdup(aCategoryName, mArena);
mTable.Put(categoryName, category);
}
}
if (!category) {
return;
}
// We will need the return value of AddLeaf even if the called doesn't want it
char* oldEntry = nullptr;
nsresult rv = category->AddLeaf(aEntryName,
aValue,
aReplace,
&oldEntry,
&mArena);
if (NS_SUCCEEDED(rv)) {
if (oldEntry) {
NotifyObservers(NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID,
aCategoryName, aEntryName);
}
NotifyObservers(NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID,
aCategoryName, aEntryName);
if (aOldValue) {
*aOldValue = oldEntry;
} else {
free(oldEntry);
}
}
}
NS_IMETHODIMP
nsCategoryManager::DeleteCategoryEntry(const char* aCategoryName,
const char* aEntryName,
bool aDontPersist)
{
if (NS_WARN_IF(!aCategoryName) ||
NS_WARN_IF(!aEntryName)) {
return NS_ERROR_INVALID_ARG;
}
/*
Note: no errors are reported since failure to delete
probably won't hurt you, and returning errors seriously
inconveniences JS clients
*/
CategoryNode* category;
{
MutexAutoLock lock(mLock);
category = get_category(aCategoryName);
}
if (category) {
category->DeleteLeaf(aEntryName);
NotifyObservers(NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID,
aCategoryName, aEntryName);
}
return NS_OK;
}
NS_IMETHODIMP
nsCategoryManager::DeleteCategory(const char* aCategoryName)
{
if (NS_WARN_IF(!aCategoryName)) {
return NS_ERROR_INVALID_ARG;
}
// the categories are arena-allocated, so we don't
// actually delete them. We just remove all of the
// leaf nodes.
CategoryNode* category;
{
MutexAutoLock lock(mLock);
category = get_category(aCategoryName);
}
if (category) {
category->Clear();
NotifyObservers(NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID,
aCategoryName, nullptr);
}
return NS_OK;
}
NS_IMETHODIMP
nsCategoryManager::EnumerateCategory(const char* aCategoryName,
nsISimpleEnumerator** aResult)
{
if (NS_WARN_IF(!aCategoryName) ||
NS_WARN_IF(!aResult)) {
return NS_ERROR_INVALID_ARG;
}
CategoryNode* category;
{
MutexAutoLock lock(mLock);
category = get_category(aCategoryName);
}
if (!category) {
return NS_NewEmptyEnumerator(aResult);
}
return category->Enumerate(aResult);
}
NS_IMETHODIMP
nsCategoryManager::EnumerateCategories(nsISimpleEnumerator** aResult)
{
if (NS_WARN_IF(!aResult)) {
return NS_ERROR_INVALID_ARG;
}
MutexAutoLock lock(mLock);
CategoryEnumerator* enumObj = CategoryEnumerator::Create(mTable);
if (!enumObj) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aResult = enumObj;
NS_ADDREF(*aResult);
return NS_OK;
}
struct writecat_struct
{
PRFileDesc* fd;
bool success;
};
nsresult
nsCategoryManager::SuppressNotifications(bool aSuppress)
{
mSuppressNotifications = aSuppress;
return NS_OK;
}
/*
* CreateServicesFromCategory()
*
* Given a category, this convenience functions enumerates the category and
* creates a service of every CID or ContractID registered under the category.
* If observerTopic is non null and the service implements nsIObserver,
* this will attempt to notify the observer with the origin, observerTopic string
* as parameter.
*/
void
NS_CreateServicesFromCategory(const char* aCategory,
nsISupports* aOrigin,
const char* aObserverTopic,
const char16_t* aObserverData)
{
nsresult rv;
nsCOMPtr<nsICategoryManager> categoryManager =
do_GetService("@mozilla.org/categorymanager;1");
if (!categoryManager) {
return;
}
nsCOMPtr<nsISimpleEnumerator> enumerator;
rv = categoryManager->EnumerateCategory(aCategory,
getter_AddRefs(enumerator));
if (NS_FAILED(rv)) {
return;
}
nsCOMPtr<nsIUTF8StringEnumerator> senumerator =
do_QueryInterface(enumerator);
if (!senumerator) {
NS_WARNING("Category enumerator doesn't support nsIUTF8StringEnumerator.");
return;
}
bool hasMore;
while (NS_SUCCEEDED(senumerator->HasMore(&hasMore)) && hasMore) {
// From here on just skip any error we get.
nsAutoCString entryString;
if (NS_FAILED(senumerator->GetNext(entryString))) {
continue;
}
nsXPIDLCString contractID;
rv = categoryManager->GetCategoryEntry(aCategory, entryString.get(),
getter_Copies(contractID));
if (NS_FAILED(rv)) {
continue;
}
nsCOMPtr<nsISupports> instance = do_GetService(contractID);
if (!instance) {
LogMessage("While creating services from category '%s', could not create service for entry '%s', contract ID '%s'",
aCategory, entryString.get(), contractID.get());
continue;
}
if (aObserverTopic) {
// try an observer, if it implements it.
nsCOMPtr<nsIObserver> observer = do_QueryInterface(instance);
if (observer) {
observer->Observe(aOrigin, aObserverTopic,
aObserverData ? aObserverData : u"");
} else {
LogMessage("While creating services from category '%s', service for entry '%s', contract ID '%s' does not implement nsIObserver.",
aCategory, entryString.get(), contractID.get());
}
}
}
}