1 files changed, 692 insertions, 0 deletions
diff --git a/xpcom/components/nsCategoryManager.cpp b/xpcom/components/nsCategoryManager.cpp
new file mode 100644
index 0000000000..a12fd510f5
--- /dev/null
+++ b/xpcom/components/nsCategoryManager.cpp
@@ -0,0 +1,692 @@
+/* -*- 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 "nsCategoryManager.h"
+#include "nsCategoryManagerUtils.h"
+
+#include "prio.h"
+#include "prlock.h"
+#include "nsArrayEnumerator.h"
+#include "nsCOMPtr.h"
+#include "nsTHashtable.h"
+#include "nsClassHashtable.h"
+#include "nsStringEnumerator.h"
+#include "nsSupportsPrimitives.h"
+#include "nsComponentManagerUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsReadableUtils.h"
+#include "nsCRT.h"
+#include "nsPrintfCString.h"
+#include "nsQuickSort.h"
+#include "nsEnumeratorUtils.h"
+#include "nsThreadUtils.h"
+#include "mozilla/ArenaAllocatorExtensions.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/ProfilerMarkers.h"
+#include "mozilla/Services.h"
+#include "mozilla/SimpleEnumerator.h"
+
+#include "ManifestParser.h"
+#include "nsSimpleEnumerator.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 ;)
+*/
+
+//
+// CategoryEnumerator class
+//
+
+class CategoryEnumerator : public nsSimpleEnumerator,
+                           private nsStringEnumeratorBase {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSISIMPLEENUMERATOR
+  NS_DECL_NSIUTF8STRINGENUMERATOR
+
+  using nsStringEnumeratorBase::GetNext;
+
+  const nsID& DefaultInterface() override {
+    return NS_GET_IID(nsISupportsCString);
+  }
+
+  static CategoryEnumerator* Create(
+      nsClassHashtable<nsDepCharHashKey, CategoryNode>& aTable);
+
+ protected:
+  CategoryEnumerator()
+      : mArray(nullptr), mCount(0), mSimpleCurItem(0), mStringCurItem(0) {}
+
+  ~CategoryEnumerator() override { delete[] mArray; }
+
+  const char** mArray;
+  uint32_t mCount;
+  uint32_t mSimpleCurItem;
+  uint32_t mStringCurItem;
+};
+
+NS_IMPL_ISUPPORTS_INHERITED(CategoryEnumerator, nsSimpleEnumerator,
+                            nsIUTF8StringEnumerator, nsIStringEnumerator)
+
+NS_IMETHODIMP
+CategoryEnumerator::HasMoreElements(bool* aResult) {
+  *aResult = (mSimpleCurItem < mCount);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CategoryEnumerator::GetNext(nsISupports** aResult) {
+  if (mSimpleCurItem >= mCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto* str = new nsSupportsDependentCString(mArray[mSimpleCurItem++]);
+
+  *aResult = str;
+  NS_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CategoryEnumerator::HasMore(bool* aResult) {
+  *aResult = (mStringCurItem < mCount);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CategoryEnumerator::GetNext(nsACString& aResult) {
+  if (mStringCurItem >= mCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  aResult = nsDependentCString(mArray[mStringCurItem++]);
+  return NS_OK;
+}
+
+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 (const auto& entry : aTable) {
+    // if a category has no entries, we pretend it doesn't exist
+    CategoryNode* aNode = entry.GetWeak();
+    if (aNode->Count()) {
+      enumObj->mArray[enumObj->mCount++] = entry.GetKey();
+    }
+  }
+
+  return enumObj;
+}
+
+class CategoryEntry final : public nsICategoryEntry {
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICATEGORYENTRY
+  NS_DECL_NSISUPPORTSCSTRING
+  NS_DECL_NSISUPPORTSPRIMITIVE
+
+  CategoryEntry(const char* aKey, const char* aValue)
+      : mKey(aKey), mValue(aValue) {}
+
+  const char* Key() const { return mKey; }
+
+  static CategoryEntry* Cast(nsICategoryEntry* aEntry) {
+    return static_cast<CategoryEntry*>(aEntry);
+  }
+
+ private:
+  ~CategoryEntry() = default;
+
+  const char* mKey;
+  const char* mValue;
+};
+
+NS_IMPL_ISUPPORTS(CategoryEntry, nsICategoryEntry, nsISupportsCString)
+
+nsresult CategoryEntry::ToString(char** aResult) {
+  *aResult = moz_xstrdup(mKey);
+  return NS_OK;
+}
+
+nsresult CategoryEntry::GetType(uint16_t* aType) {
+  *aType = TYPE_CSTRING;
+  return NS_OK;
+}
+
+nsresult CategoryEntry::GetData(nsACString& aData) {
+  aData = mKey;
+  return NS_OK;
+}
+
+nsresult CategoryEntry::SetData(const nsACString& aData) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult CategoryEntry::GetEntry(nsACString& aEntry) {
+  aEntry = mKey;
+  return NS_OK;
+}
+
+nsresult CategoryEntry::GetValue(nsACString& aValue) {
+  aValue = mValue;
+  return NS_OK;
+}
+
+static nsresult CreateEntryEnumerator(nsTHashtable<CategoryLeaf>& aTable,
+                                      nsISimpleEnumerator** aResult) {
+  nsCOMArray<nsICategoryEntry> entries(aTable.Count());
+
+  for (auto iter = aTable.Iter(); !iter.Done(); iter.Next()) {
+    CategoryLeaf* leaf = iter.Get();
+    if (leaf->value) {
+      entries.AppendElement(new CategoryEntry(leaf->GetKey(), leaf->value));
+    }
+  }
+
+  entries.Sort(
+      [](nsICategoryEntry* aA, nsICategoryEntry* aB, void*) {
+        return strcmp(CategoryEntry::Cast(aA)->Key(),
+                      CategoryEntry::Cast(aB)->Key());
+      },
+      nullptr);
+
+  return NS_NewArrayEnumerator(aResult, entries, NS_GET_IID(nsICategoryEntry));
+}
+
+//
+// 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);
+}
+
+static inline const char* MaybeStrdup(const nsACString& aStr,
+                                      CategoryAllocator* aArena) {
+  if (aStr.IsLiteral()) {
+    return aStr.BeginReading();
+  }
+  return ArenaStrdup(PromiseFlatCString(aStr).get(), *aArena);
+}
+
+nsresult CategoryNode::GetLeaf(const nsACString& aEntryName,
+                               nsACString& aResult) {
+  MutexAutoLock lock(mLock);
+  nsresult rv = NS_ERROR_NOT_AVAILABLE;
+  CategoryLeaf* ent = mTable.GetEntry(PromiseFlatCString(aEntryName).get());
+
+  if (ent && ent->value) {
+    aResult.Assign(ent->value);
+    return NS_OK;
+  }
+
+  return rv;
+}
+
+nsresult CategoryNode::AddLeaf(const nsACString& aEntryName,
+                               const nsACString& aValue, bool aReplace,
+                               nsACString& aResult, CategoryAllocator* aArena) {
+  aResult.SetIsVoid(true);
+
+  auto entryName = PromiseFlatCString(aEntryName);
+
+  MutexAutoLock lock(mLock);
+  CategoryLeaf* leaf = mTable.GetEntry(entryName.get());
+
+  if (!leaf) {
+    leaf = mTable.PutEntry(MaybeStrdup(aEntryName, aArena));
+    if (!leaf) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+
+  if (leaf->value && !aReplace) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  if (leaf->value) {
+    aResult.AssignLiteral(leaf->value, strlen(leaf->value));
+  } else {
+    aResult.SetIsVoid(true);
+  }
+  leaf->value = MaybeStrdup(aValue, aArena);
+  return NS_OK;
+}
+
+void CategoryNode::DeleteLeaf(const nsACString& 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(PromiseFlatCString(aEntryName).get());
+}
+
+nsresult CategoryNode::Enumerate(nsISimpleEnumerator** aResult) {
+  MutexAutoLock lock(mLock);
+  return CreateEntryEnumerator(mTable, aResult);
+}
+
+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);
+}
+
+//
+// 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(REFNSIID aIID, void** aResult) {
+  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 nsACString& aName) {
+  CategoryNode* node;
+  if (!mTable.Get(PromiseFlatCString(aName).get(), &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 (const auto& data : mTable.Values()) {
+    // We don't measure the key string because it's a non-owning pointer.
+    n += data->SizeOfExcludingThis(aMallocSizeOf);
+  }
+
+  return n;
+}
+
+namespace {
+
+class CategoryNotificationRunnable : public Runnable {
+ public:
+  CategoryNotificationRunnable(nsISupports* aSubject, const char* aTopic,
+                               const nsACString& 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 nsACString& aCategoryName,
+                                        const nsACString& aEntryName) {
+  if (mSuppressNotifications) {
+    return;
+  }
+
+  RefPtr<CategoryNotificationRunnable> r;
+
+  if (aEntryName.Length()) {
+    nsCOMPtr<nsISupportsCString> entry =
+        do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID);
+    if (!entry) {
+      return;
+    }
+
+    nsresult rv = entry->SetData(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 nsACString& aCategoryName,
+                                    const nsACString& aEntryName,
+                                    nsACString& aResult) {
+  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 nsACString& aCategoryName,
+                                    const nsACString& aEntryName,
+                                    const nsACString& aValue, bool aPersist,
+                                    bool aReplace, nsACString& 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 nsACString& aCategoryName,
+                                         const nsACString& aEntryName,
+                                         const nsACString& aValue,
+                                         bool aReplace, nsACString& aOldValue) {
+  aOldValue.SetIsVoid(true);
+
+  // 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 = mTable
+                     .InsertOrUpdate(
+                         MaybeStrdup(aCategoryName, &mArena),
+                         UniquePtr<CategoryNode>{CategoryNode::Create(&mArena)})
+                     .get();
+    }
+  }
+
+  if (!category) {
+    return;
+  }
+
+  nsresult rv =
+      category->AddLeaf(aEntryName, aValue, aReplace, aOldValue, &mArena);
+
+  if (NS_SUCCEEDED(rv)) {
+    if (!aOldValue.IsEmpty()) {
+      NotifyObservers(NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID,
+                      aCategoryName, aEntryName);
+    }
+    NotifyObservers(NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID, aCategoryName,
+                    aEntryName);
+  }
+}
+
+NS_IMETHODIMP
+nsCategoryManager::DeleteCategoryEntry(const nsACString& aCategoryName,
+                                       const nsACString& aEntryName,
+                                       bool aDontPersist) {
+  /*
+    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 nsACString& aCategoryName) {
+  // 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,
+                    VoidCString());
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsCategoryManager::EnumerateCategory(const nsACString& aCategoryName,
+                                     nsISimpleEnumerator** aResult) {
+  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;
+  }
+
+  nsDependentCString category(aCategory);
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  rv = categoryManager->EnumerateCategory(category, getter_AddRefs(enumerator));
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  for (auto& categoryEntry : SimpleEnumerator<nsICategoryEntry>(enumerator)) {
+    // From here on just skip any error we get.
+    nsAutoCString entryString;
+    categoryEntry->GetEntry(entryString);
+
+    nsAutoCString contractID;
+    categoryEntry->GetValue(contractID);
+
+    nsCOMPtr<nsISupports> instance = do_GetService(contractID.get());
+    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) {
+        nsPrintfCString profilerStr("%s (%s)", aObserverTopic,
+                                    entryString.get());
+        AUTO_PROFILER_MARKER_TEXT("Category observer notification", OTHER,
+                                  MarkerStack::Capture(), profilerStr);
+        AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING_NONSENSITIVE(
+            "Category observer notification -", OTHER, profilerStr);
+
+        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());
+      }
+    }
+  }
+}