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-rw-r--r--gfx/thebes/gfxGradientCache.cpp285
1 files changed, 285 insertions, 0 deletions
diff --git a/gfx/thebes/gfxGradientCache.cpp b/gfx/thebes/gfxGradientCache.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "gfxGradientCache.h"
+
+#include "MainThreadUtils.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/DataMutex.h"
+#include "nsTArray.h"
+#include "PLDHashTable.h"
+#include "nsExpirationTracker.h"
+#include "nsClassHashtable.h"
+#include <time.h>
+
+namespace mozilla {
+namespace gfx {
+
+using namespace mozilla;
+
+struct GradientCacheKey : public PLDHashEntryHdr {
+ typedef const GradientCacheKey& KeyType;
+ typedef const GradientCacheKey* KeyTypePointer;
+ enum { ALLOW_MEMMOVE = true };
+ const CopyableTArray<GradientStop> mStops;
+ ExtendMode mExtend;
+ BackendType mBackendType;
+
+ GradientCacheKey(const nsTArray<GradientStop>& aStops, ExtendMode aExtend,
+ BackendType aBackendType)
+ : mStops(aStops), mExtend(aExtend), mBackendType(aBackendType) {}
+
+ explicit GradientCacheKey(const GradientCacheKey* aOther)
+ : mStops(aOther->mStops),
+ mExtend(aOther->mExtend),
+ mBackendType(aOther->mBackendType) {}
+
+ GradientCacheKey(GradientCacheKey&& aOther) = default;
+
+ union FloatUint32 {
+ float f;
+ uint32_t u;
+ };
+
+ static PLDHashNumber HashKey(const KeyTypePointer aKey) {
+ PLDHashNumber hash = 0;
+ FloatUint32 convert;
+ hash = AddToHash(hash, int(aKey->mBackendType));
+ hash = AddToHash(hash, int(aKey->mExtend));
+ for (uint32_t i = 0; i < aKey->mStops.Length(); i++) {
+ hash = AddToHash(hash, aKey->mStops[i].color.ToABGR());
+ // Use the float bits as hash, except for the cases of 0.0 and -0.0 which
+ // both map to 0
+ convert.f = aKey->mStops[i].offset;
+ hash = AddToHash(hash, convert.f ? convert.u : 0);
+ }
+ return hash;
+ }
+
+ bool KeyEquals(KeyTypePointer aKey) const {
+ bool sameStops = true;
+ if (aKey->mStops.Length() != mStops.Length()) {
+ sameStops = false;
+ } else {
+ for (uint32_t i = 0; i < mStops.Length(); i++) {
+ if (mStops[i].color.ToABGR() != aKey->mStops[i].color.ToABGR() ||
+ mStops[i].offset != aKey->mStops[i].offset) {
+ sameStops = false;
+ break;
+ }
+ }
+ }
+
+ return sameStops && (aKey->mBackendType == mBackendType) &&
+ (aKey->mExtend == mExtend);
+ }
+ static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+};
+
+/**
+ * This class is what is cached. It need to be allocated in an object separated
+ * to the cache entry to be able to be tracked by the nsExpirationTracker.
+ * */
+struct GradientCacheData {
+ GradientCacheData(GradientStops* aStops, GradientCacheKey&& aKey)
+ : mStops(aStops), mKey(std::move(aKey)) {}
+
+ GradientCacheData(GradientCacheData&& aOther) = default;
+
+ nsExpirationState* GetExpirationState() { return &mExpirationState; }
+
+ nsExpirationState mExpirationState;
+ const RefPtr<GradientStops> mStops;
+ GradientCacheKey mKey;
+};
+
+/**
+ * This class implements a cache, that retains the GradientStops used to draw
+ * the gradients.
+ *
+ * An entry stays in the cache as long as it is used often and we don't exceed
+ * the maximum, in which case the most recently used will be kept.
+ */
+class GradientCache;
+using GradientCacheMutex = StaticDataMutex<UniquePtr<GradientCache>>;
+class MOZ_RAII LockedInstance {
+ public:
+ explicit LockedInstance(GradientCacheMutex& aDataMutex)
+ : mAutoLock(aDataMutex.Lock()) {}
+ UniquePtr<GradientCache>& operator->() const& { return mAutoLock.ref(); }
+ UniquePtr<GradientCache>& operator->() const&& = delete;
+ UniquePtr<GradientCache>& operator*() const& { return mAutoLock.ref(); }
+ UniquePtr<GradientCache>& operator*() const&& = delete;
+ explicit operator bool() const { return !!mAutoLock.ref(); }
+
+ private:
+ GradientCacheMutex::AutoLock mAutoLock;
+};
+
+class GradientCache final
+ : public ExpirationTrackerImpl<GradientCacheData, 4, GradientCacheMutex,
+ LockedInstance> {
+ public:
+ GradientCache()
+ : ExpirationTrackerImpl<GradientCacheData, 4, GradientCacheMutex,
+ LockedInstance>(MAX_GENERATION_MS,
+ "GradientCache") {}
+ static bool EnsureInstance() {
+ LockedInstance lockedInstance(sInstanceMutex);
+ return EnsureInstanceLocked(lockedInstance);
+ }
+
+ static void DestroyInstance() {
+ LockedInstance lockedInstance(sInstanceMutex);
+ if (lockedInstance) {
+ *lockedInstance = nullptr;
+ }
+ }
+
+ static void AgeAllGenerations() {
+ LockedInstance lockedInstance(sInstanceMutex);
+ if (!lockedInstance) {
+ return;
+ }
+ lockedInstance->AgeAllGenerationsLocked(lockedInstance);
+ lockedInstance->NotifyHandlerEndLocked(lockedInstance);
+ }
+
+ template <typename CreateFunc>
+ static already_AddRefed<GradientStops> LookupOrInsert(
+ const GradientCacheKey& aKey, CreateFunc aCreateFunc) {
+ uint32_t numberOfEntries;
+ RefPtr<GradientStops> stops;
+ {
+ LockedInstance lockedInstance(sInstanceMutex);
+ if (!EnsureInstanceLocked(lockedInstance)) {
+ return aCreateFunc();
+ }
+
+ GradientCacheData* gradientData = lockedInstance->mHashEntries.Get(aKey);
+ if (gradientData) {
+ if (gradientData->mStops && gradientData->mStops->IsValid()) {
+ lockedInstance->MarkUsedLocked(gradientData, lockedInstance);
+ return do_AddRef(gradientData->mStops);
+ }
+
+ lockedInstance->NotifyExpiredLocked(gradientData, lockedInstance);
+ lockedInstance->NotifyHandlerEndLocked(lockedInstance);
+ }
+
+ stops = aCreateFunc();
+ if (!stops) {
+ return nullptr;
+ }
+
+ auto data = MakeUnique<GradientCacheData>(stops, GradientCacheKey(&aKey));
+ nsresult rv = lockedInstance->AddObjectLocked(data.get(), lockedInstance);
+ if (NS_FAILED(rv)) {
+ // We are OOM, and we cannot track this object. We don't want to store
+ // entries in the hash table (since the expiration tracker is
+ // responsible for removing the cache entries), so we avoid putting that
+ // entry in the table, which is a good thing considering we are short on
+ // memory anyway, we probably don't want to retain things.
+ return stops.forget();
+ }
+ lockedInstance->mHashEntries.InsertOrUpdate(aKey, std::move(data));
+ numberOfEntries = lockedInstance->mHashEntries.Count();
+ }
+
+ if (numberOfEntries > MAX_ENTRIES) {
+ // We have too many entries force the cache to age a generation.
+ NS_DispatchToMainThread(
+ NS_NewRunnableFunction("GradientCache::OnMaxEntriesBreached", [] {
+ LockedInstance lockedInstance(sInstanceMutex);
+ if (!lockedInstance) {
+ return;
+ }
+ lockedInstance->AgeOneGenerationLocked(lockedInstance);
+ lockedInstance->NotifyHandlerEndLocked(lockedInstance);
+ }));
+ }
+
+ return stops.forget();
+ }
+
+ GradientCacheMutex& GetMutex() final { return sInstanceMutex; }
+
+ void NotifyExpiredLocked(GradientCacheData* aObject,
+ const LockedInstance& aLockedInstance) final {
+ // Remove the gradient from the tracker.
+ RemoveObjectLocked(aObject, aLockedInstance);
+
+ // If entry exists move the data to mRemovedGradientData because we want to
+ // drop it outside of the lock.
+ Maybe<UniquePtr<GradientCacheData>> gradientData =
+ mHashEntries.Extract(aObject->mKey);
+ if (gradientData.isSome()) {
+ mRemovedGradientData.AppendElement(std::move(*gradientData));
+ }
+ }
+
+ void NotifyHandlerEndLocked(const LockedInstance&) final {
+ NS_DispatchToMainThread(
+ NS_NewRunnableFunction("GradientCache::DestroyRemovedGradientStops",
+ [stops = std::move(mRemovedGradientData)] {}));
+ }
+
+ private:
+ static const uint32_t MAX_GENERATION_MS = 10000;
+
+ // On Windows some of the Direct2D objects associated with the gradient stops
+ // can be quite large, so we limit the number of cache entries.
+ static const uint32_t MAX_ENTRIES = 4000;
+ static GradientCacheMutex sInstanceMutex;
+
+ [[nodiscard]] static bool EnsureInstanceLocked(
+ LockedInstance& aLockedInstance) {
+ if (!aLockedInstance) {
+ // GradientCache must be created on the main thread.
+ if (!NS_IsMainThread()) {
+ // This should only happen at shutdown, we fall back to not caching.
+ return false;
+ }
+ *aLockedInstance = MakeUnique<GradientCache>();
+ }
+ return true;
+ }
+
+ /**
+ * FIXME use nsTHashtable to avoid duplicating the GradientCacheKey.
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=761393#c47
+ */
+ nsClassHashtable<GradientCacheKey, GradientCacheData> mHashEntries;
+ nsTArray<UniquePtr<GradientCacheData>> mRemovedGradientData;
+};
+
+GradientCacheMutex GradientCache::sInstanceMutex("GradientCache");
+
+void gfxGradientCache::Init() {
+ MOZ_RELEASE_ASSERT(GradientCache::EnsureInstance(),
+ "First call must be on main thread.");
+}
+
+already_AddRefed<GradientStops> gfxGradientCache::GetOrCreateGradientStops(
+ const DrawTarget* aDT, nsTArray<GradientStop>& aStops, ExtendMode aExtend) {
+ if (aDT->IsRecording()) {
+ return aDT->CreateGradientStops(aStops.Elements(), aStops.Length(),
+ aExtend);
+ }
+
+ return GradientCache::LookupOrInsert(
+ GradientCacheKey(aStops, aExtend, aDT->GetBackendType()),
+ [&]() -> already_AddRefed<GradientStops> {
+ return aDT->CreateGradientStops(aStops.Elements(), aStops.Length(),
+ aExtend);
+ });
+}
+
+void gfxGradientCache::PurgeAllCaches() { GradientCache::AgeAllGenerations(); }
+
+void gfxGradientCache::Shutdown() { GradientCache::DestroyInstance(); }
+
+} // namespace gfx
+} // namespace mozilla