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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
#include "CanvasImageCache.h"
#include "nsIImageLoadingContent.h"
#include "nsExpirationTracker.h"
#include "imgIRequest.h"
#include "mozilla/dom/Element.h"
#include "nsTHashtable.h"
#include "mozilla/dom/HTMLCanvasElement.h"
#include "nsContentUtils.h"
#include "mozilla/Preferences.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/gfx/2D.h"
#include "gfx2DGlue.h"
namespace mozilla {
using namespace dom;
using namespace gfx;
/**
* Used for images specific to this one canvas. Required
* due to CORS security.
*/
struct ImageCacheKey {
ImageCacheKey(imgIContainer* aImage, HTMLCanvasElement* aCanvas,
BackendType aBackendType)
: mImage(aImage), mCanvas(aCanvas), mBackendType(aBackendType) {}
nsCOMPtr<imgIContainer> mImage;
HTMLCanvasElement* mCanvas;
BackendType mBackendType;
};
/**
* Cache data needs to be separate from the entry
* for nsExpirationTracker.
*/
struct ImageCacheEntryData {
ImageCacheEntryData(const ImageCacheEntryData& aOther)
: mImage(aOther.mImage),
mCanvas(aOther.mCanvas),
mBackendType(aOther.mBackendType),
mSourceSurface(aOther.mSourceSurface),
mSize(aOther.mSize),
mIntrinsicSize(aOther.mIntrinsicSize),
mCropRect(aOther.mCropRect) {}
explicit ImageCacheEntryData(const ImageCacheKey& aKey)
: mImage(aKey.mImage),
mCanvas(aKey.mCanvas),
mBackendType(aKey.mBackendType) {}
nsExpirationState* GetExpirationState() { return &mState; }
size_t SizeInBytes() { return mSize.width * mSize.height * 4; }
// Key
nsCOMPtr<imgIContainer> mImage;
HTMLCanvasElement* mCanvas;
BackendType mBackendType;
// Value
RefPtr<SourceSurface> mSourceSurface;
IntSize mSize;
IntSize mIntrinsicSize;
Maybe<IntRect> mCropRect;
nsExpirationState mState;
};
class ImageCacheEntry : public PLDHashEntryHdr {
public:
using KeyType = ImageCacheKey;
using KeyTypePointer = const ImageCacheKey*;
explicit ImageCacheEntry(const KeyType* aKey)
: mData(new ImageCacheEntryData(*aKey)) {}
ImageCacheEntry(const ImageCacheEntry& toCopy)
: mData(new ImageCacheEntryData(*toCopy.mData)) {}
~ImageCacheEntry() = default;
bool KeyEquals(KeyTypePointer key) const {
return mData->mImage == key->mImage && mData->mCanvas == key->mCanvas &&
mData->mBackendType == key->mBackendType;
}
static KeyTypePointer KeyToPointer(KeyType& key) { return &key; }
static PLDHashNumber HashKey(KeyTypePointer key) {
return HashGeneric(key->mImage.get(), key->mCanvas, key->mBackendType);
}
enum { ALLOW_MEMMOVE = true };
UniquePtr<ImageCacheEntryData> mData;
};
/**
* Used for all images across all canvases.
*/
struct AllCanvasImageCacheKey {
explicit AllCanvasImageCacheKey(imgIContainer* aImage,
BackendType aBackendType)
: mImage(aImage), mBackendType(aBackendType) {}
nsCOMPtr<imgIContainer> mImage;
BackendType mBackendType;
};
class AllCanvasImageCacheEntry : public PLDHashEntryHdr {
public:
using KeyType = AllCanvasImageCacheKey;
using KeyTypePointer = const AllCanvasImageCacheKey*;
explicit AllCanvasImageCacheEntry(const KeyType* aKey)
: mImage(aKey->mImage), mBackendType(aKey->mBackendType) {}
AllCanvasImageCacheEntry(const AllCanvasImageCacheEntry& toCopy)
: mImage(toCopy.mImage),
mSourceSurface(toCopy.mSourceSurface),
mBackendType(toCopy.mBackendType) {}
~AllCanvasImageCacheEntry() = default;
bool KeyEquals(KeyTypePointer key) const {
return mImage == key->mImage && mBackendType == key->mBackendType;
}
static KeyTypePointer KeyToPointer(KeyType& key) { return &key; }
static PLDHashNumber HashKey(KeyTypePointer key) {
return HashGeneric(key->mImage.get(), key->mBackendType);
}
enum { ALLOW_MEMMOVE = true };
nsCOMPtr<imgIContainer> mImage;
RefPtr<SourceSurface> mSourceSurface;
BackendType mBackendType;
};
class ImageCacheObserver;
class ImageCache final : public nsExpirationTracker<ImageCacheEntryData, 4> {
public:
// We use 3 generations of 1 second each to get a 2-3 seconds timeout.
enum { GENERATION_MS = 1000 };
ImageCache();
~ImageCache();
virtual void NotifyExpired(ImageCacheEntryData* aObject) override {
RemoveObject(aObject);
// Remove from the all canvas cache entry first since nsExpirationTracker
// will delete aObject.
mAllCanvasCache.RemoveEntry(
AllCanvasImageCacheKey(aObject->mImage, aObject->mBackendType));
// Deleting the entry will delete aObject since the entry owns aObject.
mCache.RemoveEntry(ImageCacheKey(aObject->mImage, aObject->mCanvas,
aObject->mBackendType));
}
nsTHashtable<ImageCacheEntry> mCache;
nsTHashtable<AllCanvasImageCacheEntry> mAllCanvasCache;
RefPtr<ImageCacheObserver> mImageCacheObserver;
};
static ImageCache* gImageCache = nullptr;
// Listen memory-pressure event for image cache purge.
class ImageCacheObserver final : public nsIObserver {
public:
NS_DECL_ISUPPORTS
explicit ImageCacheObserver(ImageCache* aImageCache)
: mImageCache(aImageCache) {
RegisterObserverEvents();
}
void Destroy() {
UnregisterObserverEvents();
mImageCache = nullptr;
}
NS_IMETHOD Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aSomeData) override {
if (!mImageCache || (strcmp(aTopic, "memory-pressure") != 0 &&
strcmp(aTopic, "canvas-device-reset") != 0)) {
return NS_OK;
}
mImageCache->AgeAllGenerations();
return NS_OK;
}
private:
virtual ~ImageCacheObserver() = default;
void RegisterObserverEvents() {
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
MOZ_ASSERT(observerService);
if (observerService) {
observerService->AddObserver(this, "memory-pressure", false);
observerService->AddObserver(this, "canvas-device-reset", false);
}
}
void UnregisterObserverEvents() {
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
// Do not assert on observerService here. This might be triggered by
// the cycle collector at a late enough time, that XPCOM services are
if (observerService) {
observerService->RemoveObserver(this, "memory-pressure");
observerService->RemoveObserver(this, "canvas-device-reset");
}
}
ImageCache* mImageCache;
};
NS_IMPL_ISUPPORTS(ImageCacheObserver, nsIObserver)
class CanvasImageCacheShutdownObserver final : public nsIObserver {
~CanvasImageCacheShutdownObserver() = default;
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
};
ImageCache::ImageCache()
: nsExpirationTracker<ImageCacheEntryData, 4>(GENERATION_MS, "ImageCache") {
mImageCacheObserver = new ImageCacheObserver(this);
MOZ_RELEASE_ASSERT(mImageCacheObserver,
"GFX: Can't alloc ImageCacheObserver");
}
ImageCache::~ImageCache() {
AgeAllGenerations();
mImageCacheObserver->Destroy();
}
static already_AddRefed<imgIContainer> GetImageContainer(dom::Element* aImage) {
nsCOMPtr<imgIRequest> request;
nsCOMPtr<nsIImageLoadingContent> ilc = do_QueryInterface(aImage);
if (!ilc) {
return nullptr;
}
ilc->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
getter_AddRefs(request));
if (!request) {
return nullptr;
}
nsCOMPtr<imgIContainer> imgContainer;
request->GetImage(getter_AddRefs(imgContainer));
if (!imgContainer) {
return nullptr;
}
return imgContainer.forget();
}
void CanvasImageCache::NotifyDrawImage(
Element* aImage, HTMLCanvasElement* aCanvas, DrawTarget* aTarget,
SourceSurface* aSource, const IntSize& aSize, const IntSize& aIntrinsicSize,
const Maybe<IntRect>& aCropRect) {
if (!aTarget) {
return;
}
if (!gImageCache) {
gImageCache = new ImageCache();
nsContentUtils::RegisterShutdownObserver(
new CanvasImageCacheShutdownObserver());
}
nsCOMPtr<imgIContainer> imgContainer = GetImageContainer(aImage);
if (!imgContainer) {
return;
}
BackendType backendType = aTarget->GetBackendType();
AllCanvasImageCacheKey allCanvasCacheKey(imgContainer, backendType);
ImageCacheKey canvasCacheKey(imgContainer, aCanvas, backendType);
ImageCacheEntry* entry = gImageCache->mCache.PutEntry(canvasCacheKey);
if (entry) {
if (entry->mData->mSourceSurface) {
// We are overwriting an existing entry.
gImageCache->RemoveObject(entry->mData.get());
gImageCache->mAllCanvasCache.RemoveEntry(allCanvasCacheKey);
}
gImageCache->AddObject(entry->mData.get());
entry->mData->mSourceSurface = aSource;
entry->mData->mSize = aSize;
entry->mData->mIntrinsicSize = aIntrinsicSize;
entry->mData->mCropRect = aCropRect;
AllCanvasImageCacheEntry* allEntry =
gImageCache->mAllCanvasCache.PutEntry(allCanvasCacheKey);
if (allEntry) {
allEntry->mSourceSurface = aSource;
}
}
}
SourceSurface* CanvasImageCache::LookupAllCanvas(Element* aImage,
DrawTarget* aTarget) {
if (!gImageCache || !aTarget) {
return nullptr;
}
nsCOMPtr<imgIContainer> imgContainer = GetImageContainer(aImage);
if (!imgContainer) {
return nullptr;
}
AllCanvasImageCacheEntry* entry = gImageCache->mAllCanvasCache.GetEntry(
AllCanvasImageCacheKey(imgContainer, aTarget->GetBackendType()));
if (!entry) {
return nullptr;
}
return entry->mSourceSurface;
}
SourceSurface* CanvasImageCache::LookupCanvas(Element* aImage,
HTMLCanvasElement* aCanvas,
DrawTarget* aTarget,
IntSize* aSizeOut,
IntSize* aIntrinsicSizeOut,
Maybe<IntRect>* aCropRectOut) {
if (!gImageCache || !aTarget) {
return nullptr;
}
nsCOMPtr<imgIContainer> imgContainer = GetImageContainer(aImage);
if (!imgContainer) {
return nullptr;
}
// We filter based on the backend type because we don't want a surface that
// was optimized for one backend to be preferred for another backend, as this
// could have performance implications. For example, a Skia optimized surface
// given to a D2D backend would cause an upload each time, and similarly a D2D
// optimized surface given to a Skia backend would cause a readback. For
ImageCacheEntry* entry = gImageCache->mCache.GetEntry(
ImageCacheKey(imgContainer, aCanvas, aTarget->GetBackendType()));
if (!entry) {
return nullptr;
}
MOZ_ASSERT(aSizeOut);
gImageCache->MarkUsed(entry->mData.get());
*aSizeOut = entry->mData->mSize;
*aIntrinsicSizeOut = entry->mData->mIntrinsicSize;
*aCropRectOut = entry->mData->mCropRect;
return entry->mData->mSourceSurface;
}
NS_IMPL_ISUPPORTS(CanvasImageCacheShutdownObserver, nsIObserver)
NS_IMETHODIMP
CanvasImageCacheShutdownObserver::Observe(nsISupports* aSubject,
const char* aTopic,
const char16_t* aData) {
if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
delete gImageCache;
gImageCache = nullptr;
nsContentUtils::UnregisterShutdownObserver(this);
}
return NS_OK;
}
} // namespace mozilla