LCOV - code coverage report
Current view: directory - content/canvas/src - CanvasImageCache.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 64 0 0.0 %
Date: 2012-06-02 Functions: 19 0 0.0 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
       2                 :  * ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is Mozilla Corporation code.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is Mozilla Foundation.
      18                 :  * Portions created by the Initial Developer are Copyright (C) 2011
      19                 :  * the Initial Developer. All Rights Reserved.
      20                 :  *
      21                 :  * Contributor(s):
      22                 :  *   Robert O'Callahan <robert@ocallahan.org>
      23                 :  *
      24                 :  * Alternatively, the contents of this file may be used under the terms of
      25                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      26                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      27                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      28                 :  * of those above. If you wish to allow use of your version of this file only
      29                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      30                 :  * use your version of this file under the terms of the MPL, indicate your
      31                 :  * decision by deleting the provisions above and replace them with the notice
      32                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      33                 :  * the provisions above, a recipient may use your version of this file under
      34                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      35                 :  *
      36                 :  * ***** END LICENSE BLOCK ***** */
      37                 : 
      38                 : #include "CanvasImageCache.h"
      39                 : #include "nsIImageLoadingContent.h"
      40                 : #include "nsExpirationTracker.h"
      41                 : #include "imgIRequest.h"
      42                 : #include "gfxASurface.h"
      43                 : #include "gfxPoint.h"
      44                 : #include "nsIDOMElement.h"
      45                 : #include "nsTHashtable.h"
      46                 : #include "nsHTMLCanvasElement.h"
      47                 : #include "nsContentUtils.h"
      48                 : 
      49                 : namespace mozilla {
      50                 : 
      51                 : struct ImageCacheKey {
      52               0 :   ImageCacheKey(nsIDOMElement* aImage, nsHTMLCanvasElement* aCanvas)
      53               0 :     : mImage(aImage), mCanvas(aCanvas) {}
      54                 :   nsIDOMElement* mImage;
      55                 :   nsHTMLCanvasElement* mCanvas;
      56                 : };
      57                 : 
      58               0 : struct ImageCacheEntryData {
      59                 :   ImageCacheEntryData(const ImageCacheEntryData& aOther)
      60                 :     : mImage(aOther.mImage)
      61                 :     , mILC(aOther.mILC)
      62                 :     , mCanvas(aOther.mCanvas)
      63                 :     , mRequest(aOther.mRequest)
      64                 :     , mSurface(aOther.mSurface)
      65                 :     , mSize(aOther.mSize)
      66                 :   {}
      67               0 :   ImageCacheEntryData(const ImageCacheKey& aKey)
      68                 :     : mImage(aKey.mImage)
      69                 :     , mILC(nsnull)
      70               0 :     , mCanvas(aKey.mCanvas)
      71               0 :   {}
      72                 : 
      73               0 :   nsExpirationState* GetExpirationState() { return &mState; }
      74                 : 
      75                 :   // Key
      76                 :   nsCOMPtr<nsIDOMElement> mImage;
      77                 :   nsIImageLoadingContent* mILC;
      78                 :   nsRefPtr<nsHTMLCanvasElement> mCanvas;
      79                 :   // Value
      80                 :   nsCOMPtr<imgIRequest> mRequest;
      81                 :   nsRefPtr<gfxASurface> mSurface;
      82                 :   gfxIntSize mSize;
      83                 :   nsExpirationState mState;
      84                 : };
      85                 : 
      86                 : class ImageCacheEntry : public PLDHashEntryHdr {
      87                 : public:
      88                 :   typedef ImageCacheKey KeyType;
      89                 :   typedef const ImageCacheKey* KeyTypePointer;
      90                 : 
      91               0 :   ImageCacheEntry(const KeyType *key) :
      92               0 :       mData(new ImageCacheEntryData(*key)) {}
      93                 :   ImageCacheEntry(const ImageCacheEntry &toCopy) :
      94                 :       mData(new ImageCacheEntryData(*toCopy.mData)) {}
      95               0 :   ~ImageCacheEntry() {}
      96                 : 
      97               0 :   bool KeyEquals(KeyTypePointer key) const
      98                 :   {
      99               0 :     return mData->mImage == key->mImage && mData->mCanvas == key->mCanvas;
     100                 :   }
     101                 : 
     102               0 :   static KeyTypePointer KeyToPointer(KeyType& key) { return &key; }
     103               0 :   static PLDHashNumber HashKey(KeyTypePointer key)
     104                 :   {
     105               0 :     return HashGeneric(key->mImage, key->mCanvas);
     106                 :   }
     107                 :   enum { ALLOW_MEMMOVE = true };
     108                 : 
     109                 :   nsAutoPtr<ImageCacheEntryData> mData;
     110                 : };
     111                 : 
     112                 : class ImageCache MOZ_FINAL : public nsExpirationTracker<ImageCacheEntryData,4> {
     113                 : public:
     114                 :   // We use 3 generations of 1 second each to get a 2-3 seconds timeout.
     115                 :   enum { GENERATION_MS = 1000 };
     116               0 :   ImageCache()
     117               0 :     : nsExpirationTracker<ImageCacheEntryData,4>(GENERATION_MS)
     118                 :   {
     119               0 :     mCache.Init();
     120               0 :   }
     121               0 :   ~ImageCache() {
     122               0 :     AgeAllGenerations();
     123               0 :   }
     124                 : 
     125               0 :   virtual void NotifyExpired(ImageCacheEntryData* aObject)
     126                 :   {
     127               0 :     RemoveObject(aObject);
     128                 :     // Deleting the entry will delete aObject since the entry owns aObject
     129               0 :     mCache.RemoveEntry(ImageCacheKey(aObject->mImage, aObject->mCanvas));
     130               0 :   }
     131                 : 
     132                 :   nsTHashtable<ImageCacheEntry> mCache;
     133                 : };
     134                 : 
     135                 : static ImageCache* gImageCache = nsnull;
     136                 : 
     137                 : class CanvasImageCacheShutdownObserver MOZ_FINAL : public nsIObserver
     138               0 : {
     139                 : public:
     140                 :   NS_DECL_ISUPPORTS
     141                 :   NS_DECL_NSIOBSERVER
     142                 : };
     143                 : 
     144                 : void
     145               0 : CanvasImageCache::NotifyDrawImage(nsIDOMElement* aImage,
     146                 :                                   nsHTMLCanvasElement* aCanvas,
     147                 :                                   imgIRequest* aRequest,
     148                 :                                   gfxASurface* aSurface,
     149                 :                                   const gfxIntSize& aSize)
     150                 : {
     151               0 :   if (!gImageCache) {
     152               0 :     gImageCache = new ImageCache();
     153               0 :     nsContentUtils::RegisterShutdownObserver(new CanvasImageCacheShutdownObserver());
     154                 :   }
     155                 : 
     156               0 :   ImageCacheEntry* entry = gImageCache->mCache.PutEntry(ImageCacheKey(aImage, aCanvas));
     157               0 :   if (entry) {
     158               0 :     if (entry->mData->mSurface) {
     159                 :       // We are overwriting an existing entry.
     160               0 :       gImageCache->RemoveObject(entry->mData);
     161                 :     }
     162               0 :     gImageCache->AddObject(entry->mData);
     163                 : 
     164               0 :     nsCOMPtr<nsIImageLoadingContent> ilc = do_QueryInterface(aImage);
     165               0 :     if (ilc) {
     166               0 :       ilc->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
     167               0 :                       getter_AddRefs(entry->mData->mRequest));
     168                 :     }
     169               0 :     entry->mData->mILC = ilc;
     170               0 :     entry->mData->mSurface = aSurface;
     171               0 :     entry->mData->mSize = aSize;
     172                 :   }
     173               0 : }
     174                 : 
     175                 : gfxASurface*
     176               0 : CanvasImageCache::Lookup(nsIDOMElement* aImage,
     177                 :                          nsHTMLCanvasElement* aCanvas,
     178                 :                          gfxIntSize* aSize)
     179                 : {
     180               0 :   if (!gImageCache)
     181               0 :     return nsnull;
     182                 : 
     183               0 :   ImageCacheEntry* entry = gImageCache->mCache.GetEntry(ImageCacheKey(aImage, aCanvas));
     184               0 :   if (!entry || !entry->mData->mILC)
     185               0 :     return nsnull;
     186                 : 
     187               0 :   nsCOMPtr<imgIRequest> request;
     188               0 :   entry->mData->mILC->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST, getter_AddRefs(request));
     189               0 :   if (request != entry->mData->mRequest)
     190               0 :     return nsnull;
     191                 : 
     192               0 :   gImageCache->MarkUsed(entry->mData);
     193                 : 
     194               0 :   *aSize = entry->mData->mSize;
     195               0 :   return entry->mData->mSurface;
     196                 : }
     197                 : 
     198               0 : NS_IMPL_ISUPPORTS1(CanvasImageCacheShutdownObserver, nsIObserver)
     199                 : 
     200                 : NS_IMETHODIMP
     201               0 : CanvasImageCacheShutdownObserver::Observe(nsISupports *aSubject,
     202                 :                                           const char *aTopic,
     203                 :                                           const PRUnichar *aData)
     204                 : {
     205               0 :   if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
     206               0 :     delete gImageCache;
     207               0 :     gImageCache = nsnull;
     208                 : 
     209               0 :     nsContentUtils::UnregisterShutdownObserver(this);
     210                 :   }
     211                 : 
     212               0 :   return NS_OK;
     213                 : }
     214                 : 
     215                 : } // namespace mozilla

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