b=573409 expire unused cached double-buffering back surfaces r=vlad sr=roc

gfx/layers/basic/BasicLayers.cpp

@@ -750,32 +750,10 @@ BasicLayerManager::PushGroupWithCachedSurface(gfxContext *aTarget,
   gfxRect clip = aTarget->GetClipExtents();
   clip.RoundOut();
 
-  if (mCachedSurface) {
-    /* Verify the current buffer is valid for this purpose */
-    if (mCachedSurface->GetContentType() != aContent) {
-      mCachedSurface = nsnull;
-    } else {
-      /* bufferClip should always be {0,0,width,height} of the buffer surface */
-      if (clip.size.width > mCachedSurfaceSize.width ||
-          clip.size.height > mCachedSurfaceSize.height) {
-        mCachedSurface = nsnull;
-      }
-    }
-  }
-  nsRefPtr<gfxContext> ctx;
-  if (mCachedSurface) {
-    ctx = new gfxContext(mCachedSurface);
-    ctx->SetOperator(gfxContext::OPERATOR_CLEAR);
-    ctx->Paint();
-    ctx->SetOperator(gfxContext::OPERATOR_OVER);
-  } else {
-    mCachedSurfaceSize = gfxIntSize(clip.size.width, clip.size.height);
-    mCachedSurface = currentSurf->CreateSimilarSurface(aContent,
-                                                       mCachedSurfaceSize);
-    if (!mCachedSurface)
-      return nsnull;
-    ctx = new gfxContext(mCachedSurface);
-  }
+  nsRefPtr<gfxContext> ctx =
+    mCachedSurface.Get(aContent,
+                       gfxIntSize(clip.size.width, clip.size.height),
+                       currentSurf);
   /* Align our buffer for the original surface */
   ctx->Translate(-clip.pos);
   *aSavedOffset = clip.pos;
@@ -787,13 +765,13 @@ void
 BasicLayerManager::PopGroupWithCachedSurface(gfxContext *aTarget,
                                              const gfxPoint& aSavedOffset)
 {
-  if (!mCachedSurface)
+  if (!mTarget)
     return;
 
   gfxContextMatrixAutoSaveRestore saveMatrix(aTarget);
   aTarget->IdentityMatrix();
 
-  aTarget->SetSource(mCachedSurface, aSavedOffset);
+  aTarget->SetSource(mTarget->OriginalSurface(), aSavedOffset);
   aTarget->Paint();
 }
 

gfx/layers/basic/BasicLayers.h

@@ -41,6 +41,7 @@
 #include "Layers.h"
 
 #include "gfxContext.h"
+#include "gfxCachedTempSurface.h"
 #include "nsAutoRef.h"
 #include "nsThreadUtils.h"
 
@@ -133,8 +134,7 @@ private:
   nsRefPtr<gfxContext> mTarget;
 
   // Cached surface for double buffering
-  nsRefPtr<gfxASurface> mCachedSurface;
-  gfxIntSize mCachedSurfaceSize;
+  gfxCachedTempSurface mCachedSurface;
 
 #ifdef DEBUG
   enum TransactionPhase { PHASE_NONE, PHASE_CONSTRUCTION, PHASE_DRAWING };

gfx/thebes/Makefile.in

@@ -16,6 +16,7 @@ EXPORTS	= \
 	gfxASurface.h \
 	gfxAlphaRecovery.h \
 	gfxBlur.h \
+	gfxCachedTempSurface.h \
 	gfxColor.h \
 	gfxContext.h \
 	gfxFont.h \
@@ -162,6 +163,7 @@ CPPSRCS	= \
 	gfxASurface.cpp \
 	gfxAlphaRecovery.cpp \
 	gfxBlur.cpp \
+	gfxCachedTempSurface.cpp \
 	gfxContext.cpp \
 	gfxImageSurface.cpp \
 	gfxFont.cpp \

gfx/thebes/gfxCachedTempSurface.cpp

@@ -0,0 +1,139 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Corporation code.
+ *
+ * The Initial Developer of the Original Code is Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2009
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Karl Tomlinson <karlt+@karlt.net>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "gfxCachedTempSurface.h"
+#include "gfxContext.h"
+
+class CachedSurfaceExpirationTracker :
+  public nsExpirationTracker<gfxCachedTempSurface,2> {
+
+public:
+  // With K = 2, this means that surfaces will be released when they are not
+  // used for 1-2 seconds.
+  enum { TIMEOUT_MS = 1000 };
+  CachedSurfaceExpirationTracker()
+    : nsExpirationTracker<gfxCachedTempSurface,2>(TIMEOUT_MS) {}
+
+  ~CachedSurfaceExpirationTracker() {
+    AgeAllGenerations();
+  }
+
+  virtual void NotifyExpired(gfxCachedTempSurface* aSurface) {
+    RemoveObject(aSurface);
+    aSurface->Expire();
+  }
+
+  static void MarkSurfaceUsed(gfxCachedTempSurface* aSurface)
+  {
+    if (aSurface->GetExpirationState()->IsTracked()) {
+      sExpirationTracker->MarkUsed(aSurface);
+      return;
+    }
+
+    if (!sExpirationTracker) {
+      sExpirationTracker = new CachedSurfaceExpirationTracker();
+    }
+    sExpirationTracker->AddObject(aSurface);
+  }
+
+  static void RemoveSurface(gfxCachedTempSurface* aSurface)
+  {
+    if (!sExpirationTracker)
+      return;
+
+    if (aSurface->GetExpirationState()->IsTracked()) {
+      sExpirationTracker->RemoveObject(aSurface);
+    }
+    if (sExpirationTracker->IsEmpty()) {
+      delete sExpirationTracker;
+      sExpirationTracker = nsnull;
+    }
+  }
+
+private:
+  static CachedSurfaceExpirationTracker* sExpirationTracker;
+};
+
+CachedSurfaceExpirationTracker*
+CachedSurfaceExpirationTracker::sExpirationTracker = nsnull;
+
+gfxCachedTempSurface::~gfxCachedTempSurface()
+{
+  CachedSurfaceExpirationTracker::RemoveSurface(this);
+}
+
+already_AddRefed<gfxContext>
+gfxCachedTempSurface::Get(gfxASurface::gfxContentType aContentType,
+                          const gfxIntSize& aSize,
+                          gfxASurface* aSimilarTo)
+{
+  if (mSurface) {
+    /* Verify the current buffer is valid for this purpose */
+    if (mSize.width < aSize.width || mSize.height < aSize.height
+        || (mSurface->GetContentType() != aContentType
+            && mSurface->AreSimilarSurfacesSensitiveToContentType())) {
+      mSurface = nsnull;
+    } else {
+      NS_ASSERTION(mType == aSimilarTo->GetType(),
+                   "Unexpected surface type change");
+    }
+  }
+
+  PRBool cleared = PR_FALSE;
+  if (!mSurface) {
+    mSize = aSize;
+    mSurface = aSimilarTo->CreateSimilarSurface(aContentType, aSize);
+    if (!mSurface)
+      return nsnull;
+
+    cleared = PR_TRUE;
+#ifdef DEBUG
+    mType = aSimilarTo->GetType();
+#endif
+  }
+
+  nsRefPtr<gfxContext> ctx = new gfxContext(mSurface);
+  if (!cleared && aContentType != gfxASurface::CONTENT_COLOR) {
+    ctx->SetOperator(gfxContext::OPERATOR_CLEAR);
+    ctx->Paint();
+    ctx->SetOperator(gfxContext::OPERATOR_OVER);
+  }
+
+  CachedSurfaceExpirationTracker::MarkSurfaceUsed(this);
+
+  return ctx.forget();
+}

gfx/thebes/gfxCachedTempSurface.h

@@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Corporation code.
+ *
+ * The Initial Developer of the Original Code is Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2009
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Karl Tomlinson <karlt+@karlt.net>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef GFX_CACHED_TEMP_SURFACE_H
+#define GFX_CACHED_TEMP_SURFACE_H
+
+#include "gfxASurface.h"
+#include "nsExpirationTracker.h"
+
+class gfxContext;
+
+/**
+ * This class can be used to cache double-buffering back surfaces.
+ *
+ * Large resource allocations may have an overhead that can be avoided by
+ * caching.  Caching also alows the system to use history in deciding whether
+ * to manage the surfaces in video or system memory.
+ *
+ * However, because we don't want to set aside megabytes of unused resources
+ * unncessarily, these surfaces are released on a timer.
+ */
+
+class THEBES_API gfxCachedTempSurface {
+public:
+  /**
+   * Returns a context for a surface that can be efficiently copied to
+   * |aSimilarTo|.
+   *
+   * When |aContentType| has an alpha component, the surface will be cleared.
+   * For opaque surfaces, the initial surface contents are undefined.
+   * When |aContentType| differs in different invocations this is handled
+   * appropriately, creating a new surface if necessary.
+   * 
+   * |aSimilarTo| should be of the same gfxSurfaceType in each invocation.
+   * Because the cached surface may have been created during a previous
+   * invocation, this will not be efficient if the new |aSimilarTo| has a
+   * different format.
+   */
+  already_AddRefed<gfxContext> Get(gfxASurface::gfxContentType aContentType,
+                                   const gfxIntSize& aSize,
+                                   gfxASurface* aSimilarTo);
+
+  void Expire() { mSurface = nsnull; }
+  nsExpirationState* GetExpirationState() { return &mExpirationState; }
+  ~gfxCachedTempSurface();
+
+private:
+  nsRefPtr<gfxASurface> mSurface;
+  gfxIntSize mSize;
+  nsExpirationState mExpirationState;
+#ifdef DEBUG
+  gfxASurface::gfxSurfaceType mType;
+#endif 
+};
+
+#endif /* GFX_CACHED_TEMP_SURFACE_H */