Replace GrTHash with SkTDynamicHash

src/gpu/GrLayerCache.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAtlas.h"
 #include "GrGpu.h"
 #include "GrLayerCache.h"
 
-/**
- *  PictureLayerKey just wraps a saveLayer's id in a picture for GrTHashTable.
- */
-class GrLayerCache::PictureLayerKey {
-public:
-    PictureLayerKey(uint32_t pictureID, int layerID)
-        : fPictureID(pictureID)
-        , fLayerID(layerID) {
-    }
-
-    uint32_t pictureID() const { return fPictureID; }
-    int layerID() const { return fLayerID; }
-
-    uint32_t getHash() const { return (fPictureID << 16) | fLayerID; }
-
-    static bool LessThan(const GrCachedLayer& layer, const PictureLayerKey& key) {
-        if (layer.pictureID() == key.pictureID()) {
-            return layer.layerID() < key.layerID();
-        }
-
-        return layer.pictureID() < key.pictureID();
-    }
-
-    static bool Equals(const GrCachedLayer& layer, const PictureLayerKey& key) {
-        return layer.pictureID() == key.pictureID() && layer.layerID() == key.layerID();
-    }
-
-private:
-    uint32_t fPictureID;
-    int      fLayerID;
-};
-
-/**
- *  PictureKey just wraps a picture's unique ID for GrTHashTable. It is used to
- *  look up a picture's GrPictureInfo (i.e., its GrPlot usage).
- */
-class GrLayerCache::PictureKey {
-public:
-    PictureKey(uint32_t pictureID) : fPictureID(pictureID) { }
-
-    uint32_t pictureID() const { return fPictureID; }
-
-    uint32_t getHash() const { return fPictureID; }
-
-    static bool LessThan(const GrPictureInfo& pictInfo, const PictureKey& key) {
-        return pictInfo.fPictureID < key.pictureID();
-    }
-
-    static bool Equals(const GrPictureInfo& pictInfo, const PictureKey& key) {
-        return pictInfo.fPictureID == key.pictureID();
-
-    }
-
-private:
-    uint32_t fPictureID;
-};
-
 #ifdef SK_DEBUG
 void GrCachedLayer::validate(const GrTexture* backingTexture) const {
-    SkASSERT(SK_InvalidGenID != fPictureID);
-    SkASSERT(-1 != fLayerID);
+    SkASSERT(SK_InvalidGenID != fKey.getPictureID());
+    SkASSERT(-1 != fKey.getLayerID());
+
 
     if (NULL != fTexture) {
         // If the layer is in some texture then it must occupy some rectangle
         SkASSERT(!fRect.isEmpty());
         if (!this->isAtlased()) {
             // If it isn't atlased then the rectangle should start at the origin
             SkASSERT(0.0f == fRect.fLeft && 0.0f == fRect.fTop);
         }
     } else {
         SkASSERT(fRect.isEmpty());
@@ skipping 31 matching lines @@
     const GrTexture* fBackingTexture;
     const GrCachedLayer* fLayer;
 };
 #endif
 
 GrLayerCache::GrLayerCache(GrContext* context)
     : fContext(context) {
     this->initAtlas();
 }
 
-GrLayerCache::~GrLayerCache() {
-    SkTDArray<GrCachedLayer*>& layerArray = fLayerHash.getArray();
-    for (int i = 0; i < fLayerHash.count(); ++i) {
-        this->unlock(layerArray[i]);
+class UnlockAndDeleteFunctor {
+public:
+    UnlockAndDeleteFunctor(GrLayerCache* cache) : fCache(cache) {}
+
+    void operator()(GrCachedLayer& layer) {
+        fCache->unlock(&layer);
+        SkDELETE(&layer);
     }
 
-    fLayerHash.deleteAll();
+private:
+    GrLayerCache* fCache;
+};
+
+GrLayerCache::~GrLayerCache() {
+
+    fLayerHash.mutateAll(UnlockAndDeleteFunctor(this));

[mtklein, 2014/07/17 19:36:20]

Now that I'm remembering, maybe adding mutateAll makes things overcomplicated.

for (SkDynamicHash<...>::Iter it(&fLayerHash); !it.done(); ++it) {
  GrCachedLayer* layer = &(*it);
  fCache->unlock(layer);
  SkDELETE(layer);
}

[robertphillips, 2014/07/17 20:02:46]

Yeah it's not a fantastic clarity win. I think it is okay in that case since the
functor is used twice (but a sub-routine would also serve).

 
     // The atlas only lets go of its texture when the atlas is deleted. 
     fAtlas.free();    
 }
 
 void GrLayerCache::initAtlas() {
     static const int kAtlasTextureWidth = 1024;
     static const int kAtlasTextureHeight = 1024;
 
     SkASSERT(NULL == fAtlas.get());
 
     // The layer cache only gets 1 plot
     SkISize textureSize = SkISize::Make(kAtlasTextureWidth, kAtlasTextureHeight);
     fAtlas.reset(SkNEW_ARGS(GrAtlas, (fContext->getGpu(), kSkia8888_GrPixelConfig,
                                       kRenderTarget_GrTextureFlagBit,
                                       textureSize, kNumPlotsX, kNumPlotsY, false)));
 }
 
 void GrLayerCache::freeAll() {
-    SkTDArray<GrCachedLayer*>& layerArray = fLayerHash.getArray();
-    for (int i = 0; i < fLayerHash.count(); ++i) {
-        this->unlock(layerArray[i]);
-    }
 
-    fLayerHash.deleteAll();
+    fLayerHash.mutateAll(UnlockAndDeleteFunctor(this));
+    fLayerHash.rewind();
 
     // The atlas only lets go of its texture when the atlas is deleted. 
     fAtlas.free();
     // GrLayerCache always assumes an atlas exists so recreate it. The atlas 
     // lazily allocates a replacement texture so reallocating a new 
     // atlas here won't disrupt a GrContext::contextDestroyed or freeGpuResources.
     // TODO: Make GrLayerCache lazily allocate the atlas manager?
     this->initAtlas();
 }
 
 GrCachedLayer* GrLayerCache::createLayer(const SkPicture* picture, int layerID) {
-    SkASSERT(picture->uniqueID() != SK_InvalidGenID);
+    SkASSERT(picture->uniqueID() != SK_InvalidGenID && layerID >= 0);
 
     GrCachedLayer* layer = SkNEW_ARGS(GrCachedLayer, (picture->uniqueID(), layerID));
-    fLayerHash.insert(PictureLayerKey(picture->uniqueID(), layerID), layer);
+    fLayerHash.add(layer);
     return layer;
 }
 
 GrCachedLayer* GrLayerCache::findLayer(const SkPicture* picture, int layerID) {
-    SkASSERT(picture->uniqueID() != SK_InvalidGenID);
-    return fLayerHash.find(PictureLayerKey(picture->uniqueID(), layerID));
+    SkASSERT(picture->uniqueID() != SK_InvalidGenID && layerID >= 0);
+    return fLayerHash.find(GrCachedLayer::Key(picture->uniqueID(), layerID));
 }
 
 GrCachedLayer* GrLayerCache::findLayerOrCreate(const SkPicture* picture, int layerID) {
-    SkASSERT(picture->uniqueID() != SK_InvalidGenID);
-    GrCachedLayer* layer = fLayerHash.find(PictureLayerKey(picture->uniqueID(), layerID));
+    SkASSERT(picture->uniqueID() != SK_InvalidGenID && layerID >= 0);
+    GrCachedLayer* layer = fLayerHash.find(GrCachedLayer::Key(picture->uniqueID(), layerID));
     if (NULL == layer) {
         layer = this->createLayer(picture, layerID);
     }
 
     return layer;
 }
 
 bool GrLayerCache::lock(GrCachedLayer* layer, const GrTextureDesc& desc) {
     SkDEBUGCODE(GrAutoValidateLayer avl(fAtlas->getTexture(), layer);)
 
     if (NULL != layer->texture()) {
         // This layer is already locked
 #ifdef SK_DEBUG
         if (layer->isAtlased()) {
             // It claims to be atlased
             SkASSERT(layer->rect().width() == desc.fWidth);
             SkASSERT(layer->rect().height() == desc.fHeight);
         }
 #endif
         return true;
     }
 
 #if USE_ATLAS
     {
-        GrPictureInfo* pictInfo = fPictureHash.find(PictureKey(layer->pictureID()));
+        GrPictureInfo* pictInfo = fPictureHash.find(layer->pictureID());
         if (NULL == pictInfo) {
             pictInfo = SkNEW_ARGS(GrPictureInfo, (layer->pictureID()));
-            fPictureHash.insert(PictureKey(layer->pictureID()), pictInfo);
+            fPictureHash.add(pictInfo);
         }
 
         SkIPoint16 loc;
         GrPlot* plot = fAtlas->addToAtlas(&pictInfo->fPlotUsage, 
                                           desc.fWidth, desc.fHeight, 
                                           NULL, &loc);
         // addToAtlas can allocate the backing texture
         SkDEBUGCODE(avl.setBackingTexture(fAtlas->getTexture()));
         if (NULL != plot) {
             GrIRect16 bounds = GrIRect16::MakeXYWH(loc.fX, loc.fY,
@@ skipping 16 matching lines @@
 void GrLayerCache::unlock(GrCachedLayer* layer) {
     SkDEBUGCODE(GrAutoValidateLayer avl(fAtlas->getTexture(), layer);)
 
     if (NULL == layer || NULL == layer->texture()) {
         return;
     }
 
     if (layer->isAtlased()) {
         SkASSERT(layer->texture() == fAtlas->getTexture());
 
-        GrPictureInfo* pictInfo = fPictureHash.find(PictureKey(layer->pictureID()));
+        GrPictureInfo* pictInfo = fPictureHash.find(layer->pictureID());
         SkASSERT(NULL != pictInfo);
         pictInfo->fPlotUsage.isEmpty(); // just to silence compiler warnings for the time being
 
         // TODO: purging from atlas goes here
     } else {
         fContext->unlockScratchTexture(layer->texture());
         layer->setTexture(NULL, GrIRect16::MakeEmpty());
     }
 }
 
 #ifdef SK_DEBUG
 void GrLayerCache::validate() const {
-    const SkTDArray<GrCachedLayer*>& layerArray = fLayerHash.getArray();
-    for (int i = 0; i < fLayerHash.count(); ++i) {
-        layerArray[i]->validate(fAtlas->getTexture());
+    SkTDynamicHash<GrCachedLayer, GrCachedLayer::Key>::ConstIter iter(&fLayerHash);
+    for (; !iter.done(); ++iter) {
+        (*iter).validate(fAtlas->getTexture());
     }
 }
 
 class GrAutoValidateCache : ::SkNoncopyable {
 public:
     explicit GrAutoValidateCache(GrLayerCache* cache)
         : fCache(cache) {
         fCache->validate();
     }
     ~GrAutoValidateCache() {
         fCache->validate();
     }
 private:
     GrLayerCache* fCache;
 };
 #endif
 
 void GrLayerCache::purge(const SkPicture* picture) {
     SkDEBUGCODE(GrAutoValidateCache avc(this);)
 
-    // This is somewhat of an abuse of GrTHashTable. We need to find all the
-    // layers associated with 'picture' but the usual hash calls only look for
-    // exact key matches. This code peeks into the hash table's innards to
-    // find all the 'picture'-related layers.
-    // TODO: use a different data structure for the layer hash?
+    // We need to find all the layers associated with 'picture' and remove them.
     SkTDArray<GrCachedLayer*> toBeRemoved;
 
-    const SkTDArray<GrCachedLayer*>& layerArray = fLayerHash.getArray();
-    for (int i = 0; i < fLayerHash.count(); ++i) {
-        if (picture->uniqueID() == layerArray[i]->pictureID()) {
-            *toBeRemoved.append() = layerArray[i];
+    SkTDynamicHash<GrCachedLayer, GrCachedLayer::Key>::Iter iter(&fLayerHash);
+    for (; !iter.done(); ++iter) {
+        if (picture->uniqueID() == (*iter).pictureID()) {
+            *toBeRemoved.append() = &(*iter);
         }
     }
 
     for (int i = 0; i < toBeRemoved.count(); ++i) {
         this->unlock(toBeRemoved[i]);
-
-        PictureLayerKey key(picture->uniqueID(), toBeRemoved[i]->layerID());
-        fLayerHash.remove(key, toBeRemoved[i]);
+        fLayerHash.remove(GrCachedLayer::GetKey(*toBeRemoved[i]));
         SkDELETE(toBeRemoved[i]);
     }
 
-    GrPictureInfo* pictInfo = fPictureHash.find(PictureKey(picture->uniqueID()));
+    GrPictureInfo* pictInfo = fPictureHash.find(picture->uniqueID());
     if (NULL != pictInfo) {
-        fPictureHash.remove(PictureKey(picture->uniqueID()), pictInfo);
+        fPictureHash.remove(picture->uniqueID());
         SkDELETE(pictInfo);
     }
 }