Make GrGLProgramDesc's key variable length by compacting the effect key array

src/gpu/gl/GrGpuGL.h

Index: src/gpu/gl/GrGpuGL.h
diff --git a/src/gpu/gl/GrGpuGL.h b/src/gpu/gl/GrGpuGL.h
index 0f75280178a4b6b9a4eb77705e70775f25329908..02149368ee9b81baf359ff1522d25352cf45c53d 100644
--- a/src/gpu/gl/GrGpuGL.h
+++ b/src/gpu/gl/GrGpuGL.h
@@ -177,47 +177,36 @@ private:
 
         void abandon();
         GrGLProgram* getProgram(const GrGLProgramDesc& desc, const GrEffectStage* stages[]);
+
     private:
         enum {
-            kKeySize = sizeof(GrGLProgramDesc),
             // We may actually have kMaxEntries+1 shaders in the GL context because we create a new
             // shader before evicting from the cache.
-            kMaxEntries = 32
+            kMaxEntries = 32,
+            kHashBits = 6,
         };
 
-        class Entry;
-        // The value of the hash key is based on the ProgramDesc.
-        typedef GrTBinHashKey<Entry, kKeySize> ProgramHashKey;
-
-        class Entry : public ::GrNoncopyable {
-        public:
-            Entry() : fProgram(NULL), fLRUStamp(0) {}
-            Entry& operator = (const Entry& entry) {
-                GrSafeRef(entry.fProgram.get());
-                fProgram.reset(entry.fProgram.get());
-                fKey = entry.fKey;
-                fLRUStamp = entry.fLRUStamp;
-                return *this;
-            }
-            int compare(const ProgramHashKey& key) const {
-                return fKey.compare(key);
-            }
+        struct Entry;
 

[robertphillips, 2013/05/21 19:22:37]

Do we need this pre-declare?

[bsalomon, 2013/05/22 14:11:25]

It has to have access to GrGpuGL::ProgramCache::Entry, so must either be a
friend or nested class of GrGpuGL::ProgramCache.

-        public:
-            SkAutoTUnref<GrGLProgram>   fProgram;
-            ProgramHashKey              fKey;
-            unsigned int                fLRUStamp; // Move outside entry?
-        };
+        struct ProgDescLess;
+

[robertphillips, 2013/05/21 19:22:37]

of -> for?

[bsalomon, 2013/05/22 14:11:25]

Done.

+        // binary search of entry matching desc. returns index into fEntries that matches desc or ~
+        // of the index of where it should be inserted.
+        int search(const GrGLProgramDesc& desc) const;
 
-        GrTHashTable<Entry, ProgramHashKey, 8> fHashCache;
+        // sorted array of all the entries
+        Entry*                      fEntries[kMaxEntries];
+        // hash table based on lowest kHashBits bits of the program key. Used to avoid binary
+        // searching fEntries.
+        Entry*                      fHashTable[1 << kHashBits];
 
-        Entry                       fEntries[kMaxEntries];
         int                         fCount;
         unsigned int                fCurrLRUStamp;
         const GrGLContext&          fGL;
 #ifdef PROGRAM_CACHE_STATS
         int                         fTotalRequests;
         int                         fCacheMisses;
+        int                         fHashMisses; // cache hit but hash table missed
 #endif
     };