Add a way to monitor cache hits and misses for deferred decoding.

Adds a new flag to bench_pictures in order to do this. Also fix
a warning.

Review URL: https://codereview.chromium.org/12393046

git-svn-id: http://skia.googlecode.com/svn/trunk@7965 2bbb7eff-a529-9590-31e7-b0007b416f81

gyp/tools.gyp

@@ -113,6 +113,7 @@
       ],
       'include_dirs': [
         '../bench',
+        '../src/lazy/',
       ],
       'dependencies': [
         'skia_base_libs.gyp:skia_base_libs',

src/lazy/SkLazyPixelRef.cpp

@@ -12,6 +12,13 @@
 #include "SkImageCache.h"
 #include "SkImagePriv.h"
 
+#if LAZY_CACHE_STATS
+#include "SkThread.h"
+
+int32_t SkLazyPixelRef::gCacheHits;
+int32_t SkLazyPixelRef::gCacheMisses;
+#endif
+
 SkLazyPixelRef::SkLazyPixelRef(SkData* data, SkBitmapFactory::DecodeProc proc, SkImageCache* cache)
     // Pass NULL for the Mutex so that the default (ring buffer) will be used.
     : INHERITED(NULL)
@@ -61,9 +68,21 @@ void* SkLazyPixelRef::onLockPixels(SkColorTable**) {
     }
     SkBitmapFactory::Target target;
     // Check to see if the pixels still exist in the cache.
-    target.fAddr = SkImageCache::UNINITIALIZED_ID == fCacheId ?
-                   NULL : fImageCache->pinCache(fCacheId);
-    if (NULL == target.fAddr) {
+    if (SkImageCache::UNINITIALIZED_ID == fCacheId) {
+        target.fAddr = NULL;
+    } else {
+        target.fAddr = fImageCache->pinCache(fCacheId);
+        if (NULL != target.fAddr) {
+#if LAZY_CACHE_STATS
+            sk_atomic_inc(&gCacheHits);
+#endif
+            return target.fAddr;
+        }
+#if LAZY_CACHE_STATS
+        sk_atomic_inc(&gCacheMisses);
+#endif
+    }
+    SkASSERT(NULL == target.fAddr);
     SkImage::Info info;
     SkASSERT(fData != NULL && fData->size() > 0);
     // FIXME: As an optimization, only do this part once.
@@ -88,7 +107,6 @@ void* SkLazyPixelRef::onLockPixels(SkColorTable**) {
         fCacheId = SkImageCache::UNINITIALIZED_ID;
         return NULL;
     }
-    }
     return target.fAddr;
 }
 

src/lazy/SkLazyPixelRef.h

@@ -17,6 +17,12 @@ class SkColorTable;
 class SkData;
 class SkImageCache;
 
+#ifdef SK_DEBUG
+    #define LAZY_CACHE_STATS 1
+#elif !defined(LAZY_CACHE_STATS)
+    #define LAZY_CACHE_STATS 0
+#endif
+
 /**
  *  PixelRef which defers decoding until SkBitmap::lockPixels() is called.
  */
@@ -38,6 +44,12 @@ public:
     intptr_t getCacheId() const { return fCacheId; }
 #endif
 
+#if LAZY_CACHE_STATS
+    static int32_t GetCacheHits() { return gCacheHits; }
+    static int32_t GetCacheMisses() { return gCacheMisses; }
+    static void ResetCacheStats() { gCacheHits = gCacheMisses = 0; }
+#endif
+
     // No need to flatten this object. When flattening an SkBitmap, SkOrderedWriteBuffer will check
     // the encoded data and write that instead.
     // Future implementations of SkFlattenableWriteBuffer will need to special case for
@@ -57,6 +69,11 @@ private:
     SkImageCache*               fImageCache;
     intptr_t                    fCacheId;
 
+#if LAZY_CACHE_STATS
+    static int32_t              gCacheHits;
+    static int32_t              gCacheMisses;
+#endif
+
     typedef SkPixelRef INHERITED;
 };
 

tools/bench_pictures_main.cpp

@@ -44,6 +44,9 @@ DEFINE_bool(timeIndividualTiles, false, "Report times for drawing individual til
             "times for drawing the whole page. Requires tiled rendering.");
 DEFINE_string(timers, "", "[wcgWC]*: Display wall, cpu, gpu, truncated wall or truncated cpu time"
               " for each picture.");
+DEFINE_bool(trackDeferredCaching, false, "Only meaningful with --deferImageDecoding and "
+            "LAZY_CACHE_STATS set to true. Report percentage of cache hits when using deferred "
+            "image decoding.");
 
 static char const * const gFilterTypes[] = {
     "paint",
@@ -140,6 +143,7 @@ static SkString filterFlagsUsage() {
 
 #include "SkData.h"
 #include "SkLruImageCache.h"
+#include "SkLazyPixelRef.h"
 
 static SkLruImageCache gLruImageCache(1024*1024);
 
@@ -152,6 +156,11 @@ static bool lazy_decode_bitmap(const void* buffer, size_t size, SkBitmap* bitmap
     return factory.installPixelRef(data, bitmap);
 }
 
+#if LAZY_CACHE_STATS
+static int32_t gTotalCacheHits;
+static int32_t gTotalCacheMisses;
+#endif
+
 static bool run_single_benchmark(const SkString& inputPath,
                                  sk_tools::PictureBenchmark& benchmark) {
     SkFILEStream inputStream;
@@ -189,6 +198,18 @@ static bool run_single_benchmark(const SkString& inputPath,
     gLogger.logProgress(result);
 
     benchmark.run(picture);
+
+#if LAZY_CACHE_STATS
+    if (FLAGS_trackDeferredCaching) {
+        int32_t cacheHits = SkLazyPixelRef::GetCacheHits();
+        int32_t cacheMisses = SkLazyPixelRef::GetCacheMisses();
+        SkLazyPixelRef::ResetCacheStats();
+        SkDebugf("Cache hit rate: %f\n", (double) cacheHits / (cacheHits + cacheMisses));
+        gTotalCacheHits += cacheHits;
+        gTotalCacheMisses += cacheMisses;
+    }
+#endif
+
     return true;
 }
 
@@ -200,12 +221,12 @@ static void setup_benchmark(sk_tools::PictureBenchmark* benchmark) {
         const char* filters = FLAGS_filter[0];
         const char* colon = strchr(filters, ':');
         if (colon) {
-            int type = -1;
+            int32_t type = -1;
             size_t typeLen = colon - filters;
             for (size_t tIndex = 0; tIndex < kFilterTypesCount; ++tIndex) {
                 if (typeLen == strlen(gFilterTypes[tIndex])
                         && !strncmp(filters, gFilterTypes[tIndex], typeLen)) {
-                    type = tIndex;
+                    type = SkToS32(tIndex);
                     break;
                 }
             }
@@ -396,6 +417,12 @@ int tool_main(int argc, char** argv) {
         gLogger.logError(err);
         return 1;
     }
+#if LAZY_CACHE_STATS
+    if (FLAGS_trackDeferredCaching) {
+        SkDebugf("Total cache hit rate: %f\n",
+                 (double) gTotalCacheHits / (gTotalCacheHits + gTotalCacheMisses));
+    }
+#endif
     return 0;
 }