use murmur3 finisher to improve font hash efficiency

src/core/SkGlyphCache.cpp

-
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-
 #include "SkGlyphCache.h"
 #include "SkGlyphCache_Globals.h"
 #include "SkGraphics.h"
 #include "SkLazyPtr.h"
 #include "SkPaint.h"
 #include "SkPath.h"
 #include "SkTemplates.h"
 #include "SkTLS.h"
 #include "SkTypeface.h"
 
 //#define SPEW_PURGE_STATUS
-//#define RECORD_HASH_EFFICIENCY
 
 namespace {
 
 SkGlyphCache_Globals* create_globals() {
     return SkNEW_ARGS(SkGlyphCache_Globals, (SkGlyphCache_Globals::kYes_UseMutex));
 }
 
 }  // namespace
 
 SK_DECLARE_STATIC_LAZY_PTR(SkGlyphCache_Globals, globals, create_globals);
 
 // Returns the shared globals
 static SkGlyphCache_Globals& getSharedGlobals() {
     return *globals.get();
 }
 
 // Returns the TLS globals (if set), or the shared globals
 static SkGlyphCache_Globals& getGlobals() {
     SkGlyphCache_Globals* tls = SkGlyphCache_Globals::FindTLS();
     return tls ? *tls : getSharedGlobals();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-#ifdef RECORD_HASH_EFFICIENCY
-    static uint32_t gHashSuccess;
-    static uint32_t gHashCollision;
-
-    static void RecordHashSuccess() {
-        gHashSuccess += 1;
-    }
-
-    static void RecordHashCollisionIf(bool pred) {
-        if (pred) {
-            gHashCollision += 1;
-
-            uint32_t total = gHashSuccess + gHashCollision;
-            SkDebugf("Font Cache Hash success rate: %d%%\n",
-                     100 * gHashSuccess / total);
-        }
-    }
+#ifdef SK_GLYPHCACHE_TRACK_HASH_STATS
+    #define RecordHashSuccess()             fHashHitCount += 1
+    #define RecordHashCollisionIf(pred)     do { if (pred) fHashMissCount += 1; } while (0)
 #else
-    #define RecordHashSuccess() (void)0
-    #define RecordHashCollisionIf(pred) (void)0
+    #define RecordHashSuccess()             (void)0
+    #define RecordHashCollisionIf(pred)     (void)0
 #endif
 #define RecordHashCollision() RecordHashCollisionIf(true)
 
 ///////////////////////////////////////////////////////////////////////////////
 
 // so we don't grow our arrays a lot
 #define kMinGlyphCount      16
 #define kMinGlyphImageSize  (16*2)
 #define kMinAllocAmount     ((sizeof(SkGlyph) + kMinGlyphImageSize) * kMinGlyphCount)
 
@@ skipping 11 matching lines @@
     // init to 0 so that all of the pointers will be null
     memset(fGlyphHash, 0, sizeof(fGlyphHash));
     // init with 0xFF so that the charCode field will be -1, which is invalid
     memset(fCharToGlyphHash, 0xFF, sizeof(fCharToGlyphHash));
 
     fMemoryUsed = sizeof(*this);
 
     fGlyphArray.setReserve(kMinGlyphCount);
 
     fAuxProcList = NULL;
+
+#ifdef SK_GLYPHCACHE_TRACK_HASH_STATS
+    fHashHitCount = fHashMissCount = 1;

[mtklein, 2015/01/27 17:10:12]

0?

[reed1, 2015/01/27 18:33:33]

Yea, OK. That will make it more complicated for me to avoid divide-by-zero in my
dumper... but ok :)

+#endif
 }
 
 SkGlyphCache::~SkGlyphCache() {
 #if 0
     {
         size_t ptrMem = fGlyphArray.count() * sizeof(SkGlyph*);
         size_t glyphAlloc = fGlyphAlloc.totalCapacity();
         size_t glyphHashUsed = 0;
         size_t uniHashUsed = 0;
         for (int i = 0; i < kHashCount; ++i) {
@@ skipping 146 matching lines @@
     } else {
         RecordHashSuccess();
         if (glyph->isJustAdvance()) {
             fScalerContext->getMetrics(glyph);
         }
     }
     SkASSERT(glyph->isFullMetrics());
     return *glyph;
 }
 
-const SkGlyph& SkGlyphCache::getGlyphIDMetrics(uint16_t glyphID,
-                                               SkFixed x, SkFixed y) {
+const SkGlyph& SkGlyphCache::getGlyphIDMetrics(uint16_t glyphID, SkFixed x, SkFixed y) {
     VALIDATE();
     uint32_t id = SkGlyph::MakeID(glyphID, x, y);
     unsigned index = ID2HashIndex(id);
     SkGlyph* glyph = fGlyphHash[index];
 
     if (NULL == glyph || glyph->fID != id) {
         RecordHashCollisionIf(glyph != NULL);
         glyph = this->lookupMetrics(id, kFull_MetricsType);
         fGlyphHash[index] = glyph;
     } else {
@@ skipping 82 matching lines @@
         if (glyph.fPath == NULL) {
             const_cast<SkGlyph&>(glyph).fPath = SkNEW(SkPath);
             fScalerContext->getPath(glyph, glyph.fPath);
             fMemoryUsed += sizeof(SkPath) +
                     glyph.fPath->countPoints() * sizeof(SkPoint);
         }
     }
     return glyph.fPath;
 }
 
+void SkGlyphCache::dump() const {
+    const SkTypeface* face = fScalerContext->getTypeface();
+    const SkScalerContextRec& rec = fScalerContext->getRec();
+    SkMatrix matrix;
+    rec.getSingleMatrixWithoutTextSize(&matrix);
+    SkString name;
+    face->getFamilyName(&name);
+
+    SkString msg;
+    msg.printf("cache typeface:%x %25s:%d size:%2g [%g %g %g %g] lum:%02X devG:%d pntG:%d cntr:%d glyphs:%3d",
+               face->uniqueID(), name.c_str(), face->style(), rec.fTextSize,
+               matrix[SkMatrix::kMScaleX], matrix[SkMatrix::kMSkewX],
+               matrix[SkMatrix::kMSkewY], matrix[SkMatrix::kMScaleY],
+               rec.fLumBits & 0xFF, rec.fDeviceGamma, rec.fPaintGamma, rec.fContrast,
+               fGlyphArray.count());
+#ifdef SK_GLYPHCACHE_TRACK_HASH_STATS
+    msg.appendf(" hash:%2d\n", 100 * fHashHitCount / (fHashHitCount + fHashMissCount));
+#endif
+    SkDebugf("%s\n", msg.c_str());
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkGlyphCache::getAuxProcData(void (*proc)(void*), void** dataPtr) const {
     const AuxProcRec* rec = fAuxProcList;
     while (rec) {
         if (rec->fProc == proc) {
             if (dataPtr) {
                 *dataPtr = rec->fData;
             }
             return true;
@@ skipping 136 matching lines @@
     return cache;
 }
 
 void SkGlyphCache::AttachCache(SkGlyphCache* cache) {
     SkASSERT(cache);
     SkASSERT(cache->fNext == NULL);
 
     getGlobals().attachCacheToHead(cache);
 }
 
+void SkGlyphCache::Dump() {
+    SkGlyphCache_Globals& globals = getGlobals();
+    SkAutoMutexAcquire    ac(globals.fMutex);
+    SkGlyphCache*         cache;
+
+    globals.validate();
+
+    SkDebugf("SkGlyphCache strikes:%d memory:%d\n",
+             globals.getCacheCountUsed(), (int)globals.getTotalMemoryUsed());
+
+#ifdef SK_GLYPHCACHE_TRACK_HASH_STATS
+    int hitCount = 0;
+    int missCount = 0;
+#endif
+
+    for (cache = globals.internalGetHead(); cache != NULL; cache = cache->fNext) {
+#ifdef SK_GLYPHCACHE_TRACK_HASH_STATS
+        hitCount += cache->fHashHitCount;
+        missCount += cache->fHashMissCount;
+#endif
+        cache->dump();
+    }
+#ifdef SK_GLYPHCACHE_TRACK_HASH_STATS
+    SkDebugf("Hash hit percent:%2d\n", 100 * hitCount / (hitCount + missCount));
+#endif
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkGlyphCache_Globals::attachCacheToHead(SkGlyphCache* cache) {
     SkAutoMutexAcquire    ac(fMutex);
 
     this->validate();
     cache->validate();
 
     this->internalAttachCacheToHead(cache);
     this->internalPurge();
@@ skipping 168 matching lines @@
     return tls ? tls->getCacheSizeLimit() : 0;
 }
 
 void SkGraphics::SetTLSFontCacheLimit(size_t bytes) {
     if (0 == bytes) {
         SkGlyphCache_Globals::DeleteTLS();
     } else {
         SkGlyphCache_Globals::GetTLS().setCacheSizeLimit(bytes);
     }
 }