add api to SkGraphics to get/set font cache limit

add SK_DEFAULT_FONT_CACHE_LIMIT to SkUserConfig, to override our default value



git-svn-id: http://skia.googlecode.com/svn/trunk@2621 2bbb7eff-a529-9590-31e7-b0007b416f81

include/config/SkUserConfig.h

@@ -105,6 +105,12 @@
  */
 //#define SkDebugf(...)  MyFunction(__VA_ARGS__)
 
+/*
+ *  To specify a different default font cache limit, define this. If this is
+ *  undefined, skia will use a built-in value.
+ */
+//#define SK_DEFAULT_FONT_CACHE_LIMIT   (1024 * 1024)
+
 /* If defined, use CoreText instead of ATSUI on OS X.
 */
 //#define SK_USE_MAC_CORE_TEXT

include/core/SkFontHost.h

@@ -232,14 +232,6 @@ public:
 
     ///////////////////////////////////////////////////////////////////////////
 
-    /** Return the number of bytes (approx) that should be purged from the font
-        cache. The input parameter is the cache's estimate of how much as been
-        allocated by the cache so far.
-        To purge (basically) everything, return the input parameter.
-        To purge nothing, return 0
-    */
-    static size_t ShouldPurgeFontCache(size_t sizeAllocatedSoFar);
-
     /** Return SkScalerContext gamma flag, or 0, based on the paint that will be
         used to draw something with antialiasing.
     */

include/core/SkGraphics.h

@@ -17,21 +17,42 @@ public:
     static void Init();
     static void Term();
 
-    /** Return the (approximate) number of bytes used by the font cache.
-    */
-    static size_t GetFontCacheUsed();
-    
-    /** Attempt to purge the font cache until <= the specified amount remains
-        in the cache. Specifying 0 will attempt to purge the entire cache.
-        Returns true if some amount was purged from the font cache.
-    */
-    static bool SetFontCacheUsed(size_t usageInBytes);
-
-    /** Return the version numbers for the library. If the parameter is not
-        null, it is set to the version number.
+    /**
+     *  Return the version numbers for the library. If the parameter is not
+     *  null, it is set to the version number.
      */
     static void GetVersion(int32_t* major, int32_t* minor, int32_t* patch);
 
+    // Font Cache routines
+
+    /**
+     *  Return the (approximate) number of bytes used by the font cache.
+     */
+    static size_t GetFontCacheUsed();
+    
+    /**
+     *  Attempt to purge the font cache until <= the specified amount remains
+     *  in the cache. Specifying 0 will attempt to purge the entire cache.
+     *  Returns true if some amount was purged from the font cache.
+     */
+    static bool SetFontCacheUsed(size_t usageInBytes);
+
+    /**
+     *  Return the max number of bytes that should be used by the font cache.
+     *  If the cache needs to allocate more, it will purge previous entries.
+     *  This max can be changed by calling SetFontCacheLimit().
+     */
+    static size_t GetFontCacheLimit();
+    
+    /**
+     *  Specify the max number of bytes that should be used by the font cache.
+     *  If the cache needs to allocate more, it will purge previous entries.
+     *
+     *  This function returns the previous setting, as if GetFontCacheLimit()
+     *  had be called before the new limit was set.
+     */
+    static size_t SetFontCacheLimit(size_t bytes);
+
 private:
     /** This is automatically called by SkGraphics::Init(), and must be
         implemented by the host OS. This allows the host OS to register a callback

src/core/SkGlyphCache.cpp

@@ -8,7 +8,7 @@
 
 
 #include "SkGlyphCache.h"
-#include "SkFontHost.h"
+#include "SkGraphics.h"
 #include "SkPaint.h"
 #include "SkTemplates.h"
 
@@ -545,9 +545,10 @@ void SkGlyphCache::AttachCache(SkGlyphCache* cache) {
     // if we have a fixed budget for our cache, do a purge here
     {
         size_t allocated = globals.fTotalMemoryUsed + cache->fMemoryUsed;
-        size_t amountToFree = SkFontHost::ShouldPurgeFontCache(allocated);
-        if (amountToFree)
-            (void)InternalFreeCache(&globals, amountToFree);
+        size_t budgeted = SkGraphics::GetFontCacheLimit();
+        if (allocated > budgeted) {
+            (void)InternalFreeCache(&globals, allocated - budgeted);
+        }
     }
 
     cache->attachToHead(&globals.fHead);

src/core/SkGraphics.cpp

@@ -29,6 +29,18 @@
 #include "SkUtils.h"
 #include "SkXfermode.h"
 
+void SkGraphics::GetVersion(int32_t* major, int32_t* minor, int32_t* patch) {
+    if (major) {
+        *major = SKIA_VERSION_MAJOR;
+    }
+    if (minor) {
+        *minor = SKIA_VERSION_MINOR;
+    }
+    if (patch) {
+        *patch = SKIA_VERSION_PATCH;
+    }
+}
+
 #define typesizeline(type)  { #type , sizeof(type) }
 
 #ifdef BUILD_EMBOSS_TABLE
@@ -124,15 +136,27 @@ bool SkGraphics::SetFontCacheUsed(size_t usageInBytes) {
     return SkGlyphCache::SetCacheUsed(usageInBytes);
 }
 
-void SkGraphics::GetVersion(int32_t* major, int32_t* minor, int32_t* patch) {
-    if (major) {
-        *major = SKIA_VERSION_MAJOR;
+#ifndef SK_DEFAULT_FONT_CACHE_LIMIT
+    #define SK_DEFAULT_FONT_CACHE_LIMIT (1024 * 1024)
+#endif
+
+#define SK_MIN_FONT_CACHE_LIMIT    (256 * 1024)
+
+static size_t gFontCacheLimit = SK_DEFAULT_FONT_CACHE_LIMIT;
+
+size_t SkGraphics::GetFontCacheLimit() {
+    return gFontCacheLimit;
+}
+
+size_t SkGraphics::SetFontCacheLimit(size_t bytes) {
+    if (bytes < SK_MIN_FONT_CACHE_LIMIT) {
+        bytes = SK_MIN_FONT_CACHE_LIMIT;
     }
-    if (minor) {
-        *minor = SKIA_VERSION_MINOR;
-    }
-    if (patch) {
-        *patch = SKIA_VERSION_PATCH;
+    gFontCacheLimit = bytes;
+    
+    // trigger a purge if the new size is smaller that our currently used amount
+    if (bytes < GetFontCacheUsed()) {
+        SetFontCacheUsed(bytes);
     }
 }
 

src/ports/SkFontHost_FONTPATH.cpp

@@ -324,8 +324,3 @@ SkScalerContext* SkFontHost::CreateFallbackScalerContext(
     return SkFontHost::CreateScalerContext(desc);
 }
 
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar)
-{
-    return 0;   // nothing to do (change me if you want to limit the font cache)
-}
-

src/ports/SkFontHost_android.cpp

@@ -26,8 +26,6 @@
 #include "FontHostConfiguration_android.h"
 #include <stdio.h>
 
-#define FONT_CACHE_MEMORY_BUDGET    (768 * 1024)
-
 #ifndef SK_FONT_FILE_PREFIX
     #define SK_FONT_FILE_PREFIX          "/fonts/"
 #endif
@@ -763,12 +761,3 @@ SkTypeface* SkFontHost::CreateTypefaceFromFile(const char path[]) {
     return face;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
-        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
-    else
-        return 0;   // nothing to do
-}
-

src/ports/SkFontHost_fontconfig.cpp

@@ -44,9 +44,6 @@ static std::map<unsigned, std::string> global_fc_map_inverted;
 static std::map<uint32_t, SkTypeface *> global_fc_typefaces;
 static unsigned global_fc_map_next_id = 0;
 
-// This is the maximum size of the font cache.
-static const unsigned kFontCacheMemoryBudget = 2 * 1024 * 1024;  // 2MB
-
 static unsigned UniqueIdToFileId(unsigned uniqueid)
 {
     return uniqueid >> 8;
@@ -361,12 +358,3 @@ SkFontID SkFontHost::NextLogicalFont(SkFontID currFontID, SkFontID origFontID) {
     return 0;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar)
-{
-    if (sizeAllocatedSoFar > kFontCacheMemoryBudget)
-        return sizeAllocatedSoFar - kFontCacheMemoryBudget;
-    else
-        return 0;   // nothing to do
-}

src/ports/SkFontHost_linux.cpp

@@ -18,8 +18,6 @@
 #include "SkTSearch.h"
 #include <stdio.h>
 
-#define FONT_CACHE_MEMORY_BUDGET    (1 * 1024 * 1024)
-
 #ifndef SK_FONT_FILE_PREFIX
     #define SK_FONT_FILE_PREFIX      "/usr/share/fonts/truetype/msttcorefonts/"
 #endif
@@ -600,12 +598,3 @@ SkTypeface* SkFontHost::CreateTypefaceFromFile(const char path[]) {
     return face;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
-        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
-    else
-        return 0;   // nothing to do
-}
-

src/ports/SkFontHost_mac_atsui.cpp

@@ -15,9 +15,6 @@
 #include "SkPaint.h"
 #include "SkPoint.h"
 
-// Give 1MB font cache budget
-#define FONT_CACHE_MEMORY_BUDGET    (1024 * 1024)
-
 const char* gDefaultfont = "Arial"; // hard code for now
 static SkMutex      gFTMutex;
 
@@ -508,13 +505,6 @@ SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
     }
 }
 
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
-        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
-    else
-        return 0;   // nothing to do
-}
-
 int SkFontHost::ComputeGammaFlag(const SkPaint& paint) {
     return 0;
 }

src/ports/SkFontHost_mac_coretext.cpp

@@ -160,7 +160,6 @@ static unsigned CGRGBPixel_getAlpha(CGRGBPixel pixel) {
 
 using namespace skia_advanced_typeface_metrics_utils;
 
-static const size_t FONT_CACHE_MEMORY_BUDGET    = 1024 * 1024;
 static const char FONT_DEFAULT_NAME[]           = "Lucida Sans";
 
 // see Source/WebKit/chromium/base/mac/mac_util.mm DarwinMajorVersionInternal 
@@ -1612,13 +1611,6 @@ void SkFontHost::FilterRec(SkScalerContext::Rec* rec) {
 
 ///////////////////////////////////////////////////////////////////////////
 
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET) {
-        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
-    }
-    return 0;
-}
-
 #include "SkColorFilter.h"
 
 static bool justAColor(const SkPaint& paint, SkColor* color) {

src/ports/SkFontHost_none.cpp

@@ -81,10 +81,6 @@ SkFontID SkFontHost::NextLogicalFont(SkFontID currFontID, SkFontID origFontID) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    return 0;   // nothing to do (change me if you want to limit the font cache)
-}
-
 int SkFontHost::ComputeGammaFlag(const SkPaint& paint) {
     return 0;
 }

src/ports/SkFontHost_simple.cpp

@@ -17,8 +17,6 @@
 #include "SkTSearch.h"
 #include <stdio.h>
 
-#define FONT_CACHE_MEMORY_BUDGET    (768 * 1024)
-
 #ifdef SK_BUILD_FOR_MAC
     #define SK_FONT_FILE_PREFIX     "/Library/Fonts/"
 #else
@@ -653,12 +651,3 @@ SkTypeface* SkFontHost::CreateTypefaceFromFile(const char path[]) {
     return face;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
-        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
-    else
-        return 0;   // nothing to do
-}
-

src/ports/SkFontHost_win.cpp

@@ -75,9 +75,6 @@ using namespace skia_advanced_typeface_metrics_utils;
 static const uint16_t BUFFERSIZE = (16384 - 32);
 static uint8_t glyphbuf[BUFFERSIZE];
 
-// Give 1MB font cache budget
-#define FONT_CACHE_MEMORY_BUDGET    (1024 * 1024)
-
 /**
  *  Since LOGFONT wants its textsize as an int, and we support fractional sizes,
  *  and since we have a cache of LOGFONTs for our tyepfaces, we always set the
@@ -1246,13 +1243,6 @@ SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
     return SkCreateTypefaceFromLOGFONT(lf);
 }
 
-size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
-    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
-        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
-    else
-        return 0;   // nothing to do
-}
-
 SkTypeface* SkFontHost::CreateTypefaceFromFile(const char path[]) {
     printf("SkFontHost::CreateTypefaceFromFile unimplemented");
     return NULL;