skia2/include/core/SkGraphics.h
halcanary 805ef159d1 Set maximum output size for scaled-image-cache images
Accessable via:
  SkScaledImageCache::{G,S}etMaximumOutputSizeForHighQualityFilter

Also, a unit test.

BUG=389439
R=humper@google.com, tomhudson@google.com, reveman@chromium.org, vangelis@chromium.org, reed@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/394003003
2014-07-17 06:58:01 -07:00

173 lines
5.7 KiB
C++

/*
* 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.
*/
#ifndef SkGraphics_DEFINED
#define SkGraphics_DEFINED
#include "SkTypes.h"
class SK_API SkGraphics {
public:
/**
* Call this at process initialization time if your environment does not
* permit static global initializers that execute code. Note that
* Init() is not thread-safe.
*/
static void Init();
/**
* Call this to release any memory held privately, such as the font cache.
*/
static void Term();
/**
* 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);
/**
* 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);
/**
* Return the number of bytes currently used by the font cache.
*/
static size_t GetFontCacheUsed();
/**
* Return the number of entries in the font cache.
* A cache "entry" is associated with each typeface + pointSize + matrix.
*/
static int GetFontCacheCountUsed();
/**
* Return the current limit to the number of entries in the font cache.
* A cache "entry" is associated with each typeface + pointSize + matrix.
*/
static int GetFontCacheCountLimit();
/**
* Set the limit to the number of entries in the font cache, and return
* the previous value. If this new value is lower than the previous,
* it will automatically try to purge entries to meet the new limit.
*/
static int SetFontCacheCountLimit(int count);
/**
* For debugging purposes, this will attempt to purge the font cache. It
* does not change the limit, but will cause subsequent font measures and
* draws to be recreated, since they will no longer be in the cache.
*/
static void PurgeFontCache();
/**
* Scaling bitmaps with the SkPaint::kHigh_FilterLevel setting is
* expensive, so the result is saved in the global Scaled Image
* Cache.
*
* This function returns the memory usage of the Scaled Image Cache.
*/
static size_t GetImageCacheTotalBytesUsed();
/**
* These functions get/set the memory usage limit for the Scaled
* Image Cache. Bitmaps are purged from the cache when the
* memory useage exceeds this limit.
*/
static size_t GetImageCacheTotalByteLimit();
static size_t SetImageCacheTotalByteLimit(size_t newLimit);
// DEPRECATED
static size_t GetImageCacheBytesUsed() {
return GetImageCacheTotalBytesUsed();
}
// DEPRECATED
static size_t GetImageCacheByteLimit() {
return GetImageCacheTotalByteLimit();
}
// DEPRECATED
static size_t SetImageCacheByteLimit(size_t newLimit) {
return SetImageCacheTotalByteLimit(newLimit);
}
/**
* Scaling bitmaps with the SkPaint::kHigh_FilterLevel setting is
* expensive, so the result is saved in the global Scaled Image
* Cache. When the resulting bitmap is too large, this can
* overload the cache. If the ImageCacheSingleAllocationByteLimit
* is set to a non-zero number, and the resulting bitmap would be
* larger than that value, the bitmap scaling algorithm falls
* back onto a cheaper algorithm and does not cache the result.
* Zero is the default value.
*/
static size_t GetImageCacheSingleAllocationByteLimit();
static size_t SetImageCacheSingleAllocationByteLimit(size_t newLimit);
/**
* Applications with command line options may pass optional state, such
* as cache sizes, here, for instance:
* font-cache-limit=12345678
*
* The flags format is name=value[;name=value...] with no spaces.
* This format is subject to change.
*/
static void SetFlags(const char* flags);
/**
* Return the max number of bytes that should be used by the thread-local
* font cache.
* If the cache needs to allocate more, it will purge previous entries.
* This max can be changed by calling SetFontCacheLimit().
*
* If this thread has never called SetTLSFontCacheLimit, or has called it
* with 0, then this thread is using the shared font cache. In that case,
* this function will always return 0, and the caller may want to call
* GetFontCacheLimit.
*/
static size_t GetTLSFontCacheLimit();
/**
* Specify the max number of bytes that should be used by the thread-local
* font cache. If this value is 0, then this thread will use the shared
* global font cache.
*/
static void SetTLSFontCacheLimit(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
with the C++ runtime to call SkGraphics::FreeCaches()
*/
static void InstallNewHandler();
};
class SkAutoGraphics {
public:
SkAutoGraphics() {
SkGraphics::Init();
}
~SkAutoGraphics() {
SkGraphics::Term();
}
};
#endif