scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2013 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | #ifndef SkLruImageCache_DEFINED |
| 9 | #define SkLruImageCache_DEFINED |
| 10 | |
| 11 | #include "SkImageCache.h" |
| 12 | #include "SkThread.h" |
| 13 | #include "SkTInternalLList.h" |
| 14 | |
| 15 | class CachedPixels; |
| 16 | |
| 17 | /** |
| 18 | * SkImageCache implementation that uses an LRU cache to age out old images. |
| 19 | */ |
| 20 | class SkLruImageCache : public SkImageCache { |
| 21 | |
| 22 | public: |
commit-bot@chromium.org | ef284a8 | 2013-07-11 22:29:29 +0000 | [diff] [blame] | 23 | SK_DECLARE_INST_COUNT(SkLruImageCache) |
| 24 | |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 25 | SkLruImageCache(size_t budget); |
| 26 | |
| 27 | virtual ~SkLruImageCache(); |
| 28 | |
| 29 | #ifdef SK_DEBUG |
reed@google.com | 6e8b7dd | 2013-07-09 21:31:54 +0000 | [diff] [blame] | 30 | virtual MemoryStatus getMemoryStatus(ID) const SK_OVERRIDE; |
scroggo@google.com | bb281f7 | 2013-03-18 21:37:39 +0000 | [diff] [blame] | 31 | virtual void purgeAllUnpinnedCaches() SK_OVERRIDE; |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 32 | #endif |
| 33 | |
scroggo@google.com | a560d00b | 2013-03-04 21:32:32 +0000 | [diff] [blame] | 34 | /** |
| 35 | * Set the byte limit on cached pixels. If more bytes are used than this, the cache will free |
| 36 | * unpinned memory until under the new limit or until all unpinned memory is freed. This will |
| 37 | * never free pinned memory, so the cache can potentially remain over the limit. The limit is |
| 38 | * enforced each time memory is allocated or released. |
| 39 | * 0 is a special flag for an infinite budget. |
| 40 | * @return size_t The previous limit. |
| 41 | */ |
| 42 | size_t setImageCacheLimit(size_t newLimit); |
| 43 | |
| 44 | /** |
| 45 | * Return the number of bytes of memory currently in use by the cache. Can include memory that |
| 46 | * is no longer pinned, but has not been freed. |
| 47 | */ |
| 48 | size_t getImageCacheUsed() const { return fRamUsed; } |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 49 | |
reed@google.com | 6e8b7dd | 2013-07-09 21:31:54 +0000 | [diff] [blame] | 50 | virtual void* allocAndPinCache(size_t bytes, ID*) SK_OVERRIDE; |
| 51 | virtual void* pinCache(ID, SkImageCache::DataStatus*) SK_OVERRIDE; |
| 52 | virtual void releaseCache(ID) SK_OVERRIDE; |
| 53 | virtual void throwAwayCache(ID) SK_OVERRIDE; |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 54 | |
| 55 | private: |
| 56 | // Linked list of recently used. Head is the most recently used, and tail is the least. |
| 57 | SkTInternalLList<CachedPixels> fLRU; |
| 58 | typedef SkTInternalLList<CachedPixels>::Iter Iter; |
| 59 | |
| 60 | #ifdef SK_DEBUG |
scroggo@google.com | bb281f7 | 2013-03-18 21:37:39 +0000 | [diff] [blame] | 61 | // fMutex is mutable so that getMemoryStatus can be const |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 62 | mutable |
| 63 | #endif |
| 64 | SkMutex fMutex; |
| 65 | size_t fRamBudget; |
| 66 | size_t fRamUsed; |
| 67 | |
| 68 | /** |
| 69 | * Find the CachedPixels represented by ID, or NULL if not in the cache. Mutex must be locked |
| 70 | * before calling. |
| 71 | */ |
reed@google.com | 6e8b7dd | 2013-07-09 21:31:54 +0000 | [diff] [blame] | 72 | CachedPixels* findByID(ID) const; |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 73 | |
| 74 | /** |
| 75 | * If over budget, throw away pixels which are not currently in use until below budget or there |
| 76 | * are no more pixels eligible to be thrown away. Mutex must be locked before calling. |
| 77 | */ |
| 78 | void purgeIfNeeded(); |
| 79 | |
| 80 | /** |
| 81 | * Purge until below limit. Mutex must be locked before calling. |
| 82 | */ |
| 83 | void purgeTilAtOrBelow(size_t limit); |
| 84 | |
| 85 | /** |
| 86 | * Remove a set of CachedPixels. Mutex must be locked before calling. |
| 87 | */ |
| 88 | void removePixels(CachedPixels*); |
commit-bot@chromium.org | ab1c138 | 2013-12-05 12:08:12 +0000 | [diff] [blame^] | 89 | typedef SkImageCache INHERITED; |
scroggo@google.com | f8d7d27 | 2013-02-22 21:38:35 +0000 | [diff] [blame] | 90 | }; |
| 91 | |
| 92 | #endif // SkLruImageCache_DEFINED |