1 /*
2  * Copyright 2010 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 SkGlyphCache_Globals_DEFINED
9 #define SkGlyphCache_Globals_DEFINED
10 
11 #include "SkGlyphCache.h"
12 #include "SkMutex.h"
13 #include "SkSpinlock.h"
14 #include "SkTLS.h"
15 
16 #ifndef SK_DEFAULT_FONT_CACHE_COUNT_LIMIT
17     #define SK_DEFAULT_FONT_CACHE_COUNT_LIMIT   2048
18 #endif
19 
20 #ifndef SK_DEFAULT_FONT_CACHE_LIMIT
21     #define SK_DEFAULT_FONT_CACHE_LIMIT     (2 * 1024 * 1024)
22 #endif
23 
24 #ifndef SK_DEFAULT_FONT_CACHE_POINT_SIZE_LIMIT
25     #define SK_DEFAULT_FONT_CACHE_POINT_SIZE_LIMIT  256
26 #endif
27 
28 ///////////////////////////////////////////////////////////////////////////////
29 
30 class SkGlyphCache_Globals {
31 public:
32     SkGlyphCache_Globals() {
33         fHead = nullptr;
34         fTotalMemoryUsed = 0;
35         fCacheSizeLimit = SK_DEFAULT_FONT_CACHE_LIMIT;
36         fCacheCount = 0;
37         fCacheCountLimit = SK_DEFAULT_FONT_CACHE_COUNT_LIMIT;
38         fPointSizeLimit = SK_DEFAULT_FONT_CACHE_POINT_SIZE_LIMIT;
39     }
40 
41     ~SkGlyphCache_Globals() {
42         SkGlyphCache* cache = fHead;
43         while (cache) {
44             SkGlyphCache* next = cache->fNext;
45             delete cache;
46             cache = next;
47         }
48     }
49 
50     mutable SkSpinlock     fLock;
51 
52     SkGlyphCache* internalGetHead() const { return fHead; }
53     SkGlyphCache* internalGetTail() const;
54 
55     size_t getTotalMemoryUsed() const;
56     int getCacheCountUsed() const;
57 
58 #ifdef SK_DEBUG
59     void validate() const;
60 #else
61     void validate() const {}
62 #endif
63 
64     int getCacheCountLimit() const;
65     int setCacheCountLimit(int limit);
66 
67     size_t  getCacheSizeLimit() const;
68     size_t  setCacheSizeLimit(size_t limit);
69 
70     int  getCachePointSizeLimit() const;
71     int  setCachePointSizeLimit(int limit);
72 
73     void purgeAll(); // does not change budget
74 
75     // call when a glyphcache is available for caching (i.e. not in use)
76     void attachCacheToHead(SkGlyphCache*);
77 
78     // can only be called when the mutex is already held
79     void internalDetachCache(SkGlyphCache*);
80     void internalAttachCacheToHead(SkGlyphCache*);
81 
82 private:
83     SkGlyphCache* fHead;
84     size_t  fTotalMemoryUsed;
85     size_t  fCacheSizeLimit;
86     int32_t fCacheCountLimit;
87     int32_t fCacheCount;
88     int32_t fPointSizeLimit;
89 
90     // Checkout budgets, modulated by the specified min-bytes-needed-to-purge,
91     // and attempt to purge caches to match.
92     // Returns number of bytes freed.
93     size_t internalPurge(size_t minBytesNeeded = 0);
94 };
95 
96 #endif
97