1 /*
2  * Copyright 2015 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 GrTextBlobCache_DEFINED
9 #define GrTextBlobCache_DEFINED
10 
11 #include "include/core/SkRefCnt.h"
12 #include "include/private/SkMutex.h"
13 #include "include/private/SkTArray.h"
14 #include "include/private/SkTHash.h"
15 #include "src/core/SkMessageBus.h"
16 #include "src/core/SkTextBlobPriv.h"
17 #include "src/gpu/text/GrTextBlob.h"
18 
19 #include <functional>
20 
21 class GrTextBlobCache {
22 public:
23     GrTextBlobCache(uint32_t messageBusID);
24 
25     // If not already in the cache, then add it else, return the text blob from the cache.
26     sk_sp<GrTextBlob> addOrReturnExisting(
27             const SkGlyphRunList& glyphRunList, sk_sp<GrTextBlob> blob) SK_EXCLUDES(fSpinLock);
28 
29     sk_sp<GrTextBlob> find(const GrTextBlob::Key& key) SK_EXCLUDES(fSpinLock);
30 
31     void remove(GrTextBlob* blob) SK_EXCLUDES(fSpinLock);
32 
33     void freeAll() SK_EXCLUDES(fSpinLock);
34 
35     struct PurgeBlobMessage {
PurgeBlobMessagePurgeBlobMessage36         PurgeBlobMessage(uint32_t blobID, uint32_t contextUniqueID)
37                 : fBlobID(blobID), fContextID(contextUniqueID) {}
38 
39         uint32_t fBlobID;
40         uint32_t fContextID;
41     };
42 
43     static void PostPurgeBlobMessage(uint32_t blobID, uint32_t cacheID);
44 
45     void purgeStaleBlobs() SK_EXCLUDES(fSpinLock);
46 
47     size_t usedBytes() const SK_EXCLUDES(fSpinLock);
48 
49     bool isOverBudget() const SK_EXCLUDES(fSpinLock);
50 
51 private:
52     friend class GrTextBlobTestingPeer;
53     using TextBlobList = SkTInternalLList<GrTextBlob>;
54 
55     struct BlobIDCacheEntry {
56         BlobIDCacheEntry();
57         explicit BlobIDCacheEntry(uint32_t id);
58 
59         static uint32_t GetKey(const BlobIDCacheEntry& entry);
60 
61         void addBlob(sk_sp<GrTextBlob> blob);
62 
63         void removeBlob(GrTextBlob* blob);
64 
65         sk_sp<GrTextBlob> find(const GrTextBlob::Key& key) const;
66 
67         int findBlobIndex(const GrTextBlob::Key& key) const;
68 
69         uint32_t fID;
70         // Current clients don't generate multiple GrAtlasTextBlobs per SkTextBlob, so an array w/
71         // linear search is acceptable.  If usage changes, we should re-evaluate this structure.
72         SkSTArray<1, sk_sp<GrTextBlob>> fBlobs;
73     };
74 
75     void internalPurgeStaleBlobs() SK_REQUIRES(fSpinLock);
76 
77     sk_sp<GrTextBlob> internalAdd(sk_sp<GrTextBlob> blob) SK_REQUIRES(fSpinLock);
78     void internalRemove(GrTextBlob* blob) SK_REQUIRES(fSpinLock);
79 
80     void internalCheckPurge(GrTextBlob* blob = nullptr) SK_REQUIRES(fSpinLock);
81 
82     static const int kDefaultBudget = 1 << 22;
83 
84     mutable SkSpinlock fSpinLock;
85     TextBlobList fBlobList SK_GUARDED_BY(fSpinLock);
86     SkTHashMap<uint32_t, BlobIDCacheEntry> fBlobIDCache SK_GUARDED_BY(fSpinLock);
87     size_t fSizeBudget SK_GUARDED_BY(fSpinLock);
SK_GUARDED_BY(fSpinLock)88     size_t fCurrentSize SK_GUARDED_BY(fSpinLock) {0};
89 
90     // In practice 'messageBusID' is always the unique ID of the owning GrContext
91     const uint32_t fMessageBusID;
92     SkMessageBus<PurgeBlobMessage, uint32_t>::Inbox fPurgeBlobInbox SK_GUARDED_BY(fSpinLock);
93 };
94 
95 #endif
96