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/SkSpinlock.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
21class GrTextBlobCache {
22public:
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 {
36        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
51private:
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);
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