1#include "SkPixelRef.h"
2#include "SkFlattenable.h"
3#include "SkThread.h"
4
5static SkMutex  gPixelRefMutex;
6
7extern int32_t SkNextPixelRefGenerationID() {
8    static int32_t  gPixelRefGenerationID;
9    // do a loop in case our global wraps around, as we never want to
10    // return a 0
11    int32_t genID;
12    do {
13        genID = sk_atomic_inc(&gPixelRefGenerationID) + 1;
14    } while (0 == genID);
15    return genID;
16}
17
18
19SkPixelRef::SkPixelRef(SkMutex* mutex) {
20    if (NULL == mutex) {
21        mutex = &gPixelRefMutex;
22    }
23    fMutex = mutex;
24    fPixels = NULL;
25    fColorTable = NULL; // we do not track ownership of this
26    fLockCount = 0;
27    fGenerationID = 0;  // signal to rebuild
28    fIsImmutable = false;
29}
30
31SkPixelRef::SkPixelRef(SkFlattenableReadBuffer& buffer, SkMutex* mutex) {
32    if (NULL == mutex) {
33        mutex = &gPixelRefMutex;
34    }
35    fMutex = mutex;
36    fPixels = NULL;
37    fColorTable = NULL; // we do not track ownership of this
38    fLockCount = 0;
39    fGenerationID = 0;  // signal to rebuild
40    fIsImmutable = buffer.readBool();
41}
42
43void SkPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
44    buffer.writeBool(fIsImmutable);
45}
46
47void SkPixelRef::lockPixels() {
48    SkAutoMutexAcquire  ac(*fMutex);
49
50    if (1 == ++fLockCount) {
51        fPixels = this->onLockPixels(&fColorTable);
52    }
53}
54
55void SkPixelRef::unlockPixels() {
56    SkAutoMutexAcquire  ac(*fMutex);
57
58    SkASSERT(fLockCount > 0);
59    if (0 == --fLockCount) {
60        this->onUnlockPixels();
61        fPixels = NULL;
62        fColorTable = NULL;
63    }
64}
65
66uint32_t SkPixelRef::getGenerationID() const {
67    if (0 == fGenerationID) {
68        fGenerationID = SkNextPixelRefGenerationID();
69    }
70    return fGenerationID;
71}
72
73void SkPixelRef::notifyPixelsChanged() {
74#ifdef SK_DEBUG
75    if (fIsImmutable) {
76        SkDebugf("========== notifyPixelsChanged called on immutable pixelref");
77    }
78#endif
79    // this signals us to recompute this next time around
80    fGenerationID = 0;
81}
82
83void SkPixelRef::setImmutable() {
84    fIsImmutable = true;
85}
86
87bool SkPixelRef::readPixels(SkBitmap* dst, const SkIRect* subset) {
88    return this->onReadPixels(dst, subset);
89}
90
91bool SkPixelRef::onReadPixels(SkBitmap* dst, const SkIRect* subset) {
92    return false;
93}
94
95///////////////////////////////////////////////////////////////////////////////
96
97#define MAX_PAIR_COUNT  16
98
99struct Pair {
100    const char*          fName;
101    SkPixelRef::Factory  fFactory;
102};
103
104static int gCount;
105static Pair gPairs[MAX_PAIR_COUNT];
106
107void SkPixelRef::Register(const char name[], Factory factory) {
108    SkASSERT(name);
109    SkASSERT(factory);
110
111    static bool gOnce;
112    if (!gOnce) {
113        gCount = 0;
114        gOnce = true;
115    }
116
117    SkASSERT(gCount < MAX_PAIR_COUNT);
118
119    gPairs[gCount].fName = name;
120    gPairs[gCount].fFactory = factory;
121    gCount += 1;
122}
123
124SkPixelRef::Factory SkPixelRef::NameToFactory(const char name[]) {
125    const Pair* pairs = gPairs;
126    for (int i = gCount - 1; i >= 0; --i) {
127        if (strcmp(pairs[i].fName, name) == 0) {
128            return pairs[i].fFactory;
129        }
130    }
131    return NULL;
132}
133
134const char* SkPixelRef::FactoryToName(Factory fact) {
135    const Pair* pairs = gPairs;
136    for (int i = gCount - 1; i >= 0; --i) {
137        if (pairs[i].fFactory == fact) {
138            return pairs[i].fName;
139        }
140    }
141    return NULL;
142}
143
144///////////////////////////////////////////////////////////////////////////////
145
146#ifdef ANDROID
147void SkPixelRef::globalRef(void* data) {
148    this->ref();
149}
150
151void SkPixelRef::globalUnref() {
152    this->unref();
153}
154#endif
155