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#include "SkDiscardablePixelRef.h"
9#include "SkDiscardableMemory.h"
10#include "SkImageGenerator.h"
11
12SkDiscardablePixelRef::SkDiscardablePixelRef(const SkImageInfo& info,
13                                             SkImageGenerator* generator,
14                                             size_t rowBytes,
15                                             SkDiscardableMemory::Factory* fact)
16    : INHERITED(info)
17    , fGenerator(generator)
18    , fDMFactory(fact)
19    , fRowBytes(rowBytes)
20    , fDiscardableMemory(NULL)
21{
22    SkASSERT(fGenerator != NULL);
23    SkASSERT(fRowBytes > 0);
24    // The SkImageGenerator contract requires fGenerator to always
25    // decode the same image on each call to getPixels().
26    this->setImmutable();
27    SkSafeRef(fDMFactory);
28}
29
30SkDiscardablePixelRef::~SkDiscardablePixelRef() {
31    if (this->isLocked()) {
32        fDiscardableMemory->unlock();
33    }
34    SkDELETE(fDiscardableMemory);
35    SkSafeUnref(fDMFactory);
36    SkDELETE(fGenerator);
37}
38
39bool SkDiscardablePixelRef::onNewLockPixels(LockRec* rec) {
40    if (fDiscardableMemory != NULL) {
41        if (fDiscardableMemory->lock()) {
42            rec->fPixels = fDiscardableMemory->data();
43            rec->fColorTable = NULL;
44            rec->fRowBytes = fRowBytes;
45            return true;
46        }
47        SkDELETE(fDiscardableMemory);
48        fDiscardableMemory = NULL;
49    }
50
51    const size_t size = this->info().getSafeSize(fRowBytes);
52
53    if (fDMFactory != NULL) {
54        fDiscardableMemory = fDMFactory->create(size);
55    } else {
56        fDiscardableMemory = SkDiscardableMemory::Create(size);
57    }
58    if (NULL == fDiscardableMemory) {
59        return false;  // Memory allocation failed.
60    }
61
62    void* pixels = fDiscardableMemory->data();
63    const SkImageInfo& info = this->info();
64    SkPMColor colors[256];
65    int colorCount = 0;
66
67#ifdef SK_SUPPORT_LEGACY_IMAGEGENERATORAPI
68    if (!fGenerator->getPixels(info, pixels, fRowBytes)) {
69#else
70    if (!fGenerator->getPixels(info, pixels, fRowBytes, colors, &colorCount)) {
71#endif
72        fDiscardableMemory->unlock();
73        SkDELETE(fDiscardableMemory);
74        fDiscardableMemory = NULL;
75        return false;
76    }
77
78    // Note: our ctable is not purgable, as it is not stored in the discardablememory block.
79    // This is because SkColorTable is refcntable, and therefore our caller could hold onto it
80    // beyond the scope of a lock/unlock. If we change the API/lifecycle for SkColorTable, we
81    // could move it into the block, but then again perhaps it is small enough that this doesn't
82    // really matter.
83    if (colorCount > 0) {
84        fCTable.reset(SkNEW_ARGS(SkColorTable, (colors, colorCount)));
85    } else {
86        fCTable.reset(NULL);
87    }
88
89    rec->fPixels = pixels;
90    rec->fColorTable = fCTable.get();
91    rec->fRowBytes = fRowBytes;
92    return true;
93}
94
95void SkDiscardablePixelRef::onUnlockPixels() {
96    fDiscardableMemory->unlock();
97}
98
99bool SkInstallDiscardablePixelRef(SkImageGenerator* generator, SkBitmap* dst,
100                                  SkDiscardableMemory::Factory* factory) {
101    SkImageInfo info;
102    SkAutoTDelete<SkImageGenerator> autoGenerator(generator);
103    if ((NULL == autoGenerator.get())
104        || (!autoGenerator->getInfo(&info))
105        || (!dst->setInfo(info))) {
106        return false;
107    }
108    SkASSERT(dst->colorType() != kUnknown_SkColorType);
109    if (dst->empty()) {  // Use a normal pixelref.
110        return dst->allocPixels();
111    }
112    SkAutoTUnref<SkDiscardablePixelRef> ref(
113        SkNEW_ARGS(SkDiscardablePixelRef,
114                   (info, autoGenerator.detach(), dst->rowBytes(), factory)));
115    dst->setPixelRef(ref);
116    return true;
117}
118
119// This is the public API
120bool SkInstallDiscardablePixelRef(SkImageGenerator* generator, SkBitmap* dst) {
121    return SkInstallDiscardablePixelRef(generator, dst, NULL);
122}
123