SkDiscardablePixelRef.cpp revision 2c7c7ee47d75e7815ea8db05e924ab55958cb402 
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
11SkDiscardablePixelRef::SkDiscardablePixelRef(SkImageGenerator* generator,
12                                             const SkImageInfo& info,
13                                             size_t size,
14                                             size_t rowBytes,
15                                             SkDiscardableMemory::Factory* fact)
16    : fGenerator(generator)
17    , fDMFactory(fact)
18    , fInfo(info)
19    , fSize(size)
20    , fRowBytes(rowBytes)
21    , fDiscardableMemory(NULL) {
22    SkASSERT(fGenerator != NULL);
23    SkASSERT(fSize > 0);
24    SkASSERT(fRowBytes > 0);
25    // The SkImageGenerator contract requires fGenerator to always
26    // decode the same image on each call to getPixels().
27    this->setImmutable();
28    SkSafeRef(fDMFactory);
29}
30
31SkDiscardablePixelRef::~SkDiscardablePixelRef() {
32    SkDELETE(fDiscardableMemory);
33    SkSafeUnref(fDMFactory);
34    SkDELETE(fGenerator);
35}
36
37void* SkDiscardablePixelRef::onLockPixels(SkColorTable**) {
38    if (fDiscardableMemory != NULL) {
39        if (fDiscardableMemory->lock()) {
40            return fDiscardableMemory->data();
41        }
42        SkDELETE(fDiscardableMemory);
43        fDiscardableMemory = NULL;
44    }
45    if (fDMFactory != NULL) {
46        fDiscardableMemory = fDMFactory->create(fSize);
47    } else {
48        fDiscardableMemory = SkDiscardableMemory::Create(fSize);
49    }
50    if (NULL == fDiscardableMemory) {
51        return NULL;  // Memory allocation failed.
52    }
53    void* pixels = fDiscardableMemory->data();
54    if (!fGenerator->getPixels(fInfo, pixels, fRowBytes)) {
55        return NULL;  // TODO(halcanary) Find out correct thing to do.
56    }
57    return pixels;
58}
59void SkDiscardablePixelRef::onUnlockPixels() {
60    if (fDiscardableMemory != NULL) {
61        fDiscardableMemory->unlock();
62    }
63}
64
65bool SkDiscardablePixelRef::Install(SkImageGenerator* generator,
66                                    SkBitmap* dst,
67                                    SkDiscardableMemory::Factory* factory) {
68    SkImageInfo info;
69    SkASSERT(generator != NULL);
70    if ((NULL == generator)
71        || (!generator->getInfo(&info))
72        || (!dst->setConfig(info, 0))
73        || (0 == dst->getSize())) {  // dst->getSize=0 Probably a bad config
74        SkDELETE(generator);
75        return false;
76    }
77    SkAutoTUnref<SkDiscardablePixelRef> ref(SkNEW_ARGS(SkDiscardablePixelRef,
78                                                   (generator, info,
79                                                    dst->getSize(),
80                                                    dst->rowBytes(),
81                                                    factory)));
82    dst->setPixelRef(ref);
83    return true;
84}
85