SkDiscardablePixelRef.cpp revision edd370f949a457f5d8f7a62efdaf685d4caf46fe 
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(SkImageGenerator* generator,
13                                             const SkImageInfo& info,
14                                             size_t size,
15                                             size_t rowBytes,
16                                             SkDiscardableMemory::Factory* fact)
17    : fGenerator(generator)
18    , fDMFactory(fact)
19    , fInfo(info)
20    , fSize(size)
21    , fRowBytes(rowBytes)
22    , fDiscardableMemory(NULL) {
23    SkASSERT(fGenerator != NULL);
24    SkASSERT(fSize > 0);
25    SkASSERT(fRowBytes > 0);
26    // The SkImageGenerator contract requires fGenerator to always
27    // decode the same image on each call to getPixels().
28    this->setImmutable();
29    SkSafeRef(fDMFactory);
30}
31
32SkDiscardablePixelRef::~SkDiscardablePixelRef() {
33    SkDELETE(fDiscardableMemory);
34    SkSafeUnref(fDMFactory);
35    SkDELETE(fGenerator);
36}
37
38void* SkDiscardablePixelRef::onLockPixels(SkColorTable**) {
39    if (fDiscardableMemory != NULL) {
40        if (fDiscardableMemory->lock()) {
41            return fDiscardableMemory->data();
42        }
43        SkDELETE(fDiscardableMemory);
44        fDiscardableMemory = NULL;
45    }
46    if (fDMFactory != NULL) {
47        fDiscardableMemory = fDMFactory->create(fSize);
48    } else {
49        fDiscardableMemory = SkDiscardableMemory::Create(fSize);
50    }
51    if (NULL == fDiscardableMemory) {
52        return NULL;  // Memory allocation failed.
53    }
54    void* pixels = fDiscardableMemory->data();
55    if (!fGenerator->getPixels(fInfo, pixels, fRowBytes)) {
56        return NULL;  // TODO(halcanary) Find out correct thing to do.
57    }
58    return pixels;
59}
60void SkDiscardablePixelRef::onUnlockPixels() {
61    if (fDiscardableMemory != NULL) {
62        fDiscardableMemory->unlock();
63    }
64}
65
66bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,
67                                  SkBitmap* dst,
68                                  SkDiscardableMemory::Factory* factory) {
69    SkImageInfo info;
70    SkASSERT(generator != NULL);
71    if ((NULL == generator)
72        || (!generator->getInfo(&info))
73        || (!dst->setConfig(info, 0))) {
74        SkDELETE(generator);
75        return false;
76    }
77    SkASSERT(dst->config() != SkBitmap::kNo_Config);
78    if (dst->empty()) { // Use a normal pixelref.
79        SkDELETE(generator);  // Do not need this anymore.
80        return dst->allocPixels(NULL, NULL);
81    }
82    SkAutoTUnref<SkDiscardablePixelRef> ref(SkNEW_ARGS(SkDiscardablePixelRef,
83                                                   (generator, info,
84                                                    dst->getSize(),
85                                                    dst->rowBytes(),
86                                                    factory)));
87    dst->setPixelRef(ref);
88    return true;
89}
90