SkDiscardablePixelRef.cpp revision 27f890219b09e4774da75e6a11ec82849eadae5a 
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
39void* SkDiscardablePixelRef::onLockPixels(SkColorTable**) {
40    if (fDiscardableMemory != NULL) {
41        if (fDiscardableMemory->lock()) {
42            return fDiscardableMemory->data();
43        }
44        SkDELETE(fDiscardableMemory);
45        fDiscardableMemory = NULL;
46    }
47
48    const size_t size = this->info().getSafeSize(fRowBytes);
49
50    if (fDMFactory != NULL) {
51        fDiscardableMemory = fDMFactory->create(size);
52    } else {
53        fDiscardableMemory = SkDiscardableMemory::Create(size);
54    }
55    if (NULL == fDiscardableMemory) {
56        return NULL;  // Memory allocation failed.
57    }
58    void* pixels = fDiscardableMemory->data();
59    if (!fGenerator->getPixels(this->info(), pixels, fRowBytes)) {
60        fDiscardableMemory->unlock();
61        SkDELETE(fDiscardableMemory);
62        fDiscardableMemory = NULL;
63        return NULL;
64    }
65    return pixels;
66}
67void SkDiscardablePixelRef::onUnlockPixels() {
68    fDiscardableMemory->unlock();
69}
70
71bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,
72                                  SkBitmap* dst,
73                                  SkDiscardableMemory::Factory* factory) {
74    SkImageInfo info;
75    SkAutoTDelete<SkImageGenerator> autoGenerator(generator);
76    if ((NULL == autoGenerator.get())
77        || (!autoGenerator->getInfo(&info))
78        || (!dst->setConfig(info, 0))) {
79        return false;
80    }
81    SkASSERT(dst->config() != SkBitmap::kNo_Config);
82    if (dst->empty()) {  // Use a normal pixelref.
83        return dst->allocPixels(NULL, NULL);
84    }
85    SkAutoTUnref<SkDiscardablePixelRef> ref(
86        SkNEW_ARGS(SkDiscardablePixelRef,
87                   (info, autoGenerator.detach(), dst->rowBytes(), factory)));
88    dst->setPixelRef(ref);
89    return true;
90}
91