SkDiscardablePixelRef.cpp revision e13af711d4ff9031c9ed3054a4c33a56a0c62e1f 
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    if (!fGenerator->getPixels(this->info(), pixels, fRowBytes)) {
64        fDiscardableMemory->unlock();
65        SkDELETE(fDiscardableMemory);
66        fDiscardableMemory = NULL;
67        return false;
68    }
69
70    rec->fPixels = pixels;
71    rec->fColorTable = NULL;
72    rec->fRowBytes = fRowBytes;
73    return true;
74}
75
76void SkDiscardablePixelRef::onUnlockPixels() {
77    fDiscardableMemory->unlock();
78}
79
80bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,
81                                  SkBitmap* dst,
82                                  SkDiscardableMemory::Factory* factory) {
83    SkImageInfo info;
84    SkAutoTDelete<SkImageGenerator> autoGenerator(generator);
85    if ((NULL == autoGenerator.get())
86        || (!autoGenerator->getInfo(&info))
87        || (!dst->setConfig(info, 0))) {
88        return false;
89    }
90    SkASSERT(dst->config() != SkBitmap::kNo_Config);
91    if (dst->empty()) {  // Use a normal pixelref.
92        return dst->allocPixels(NULL, NULL);
93    }
94    SkAutoTUnref<SkDiscardablePixelRef> ref(
95        SkNEW_ARGS(SkDiscardablePixelRef,
96                   (info, autoGenerator.detach(), dst->rowBytes(), factory)));
97    dst->setPixelRef(ref);
98    return true;
99}
100