The Tor Browser: comparison gfx/skia/trunk/src/images/SkDecodingImageGenerator.cpp

--1:000000000000
+:117d7e89fa3b
+/*
+* Copyright 2013 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+#include "SkData.h"
+#include "SkDecodingImageGenerator.h"
+#include "SkImageDecoder.h"
+#include "SkImageInfo.h"
+#include "SkImageGenerator.h"
+#include "SkImagePriv.h"
+#include "SkStream.h"
+#include "SkUtils.h"
+static bool equal_modulo_alpha(const SkImageInfo& a, const SkImageInfo& b) {
+return a.width() == b.width() && a.height() == b.height() &&
+a.colorType() == b.colorType();
+}
+namespace {
+/**
+*  Special allocator used by getPixels(). Uses preallocated memory
+*  provided if possible, else fall-back on the default allocator
+*/
+class TargetAllocator : public SkBitmap::Allocator {
+public:
+TargetAllocator(const SkImageInfo& info,
+void* target,
+size_t rowBytes)
+: fInfo(info)
+, fTarget(target)
+, fRowBytes(rowBytes)
+{}
+bool isReady() { return (fTarget != NULL); }
+virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) {
+if (NULL == fTarget || !equal_modulo_alpha(fInfo, bm->info())) {
+// Call default allocator.
+return bm->allocPixels(NULL, ct);
+}
+// TODO(halcanary): verify that all callers of this function
+// will respect new RowBytes.  Will be moot once rowbytes belongs
+// to PixelRef.
+bm->installPixels(fInfo, fTarget, fRowBytes, NULL, NULL);
+fTarget = NULL;  // never alloc same pixels twice!
+return true;
+}
+private:
+const SkImageInfo fInfo;
+void* fTarget;  // Block of memory to be supplied as pixel memory
+// in allocPixelRef.  Must be large enough to hold
+// a bitmap described by fInfo and fRowBytes
+const size_t fRowBytes;  // rowbytes for the destination bitmap
+typedef SkBitmap::Allocator INHERITED;
+};
+// TODO(halcanary): Give this macro a better name and move it into SkTypes.h
+#ifdef SK_DEBUG
+#define SkCheckResult(expr, value)  SkASSERT((value) == (expr))
+#else
+#define SkCheckResult(expr, value)  (void)(expr)
+#endif
+#ifdef SK_DEBUG
+inline bool check_alpha(SkAlphaType reported, SkAlphaType actual) {
+return ((reported == actual)
+|| ((reported == kPremul_SkAlphaType)
+&& (actual == kOpaque_SkAlphaType)));
+}
+#endif  // SK_DEBUG
+}  // namespace
+////////////////////////////////////////////////////////////////////////////////
+SkDecodingImageGenerator::SkDecodingImageGenerator(
+SkData* data,
+SkStreamRewindable* stream,
+const SkImageInfo& info,
+int sampleSize,
+bool ditherImage)
+: fData(data)
+, fStream(stream)
+, fInfo(info)
+, fSampleSize(sampleSize)
+, fDitherImage(ditherImage)
+{
+SkASSERT(stream != NULL);
+SkSafeRef(fData);  // may be NULL.
+}
+SkDecodingImageGenerator::~SkDecodingImageGenerator() {
+SkSafeUnref(fData);
+fStream->unref();
+}
+bool SkDecodingImageGenerator::getInfo(SkImageInfo* info) {
+if (info != NULL) {
+*info = fInfo;
+}
+return true;
+}
+SkData* SkDecodingImageGenerator::refEncodedData() {
+// This functionality is used in `gm --serialize`
+// Does not encode options.
+if (fData != NULL) {
+return SkSafeRef(fData);
+}
+// TODO(halcanary): SkStreamRewindable needs a refData() function
+// which returns a cheap copy of the underlying data.
+if (!fStream->rewind()) {
+return NULL;
+}
+size_t length = fStream->getLength();
+if (0 == length) {
+return NULL;
+}
+void* buffer = sk_malloc_flags(length, 0);
+SkCheckResult(fStream->read(buffer, length), length);
+fData = SkData::NewFromMalloc(buffer, length);
+return SkSafeRef(fData);
+}
+bool SkDecodingImageGenerator::getPixels(const SkImageInfo& info,
+void* pixels,
+size_t rowBytes) {
+if (NULL == pixels) {
+return false;
+}
+if (fInfo != info) {
+// The caller has specified a different info.  This is an
+// error for this kind of SkImageGenerator.  Use the Options
+// to change the settings.
+return false;
+}
+if (info.minRowBytes() > rowBytes) {
+// The caller has specified a bad rowBytes.
+return false;
+}
+SkAssertResult(fStream->rewind());
+SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
+if (NULL == decoder.get()) {
+return false;
+}
+decoder->setDitherImage(fDitherImage);
+decoder->setSampleSize(fSampleSize);
+SkBitmap bitmap;
+TargetAllocator allocator(fInfo, pixels, rowBytes);
+decoder->setAllocator(&allocator);
+// TODO: need to be able to pass colortype directly to decoder
+SkBitmap::Config legacyConfig = SkColorTypeToBitmapConfig(info.colorType());
+bool success = decoder->decode(fStream, &bitmap, legacyConfig,
+SkImageDecoder::kDecodePixels_Mode);
+decoder->setAllocator(NULL);
+if (!success) {
+return false;
+}
+if (allocator.isReady()) {  // Did not use pixels!
+SkBitmap bm;
+SkASSERT(bitmap.canCopyTo(info.colorType()));
+bool copySuccess = bitmap.copyTo(&bm, info.colorType(), &allocator);
+if (!copySuccess || allocator.isReady()) {
+SkDEBUGFAIL("bitmap.copyTo(requestedConfig) failed.");
+// Earlier we checked canCopyto(); we expect consistency.
+return false;
+}
+SkASSERT(check_alpha(info.alphaType(), bm.alphaType()));
+} else {
+SkASSERT(check_alpha(info.alphaType(), bitmap.alphaType()));
+}
+return true;
+}
+SkImageGenerator* SkDecodingImageGenerator::Create(
+SkData* data,
+const SkDecodingImageGenerator::Options& opts) {
+SkASSERT(data != NULL);
+if (NULL == data) {
+return NULL;
+}
+SkStreamRewindable* stream = SkNEW_ARGS(SkMemoryStream, (data));
+SkASSERT(stream != NULL);
+SkASSERT(stream->unique());
+return SkDecodingImageGenerator::Create(data, stream, opts);
+}
+SkImageGenerator* SkDecodingImageGenerator::Create(
+SkStreamRewindable* stream,
+const SkDecodingImageGenerator::Options& opts) {
+SkASSERT(stream != NULL);
+SkASSERT(stream->unique());
+if ((stream == NULL) || !stream->unique()) {
+SkSafeUnref(stream);
+return NULL;
+}
+return SkDecodingImageGenerator::Create(NULL, stream, opts);
+}
+// A contructor-type function that returns NULL on failure.  This
+// prevents the returned SkImageGenerator from ever being in a bad
+// state.  Called by both Create() functions
+SkImageGenerator* SkDecodingImageGenerator::Create(
+SkData* data,
+SkStreamRewindable* stream,
+const SkDecodingImageGenerator::Options& opts) {
+SkASSERT(stream);
+SkAutoTUnref<SkStreamRewindable> autoStream(stream);  // always unref this.
+if (opts.fUseRequestedColorType &&
+(kIndex_8_SkColorType == opts.fRequestedColorType)) {
+// We do not support indexed color with SkImageGenerators,
+return NULL;
+}
+SkAssertResult(autoStream->rewind());
+SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(autoStream));
+if (NULL == decoder.get()) {
+return NULL;
+}
+SkBitmap bitmap;
+decoder->setSampleSize(opts.fSampleSize);
+if (!decoder->decode(stream, &bitmap,
+SkImageDecoder::kDecodeBounds_Mode)) {
+return NULL;
+}
+if (bitmap.config() == SkBitmap::kNo_Config) {
+return NULL;
+}
+SkImageInfo info = bitmap.info();
+if (!opts.fUseRequestedColorType) {
+// Use default
+if (kIndex_8_SkColorType == bitmap.colorType()) {
+// We don't support kIndex8 because we don't support
+// colortables in this workflow.
+info.fColorType = kPMColor_SkColorType;
+}
+} else {
+if (!bitmap.canCopyTo(opts.fRequestedColorType)) {
+SkASSERT(bitmap.colorType() != opts.fRequestedColorType);
+return NULL;  // Can not translate to needed config.
+}
+info.fColorType = opts.fRequestedColorType;
+}
+return SkNEW_ARGS(SkDecodingImageGenerator,
+(data, autoStream.detach(), info,
+opts.fSampleSize, opts.fDitherImage));
+}

The Tor Browser / file comparison

comparison: gfx/skia/trunk/src/images/SkDecodingImageGenerator.cpp

gfx/skia/trunk/src/images/SkDecodingImageGenerator.cpp