skia2/bench/subset/SubsetSingleBench.cpp
scroggo 9b2cdbf481 Allow creating multiple scanline decoders.
Make getScanlineDecoder return a new object each time, which is
owned by the caller, and independent from any existing scanline
decoders and the SkCodec itself.

Since the SkCodec already contains the entire state machine, and it
is used by the scanline decoders, simply create a new SkCodec which
is now owned by the scanline decoder.

Move code that cleans up after using a scanline decoder into its
destructor

One side effect is that creating the first scanline decoder requires
a duplication of the stream and re-reading the header. (With some
more complexity/changes, we could pass the state machine to the
scanline decoder and make the SkCodec recreate its own state machine
instead.) The typical client of the scanline decoder (region decoder)
uses an SkMemoryStream, so the duplication is cheap, although we
should consider the extra time to reread the header/recreate the state
machine. (If/when we use the scanline decoder for other purposes,
where the stream may not be cheaply duplicated, we should consider
passing the state machine.)

One (intended) result of this change is that a client can create a
new scanline decoder in a new thread, and decode different pieces of
the image simultaneously.

In SkPngCodec::decodePalette, use fBitDepth rather than a parameter.

Review URL: https://codereview.chromium.org/1230033004
2015-07-10 12:07:02 -07:00

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C++

/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SubsetSingleBench.h"
#include "SubsetBenchPriv.h"
#include "SkData.h"
#include "SkCodec.h"
#include "SkImageDecoder.h"
#include "SkOSFile.h"
#include "SkScanlineDecoder.h"
#include "SkStream.h"
/*
*
* This benchmark is designed to test the performance of subset decoding.
* It uses an input width, height, left, and top to decode a single subset.
*
*/
SubsetSingleBench::SubsetSingleBench(const SkString& path,
SkColorType colorType,
uint32_t subsetWidth,
uint32_t subsetHeight,
uint32_t offsetLeft,
uint32_t offsetTop,
bool useCodec)
: fColorType(colorType)
, fSubsetWidth(subsetWidth)
, fSubsetHeight(subsetHeight)
, fOffsetLeft(offsetLeft)
, fOffsetTop(offsetTop)
, fUseCodec(useCodec)
{
// Parse the filename
SkString baseName = SkOSPath::Basename(path.c_str());
// Choose an informative color name
const char* colorName = get_color_name(fColorType);
fName.printf("%sSubsetSingle_%dx%d +%d_+%d_%s_%s", fUseCodec ? "Codec" : "Image", fSubsetWidth,
fSubsetHeight, fOffsetLeft, fOffsetTop, baseName.c_str(), colorName);
// Perform the decode setup
SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(path.c_str()));
fStream.reset(new SkMemoryStream(encoded));
}
const char* SubsetSingleBench::onGetName() {
return fName.c_str();
}
bool SubsetSingleBench::isSuitableFor(Backend backend) {
return kNonRendering_Backend == backend;
}
void SubsetSingleBench::onDraw(const int n, SkCanvas* canvas) {
// When the color type is kIndex8, we will need to store the color table. If it is
// used, it will be initialized by the codec.
int colorCount;
SkPMColor colors[256];
if (fUseCodec) {
for (int count = 0; count < n; count++) {
SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
SkAutoTDeleteArray<uint8_t> row(SkNEW_ARRAY(uint8_t, info.minRowBytes()));
SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(codec->getScanlineDecoder(
info, NULL, colors, &colorCount));
SkBitmap bitmap;
SkImageInfo subsetInfo = info.makeWH(fSubsetWidth, fSubsetHeight);
alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
scanlineDecoder->skipScanlines(fOffsetTop);
uint32_t bpp = info.bytesPerPixel();
for (uint32_t y = 0; y < fSubsetHeight; y++) {
scanlineDecoder->getScanlines(row.get(), 1, 0);
memcpy(bitmap.getAddr(0, y), row.get() + fOffsetLeft * bpp,
fSubsetWidth * bpp);
}
}
} else {
for (int count = 0; count < n; count++) {
SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
int width, height;
decoder->buildTileIndex(fStream->duplicate(), &width, &height);
SkBitmap bitmap;
SkIRect rect = SkIRect::MakeXYWH(fOffsetLeft, fOffsetTop, fSubsetWidth,
fSubsetHeight);
decoder->decodeSubset(&bitmap, rect, fColorType);
}
}
}