Subset decoding benchmarks

bench/DecodingSubsetBench.cpp

-/*
- * 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 "DecodingSubsetBench.h"
-#include "SkData.h"
-#include "SkImageDecoder.h"
-#include "SkOSFile.h"
-#include "SkStream.h"
-
-/*
- *
- * This benchmark is designed to test the performance of image subset decoding.
- * It is invoked from the nanobench.cpp file.
- *
- */
-DecodingSubsetBench::DecodingSubsetBench(SkString path, SkColorType colorType,
-        const int divisor)
-    : fColorType(colorType)
-    , fDivisor(divisor)
-{
-    // Parse filename and the color type to give the benchmark a useful name
-    SkString baseName = SkOSPath::Basename(path.c_str());
-    const char* colorName;
-    switch(colorType) {
-        case kN32_SkColorType:
-            colorName = "N32";
-            break;
-        case kRGB_565_SkColorType:
-            colorName = "565";
-            break;
-        case kAlpha_8_SkColorType:
-            colorName = "Alpha8";
-            break;
-        default:
-            colorName = "Unknown";
-    }
-    fName.printf("DecodeSubset_%dx%d_%s_%s", fDivisor, fDivisor,
-            baseName.c_str(), colorName);
-    
-    // Perform the decode setup
-    SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(path.c_str()));
-    fStream.reset(new SkMemoryStream(encoded));
-    fDecoder.reset(SkImageDecoder::Factory(fStream));
-}
-
-const char* DecodingSubsetBench::onGetName() {
-    return fName.c_str();
-}
-
-bool DecodingSubsetBench::isSuitableFor(Backend backend) {
-    return kNonRendering_Backend == backend;
-}
-    
-void DecodingSubsetBench::onDraw(const int n, SkCanvas* canvas) {
-    for (int i = 0; i < n; i++) {
-        int w, h;
-        fDecoder->buildTileIndex(fStream->duplicate(), &w, &h);
-        // Divide the image into subsets and decode each subset
-        const int sW  = w / fDivisor;
-        const int sH = h / fDivisor;
-        for (int y = 0; y < h; y += sH) {
-            for (int x = 0; x < w; x += sW) {
-                SkBitmap bitmap;
-                SkIRect rect = SkIRect::MakeXYWH(x, y, sW, sH);
-                fDecoder->decodeSubset(&bitmap, rect, fColorType);
-            }
-        }
-    }
-}