Subset decoding benchmarks

bench/subset/SubsetDivisorBench.h

+/*
+ * 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 "Benchmark.h"
+#include "SkImageDecoder.h"
+#include "SkImageInfo.h"
+#include "SkStream.h"
+#include "SkString.h"
+
+/*
+ *
+ * This benchmark is designed to test the performance of subset decoding.
+ * It uses a divisor to decode the entire image in a grid of divisor x divisor blocks.
+ *
+ */
+class SubsetDivisorBench : public Benchmark {
+public:
+
+    SubsetDivisorBench(const SkString& path,
+                       SkColorType colorType,
+                       uint32_t divisor,
+                       bool useCodec);
+
+protected:
+    const char* onGetName() override;
+    bool isSuitableFor(Backend backend) override;
+    void onDraw(const int n, SkCanvas* canvas) override;
+
+private:
+    SkString                      fName;
+    SkColorType                   fColorType;
+    const uint32_t                fDivisor;
+    const bool                    fUseCodec;
+    SkAutoTDelete<SkMemoryStream> fStream;
+    typedef Benchmark INHERITED;
+};