Tweak libpng encoding parameters to increase speed on very large images.

ui/gfx/codec/png_codec_perftest.cc

Index: ui/gfx/codec/png_codec_perftest.cc
diff --git a/ui/gfx/codec/png_codec_perftest.cc b/ui/gfx/codec/png_codec_perftest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8ca75c23ae245a333c4b464417466c167933fd21
--- /dev/null
+++ b/ui/gfx/codec/png_codec_perftest.cc
@@ -0,0 +1,113 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/gfx/codec/png_codec.h"
+
+#include <stdint.h>
+
+#include <memory>
+
+#include "base/rand_util.h"
+#include "cc/debug/lap_timer.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/perf/perf_test.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "third_party/skia/include/core/SkImageInfo.h"
+
+namespace gfx {
+
+namespace {
+
+const int kTimeLimitMillis = 5000;
+const int kWarmupRuns = 3;
+const int kTimeCheckInterval = 1;
+
+SkBitmap CreateSimpleBitmap() {
+  SkBitmap bitmap;
+  EXPECT_TRUE(bitmap.tryAllocPixels(SkImageInfo::MakeN32Premul(2000, 2000)));
+  bitmap.eraseARGB(0x87, 0x65, 0x43, 0x21);
+  return bitmap;
+}
+
+SkBitmap CreateRandomBitmap() {
+  SkBitmap bitmap;
+  EXPECT_TRUE(bitmap.tryAllocPixels(SkImageInfo::MakeN32Premul(2000, 2000)));
+  SkAutoLockPixels lock(bitmap);
+  base::RandBytes(bitmap.getPixels(), bitmap.getSize());
+  for (int i = 0; i < bitmap.width(); ++i) {
+    for (int j = 0; j < bitmap.width(); ++j) {
+      uint32_t* pixel = bitmap.getAddr32(i, j);
+      *pixel = SkPreMultiplyColor(*pixel);
+    }
+  }
+  return bitmap;
+}
+
+}  // namespace
+
+class PngCodecPerfTest : public ::testing::Test {
+ public:
+  PngCodecPerfTest()
+      : timer_(kWarmupRuns,
+               base::TimeDelta::FromMilliseconds(kTimeLimitMillis),
+               kTimeCheckInterval) {}
+
+ protected:
+  void PrintResult(const char* trace) {
+    perf_test::PrintResult("png_encode", "", trace, timer_.MsPerLap(), "ms/run",
+                           true);
+  }
+
+  cc::LapTimer timer_;
+  SkBitmap bitmap_;
+};
+
+TEST_F(PngCodecPerfTest, SimpleFastEncode) {
+  bitmap_ = CreateSimpleBitmap();
+  timer_.Reset();
+  do {
+    std::vector<uint8_t> output;
+    ASSERT_TRUE(PNGCodec::FastEncodeBGRASkBitmap(bitmap_, false, &output));
+    timer_.NextLap();
+  } while (!timer_.HasTimeLimitExpired());
+  PrintResult("fast encode");
+}
+
+TEST_F(PngCodecPerfTest, SimpleNoCompress) {
+  bitmap_ = CreateSimpleBitmap();
+  timer_.Reset();
+  do {
+    std::vector<uint8_t> output;
+    ASSERT_TRUE(
+        PNGCodec::NoCompressEncodeBGRASkBitmap(bitmap_, false, &output));
+    timer_.NextLap();
+  } while (!timer_.HasTimeLimitExpired());
+  PrintResult("no compress encode");
+}
+
+TEST_F(PngCodecPerfTest, RandomFastEncode) {
+  bitmap_ = CreateRandomBitmap();
+  timer_.Reset();
+  do {
+    std::vector<uint8_t> output;
+    ASSERT_TRUE(PNGCodec::FastEncodeBGRASkBitmap(bitmap_, false, &output));
+    timer_.NextLap();
+  } while (!timer_.HasTimeLimitExpired());
+  PrintResult("fast encode");
+}
+
+TEST_F(PngCodecPerfTest, RandomNoCompress) {
+  bitmap_ = CreateRandomBitmap();
+  timer_.Reset();
+  do {
+    std::vector<uint8_t> output;
+    ASSERT_TRUE(
+        PNGCodec::NoCompressEncodeBGRASkBitmap(bitmap_, false, &output));
+    timer_.NextLap();
+  } while (!timer_.HasTimeLimitExpired());
+  PrintResult("no compress encode");
+}
+
+}  // namespace gfx