Remove redundant reading and writing of data about SharedBuffer.

third_party/WebKit/Source/platform/testing/DeferredImageDecodeBench.cpp

Index: third_party/WebKit/Source/platform/testing/DeferredImageDecodeBench.cpp
diff --git a/third_party/WebKit/Source/platform/testing/DeferredImageDecodeBench.cpp b/third_party/WebKit/Source/platform/testing/DeferredImageDecodeBench.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..9f8108fe79e367bdd0dd2c642a762006c5557f7c
--- /dev/null
+++ b/third_party/WebKit/Source/platform/testing/DeferredImageDecodeBench.cpp
@@ -0,0 +1,473 @@
+// Copyright 2015 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.
+
+// Provides a minimal wrapping of the Blink deferred image decoders. Used to
+// perform a non-threaded/non-threaded, memory-to-memory image decode using
+// micro second accuracy clocks to measure image decode time. Optionally applies
+// color correction during image decoding on supported platforms (default off).
+// Usage:
+//
+//   % ninja -C out/Release deferred_image_decode_bench &&
+//      ./out/Release/deferred_image_decode_bench file [iterations]
+//
+// TODO(noel): Consider adding md5 checksum support to WTF. Use it to compute
+// the decoded image frame md5 and output that value.
+//
+// TODO(noel): Consider integrating this tool in Chrome telemetry for realz,
+// using the image corpii used to assess Blink image decode performance. Refer
+// to http://crbug.com/398235#c103 and http://crbug.com/258324#c5
+
+#include <memory>
+#include <thread>
+
+#include "base/command_line.h"
+#include "base/test/test_discardable_memory_allocator.h"
+#include "platform/SharedBuffer.h"
+#include "platform/graphics/DeferredImageDecoder.h"
+#include "platform/image-decoders/ImageDecoder.h"
+#include "platform/wtf/PassRefPtr.h"
+#include "platform/wtf/PtrUtil.h"
+#include "platform/wtf/WTF.h"
+#include "platform/wtf/allocator/Partitions.h"
+#include "public/platform/Platform.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "ui/gfx/test/icc_profiles.h"
+
+#include <sys/stat.h>
+
+#if defined(_WIN32)
+#include <mmsystem.h>
+#include <time.h>
+#define stat(x, y) _stat(x, y)
+typedef struct _stat sttype;
+#else
+#include <sys/time.h>
+typedef struct stat sttype;
+#endif
+
+namespace blink {
+
+namespace {
+
+#if defined(_WIN32)
+
+// There is no real platform support herein, so adopt the WIN32 performance
+// counter from WTF
+// http://trac.webkit.org/browser/trunk/Source/WTF/wtf/CurrentTime.cpp?rev=152438
+
+static double LowResUTCTime() {
+  FILETIME file_time;
+  GetSystemTimeAsFileTime(&file_time);
+
+  // As per Windows documentation for FILETIME, copy the resulting FILETIME
+  // structure to a ULARGE_INTEGER structure using memcpy (using memcpy instead
+  // of direct assignment can prevent alignment faults on 64-bit Windows).
+  ULARGE_INTEGER date_time;
+  memcpy(&date_time, &file_time, sizeof(date_time));
+
+  // Number of 100 nanosecond between January 1, 1601 and January 1, 1970.
+  static const ULONGLONG kEpochBias = 116444736000000000ULL;
+  // Windows file times are in 100s of nanoseconds.
+  static const double kHundredsOfNanosecondsPerMillisecond = 10000;
+  return (date_time.QuadPart - kEpochBias) /
+         kHundredsOfNanosecondsPerMillisecond;
+}
+
+static LARGE_INTEGER g_qpc_frequency;
+static bool g_synced_time;
+
+static double HighResUpTime() {
+  // We use QPC, but only after sanity checking its result, due to bugs:
+  // http://support.microsoft.com/kb/274323
+  // http://support.microsoft.com/kb/895980
+  // http://msdn.microsoft.com/en-us/library/ms644904.aspx ("you can get
+  // different results on different processors due to bugs in the basic
+  // input/output system (BIOS) or the hardware abstraction layer (HAL).").
+
+  static LARGE_INTEGER qpc_last;
+  static DWORD tick_count_last;
+  static bool inited;
+
+  LARGE_INTEGER qpc;
+  QueryPerformanceCounter(&qpc);
+  DWORD tick_count = GetTickCount();
+
+  if (inited) {
+    __int64 qpc_elapsed =
+        ((qpc.QuadPart - qpc_last.QuadPart) * 1000) / g_qpc_frequency.QuadPart;
+    __int64 tick_count_elapsed;
+    if (tick_count >= tick_count_last) {
+      tick_count_elapsed = (tick_count - tick_count_last);
+    } else {
+      __int64 tick_count_large = tick_count + 0x100000000I64;
+      tick_count_elapsed = tick_count_large - tick_count_last;
+    }
+
+    // Force a re-sync if QueryPerformanceCounter differs from GetTickCount() by
+    // more than 500ms. (The 500ms value is from
+    // http://support.microsoft.com/kb/274323).
+    __int64 diff = tick_count_elapsed - qpc_elapsed;
+    if (diff > 500 || diff < -500)
+      g_synced_time = false;
+  } else {
+    inited = true;
+  }
+
+  qpc_last = qpc;
+  tick_count_last = tick_count;
+
+  return (1000.0 * qpc.QuadPart) /
+         static_cast<double>(g_qpc_frequency.QuadPart);
+}
+
+static bool QpcAvailable() {
+  static bool available;
+  static bool checked;
+
+  if (checked)
+    return available;
+
+  available = QueryPerformanceFrequency(&g_qpc_frequency);
+  checked = true;
+  return available;
+}
+
+static double GetCurrentTime() {
+  // Use a combination of ftime and QueryPerformanceCounter.
+  // ftime returns the information we want, but doesn't have sufficient
+  // resolution.  QueryPerformanceCounter has high resolution, but is only
+  // usable to measure time intervals.  To combine them, we call ftime and
+  // QueryPerformanceCounter initially. Later calls will use
+  // QueryPerformanceCounter by itself, adding the delta to the saved ftime.  We
+  // periodically re-sync to correct for drift.
+  static double sync_low_res_utc_time;
+  static double sync_high_res_up_time;
+  static double last_utc_time;
+
+  double low_res_time = LowResUTCTime();
+  if (!QpcAvailable())
+    return low_res_time * (1.0 / 1000.0);
+
+  double high_res_time = HighResUpTime();
+  if (!g_synced_time) {
+    timeBeginPeriod(1);  // increase time resolution around low-res time getter
+    sync_low_res_utc_time = low_res_time = LowResUTCTime();
+    timeEndPeriod(1);  // restore time resolution
+    sync_high_res_up_time = high_res_time;
+    g_synced_time = true;
+  }
+
+  double high_res_elapsed = high_res_time - sync_high_res_up_time;
+  double utc = sync_low_res_utc_time + high_res_elapsed;
+
+  // Force a clock re-sync if we've drifted.
+  double low_res_elapsed = low_res_time - sync_low_res_utc_time;
+  const double kMaximumAllowedDriftMsec =
+      15.625 * 2.0;  // 2x the typical low-res accuracy
+  if (fabs(high_res_elapsed - low_res_elapsed) > kMaximumAllowedDriftMsec)
+    g_synced_time = false;
+
+  // Make sure time doesn't run backwards (only correct if the difference is < 2
+  // seconds, since DST or clock changes could occur).
+  const double kBackwardTimeLimit = 2000.0;
+  if (utc < last_utc_time && (last_utc_time - utc) < kBackwardTimeLimit)
+    return last_utc_time * (1.0 / 1000.0);
+
+  last_utc_time = utc;
+  return utc * (1.0 / 1000.0);
+}
+
+#else
+
+static double GetCurrentTime() {
+  struct timeval now;
+  gettimeofday(&now, 0);
+  return now.tv_sec + now.tv_usec * (1.0 / 1000000.0);
+}
+
+#endif
+
+PassRefPtr<SharedBuffer> ReadFile(const char* file_name) {
+  FILE* fp = fopen(file_name, "rb");
+  if (!fp) {
+    fprintf(stderr, "Can't open file %s\n", file_name);
+    exit(2);
+  }
+
+  sttype s;
+  stat(file_name, &s);
+  size_t file_size = s.st_size;
+  if (s.st_size <= 0)
+    return SharedBuffer::Create();
+
+  std::unique_ptr<unsigned char[]> buffer =
+      WrapArrayUnique(new unsigned char[file_size]);
+  if (file_size != fread(buffer.get(), 1, file_size, fp)) {
+    fprintf(stderr, "Error reading file %s\n", file_name);
+    exit(2);
+  }
+
+  fclose(fp);
+  return SharedBuffer::Create(buffer.get(), file_size);
+}
+
+bool ReadPixels(SkImage* image) {
+  SkBitmap bitmap;
+  bitmap.allocPixels(
+      SkImageInfo::MakeN32Premul(image->width(), image->width()));
+  return image->readPixels(bitmap.info(), bitmap.getPixels(), bitmap.rowBytes(),
+                           0, 0);
+}
+
+struct RealDecodeImages {
+  sk_sp<SkImage>* images;
+  size_t* frame_index_arr;
+  size_t count;
+  size_t avail;
+};
+
+void RealDecode(RealDecodeImages* real_decoded_images) {
+  size_t to_decod_index = 0;
+  size_t current_frame_index = 0;
+
+  while (true) {
+    bool ret = true;
+    bool need_decode = false;
+
+    for (size_t i = to_decod_index; i < real_decoded_images->avail; i++) {
+      if (real_decoded_images->frame_index_arr[i] != current_frame_index) {
+        current_frame_index = real_decoded_images->frame_index_arr[i];
+        break;
+      }
+      need_decode = true;
+      to_decod_index = i;
+    }
+
+    if (need_decode) {
+      sk_sp<SkImage>* image = real_decoded_images->images + to_decod_index;
+      if (image->get()) {
+        ret = ReadPixels(image->get());
+      }
+      ++to_decod_index;
+    }
+
+    if (to_decod_index == real_decoded_images->count) {
+      if (!ret) {
+        fprintf(stderr, "RealDecode failed!\n");
+        exit(3);
+      }
+      break;
+    }
+  }
+}
+
+bool DecodeImageData(SharedBuffer* data,
+                     bool color_correction,
+                     size_t packet_size) {
+  std::unique_ptr<ImageDecoder> info_decoder = ImageDecoder::Create(
+      data, true, ImageDecoder::kAlphaPremultiplied,
+      color_correction ? ColorBehavior::TransformToTargetForTesting()
+                       : ColorBehavior::Ignore());
+  bool all_data_received = true;
+  info_decoder->SetData(data, all_data_received);
+
+  int frame_count = info_decoder->FrameCount();
+
+  if (!packet_size) {
+    std::unique_ptr<DeferredImageDecoder> decoder =
+        DeferredImageDecoder::Create(
+            data, false, ImageDecoder::kAlphaPremultiplied,
+            color_correction ? ColorBehavior::TransformToTargetForTesting()
+                             : ColorBehavior::Ignore());
+
+    bool all_data_received = true;
+    decoder->SetData(data, all_data_received);
+
+    int frame_count = decoder->FrameCount();
+    for (int i = 0; i < frame_count; ++i) {
+      sk_sp<SkImage> image = decoder->CreateFrameAtIndex(i);
+      if (!image)
+        return false;
+      bool ret = ReadPixels(image.get());
+      if (!ret) {
+        fprintf(stderr, "DecodeImageData failed!\n");
+        exit(3);
+      }
+    }
+
+    return true;
+  }
+
+  size_t cirle_count = data->size() / packet_size + data->size() % packet_size;
+  size_t images_count = frame_count * cirle_count;
+  sk_sp<SkImage>* images = new sk_sp<SkImage>[images_count];
+  size_t* frame_index_arr = new size_t[images_count];
+  memset(frame_index_arr, 0, sizeof(size_t[images_count]));
+  size_t image_index = 0;
+
+  RealDecodeImages real_decode_images{images, frame_index_arr, images_count, 0};
+
+  std::thread real_decode_thread(RealDecode, &real_decode_images);
+
+  RefPtr<SharedBuffer> packet_data = SharedBuffer::Create();
+  size_t position = 0;
+  size_t next_frame_to_decode = 0;
+
+  std::unique_ptr<DeferredImageDecoder> pakcet_decoder;
+
+  while (true) {
+    const char* packet;
+    size_t length = data->GetSomeData(packet, position);
+
+    length = std::min(length, packet_size);
+    packet_data->Append(packet, length);
+    position += length;
+
+    bool all_data_received = position == data->size();
+    if (!pakcet_decoder) {
+      pakcet_decoder = DeferredImageDecoder::Create(
+          packet_data, false, ImageDecoder::kAlphaPremultiplied,
+          color_correction ? ColorBehavior::TransformToTargetForTesting()
+                           : ColorBehavior::Ignore());
+    }
+    if (!pakcet_decoder) {
+      continue;
+    }
+
+    pakcet_decoder->SetData(packet_data.Get(), all_data_received);
+
+    size_t frame_count = pakcet_decoder->FrameCount();
+    for (size_t i = next_frame_to_decode; i < frame_count; ++i) {
+      images[image_index] = pakcet_decoder->CreateFrameAtIndex(i);
+      frame_index_arr[image_index] = i;
+      ++image_index;
+      if (pakcet_decoder->FrameIsCompleteAtIndex(i)) {
+        next_frame_to_decode = i + 1;
+        real_decode_images.avail = image_index;
+      }
+    }
+
+    if (all_data_received)
+      break;
+  }
+
+  real_decode_images.count = real_decode_images.avail;
+
+  real_decode_thread.join();
+
+  delete[] images;
+  delete[] frame_index_arr;
+
+  return true;
+}
+
+}  // namespace
+
+int Main(int argc, char* argv[]) {
+  base::CommandLine::Init(argc, argv);
+
+  base::TestDiscardableMemoryAllocator memoryAllocator;
+  base::DiscardableMemoryAllocator::SetInstance(&memoryAllocator);
+
+  WTF::Partitions::Initialize(nullptr);
+
+  // If the platform supports color correction, allow it to be controlled.
+
+  bool apply_color_correction = false;
+
+  if (argc >= 2 && strcmp(argv[1], "--color-correct") == 0) {
+    apply_color_correction = (--argc, ++argv, true);
+    gfx::ICCProfile profile = gfx::ICCProfileForTestingColorSpin();
+    ColorBehavior::SetGlobalTargetColorProfile(profile);
+  }
+
+  if (argc < 2) {
+    fprintf(stderr,
+            "Usage: %s [--color-correct] file [iterations] [packetSize]\n",
+            argv[0]);
+    exit(1);
+  }
+
+  // Control decode bench iterations and packet size.
+
+  size_t iterations = 1;
+  if (argc >= 3) {
+    char* end = 0;
+    iterations = strtol(argv[2], &end, 10);
+    if (*end != '\0' || !iterations) {
+      fprintf(stderr,
+              "Second argument should be number of iterations. "
+              "The default is 1. You supplied %s\n",
+              argv[2]);
+      exit(1);
+    }
+  }
+
+  size_t packet_size = 0;
+  if (argc >= 4) {
+    char* end = 0;
+    packet_size = strtol(argv[3], &end, 10);
+    if (*end != '\0') {
+      fprintf(stderr,
+              "Third argument should be packet size. Default is "
+              "0, meaning to decode the entire image in one packet. You "
+              "supplied %s\n",
+              argv[3]);
+      exit(1);
+    }
+  }
+
+  // Create a web platform.  blink::Platform can't be used directly because its
+  // constructor is protected.
+
+  class WebPlatform : public blink::Platform {};
+
+  Platform::Initialize(new WebPlatform());
+
+  // Read entire file content to data, and consolidate the SharedBuffer data
+  // segments into one, contiguous block of memory.
+
+  RefPtr<SharedBuffer> data = ReadFile(argv[1]);
+  if (!data.Get() || !data->size()) {
+    fprintf(stderr, "Error reading image data from [%s]\n", argv[1]);
+    exit(2);
+  }
+
+  data->Data();
+
+  // Warm-up: throw out the first iteration for more consistent results.
+
+  if (!DecodeImageData(data.Get(), apply_color_correction, packet_size)) {
+    fprintf(stderr, "Image decode failed [%s]\n", argv[1]);
+    exit(3);
+  }
+
+  // Image decode bench for iterations.
+
+  double total_time = 0.0;
+
+  for (size_t i = 0; i < iterations; ++i) {
+    double start_time = GetCurrentTime();
+    bool decoded =
+        DecodeImageData(data.Get(), apply_color_correction, packet_size);
+    double elapsed_time = GetCurrentTime() - start_time;
+    total_time += elapsed_time;
+    if (!decoded) {
+      fprintf(stderr, "Image decode failed [%s]\n", argv[1]);
+      exit(3);
+    }
+  }
+
+  // Results to stdout.
+  double average_time = total_time / static_cast<double>(iterations);
+  printf("%f %f\n", total_time, average_time);
+  return 0;
+}
+
+}  // namespace blink
+
+int main(int argc, char* argv[]) {
+  return blink::Main(argc, argv);
+}