Add a PartialPreReadImage function to file_util (on Windows).

chrome_frame/test/perf/chrome_frame_perftest.cc

Index: chrome_frame/test/perf/chrome_frame_perftest.cc
diff --git a/chrome_frame/test/perf/chrome_frame_perftest.cc b/chrome_frame/test/perf/chrome_frame_perftest.cc
index 06de3432a2eaf531a929568adb0de60bceee8a4b..c96169a20da514a72534596d09a3ea3b11eaeada 100644
--- a/chrome_frame/test/perf/chrome_frame_perftest.cc
+++ b/chrome_frame/test/perf/chrome_frame_perftest.cc
@@ -26,6 +26,7 @@
 #include "base/win/scoped_bstr.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/scoped_variant.h"
+#include "chrome/app/image_pre_reader_win.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_paths_internal.h"
@@ -408,23 +409,39 @@ class ChromeFrameStartupTestActiveX : public ChromeFrameStartupTest {
 class ChromeFrameBinariesLoadTest : public ChromeFrameStartupTestActiveX {
   static const size_t kStepSize = 4 * 1024;
  public:
+  enum PreReadType {
+    kPreReadNone,
+    kPreReadPartial,
+    kPreReadFull
+  };
+
   ChromeFrameBinariesLoadTest()
-      : pre_read_(false),
+      : pre_read_type_(kPreReadNone),
         step_size_(kStepSize),
-        bytes_to_read_(0) {}
+        bytes_to_read_(0),
+        percentage_to_preread_(25) {}
 
  protected:
   virtual void RunStartupTestImpl(TimeTicks* start_time,
                                   TimeTicks* end_time) {
     *start_time = TimeTicks::Now();
 
-    if (pre_read_) {
-      EXPECT_TRUE(file_util::PreReadImage(chrome_exe_.value().c_str(),
-                                          bytes_to_read_,
-                                          step_size_));
-      EXPECT_TRUE(file_util::PreReadImage(chrome_dll_.value().c_str(),
-                                          bytes_to_read_,
-                                          step_size_));
+    if (pre_read_type_ == kPreReadFull) {
+      EXPECT_TRUE(ImagePreReader::PreReadImage(chrome_exe_.value().c_str(),
+                                               bytes_to_read_,
+                                               step_size_));
+      EXPECT_TRUE(ImagePreReader::PreReadImage(chrome_dll_.value().c_str(),
+                                               bytes_to_read_,
+                                               step_size_));
+    } else if (pre_read_type_ == kPreReadPartial) {
+      EXPECT_TRUE(
+          ImagePreReader::PartialPreReadImage(chrome_exe_.value().c_str(),
+                                              percentage_to_preread_,
+                                              step_size_));
+      EXPECT_TRUE(
+          ImagePreReader::PartialPreReadImage(chrome_dll_.value().c_str(),
+                                              percentage_to_preread_,
+                                              step_size_));
     }
 
     HMODULE chrome_exe = LoadLibrary(chrome_exe_.value().c_str());
@@ -439,9 +456,10 @@ class ChromeFrameBinariesLoadTest : public ChromeFrameStartupTestActiveX {
     FreeLibrary(chrome_dll);
   }
 
-  bool pre_read_;
+  PreReadType pre_read_type_;
   size_t bytes_to_read_;
   size_t step_size_;
+  uint8 percentage_to_preread_;
 };
 
 // This class provides functionality to run the startup performance test for
@@ -926,6 +944,91 @@ class SilverlightCreationTest : public ChromeFrameStartupTest {
   }
 };
 
+// TODO(rogerm): Flesh out the *PreReadImage* tests to validate an observed
+//     change in paging behaviour between raw loading and pre-reading.
+
+// TODO(rogerm): Add checks to the *PreReadImage* tests to validate the
+//     handling of invalid pe files and paths as input.
+
+TEST(ImagePreReader, PreReadImage) {
+  FilePath current_exe;
+  ASSERT_TRUE(PathService::Get(base::FILE_EXE, &current_exe));
+
+  int64 file_size_64 = 0;
+  ASSERT_TRUE(file_util::GetFileSize(current_exe, &file_size_64));
+  ASSERT_TRUE(file_size_64 < std::numeric_limits<std::size_t>::max());
+  size_t file_size = static_cast<size_t>(file_size_64);
+
+  const wchar_t* module_path = current_exe.value().c_str();
+  const size_t kStepSize = 2 * 1024 * 1024;
+
+  ASSERT_TRUE(
+      ImagePreReader::PreReadImage(module_path, 0, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PreReadImage(module_path, file_size / 4, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PreReadImage(module_path, file_size / 2, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PreReadImage(module_path, file_size, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PreReadImage(module_path, file_size * 2, kStepSize));
+}
+
+TEST(ImagePreReader, PartialPreReadImage) {
+  FilePath current_exe;
+  ASSERT_TRUE(PathService::Get(base::FILE_EXE, &current_exe));
+
+  const wchar_t* module_path = current_exe.value().c_str();
+  const size_t kStepSize = 2 * 1024 * 1024;
+
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImage(module_path, 0, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImage(module_path, 25, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImage(module_path, 50, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImage(module_path, 100, kStepSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImage(module_path, 150, kStepSize));
+}
+
+TEST(ImagePreReader, PartialPreReadImageOnDisk) {
+  FilePath current_exe;
+  ASSERT_TRUE(PathService::Get(base::FILE_EXE, &current_exe));
+
+  const wchar_t* module_path = current_exe.value().c_str();
+  const size_t kChunkSize = 2 * 1024 * 1024;
+
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageOnDisk(module_path, 0, kChunkSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageOnDisk(module_path, 25, kChunkSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageOnDisk(module_path, 50, kChunkSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageOnDisk(module_path, 100, kChunkSize));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageOnDisk(module_path, 150, kChunkSize));
+}
+
+TEST(ImagePreReader, PartialPreReadImageInMemory) {
+  FilePath current_exe;
+  ASSERT_TRUE(PathService::Get(base::FILE_EXE, &current_exe));
+  const wchar_t* module_path = current_exe.value().c_str();
+
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageInMemory(module_path, 0));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageInMemory(module_path, 25));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageInMemory(module_path, 50));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageInMemory(module_path, 100));
+  ASSERT_TRUE(
+      ImagePreReader::PartialPreReadImageInMemory(module_path, 150));
+}
+
 TEST(ChromeFramePerf, DISABLED_HostActiveX) {
   // TODO(stoyan): Create a low integrity level thread && perform the test there
   SimpleModule module;
@@ -989,12 +1092,40 @@ TEST_F(ChromeFrameBinariesLoadTest, PerfCold) {
 
 TEST_F(ChromeFrameBinariesLoadTest, PerfColdPreRead) {
   FilePath binaries_to_evict[] = {chrome_exe_, chrome_dll_};
-  pre_read_ = true;
+  pre_read_type_ = kPreReadFull;
   RunStartupTest("binary_load_cold_preread", "t", "", true /* cold */,
                  arraysize(binaries_to_evict), binaries_to_evict,
                  false /* not important */, false);
 }
 
+TEST_F(ChromeFrameBinariesLoadTest, PerfColdPartialPreRead15) {
+  FilePath binaries_to_evict[] = {chrome_exe_, chrome_dll_};
+  pre_read_type_ = kPreReadPartial;
+  percentage_to_preread_ = 15;
+  RunStartupTest("binary_load_cold_partial_preread", "t", "", true /* cold */,
+                 arraysize(binaries_to_evict), binaries_to_evict,
+                 false /* not important */, false);
+}
+
+
+TEST_F(ChromeFrameBinariesLoadTest, PerfColdPartialPreRead25) {
+  FilePath binaries_to_evict[] = {chrome_exe_, chrome_dll_};
+  pre_read_type_ = kPreReadPartial;
+  percentage_to_preread_ = 25;
+  RunStartupTest("binary_load_cold_partial_preread", "t", "", true /* cold */,
+                 arraysize(binaries_to_evict), binaries_to_evict,
+                 false /* not important */, false);
+}
+
+TEST_F(ChromeFrameBinariesLoadTest, PerfColdPartialPreRead40) {
+  FilePath binaries_to_evict[] = {chrome_exe_, chrome_dll_};
+  pre_read_type_ = kPreReadPartial;
+  percentage_to_preread_ = 40;
+  RunStartupTest("binary_load_cold_partial_preread", "t", "", true /* cold */,
+                 arraysize(binaries_to_evict), binaries_to_evict,
+                 false /* not important */, false);
+}
+
 TEST_F(ChromeFrameStartupTestActiveXReference, PerfWarm) {
   RunStartupTest("warm", "t_ref", "about:blank", false /* cold */, 0, NULL,
                  true /* important */, false);