Add granular file tracing.
R=thestig@chromium.org,nduca@chromium.org
BUG=480665
Review URL: https://codereview.chromium.org/1072133006
Cr-Commit-Position: refs/heads/master@{#329114}
CrOS-Libchrome-Original-Commit: 492dc31b433656444c9c74213a133c19c8ebfa21
diff --git a/base/files/file_tracing.cc b/base/files/file_tracing.cc
new file mode 100644
index 0000000..a1919c4
--- /dev/null
+++ b/base/files/file_tracing.cc
@@ -0,0 +1,56 @@
+// 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.
+
+#include "base/files/file_tracing.h"
+
+#include "base/files/file.h"
+
+namespace base {
+
+namespace {
+FileTracing::Provider* g_provider = nullptr;
+}
+
+// static
+void FileTracing::SetProvider(FileTracing::Provider* provider) {
+ g_provider = provider;
+}
+
+FileTracing::ScopedEnabler::ScopedEnabler() {
+ if (g_provider)
+ g_provider->FileTracingEnable(this);
+}
+
+FileTracing::ScopedEnabler::~ScopedEnabler() {
+ if (g_provider)
+ g_provider->FileTracingDisable(this);
+}
+
+FileTracing::ScopedTrace::ScopedTrace() : initialized_(false) {}
+
+FileTracing::ScopedTrace::~ScopedTrace() {
+ if (initialized_ && g_provider) {
+ g_provider->FileTracingEventEnd(
+ name_, &file_->trace_enabler_, file_->path_, size_);
+ }
+}
+
+bool FileTracing::ScopedTrace::ShouldInitialize() const {
+ return g_provider && g_provider->FileTracingCategoryIsEnabled();
+}
+
+void FileTracing::ScopedTrace::Initialize(
+ const char* name, File* file, int64 size) {
+ file_ = file;
+ name_ = name;
+ size_ = size;
+ initialized_ = true;
+
+ if (g_provider) {
+ g_provider->FileTracingEventBegin(
+ name_, &file_->trace_enabler_, file_->path_, size_);
+ }
+}
+
+} // namespace base