Add --trace-rotate-startup-file option and store unsaved trace data on exit.

content/browser/browser_shutdown_profile_dumper.cc

 // Copyright 2013 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 "content/browser/browser_shutdown_profile_dumper.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_impl.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/public/common/content_switches.h"
 
 namespace content {
 
-BrowserShutdownProfileDumper::BrowserShutdownProfileDumper()
-    : blocks_(0),
+BrowserShutdownProfileDumper::BrowserShutdownProfileDumper(
+    const base::FilePath& dump_file_name)
+    : dump_file_name_(dump_file_name),
+      blocks_(0),
       dump_file_(NULL) {
 }
 
 BrowserShutdownProfileDumper::~BrowserShutdownProfileDumper() {
-  WriteTracesToDisc(GetFileName());
+  WriteTracesToDisc();
 }
 
-void BrowserShutdownProfileDumper::WriteTracesToDisc(
-    const base::FilePath& file_name) {
+void BrowserShutdownProfileDumper::WriteTracesToDisc() {
   // Note: I have seen a usage of 0.000xx% when dumping - which fits easily.
   // Since the tracer stops when the trace buffer is filled, we'd rather save
   // what we have than nothing since we might see from the amount of events
   // that caused the problem.
   DVLOG(1) << "Flushing shutdown traces to disc. The buffer is %" <<
       base::debug::TraceLog::GetInstance()->GetBufferPercentFull() <<
       " full.";
   DCHECK(!dump_file_);
-  dump_file_ = base::OpenFile(file_name, "w+");
+  dump_file_ = base::OpenFile(dump_file_name_, "w+");
   if (!IsFileValid()) {
-    LOG(ERROR) << "Failed to open performance trace file: " <<
-        file_name.value();
+    LOG(ERROR) << "Failed to open performance trace file: "
+               << dump_file_name_.value();
     return;
   }
   WriteString("{\"traceEvents\":");
   WriteString("[");
 
   // TraceLog::Flush() requires the calling thread to have a message loop.
   // As the message loop of the current thread may have quit, start another
   // thread for flushing the trace.
   base::WaitableEvent flush_complete_event(false, false);
   base::Thread flush_thread("browser_shutdown_trace_event_flush");
@@ skipping 11 matching lines @@
 
 void BrowserShutdownProfileDumper::EndTraceAndFlush(
     base::WaitableEvent* flush_complete_event) {
   base::debug::TraceLog::GetInstance()->SetDisabled();
   base::debug::TraceLog::GetInstance()->Flush(
       base::Bind(&BrowserShutdownProfileDumper::WriteTraceDataCollected,
                  base::Unretained(this),
                  base::Unretained(flush_complete_event)));
 }
 
-base::FilePath BrowserShutdownProfileDumper::GetFileName() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  base::FilePath trace_file =
-      command_line.GetSwitchValuePath(switches::kTraceShutdownFile);
-
-  if (!trace_file.empty())
-    return trace_file;
-
-  // Default to saving the startup trace into the current dir.
-  return base::FilePath().AppendASCII("chrometrace.log");
-}
-
 void BrowserShutdownProfileDumper::WriteTraceDataCollected(
     base::WaitableEvent* flush_complete_event,
     const scoped_refptr<base::RefCountedString>& events_str,
     bool has_more_events) {
   if (!IsFileValid()) {
     flush_complete_event->Signal();
     return;
   }
   if (blocks_) {
     // Blocks are not comma separated. Beginning with the second block we
@@ skipping 18 matching lines @@
 void BrowserShutdownProfileDumper::WriteString(const std::string& string) {
   WriteChars(string.data(), string.size());
 }
 
 void BrowserShutdownProfileDumper::WriteChars(const char* chars, size_t size) {
   if (!IsFileValid())
     return;
 
   size_t written = fwrite(chars, 1, size, dump_file_);
   if (written != size) {
-    LOG(ERROR) << "Error " << ferror(dump_file_) <<
-        " in fwrite() to trace file";
+    LOG(ERROR) << "Error " << ferror(dump_file_)
+               << " in fwrite() to trace file '" << dump_file_name_.value()
+               << "'";
     CloseFile();
   }
 }
 
 void BrowserShutdownProfileDumper::CloseFile() {
   if (!dump_file_)
     return;
   base::CloseFile(dump_file_);
   dump_file_ = NULL;
 }
 
 }  // namespace content