Provide lazy CommitPendingWrites in addition to eager SavePersistentPrefs.

chrome/common/important_file_writer.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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 "chrome/common/important_file_writer.h"
 
 #include <stdio.h>
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/message_loop_proxy.h"
 #include "base/string_number_conversions.h"
 #include "base/task.h"
 #include "base/threading/thread.h"
 #include "base/time.h"
+#include "content/browser/browser_thread.h"
+#include "content/common/notification_service.h"
 
 using base::TimeDelta;
 
 namespace {
 
 const int kDefaultCommitIntervalMs = 10000;
 
-class WriteToDiskTask : public Task {
+class CommitNotificationTask: public Task {
  public:
-  WriteToDiskTask(const FilePath& path, const std::string& data)
-      : path_(path),
-        data_(data) {
+  CommitNotificationTask(bool success, NotificationSource source)
+      : success_(success),
+        source_(source) {
   }
 
   virtual void Run() {
+    // At this moment we do not send notification in case of failure but we may
+    // want to send it including additional information in details.
+    if (success_ && NotificationService::current()) {
+      NotificationService::current()->Notify(
+          NotificationType::PREF_COMMITTED,
+          source_,
+          NotificationService::NoDetails());
+    }
+  }
+
+ private:
+  bool success_;
+  NotificationSource source_;
+};
+
+class WriteToDiskTask : public Task {
+ public:
+  WriteToDiskTask(const FilePath& path,
+                  const std::string& data,
+                  NotificationSource source)
+      : path_(path),
+        data_(data),
+        source_(source) {
+  }
+
+  virtual void Run() {
     // Write the data to a temp file then rename to avoid data loss if we crash
     // while writing the file. Ensure that the temp file is on the same volume
     // as target file, so it can be moved in one step, and that the temp file
     // is securely created.
     FilePath tmp_file_path;
     FILE* tmp_file = file_util::CreateAndOpenTemporaryFileInDir(
         path_.DirName(), &tmp_file_path);
     if (!tmp_file) {
       LogFailure("could not create temporary file");
       return;
@@ skipping 10 matching lines @@
                  base::Uint64ToString(bytes_written));
       file_util::Delete(tmp_file_path, false);
       return;
     }
 
     if (!file_util::ReplaceFile(tmp_file_path, path_)) {
       LogFailure("could not rename temporary file");
       file_util::Delete(tmp_file_path, false);
       return;
     }
+#if defined(OS_CHROMEOS)
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        new CommitNotificationTask(true, source_));
+#endif
   }
 
  private:
   void LogFailure(const std::string& message) {
     PLOG(WARNING) << "failed to write " << path_.value()
                   << ": " << message;
   }
 
   const FilePath path_;
   const std::string data_;
+  const NotificationSource source_;
 
   DISALLOW_COPY_AND_ASSIGN(WriteToDiskTask);
 };
 
 }  // namespace
 
 ImportantFileWriter::ImportantFileWriter(
     const FilePath& path, base::MessageLoopProxy* file_message_loop_proxy)
         : path_(path),
           file_message_loop_proxy_(file_message_loop_proxy),
           serializer_(NULL),
           commit_interval_(TimeDelta::FromMilliseconds(
-              kDefaultCommitIntervalMs)) {
+              kDefaultCommitIntervalMs)),
+          source_(NotificationService::AllSources()) {
   DCHECK(CalledOnValidThread());
   DCHECK(file_message_loop_proxy_.get());
 }
 
 ImportantFileWriter::~ImportantFileWriter() {
   // We're usually a member variable of some other object, which also tends
   // to be our serializer. It may not be safe to call back to the parent object
   // being destructed.
   DCHECK(!HasPendingWrite());
 }
 
 bool ImportantFileWriter::HasPendingWrite() const {
   DCHECK(CalledOnValidThread());
   return timer_.IsRunning();
 }
 
 void ImportantFileWriter::WriteNow(const std::string& data) {
   DCHECK(CalledOnValidThread());
 
   if (HasPendingWrite())
     timer_.Stop();
 
-  if (!file_message_loop_proxy_->PostTask(FROM_HERE,
-                                          new WriteToDiskTask(path_, data))) {
+  if (!file_message_loop_proxy_->PostTask(
+      FROM_HERE, new WriteToDiskTask(path_, data, source_))) {
     // Posting the task to background message loop is not expected
     // to fail, but if it does, avoid losing data and just hit the disk
     // on the current thread.
     NOTREACHED();
 
-    WriteToDiskTask write_task(path_, data);
+    WriteToDiskTask write_task(path_, data, source_);
     write_task.Run();
   }
 }
 
 void ImportantFileWriter::ScheduleWrite(DataSerializer* serializer) {
   DCHECK(CalledOnValidThread());
 
   DCHECK(serializer);
   serializer_ = serializer;
 
@@ skipping 13 matching lines @@
   DCHECK(serializer_);
   std::string data;
   if (serializer_->SerializeData(&data)) {
     WriteNow(data);
   } else {
     LOG(WARNING) << "failed to serialize data to be saved in "
                  << path_.value();
   }
   serializer_ = NULL;
 }