cros: Flush profile files at critical moments

chrome/browser/chromeos/base/file_flusher.h

+// Copyright 2016 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_BASE_FILE_FLUSHER_H_
+#define CHROME_BROWSER_CHROMEOS_BASE_FILE_FLUSHER_H_
+
+#include <vector>
+
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+
+namespace chromeos {
+
+// Flushes files under the requested directories in the blocking pool. If the
+// same directory is requested more than once, the last request cancels all
+// previous ones and start a new flushing process.
+class FileFlusher {
+ public:
+  FileFlusher();
+  ~FileFlusher();
+
+  // Flush everything under |path| except the directories/files in |excludes|.
+  // |excluedes| can hold both absolute or relative paths, where absolute paths
+  // are used as-is and relative paths are appended to |path| to make it
+  // absolute. |callback| is invoked when the request is finished or canceled.
+  void RequestFlush(const base::FilePath& path,
+                    const std::vector<base::FilePath>& excludes,
+                    const base::Closure& callback);
+
+  // Set a callback for every file flush for test. Note the callback is
+  // called on a blocking pool thread.
+  using OnFlushCallback = base::Callback<void(const base::FilePath&)>;
+  void set_on_flush_callback_for_test(
+      const OnFlushCallback& on_flush_callback) {
+    on_flush_callback_for_test_ = on_flush_callback;
+  }
+
+ private:
+  // Job for the flushing requests.
+  class Job;
+
+  // Starts the first job in |jobs_|.
+  void ScheduleJob();
+
+  // Invoked by a Job when it finishes.
+  void OnJobDone(Job* job);
+
+  // Not owned. Job manages its own life time.
+  std::vector<Job*> jobs_;
+
+  // A callback for testing to be invoked when a file is flushed.
+  OnFlushCallback on_flush_callback_for_test_;
+
+  base::WeakPtrFactory<FileFlusher> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(FileFlusher);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_BASE_FILE_FLUSHER_H_