Move MTPDeviceDelegateImplLinux worker classes to its own files.

chrome/browser/media_gallery/linux/mtp_read_directory_worker.h

+// Copyright (c) 2012 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_MEDIA_GALLERY_LINUX_MTP_READ_DIRECTORY_WORKER_H_
+#define CHROME_BROWSER_MEDIA_GALLERY_LINUX_MTP_READ_DIRECTORY_WORKER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner_helpers.h"
+#include "base/synchronization/cancellation_flag.h"
+#include "chrome/browser/media_gallery/linux/mtp_device_operations_utils.h"
+#include "chrome/browser/media_transfer_protocol/mtp_file_entry.pb.h"
+
+namespace base {
+class SequencedTaskRunner;
+class WaitableEvent;
+}
+
+namespace chrome {
+
+class MTPReadDirectoryWorker;
+typedef struct WorkerDeleter<class MTPReadDirectoryWorker>
+    MTPReadDirectoryWorkerDeleter;
+
+// Worker class to read directory contents. Device is already opened for
+// communication.
+class MTPReadDirectoryWorker
+    : public base::RefCountedThreadSafe<MTPReadDirectoryWorker,
+                                        MTPReadDirectoryWorkerDeleter> {
+ public:
+  // Construct a worker object given the directory |path|. This object is
+  // constructed on |media_task_runner_| thread.
+  MTPReadDirectoryWorker(const std::string& handle,
+                         const std::string& path,
+                         base::SequencedTaskRunner* task_runner,
+                         base::WaitableEvent* task_completed_event,
+                         base::WaitableEvent* shutdown_event);
+
+  // Construct a worker object given the directory |entry_id|. This object is
+  // constructed on |media_task_runner_| thread.
+  MTPReadDirectoryWorker(const std::string& storage_name,
+                         const uint32_t entry_id,
+                         base::SequencedTaskRunner* task_runner,
+                         base::WaitableEvent* task_completed_event,
+                         base::WaitableEvent* shutdown_event);
+
+  // This function is invoked on |media_task_runner_| to post the task on UI
+  // thread. This blocks the |media_task_runner_| until the task is complete.
+  void Run();
+
+  // Returns the directory entries for the given directory path.
+  const std::vector<MtpFileEntry>& get_file_entries() const {
+    return file_entries_;
+  }
+
+  // Returns the |media_task_runner_| associated with this worker object.
+  // This function is exposed for WorkerDeleter struct to access the
+  // |media_task_runner_|.
+  base::SequencedTaskRunner* media_task_runner() const {
+    return media_task_runner_.get();
+  }
+
+ private:
+  friend struct WorkerDeleter<MTPReadDirectoryWorker>;
+  friend class base::DeleteHelper<MTPReadDirectoryWorker>;
+  friend class base::RefCountedThreadSafe<MTPReadDirectoryWorker,
+                                          MTPReadDirectoryWorkerDeleter>;
+
+  // Destructed via MTPReadDirectoryWorkerDeleter.
+  virtual ~MTPReadDirectoryWorker();
+
+  // Dispatches a request to MediaTransferProtocolManager to read the directory
+  // entries. This is called on UI thread.
+  void DoWorkOnUIThread();
+
+  // Query callback for DoWorkOnUIThread(). On success, |file_entries| has the
+  // directory file entries. |error| is true if there was an error. This
+  // function signals to unblock |media_task_runner_|.
+  void OnDidWorkOnUIThread(const std::vector<MtpFileEntry>& file_entries,
+                           bool error);
+
+  // Stores the device handle to communicate with storage device.
+  const std::string device_handle_;
+
+  // Stores the directory path whose contents needs to be listed.
+  const std::string dir_path_;
+
+  // Stores the directory entry id whose contents needs to be listed.
+  const uint32_t dir_entry_id_;
+
+  // Stores a reference to |media_task_runner_| to destruct this object on the
+  // correct thread.
+  scoped_refptr<base::SequencedTaskRunner> media_task_runner_;
+
+  // |media_task_runner_| can wait on this event until the required operation
+  // is complete.
+  // TODO(kmadhusu): Remove this WaitableEvent after modifying the
+  // DeviceMediaFileUtil functions as asynchronous functions.
+  base::WaitableEvent* on_task_completed_event_;
+
+  // Stores a reference to waitable event associated with the shut down message.
+  base::WaitableEvent* on_shutdown_event_;
+
+  // Stores the result of read directory request.
+  std::vector<MtpFileEntry> file_entries_;
+
+  // Set to ignore the request results. This will be set when
+  // MTPDeviceDelegateImplLinux object is about to be deleted.
+  // |on_task_completed_event_| and |on_shutdown_event_| should not be
+  // dereferenced when this is set.
+  base::CancellationFlag cancel_tasks_flag_;
+
+  DISALLOW_COPY_AND_ASSIGN(MTPReadDirectoryWorker);
+};
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_MEDIA_GALLERY_LINUX_MTP_READ_DIRECTORY_WORKER_H_