Move file_util_proxy to base/files.

BUG=

Review URL: https://codereview.chromium.org/12035111

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@178952 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: cf7405ff9dd49a6adf3c481f3cb439184bcc7f80
diff --git a/base/files/file_util_proxy.h b/base/files/file_util_proxy.h
new file mode 100644
index 0000000..8cbdfcb
--- /dev/null
+++ b/base/files/file_util_proxy.h
@@ -0,0 +1,211 @@
+// 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 BASE_FILES_FILE_UTIL_PROXY_H_
+#define BASE_FILES_FILE_UTIL_PROXY_H_
+
+#include "base/base_export.h"
+#include "base/callback_forward.h"
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/platform_file.h"
+
+namespace tracked_objects {
+class Location;
+};
+
+namespace base {
+
+class TaskRunner;
+class Time;
+
+// This class provides asynchronous access to common file routines.
+class BASE_EXPORT FileUtilProxy {
+ public:
+  // Holds metadata for file or directory entry.
+  struct Entry {
+    FilePath::StringType name;
+    bool is_directory;
+    int64 size;
+    base::Time last_modified_time;
+  };
+
+  // This callback is used by methods that report only an error code.  It is
+  // valid to pass a null callback to any function that takes a StatusCallback,
+  // in which case the operation will complete silently.
+  typedef Callback<void(PlatformFileError)> StatusCallback;
+
+  typedef Callback<void(PlatformFileError,
+                        PassPlatformFile,
+                        bool /* created */)> CreateOrOpenCallback;
+  typedef Callback<void(PlatformFileError,
+                        PassPlatformFile,
+                        const FilePath&)> CreateTemporaryCallback;
+  typedef Callback<void(PlatformFileError,
+                        const PlatformFileInfo&)> GetFileInfoCallback;
+  typedef Callback<void(PlatformFileError,
+                        const char* /* data */,
+                        int /* bytes read */)> ReadCallback;
+  typedef Callback<void(PlatformFileError,
+                        int /* bytes written */)> WriteCallback;
+
+  typedef Callback<PlatformFileError(PlatformFile*, bool*)> CreateOrOpenTask;
+  typedef Callback<PlatformFileError(PlatformFile)> CloseTask;
+  typedef Callback<PlatformFileError(void)> FileTask;
+
+  // Creates or opens a file with the given flags. It is invalid to pass a null
+  // callback. If PLATFORM_FILE_CREATE is set in |file_flags| it always tries to
+  // create a new file at the given |file_path| and calls back with
+  // PLATFORM_FILE_ERROR_FILE_EXISTS if the |file_path| already exists.
+  //
+  // This returns false if task posting to |task_runner| has failed.
+  static bool CreateOrOpen(TaskRunner* task_runner,
+                           const FilePath& file_path,
+                           int file_flags,
+                           const CreateOrOpenCallback& callback);
+
+  // Creates a temporary file for writing. The path and an open file handle are
+  // returned. It is invalid to pass a null callback. The additional file flags
+  // will be added on top of the default file flags which are:
+  //   base::PLATFORM_FILE_CREATE_ALWAYS
+  //   base::PLATFORM_FILE_WRITE
+  //   base::PLATFORM_FILE_TEMPORARY.
+  // Set |additional_file_flags| to 0 for synchronous writes and set to
+  // base::PLATFORM_FILE_ASYNC to support asynchronous file operations.
+  //
+  // This returns false if task posting to |task_runner| has failed.
+  static bool CreateTemporary(
+      TaskRunner* task_runner,
+      int additional_file_flags,
+      const CreateTemporaryCallback& callback);
+
+  // Close the given file handle.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Close(TaskRunner* task_runner,
+                    PlatformFile,
+                    const StatusCallback& callback);
+
+  // Retrieves the information about a file. It is invalid to pass a null
+  // callback.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool GetFileInfo(
+      TaskRunner* task_runner,
+      const FilePath& file_path,
+      const GetFileInfoCallback& callback);
+
+  // Does the same as GetFileInfo but takes PlatformFile instead of FilePath.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool GetFileInfoFromPlatformFile(
+      TaskRunner* task_runner,
+      PlatformFile file,
+      const GetFileInfoCallback& callback);
+
+  // Deletes a file or a directory.
+  // It is an error to delete a non-empty directory with recursive=false.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Delete(TaskRunner* task_runner,
+                     const FilePath& file_path,
+                     bool recursive,
+                     const StatusCallback& callback);
+
+  // Deletes a directory and all of its contents.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool RecursiveDelete(
+      TaskRunner* task_runner,
+      const FilePath& file_path,
+      const StatusCallback& callback);
+
+  // Reads from a file. On success, the file pointer is moved to position
+  // |offset + bytes_to_read| in the file. The callback can be null.
+  //
+  // This returns false if |bytes_to_read| is less than zero, or
+  // if task posting to |task_runner| has failed.
+  static bool Read(
+      TaskRunner* task_runner,
+      PlatformFile file,
+      int64 offset,
+      int bytes_to_read,
+      const ReadCallback& callback);
+
+  // Writes to a file. If |offset| is greater than the length of the file,
+  // |false| is returned. On success, the file pointer is moved to position
+  // |offset + bytes_to_write| in the file. The callback can be null.
+  // |bytes_to_write| must be greater than zero.
+  //
+  // This returns false if |bytes_to_write| is less than or equal to zero,
+  // if |buffer| is NULL, or if task posting to |task_runner| has failed.
+  static bool Write(
+      TaskRunner* task_runner,
+      PlatformFile file,
+      int64 offset,
+      const char* buffer,
+      int bytes_to_write,
+      const WriteCallback& callback);
+
+  // Touches a file. The callback can be null.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Touch(
+      TaskRunner* task_runner,
+      PlatformFile file,
+      const Time& last_access_time,
+      const Time& last_modified_time,
+      const StatusCallback& callback);
+
+  // Touches a file. The callback can be null.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Touch(
+      TaskRunner* task_runner,
+      const FilePath& file_path,
+      const Time& last_access_time,
+      const Time& last_modified_time,
+      const StatusCallback& callback);
+
+  // Truncates a file to the given length. If |length| is greater than the
+  // current length of the file, the file will be extended with zeroes.
+  // The callback can be null.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Truncate(
+      TaskRunner* task_runner,
+      PlatformFile file,
+      int64 length,
+      const StatusCallback& callback);
+
+  // Truncates a file to the given length. If |length| is greater than the
+  // current length of the file, the file will be extended with zeroes.
+  // The callback can be null.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Truncate(
+      TaskRunner* task_runner,
+      const FilePath& path,
+      int64 length,
+      const StatusCallback& callback);
+
+  // Flushes a file. The callback can be null.
+  // This returns false if task posting to |task_runner| has failed.
+  static bool Flush(
+      TaskRunner* task_runner,
+      PlatformFile file,
+      const StatusCallback& callback);
+
+  // Relay helpers.
+  // They return false if posting a given task to |task_runner| has failed.
+  static bool RelayCreateOrOpen(
+      TaskRunner* task_runner,
+      const CreateOrOpenTask& open_task,
+      const CloseTask& close_task,
+      const CreateOrOpenCallback& callback);
+  static bool RelayClose(
+      TaskRunner* task_runner,
+      const CloseTask& close_task,
+      PlatformFile,
+      const StatusCallback& callback);
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(FileUtilProxy);
+};
+
+}  // namespace base
+
+#endif  // BASE_FILES_FILE_UTIL_PROXY_H_