Move some file api files to fileapi folder

storage/browser/blob/file_stream_reader.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 STORAGE_BLOB_FILE_STREAM_READER_H_
-#define STORAGE_BLOB_FILE_STREAM_READER_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/files/file.h"
-#include "net/base/completion_callback.h"
-#include "storage/browser/storage_browser_export.h"
-
-namespace base {
-class FilePath;
-class TaskRunner;
-class Time;
-}
-
-namespace net {
-class IOBuffer;
-}
-
-namespace storage {
-class FileSystemContext;
-class FileSystemURL;
-}
-
-namespace storage {
-
-// A generic interface for reading a file-like object.
-class FileStreamReader {
- public:
-  // Creates a new FileReader for a local file |file_path|.
-  // |initial_offset| specifies the offset in the file where the first read
-  // should start.  If the given offset is out of the file range any
-  // read operation may error out with net::ERR_REQUEST_RANGE_NOT_SATISFIABLE.
-  // |expected_modification_time| specifies the expected last modification
-  // If the value is non-null, the reader will check the underlying file's
-  // actual modification time to see if the file has been modified, and if
-  // it does any succeeding read operations should fail with
-  // ERR_UPLOAD_FILE_CHANGED error.
-  STORAGE_EXPORT static FileStreamReader*
-      CreateForLocalFile(base::TaskRunner* task_runner,
-                         const base::FilePath& file_path,
-                         int64 initial_offset,
-                         const base::Time& expected_modification_time);
-
-  // Creates a new reader for a filesystem URL |url| form |initial_offset|.
-  // |expected_modification_time| specifies the expected last modification if
-  // the value is non-null, the reader will check the underlying file's actual
-  // modification time to see if the file has been modified, and if it does any
-  // succeeding read operations should fail with ERR_UPLOAD_FILE_CHANGED error.
-  STORAGE_EXPORT static FileStreamReader*
-      CreateForFileSystemFile(storage::FileSystemContext* context,
-                              const storage::FileSystemURL& url,
-                              int64 initial_offset,
-                              const base::Time& expected_modification_time);
-
-  // Verify if the underlying file has not been modified.
-  STORAGE_EXPORT static bool VerifySnapshotTime(
-      const base::Time& expected_modification_time,
-      const base::File::Info& file_info);
-
-  // It is valid to delete the reader at any time.  If the stream is deleted
-  // while it has a pending read, its callback will not be called.
-  virtual ~FileStreamReader() {}
-
-  // Reads from the current cursor position asynchronously.
-  //
-  // Up to buf_len bytes will be copied into buf.  (In other words, partial
-  // reads are allowed.)  Returns the number of bytes copied, 0 if at
-  // end-of-file, or an error code if the operation could not be performed.
-  // If the read could not complete synchronously, then ERR_IO_PENDING is
-  // returned, and the callback will be run on the thread where Read()
-  // was called, when the read has completed.
-  //
-  // It is invalid to call Read while there is an in-flight Read operation.
-  //
-  // If the stream is deleted while it has an in-flight Read operation
-  // |callback| will not be called.
-  virtual int Read(net::IOBuffer* buf, int buf_len,
-                   const net::CompletionCallback& callback) = 0;
-
-  // Returns the length of the file if it could successfully retrieve the
-  // file info *and* its last modification time equals to
-  // expected modification time (rv >= 0 cases).
-  // Otherwise, a negative error code is returned (rv < 0 cases).
-  // If the stream is deleted while it has an in-flight GetLength operation
-  // |callback| will not be called.
-  // Note that the return type is int64 to return a larger file's size (a file
-  // larger than 2G) but an error code should fit in the int range (may be
-  // smaller than int64 range).
-  virtual int64 GetLength(const net::Int64CompletionCallback& callback) = 0;
-};
-
-}  // namespace storage
-
-#endif  // STORAGE_BLOB_FILE_STREAM_READER_H_