input_stream_reader.h revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef ANDROID_WEBVIEW_NATIVE_INPUT_STREAM_READER_H_
6#define ANDROID_WEBVIEW_NATIVE_INPUT_STREAM_READER_H_
7
8#include "base/memory/ref_counted.h"
9
10namespace net {
11class HttpByteRange;
12class IOBuffer;
13}
14
15namespace android_webview {
16
17class InputStream;
18
19// Class responsible for reading the InputStream.
20class InputStreamReader {
21 public:
22  // The constructor is called on the IO thread, not on the worker thread.
23  InputStreamReader(android_webview::InputStream* stream);
24  virtual ~InputStreamReader();
25
26  // Perform a seek operation on the InputStream associated with this job.
27  // On successful completion the InputStream would have skipped reading the
28  // number of bytes equal to the lower range of |byte_range|.
29  // This method should be called on the |g_worker_thread| thread.
30  //
31  // |byte_range| is the range of bytes to be read from |stream|
32  //
33  // A negative return value will indicate an error code, a positive value
34  // will indicate the expected size of the content.
35  virtual int Seek(const net::HttpByteRange& byte_range);
36
37  // Read data from |stream_|.  This method should be called on the
38  // |g_worker_thread| thread.
39  //
40  // A negative return value will indicate an error code, a positive value
41  // will indicate the expected size of the content.
42  virtual int ReadRawData(net::IOBuffer* buffer, int buffer_size);
43
44 private:
45  // Verify the requested range against the stream size.
46  // net::OK is returned on success, the error code otherwise.
47  int VerifyRequestedRange(net::HttpByteRange* byte_range,
48                           int* content_size);
49
50  // Skip to the first byte of the requested read range.
51  // net::OK is returned on success, the error code otherwise.
52  int SkipToRequestedRange(const net::HttpByteRange& byte_range);
53
54  android_webview::InputStream* stream_;
55
56  DISALLOW_COPY_AND_ASSIGN(InputStreamReader);
57};
58
59} // namespace android_webview
60
61#endif //  ANDROID_WEBVIEW_NATIVE_INPUT_STREAM_READER_H_
62