1 /*
2  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_FILE_WRAPPER_H_
12 #define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_FILE_WRAPPER_H_
13 
14 #include <stddef.h>
15 
16 #include "common_types.h"
17 #include "typedefs.h"
18 
19 // Implementation of an InStream and OutStream that can read (exclusive) or
20 // write from/to a file.
21 
22 namespace webrtc {
23 
24 class FileWrapper : public InStream, public OutStream
25 {
26 public:
27     static const size_t kMaxFileNameSize = 1024;
28 
29     // Factory method. Constructor disabled.
30     static FileWrapper* Create();
31 
32     // Returns true if a file has been opened.
33     virtual bool Open() const = 0;
34 
35     // Opens a file in read or write mode, decided by the readOnly parameter.
36     virtual int OpenFile(const char* fileNameUTF8,
37                          bool readOnly,
38                          bool loop = false,
39                          bool text = false) = 0;
40 
41     virtual int CloseFile() = 0;
42 
43     // Limits the file size to |bytes|. Writing will fail after the cap
44     // is hit. Pass zero to use an unlimited size.
45     virtual int SetMaxFileSize(size_t bytes)  = 0;
46 
47     // Flush any pending writes.
48     virtual int Flush() = 0;
49 
50     // Returns the opened file's name in |fileNameUTF8|. Provide the size of
51     // the buffer in bytes in |size|. The name will be truncated if |size| is
52     // too small.
53     virtual int FileName(char* fileNameUTF8,
54                          size_t size) const = 0;
55 
56     // Write |format| to the opened file. Arguments are taken in the same manner
57     // as printf. That is, supply a format string containing text and
58     // specifiers. Returns the number of characters written or -1 on error.
59     virtual int WriteText(const char* format, ...) = 0;
60 
61     // Inherited from Instream.
62     // Reads |length| bytes from file to |buf|. Returns the number of bytes read
63     // or -1 on error.
64     virtual int Read(void* buf, int length) = 0;
65 
66     // Inherited from OutStream.
67     // Writes |length| bytes from |buf| to file. The actual writing may happen
68     // some time later. Call Flush() to force a write.
69     virtual bool Write(const void *buf, int length) = 0;
70 
71     // Inherited from both Instream and OutStream.
72     // Rewinds the file to the start. Only available when OpenFile() has been
73     // called with |loop| == true or |readOnly| == true.
74     virtual int Rewind() = 0;
75 };
76 
77 } // namespace webrtc
78 
79 #endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_FILE_WRAPPER_H_
80