1// tStream.h 
2// 
3// A stream is an abstract base class that specifies a consistent and simple API for input and output. For example, if 
4// a tool needs to write files to disk, or memory, or possibly a custom file system, it makes sense to use the tStream 
5// API since it abstracts away the underlying device. Essentially a stream is any object that can have bytes written 
6// to, or read from. All streams support the idea of a current read/write index, along with read and write functions. 
7// 
8// Copyright (c) 2006, 2017 Tristan Grimmer. 
9// Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby 
10// granted, provided that the above copyright notice and this permission notice appear in all copies. 
11// 
12// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL 
13// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, 
14// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
15// AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 
16// PERFORMANCE OF THIS SOFTWARE. 
17 
18#pragma once 
19namespace tSystem 
20{ 
21 
22 
23class tStream 
24{ 
25public: 
26 enum tMode 
27 { 
28 tMode_Invalid = 1 << 0, 
29 tMode_Null = tMode_Invalid, 
30 tMode_Read = 1 << 1, 
31 tMode_Write = 1 << 2, 
32 }; 
33 typedef uint32 tModes; 
34 
35 tStream(tModes); 
36 virtual ~tStream(); 
37 
38 void SetMode(uint32 modeBits); 
39 tModes GetMode() const { return Modes; } 
40 
41 int GetPos() const { return Position; } 
42 int Tell() const { return GetPos(); } 
43 
44 // Returns the number of bytes read from the stream and written to the dest buffer. If an error occurs, -1 is 
45 // returned. This can happen if, but not iff: a) The stream is not in read mode. b) 'dest' is null. c) 'numBytes' 
46 // is not >= 0, or d) There was a read error. 
47 virtual int Read(uint8* dest, int numBytes) = 0; 
48 
49 // Returns the number of bytes written to the stream and read from the src buffer. If an error occurs, -1 is 
50 // returned. This can happen if, but not iff: a) The stream is not in write mode. b) 'src' is null. c) 'numBytes' 
51 // is not >= 0, or d) There was a write error. 
52 virtual int Write(const uint8* src, int numBytes) = 0; 
53 
54protected: 
55 tModes Modes; 
56 int Position; 
57}; 
58 
59 
60} 
61