1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
// --------------------------------------------------------------------------
//
// File
// Name: ZeroStream.cpp
// Purpose: An IOStream which returns all zeroes up to a certain size
// Created: 2007/04/28
//
// --------------------------------------------------------------------------
#include "Box.h"
#include "ZeroStream.h"
#include "CommonException.h"
#include <string.h>
#include "MemLeakFindOn.h"
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::ZeroStream(IOStream::pos_type)
// Purpose: Constructor
// Created: 2007/04/28
//
// --------------------------------------------------------------------------
ZeroStream::ZeroStream(IOStream::pos_type size)
: mSize(size), mPosition(0)
{ }
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::Read(void *, int)
// Purpose: Reads bytes from the file
// Created: 2007/01/16
//
// --------------------------------------------------------------------------
int ZeroStream::Read(void *pBuffer, int NBytes, int Timeout)
{
ASSERT(NBytes > 0);
int bytesToRead = NBytes;
if (bytesToRead > mSize - mPosition)
{
bytesToRead = mSize - mPosition;
}
memset(pBuffer, 0, bytesToRead);
mPosition += bytesToRead;
return bytesToRead;
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::BytesLeftToRead()
// Purpose: Returns number of bytes to read (may not be most efficient function ever)
// Created: 2007/01/16
//
// --------------------------------------------------------------------------
IOStream::pos_type ZeroStream::BytesLeftToRead()
{
return mSize - mPosition;
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::Write(void *, int)
// Purpose: Writes bytes to the underlying stream (not supported)
// Created: 2003/07/31
//
// --------------------------------------------------------------------------
void ZeroStream::Write(const void *pBuffer, int NBytes, int Timeout)
{
THROW_EXCEPTION(CommonException, NotSupported);
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::GetPosition()
// Purpose: Get position in stream
// Created: 2003/08/21
//
// --------------------------------------------------------------------------
IOStream::pos_type ZeroStream::GetPosition() const
{
return mPosition;
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::Seek(pos_type, int)
// Purpose: Seeks within file, as lseek, invalidate buffer
// Created: 2003/07/31
//
// --------------------------------------------------------------------------
void ZeroStream::Seek(IOStream::pos_type Offset, int SeekType)
{
switch (SeekType)
{
case SeekType_Absolute:
{
mPosition = Offset;
}
break;
case SeekType_Relative:
{
mPosition += Offset;
}
break;
case SeekType_End:
{
mPosition = mSize - Offset;
}
}
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::Close()
// Purpose: Closes the underlying stream (not needed)
// Created: 2003/07/31
//
// --------------------------------------------------------------------------
void ZeroStream::Close()
{
THROW_EXCEPTION(CommonException, NotSupported);
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::StreamDataLeft()
// Purpose: Any data left to write?
// Created: 2003/08/02
//
// --------------------------------------------------------------------------
bool ZeroStream::StreamDataLeft()
{
return (BytesLeftToRead() > 0);
}
// --------------------------------------------------------------------------
//
// Function
// Name: ZeroStream::StreamClosed()
// Purpose: Is the stream closed?
// Created: 2003/08/02
//
// --------------------------------------------------------------------------
bool ZeroStream::StreamClosed()
{
return false;
}
|
