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
|
// --------------------------------------------------------------------------
//
// File
// Name: PartialReadStream.h
// Purpose: Read part of another stream
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
#include "Box.h"
#include "PartialReadStream.h"
#include "CommonException.h"
#include "MemLeakFindOn.h"
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::PartialReadStream(IOStream &,
// pos_type)
// Purpose: Constructor, taking another stream and the number of
// bytes to be read from it.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
PartialReadStream::PartialReadStream(IOStream &rSource,
pos_type BytesToRead)
: mrSource(rSource),
mBytesLeft(BytesToRead)
{
ASSERT(BytesToRead > 0);
}
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::~PartialReadStream()
// Purpose: Destructor. Won't absorb any unread bytes.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
PartialReadStream::~PartialReadStream()
{
// Warn in debug mode
if(mBytesLeft != 0)
{
BOX_TRACE("PartialReadStream destroyed with " << mBytesLeft <<
" bytes remaining");
}
}
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::Read(void *, int, int)
// Purpose: As interface.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
int PartialReadStream::Read(void *pBuffer, int NBytes, int Timeout)
{
// Finished?
if(mBytesLeft <= 0)
{
return 0;
}
// Asking for more than is allowed?
if(NBytes > mBytesLeft)
{
// Adjust downwards
NBytes = mBytesLeft;
}
// Route the request to the source
int read = mrSource.Read(pBuffer, NBytes, Timeout);
ASSERT(read <= mBytesLeft);
// Adjust the count
mBytesLeft -= read;
// Return the number read
return read;
}
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::BytesLeftToRead()
// Purpose: As interface.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
IOStream::pos_type PartialReadStream::BytesLeftToRead()
{
return mBytesLeft;
}
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::Write(const void *, int)
// Purpose: As interface. But will exception.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
void PartialReadStream::Write(const void *pBuffer, int NBytes, int Timeout)
{
THROW_EXCEPTION(CommonException, CantWriteToPartialReadStream)
}
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::StreamDataLeft()
// Purpose: As interface.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
bool PartialReadStream::StreamDataLeft()
{
return mBytesLeft != 0;
}
// --------------------------------------------------------------------------
//
// Function
// Name: PartialReadStream::StreamClosed()
// Purpose: As interface.
// Created: 2003/08/26
//
// --------------------------------------------------------------------------
bool PartialReadStream::StreamClosed()
{
// always closed
return true;
}
|
