-
Notifications
You must be signed in to change notification settings - Fork 531
/
RestartableStream.cs
129 lines (112 loc) · 4.15 KB
/
RestartableStream.cs
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
using System;
using System.Collections.Generic;
using System.IO;
namespace iSpyApplication.Server
{
public sealed class RestartableReadStream : Stream
{
private readonly Stream _inner;
private List<byte[]> _buffers;
private bool _buffering;
private int? _currentBuffer;
private int? _currentBufferPosition;
public RestartableReadStream(Stream inner)
{
if (!inner.CanRead) throw new NotSupportedException(); //Don't know what else is being expected of us
if (inner.CanSeek) throw new NotSupportedException(); //Just use the underlying streams ability to seek, no need for this class
_inner = inner;
_buffering = true;
_buffers = new List<byte[]>();
}
public void StopBuffering()
{
_buffering = false;
if (!_currentBuffer.HasValue)
{
//We aren't currently using the buffers
_buffers = null;
_currentBufferPosition = null;
}
}
public void Restart()
{
if (!_buffering) throw new NotSupportedException(); //Buffering got turned off already
if (_buffers.Count == 0) return;
_currentBuffer = 0;
_currentBufferPosition = 0;
}
public override void Flush()
{
_inner.Flush();
}
public override long Seek(long offset, SeekOrigin origin)
{
return 0L;
}
public override void SetLength(long value)
{
}
public override int Read(byte[] buffer, int offset, int count)
{
if (_currentBuffer.HasValue)
{
//Try to satisfy the read request from the current buffer
byte[] rbuffer = _buffers[_currentBuffer.Value];
if (_currentBufferPosition != null)
{
int roffset = _currentBufferPosition.Value;
if ((rbuffer.Length - roffset) <= count)
{
//Just give them what we have in the current buffer (exhausting it)
count = (rbuffer.Length - roffset);
for (int i = 0; i < count; i++)
{
buffer[offset + i] = rbuffer[roffset + i];
}
_currentBuffer++;
if (_currentBuffer.Value == _buffers.Count)
{
//We've stopped reading from the buffers
if (!_buffering)
_buffers = null;
_currentBuffer = null;
_currentBufferPosition = null;
}
return count;
}
else
{
for (int i = 0; i < count; i++)
{
buffer[offset + i] = rbuffer[roffset + i];
}
_currentBufferPosition += count;
return count;
}
}
}
//If we reach here, we're currently using the inner stream. But may be buffering the results
int ncount = _inner.Read(buffer, offset, count);
if (_buffering)
{
byte[] rbuffer = new byte[ncount];
for (int i = 0; i < ncount; i++)
{
rbuffer[i] = buffer[offset + i];
}
_buffers.Add(rbuffer);
}
return ncount;
}
public override void Write(byte[] buffer, int offset, int count)
{
_inner.Write(buffer, offset, count);
}
public override bool CanRead => true;
public override bool CanSeek => false;
public override bool CanWrite => true;
public override long Length => 0L;
public override long Position { get; set; }
//No more interesting code below here
}
}