blob: 0e1b9dd8a99506a12331083c15d23b5d0982abf5 (
plain)
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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*-------------------------------------------------------------------------
*
* BlobInputStream.java
* This is an implementation of an InputStream from a large object.
*
* Copyright (c) 2003, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/largeobject/Attic/BlobInputStream.java,v 1.5 2003/03/07 18:39:45 barry Exp $
*
*-------------------------------------------------------------------------
*/
package org.postgresql.largeobject;
import java.io.InputStream;
import java.io.IOException;
import java.sql.SQLException;
public class BlobInputStream extends InputStream
{
/*
* The parent LargeObject
*/
private LargeObject lo;
/*
* Buffer used to improve performance
*/
private byte[] buffer;
/*
* Position within buffer
*/
private int bpos;
/*
* The buffer size
*/
private int bsize;
/*
* The mark position
*/
private int mpos = 0;
/*
* @param lo LargeObject to read from
*/
public BlobInputStream(LargeObject lo)
{
this(lo, 1024);
}
/*
* @param lo LargeObject to read from
* @param bsize buffer size
*/
public BlobInputStream(LargeObject lo, int bsize)
{
this.lo = lo;
buffer = null;
bpos = 0;
this.bsize = bsize;
}
/*
* The minimum required to implement input stream
*/
public int read() throws java.io.IOException
{
try
{
if (buffer == null || bpos >= buffer.length)
{
buffer = lo.read(bsize);
bpos = 0;
}
// Handle EOF
if (bpos >= buffer.length)
{
return -1;
}
int ret = (buffer[bpos] & 0x7F);
if ((buffer[bpos] &0x80) == 0x80)
{
ret |= 0x80;
}
bpos++;
return ret;
}
catch (SQLException se)
{
throw new IOException(se.toString());
}
}
/*
* Closes this input stream and releases any system resources associated
* with the stream.
*
* <p> The <code>close</code> method of <code>InputStream</code> does
* nothing.
*
* @exception IOException if an I/O error occurs.
*/
public void close() throws IOException
{
try
{
lo.close();
lo = null;
}
catch (SQLException se)
{
throw new IOException(se.toString());
}
}
/*
* Marks the current position in this input stream. A subsequent call to
* the <code>reset</code> method repositions this stream at the last marked
* position so that subsequent reads re-read the same bytes.
*
* <p> The <code>readlimit</code> arguments tells this input stream to
* allow that many bytes to be read before the mark position gets
* invalidated.
*
* <p> The general contract of <code>mark</code> is that, if the method
* <code>markSupported</code> returns <code>true</code>, the stream somehow
* remembers all the bytes read after the call to <code>mark</code> and
* stands ready to supply those same bytes again if and whenever the method
* <code>reset</code> is called. However, the stream is not required to
* remember any data at all if more than <code>readlimit</code> bytes are
* read from the stream before <code>reset</code> is called.
*
* <p> The <code>mark</code> method of <code>InputStream</code> does
* nothing.
*
* @param readlimit the maximum limit of bytes that can be read before
* the mark position becomes invalid.
* @see java.io.InputStream#reset()
*/
public synchronized void mark(int readlimit)
{
try
{
mpos = lo.tell();
}
catch (SQLException se)
{
//throw new IOException(se.toString());
}
}
/*
* Repositions this stream to the position at the time the
* <code>mark</code> method was last called on this input stream.
* NB: If mark is not called we move to the begining.
* @see java.io.InputStream#mark(int)
* @see java.io.IOException
*/
public synchronized void reset()
throws IOException
{
try
{
lo.seek(mpos);
}
catch (SQLException se)
{
throw new IOException(se.toString());
}
}
/*
* Tests if this input stream supports the <code>mark</code> and
* <code>reset</code> methods. The <code>markSupported</code> method of
* <code>InputStream</code> returns <code>false</code>.
*
* @return <code>true</code> if this true type supports the mark and reset
* method; <code>false</code> otherwise.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
public boolean markSupported()
{
return true;
}
}
|
