01: /*
02: * $RCSfile: PositionInputStream.java,v $
03: *
04: * Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions
08: * are met:
09: *
10: * - Redistribution of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: *
13: * - Redistribution in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in
15: * the documentation and/or other materials provided with the
16: * distribution.
17: *
18: * Neither the name of Sun Microsystems, Inc. or the names of
19: * contributors may be used to endorse or promote products derived
20: * from this software without specific prior written permission.
21: *
22: * This software is provided "AS IS," without a warranty of any
23: * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
24: * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
25: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
26: * EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
27: * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
28: * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
29: * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
30: * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
31: * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
32: * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
33: * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
34: * POSSIBILITY OF SUCH DAMAGES.
35: *
36: * You acknowledge that this software is not designed, licensed or
37: * intended for use in the design, construction, operation or
38: * maintenance of any nuclear facility.
39: *
40: * $Revision: 1.4 $
41: * $Date: 2007/02/09 17:20:28 $
42: * $State: Exp $
43: */
44:
45: package com.sun.j3d.utils.scenegraph.io.retained;
46:
47: import java.io.DataInputStream;
48: import java.io.IOException;
49:
50: class PositionInputStream extends java.io.InputStream {
51:
52: private long pos = 0;
53: private java.io.InputStream stream;
54:
55: public PositionInputStream(java.io.InputStream stream) {
56: this .stream = stream;
57: }
58:
59: public int read() throws IOException {
60: pos++;
61: return stream.read();
62: }
63:
64: public int read(byte[] b) throws IOException {
65: int s = stream.read(b);
66: pos += s;
67: return s;
68: }
69:
70: public int read(byte[] b, int off, int len) throws IOException {
71: int s = stream.read(b, off, len);
72: pos += s;
73: return s;
74: }
75:
76: public long skip(long n) throws IOException {
77: long s = stream.skip(n);
78: pos += s;
79: return s;
80: }
81:
82: /**
83: * Move the file pointer to the specified position.
84: * The position MUST be greater or equal to the current position
85: */
86: public void seekForward(long position) throws IOException {
87: if (pos > position)
88: throw new SGIORuntimeException("Seeking Backward " + pos
89: + " " + position);
90: else
91: stream.skip((int) (position - pos));
92:
93: pos = position;
94: }
95:
96: public long getFilePointer() {
97: return pos;
98: }
99: }
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