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comparison src/org/tmatesoft/hg/internal/ByteArrayDataAccess.java @ 157:d5268ca7715b

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Merged branch wrap-data-access into default for resource-friendly data access. Updated API to promote that friendliness to clients (channels, not byte[]). More exceptions
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Wed, 09 Mar 2011 05:22:17 +0100
parents src/com/tmate/hgkit/fs/ByteArrayDataAccess.java@9429c7bd1920
children b413b16d10a5
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156:643ddec3be36 157:d5268ca7715b
1 /*
2 * Copyright (c) 2011 TMate Software Ltd
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * For information on how to redistribute this software under
14 * the terms of a license other than GNU General Public License
15 * contact TMate Software at support@hg4j.com
16 */
17 package org.tmatesoft.hg.internal;
18
19 import java.io.IOException;
20
21
22 /**
23 *
24 * @author Artem Tikhomirov
25 * @author TMate Software Ltd.
26 */
27 public class ByteArrayDataAccess extends DataAccess {
28
29 private final byte[] data;
30 private final int offset;
31 private final int length;
32 private int pos;
33
34 public ByteArrayDataAccess(byte[] data) {
35 this(data, 0, data.length);
36 }
37
38 public ByteArrayDataAccess(byte[] data, int offset, int length) {
39 this.data = data;
40 this.offset = offset;
41 this.length = length;
42 pos = 0;
43 }
44
45 @Override
46 public byte readByte() throws IOException {
47 if (pos >= length) {
48 throw new IOException();
49 }
50 return data[offset + pos++];
51 }
52 @Override
53 public void readBytes(byte[] buf, int off, int len) throws IOException {
54 if (len > (this.length - pos)) {
55 throw new IOException();
56 }
57 System.arraycopy(data, pos, buf, off, len);
58 pos += len;
59 }
60
61 @Override
62 public ByteArrayDataAccess reset() {
63 pos = 0;
64 return this;
65 }
66 @Override
67 public long length() {
68 return length;
69 }
70 @Override
71 public void seek(long offset) {
72 pos = (int) offset;
73 }
74 @Override
75 public void skip(int bytes) throws IOException {
76 seek(pos + bytes);
77 }
78 @Override
79 public boolean isEmpty() {
80 return pos >= length;
81 }
82
83 //
84
85 // when byte[] needed from DA, we may save few cycles and some memory giving this (otherwise unsafe) access to underlying data
86 @Override
87 public byte[] byteArray() {
88 return data;
89 }
90 }