Source code: org/hsqldb/DatabaseFile.java
1 /* Copyrights and Licenses
2 *
3 * This product includes Hypersonic SQL.
4 * Originally developed by Thomas Mueller and the Hypersonic SQL Group.
5 *
6 * Copyright (c) 1995-2000 by the Hypersonic SQL Group. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without modification, are permitted
8 * provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice, this list of conditions
10 * and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice, this list of
12 * conditions and the following disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 * - All advertising materials mentioning features or use of this software must display the
15 * following acknowledgment: "This product includes Hypersonic SQL."
16 * - Products derived from this software may not be called "Hypersonic SQL" nor may
17 * "Hypersonic SQL" appear in their names without prior written permission of the
18 * Hypersonic SQL Group.
19 * - Redistributions of any form whatsoever must retain the following acknowledgment: "This
20 * product includes Hypersonic SQL."
21 * This software is provided "as is" and any expressed or implied warranties, including, but
22 * not limited to, the implied warranties of merchantability and fitness for a particular purpose are
23 * disclaimed. In no event shall the Hypersonic SQL Group or its contributors be liable for any
24 * direct, indirect, incidental, special, exemplary, or consequential damages (including, but
25 * not limited to, procurement of substitute goods or services; loss of use, data, or profits;
26 * or business interruption). However caused any on any theory of liability, whether in contract,
27 * strict liability, or tort (including negligence or otherwise) arising in any way out of the use of this
28 * software, even if advised of the possibility of such damage.
29 * This software consists of voluntary contributions made by many individuals on behalf of the
30 * Hypersonic SQL Group.
31 *
32 *
33 * For work added by the HSQL Development Group:
34 *
35 * Copyright (c) 2001-2002, The HSQL Development Group
36 * All rights reserved.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions are met:
40 *
41 * Redistributions of source code must retain the above copyright notice, this
42 * list of conditions and the following disclaimer, including earlier
43 * license statements (above) and comply with all above license conditions.
44 *
45 * Redistributions in binary form must reproduce the above copyright notice,
46 * this list of conditions and the following disclaimer in the documentation
47 * and/or other materials provided with the distribution, including earlier
48 * license statements (above) and comply with all above license conditions.
49 *
50 * Neither the name of the HSQL Development Group nor the names of its
51 * contributors may be used to endorse or promote products derived from this
52 * software without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
55 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
58 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
59 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
60 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
61 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
62 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
63 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
64 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
65 */
66
67
68 package org.hsqldb;
69
70 import java.io.RandomAccessFile;
71 import java.io.IOException;
72 import java.io.EOFException;
73 import java.io.FileNotFoundException;
74
75 // fredt@users 20020221 - patch 513005 by sqlbob@users (RMP) - new method
76
77 /**
78 * This class provides methods for reading and writing data from a
79 * database file such as that used for storing a cached table.
80 *
81 * @version 1.7.0
82 */
83 class DatabaseFile extends RandomAccessFile {
84
85 protected byte in[];
86 protected long pos;
87 protected int index;
88 protected int count;
89
90 DatabaseFile(String name, String mode,
91 int inSize) throws FileNotFoundException, IOException {
92
93 super(name, mode);
94
95 in = new byte[inSize];
96 }
97
98 protected void realSeek(long newPos) throws IOException {
99 super.seek(newPos);
100 }
101
102 public void seek(long newPos) throws IOException {
103
104 super.seek(newPos);
105
106 pos = newPos;
107 index = count = 0;
108 }
109
110 public void readSeek(long newPos) throws IOException {
111
112 if (in == null) {
113 seek(newPos);
114 } else if (newPos != pos) {
115 index += (int) (newPos - pos);
116
117 if ((index < 0) || (index > count)) {
118 seek(newPos);
119 } else {
120 pos = newPos;
121 }
122 }
123 }
124
125 public int read() throws IOException {
126
127 if (in == null) {
128 return (super.read());
129 }
130
131 if (index == count) {
132 index = 0;
133 count = super.read(in);
134
135 if (count == -1) {
136 count = 0;
137 }
138 }
139
140 if (index == count) {
141 return (-1);
142 }
143
144 pos++;
145
146 return (in[index++] & 0xff);
147 }
148
149 public int read(byte[] b) throws IOException {
150
151 int i = 0;
152 int next;
153
154 for (; i < b.length; i++) {
155 next = read();
156
157 if (next == -1) {
158 return (-1);
159 }
160
161 b[i] = (byte) next;
162 }
163
164 return (i);
165 }
166
167 //-- readInt is final.
168 public int readInteger() throws IOException {
169
170 int ret = 0;
171 int next;
172
173 for (int i = 0; i < 4; i++) {
174 next = read();
175
176 if (next == -1) {
177 throw (new EOFException());
178 }
179
180 ret <<= 8;
181 ret += (next & 0xff);
182 }
183
184 return (ret);
185 }
186
187 public void write(byte[] b) throws IOException {
188
189 index = count = 0;
190 pos += b.length;
191
192 super.write(b);
193 }
194
195 //-- writeInt is final.
196 public void writeInteger(int i) throws IOException {
197
198 index = count = 0;
199 pos += 4;
200
201 writeInt(i);
202 }
203
204 public void close() throws IOException {
205
206 super.close();
207
208 in = null;
209 }
210 }