1 package org.apache.lucene.store.db;
2
3 /**
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 import java.io.IOException;
21 import java.io.ByteArrayOutputStream;
22 import java.io.DataOutputStream;
23 import java.io.ByteArrayInputStream;
24 import java.io.DataInputStream;
25 import java.util.Random;
26
27 import com.sleepycat.db.DatabaseEntry;
28 import com.sleepycat.db.internal.DbConstants;
29 import com.sleepycat.db.internal.Dbc;
30 import com.sleepycat.db.internal.Db;
31 import com.sleepycat.db.internal.DbTxn;
32 import com.sleepycat.db.DatabaseException;
33
34
35
36 public class File extends Object {
37
38 static protected Random random = new Random();
39
40 protected DatabaseEntry key, data;
41 protected long length, timeModified;
42 protected String name;
43 protected byte[] uuid;
44
45 protected File(String name)
46 throws IOException
47 {
48 setName(name);
49
50 data = new DatabaseEntry(new byte[32]);
51 data.setUserBuffer(data.getSize(), true);
52 }
53
54 protected File(DbDirectory directory, String name, boolean create)
55 throws IOException
56 {
57 this(name);
58
59 if (!exists(directory))
60 {
61 if (!create)
62 throw new IOException("File does not exist: " + name);
63 else
64 {
65 DatabaseEntry key = new DatabaseEntry(new byte[24]);
66 DatabaseEntry data = new DatabaseEntry((byte[]) null);
67 Db blocks = directory.blocks;
68 DbTxn txn = directory.txn;
69 int flags = directory.flags;
70
71 key.setUserBuffer(24, true);
72 data.setPartial(true);
73
74 uuid = new byte[16];
75
76 try {
77 do {
78 /* generate a v.4 random-uuid unique to this db */
79 random.nextBytes(uuid);
80 uuid[6] = (byte) ((byte) 0x40 |
81 (uuid[6] & (byte) 0x0f));
82 uuid[8] = (byte) ((byte) 0x80 |
83 (uuid[8] & (byte) 0x3f));
84 System.arraycopy(uuid, 0, key.getData(), 0, 16);
85 } while (blocks.get(txn, key, data,
86 flags) != DbConstants.DB_NOTFOUND);
87 } catch (DatabaseException e) {
88 throw new IOException(e.getMessage());
89 }
90 }
91 }
92 else if (create)
93 length = 0L;
94 }
95
96 protected String getName()
97 {
98 return name;
99 }
100
101 private void setName(String name)
102 throws IOException
103 {
104 ByteArrayOutputStream buffer = new ByteArrayOutputStream(128);
105 DataOutputStream out = new DataOutputStream(buffer);
106
107 out.writeUTF(name);
108 out.close();
109
110 key = new DatabaseEntry(buffer.toByteArray());
111 key.setUserBuffer(key.getSize(), true);
112
113 this.name = name;
114 }
115
116 protected byte[] getKey()
117 throws IOException
118 {
119 if (uuid == null)
120 throw new IOException("Uninitialized file");
121
122 return uuid;
123 }
124
125 protected long getLength()
126 {
127 return length;
128 }
129
130 protected long getTimeModified()
131 {
132 return timeModified;
133 }
134
135 protected boolean exists(DbDirectory directory)
136 throws IOException
137 {
138 Db files = directory.files;
139 DbTxn txn = directory.txn;
140 int flags = directory.flags;
141
142 try {
143 if (files.get(txn, key, data, flags) == DbConstants.DB_NOTFOUND)
144 return false;
145 } catch (DatabaseException e) {
146 throw new IOException(e.getMessage());
147 }
148
149 byte[] bytes = data.getData();
150 ByteArrayInputStream buffer = new ByteArrayInputStream(bytes);
151 DataInputStream in = new DataInputStream(buffer);
152
153 length = in.readLong();
154 timeModified = in.readLong();
155 in.close();
156
157 uuid = new byte[16];
158 System.arraycopy(bytes, 16, uuid, 0, 16);
159
160 return true;
161 }
162
163 protected void modify(DbDirectory directory, long length, long timeModified)
164 throws IOException
165 {
166 ByteArrayOutputStream buffer = new ByteArrayOutputStream(32);
167 DataOutputStream out = new DataOutputStream(buffer);
168 Db files = directory.files;
169 DbTxn txn = directory.txn;
170
171 out.writeLong(length);
172 out.writeLong(timeModified);
173 out.write(getKey());
174 out.close();
175
176 System.arraycopy(buffer.toByteArray(), 0, data.getData(), 0, 32);
177
178 try {
179 files.put(txn, key, data, 0);
180 } catch (DatabaseException e) {
181 throw new IOException(e.getMessage());
182 }
183
184 this.length = length;
185 this.timeModified = timeModified;
186 }
187
188 protected void delete(DbDirectory directory)
189 throws IOException
190 {
191 if (!exists(directory))
192 throw new IOException("File does not exist: " + getName());
193
194 Dbc cursor = null;
195
196 try {
197 try {
198 byte[] bytes = getKey();
199 int ulen = bytes.length + 8;
200 byte[] cursorBytes = new byte[ulen];
201 DatabaseEntry cursorKey = new DatabaseEntry(cursorBytes);
202 DatabaseEntry cursorData = new DatabaseEntry((byte[]) null);
203 Db files = directory.files;
204 Db blocks = directory.blocks;
205 DbTxn txn = directory.txn;
206 int flags = directory.flags;
207
208 System.arraycopy(bytes, 0, cursorBytes, 0, bytes.length);
209 cursorKey.setUserBuffer(ulen, true);
210 cursorData.setPartial(true);
211
212 cursor = blocks.cursor(txn, flags);
213
214 if (cursor.get(cursorKey, cursorData,
215 DbConstants.DB_SET_RANGE | flags) != DbConstants.DB_NOTFOUND)
216 {
217 cursor.del(0);
218
219 outer:
220 while (cursor.get(cursorKey, cursorData,
221 DbConstants.DB_NEXT | flags) != DbConstants.DB_NOTFOUND)
222 {
223 for (int i = 0; i < bytes.length; i++)
224 if (bytes[i] != cursorBytes[i])
225 break outer;
226
227 cursor.del(0);
228 }
229 }
230
231 files.del(txn, key, 0);
232 } finally {
233 if (cursor != null)
234 cursor.close();
235 }
236 } catch (DatabaseException e) {
237 throw new IOException(e.getMessage());
238 }
239 }
240
241 protected void rename(DbDirectory directory, String name)
242 throws IOException
243 {
244 if (!exists(directory))
245 throw new IOException("File does not exist: " + getName());
246
247 File newFile = new File(name);
248
249 if (newFile.exists(directory))
250 newFile.delete(directory);
251
252 try {
253 Db files = directory.files;
254 DbTxn txn = directory.txn;
255
256 files.del(txn, key, 0);
257 setName(name);
258 files.put(txn, key, data, 0);
259 } catch (DatabaseException e) {
260 throw new IOException(e.getMessage());
261 }
262 }
263 }