package org.apache.lucene.store.db;
/**
* Copyright 2002-2006 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.IOException;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.util.Random;
import com.sleepycat.db.DatabaseEntry;
import com.sleepycat.db.internal.DbConstants;
import com.sleepycat.db.internal.Dbc;
import com.sleepycat.db.internal.Db;
import com.sleepycat.db.internal.DbTxn;
import com.sleepycat.db.DatabaseException;
/**
* @author Andi Vajda
*/
public class File extends Object {
static protected Random random = new Random();
protected DatabaseEntry key, data;
protected long length, timeModified;
protected String name;
protected byte[] uuid;
protected File(String name)
throws IOException
{
setName(name);
data = new DatabaseEntry(new byte[32]);
data.setUserBuffer(data.getSize(), true);
}
protected File(DbDirectory directory, String name, boolean create)
throws IOException
{
this(name);
if (!exists(directory))
{
if (!create)
throw new IOException("File does not exist: " + name);
else
{
DatabaseEntry key = new DatabaseEntry(new byte[24]);
DatabaseEntry data = new DatabaseEntry(null);
Db blocks = directory.blocks;
DbTxn txn = directory.txn;
int flags = directory.flags;
key.setUserBuffer(24, true);
data.setPartial(true);
uuid = new byte[16];
try {
do {
/* generate a v.4 random-uuid unique to this db */
random.nextBytes(uuid);
uuid[6] = (byte) ((byte) 0x40 |
(uuid[6] & (byte) 0x0f));
uuid[8] = (byte) ((byte) 0x80 |
(uuid[8] & (byte) 0x3f));
System.arraycopy(uuid, 0, key.getData(), 0, 16);
} while (blocks.get(txn, key, data,
flags) != DbConstants.DB_NOTFOUND);
} catch (DatabaseException e) {
throw new IOException(e.getMessage());
}
}
}
else if (create)
length = 0L;
}
protected String getName()
{
return name;
}
private void setName(String name)
throws IOException
{
ByteArrayOutputStream buffer = new ByteArrayOutputStream(128);
DataOutputStream out = new DataOutputStream(buffer);
out.writeUTF(name);
out.close();
key = new DatabaseEntry(buffer.toByteArray());
key.setUserBuffer(key.getSize(), true);
this.name = name;
}
protected byte[] getKey()
throws IOException
{
if (uuid == null)
throw new IOException("Uninitialized file");
return uuid;
}
protected long getLength()
{
return length;
}
protected long getTimeModified()
{
return timeModified;
}
protected boolean exists(DbDirectory directory)
throws IOException
{
Db files = directory.files;
DbTxn txn = directory.txn;
int flags = directory.flags;
try {
if (files.get(txn, key, data, flags) == DbConstants.DB_NOTFOUND)
return false;
} catch (DatabaseException e) {
throw new IOException(e.getMessage());
}
byte[] bytes = data.getData();
ByteArrayInputStream buffer = new ByteArrayInputStream(bytes);
DataInputStream in = new DataInputStream(buffer);
length = in.readLong();
timeModified = in.readLong();
in.close();
uuid = new byte[16];
System.arraycopy(bytes, 16, uuid, 0, 16);
return true;
}
protected void modify(DbDirectory directory, long length, long timeModified)
throws IOException
{
ByteArrayOutputStream buffer = new ByteArrayOutputStream(32);
DataOutputStream out = new DataOutputStream(buffer);
Db files = directory.files;
DbTxn txn = directory.txn;
out.writeLong(length);
out.writeLong(timeModified);
out.write(getKey());
out.close();
System.arraycopy(buffer.toByteArray(), 0, data.getData(), 0, 32);
try {
files.put(txn, key, data, 0);
} catch (DatabaseException e) {
throw new IOException(e.getMessage());
}
this.length = length;
this.timeModified = timeModified;
}
protected void delete(DbDirectory directory)
throws IOException
{
if (!exists(directory))
throw new IOException("File does not exist: " + getName());
Dbc cursor = null;
try {
try {
byte[] bytes = getKey();
int ulen = bytes.length + 8;
byte[] cursorBytes = new byte[ulen];
DatabaseEntry cursorKey = new DatabaseEntry(cursorBytes);
DatabaseEntry cursorData = new DatabaseEntry(null);
Db files = directory.files;
Db blocks = directory.blocks;
DbTxn txn = directory.txn;
int flags = directory.flags;
System.arraycopy(bytes, 0, cursorBytes, 0, bytes.length);
cursorKey.setUserBuffer(ulen, true);
cursorData.setPartial(true);
cursor = blocks.cursor(txn, flags);
if (cursor.get(cursorKey, cursorData,
DbConstants.DB_SET_RANGE | flags) != DbConstants.DB_NOTFOUND)
{
cursor.del(0);
outer:
while (cursor.get(cursorKey, cursorData,
DbConstants.DB_NEXT | flags) != DbConstants.DB_NOTFOUND)
{
for (int i = 0; i < bytes.length; i++)
if (bytes[i] != cursorBytes[i])
break outer;
cursor.del(0);
}
}
files.del(txn, key, 0);
} finally {
if (cursor != null)
cursor.close();
}
} catch (DatabaseException e) {
throw new IOException(e.getMessage());
}
}
protected void rename(DbDirectory directory, String name)
throws IOException
{
if (!exists(directory))
throw new IOException("File does not exist: " + getName());
File newFile = new File(name);
if (newFile.exists(directory))
newFile.delete(directory);
try {
Db files = directory.files;
DbTxn txn = directory.txn;
files.del(txn, key, 0);
setName(name);
files.put(txn, key, data, 0);
} catch (DatabaseException e) {
throw new IOException(e.getMessage());
}
}
}
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