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30 day Evaluation Version distributed via the Maven Jar Repository. Clover is not free. You have 30 days to evaluate it. Please visit http://www.thecortex.net/clover to obtain a licensed version of Clover | |||||||||||||||||||
Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
ControlFile.java | 35.7% | 62.1% | 100% | 60.8% |
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/**
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*
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* Copyright 2004 Hiram Chirino
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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**/
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package org.activeio.journal.active;
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import java.io.File;
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import java.io.IOException;
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import java.io.RandomAccessFile;
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import java.nio.ByteBuffer;
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import java.nio.channels.FileChannel;
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import java.nio.channels.FileLock;
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import org.activeio.Disposable;
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import org.activeio.Packet;
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import org.activeio.packet.ByteBufferPacket;
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/**
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* Control file holds the last known good state of the journal. It stores the state in
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* record that is versioned and repeated twice in the file so that a failure in the
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* middle of the write of the first or second record do not not result in an unknown
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* state.
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*
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* @version $Revision: 1.1 $
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*/
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final public class ControlFile implements Disposable { |
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/** The File that holds the control data. */
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private final RandomAccessFile file;
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private final FileChannel channel;
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private final ByteBufferPacket controlData;
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private long controlDataVersion=0; |
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private FileLock lock;
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private boolean disposed; |
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public ControlFile(File fileName, int controlDataSize) throws IOException { |
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boolean existed = fileName.exists();
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file = new RandomAccessFile(fileName, "rw"); |
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channel = file.getChannel(); |
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controlData = new ByteBufferPacket(ByteBuffer.allocateDirect(controlDataSize));
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} |
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/**
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* Locks the control file.
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* @throws IOException
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*/
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public void lock() throws IOException { |
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if( lock==null ) { |
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lock = channel.tryLock(); |
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if( lock ==null ) |
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throw new IOException("Journal is allready opened by another application"); |
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} |
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} |
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/**
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* Un locks the control file.
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* @throws IOException
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*/
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public void unlock() throws IOException { |
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if( lock != null ) { |
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lock.release(); |
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lock=null;
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} |
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} |
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public boolean load() throws IOException { |
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long l = file.length();
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if( l < controlData.capacity() ) {
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controlDataVersion=0; |
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controlData.position(0); |
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controlData.limit(0); |
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return false; |
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} else {
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file.seek(0); |
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long v1 = file.readLong();
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file.seek(controlData.capacity()+8); |
93 | 0 |
long v1check = file.readLong();
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95 | 0 |
file.seek(controlData.capacity()+16); |
96 | 0 |
long v2 = file.readLong();
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97 | 0 |
file.seek((controlData.capacity()*2)+24); |
98 | 0 |
long v2check = file.readLong();
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if( v2 == v2check ) {
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controlDataVersion = v2; |
102 | 0 |
file.seek(controlData.capacity()+24); |
103 | 0 |
controlData.clear(); |
104 | 0 |
channel.read(controlData.getByteBuffer()); |
105 | 0 |
} else if ( v1 == v1check ){ |
106 | 0 |
controlDataVersion = v1; |
107 | 0 |
file.seek(controlData.capacity()+8); |
108 | 0 |
controlData.clear(); |
109 | 0 |
channel.read(controlData.getByteBuffer()); |
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} else {
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// Bummer.. Both checks are screwed. we don't know
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// if any of the two buffer are ok. This should
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// only happen is data got corrupted.
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throw new IOException("Control data corrupted."); |
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} |
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return true; |
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} |
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} |
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public void store() throws IOException { |
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controlDataVersion++; |
122 | 36 |
file.setLength((controlData.capacity()*2)+32); |
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file.seek(0); |
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// Write the first copy of the control data.
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126 | 36 |
file.writeLong(controlDataVersion); |
127 | 36 |
controlData.clear(); |
128 | 36 |
channel.write(controlData.getByteBuffer()); |
129 | 36 |
file.writeLong(controlDataVersion); |
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// Write the second copy of the control data.
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132 | 36 |
file.writeLong(controlDataVersion); |
133 | 36 |
controlData.clear(); |
134 | 36 |
channel.write(controlData.getByteBuffer()); |
135 | 36 |
file.writeLong(controlDataVersion); |
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137 | 36 |
channel.force(false);
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} |
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140 | 36 |
public Packet getControlData() {
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141 | 36 |
controlData.clear(); |
142 | 36 |
return controlData;
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} |
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145 | 10 |
public void dispose() { |
146 | 10 |
if( disposed )
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147 | 0 |
return;
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148 | 10 |
disposed=true;
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149 | 10 |
try {
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150 | 10 |
unlock(); |
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} catch (IOException e) {
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} |
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153 | 10 |
try {
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file.close(); |
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} catch (IOException e) {
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} |
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} |
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} |
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