001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.kahadb.journal;
018    
019    import java.io.DataInput;
020    import java.io.DataOutput;
021    import java.io.IOException;
022    import java.util.concurrent.CountDownLatch;
023    
024    /**
025     * Used as a location in the data store.
026     * 
027     * @version $Revision: 741741 $
028     */
029    public final class Location implements Comparable<Location> {
030    
031        public static final byte USER_TYPE = 1;
032        public static final byte NOT_SET_TYPE = 0;
033        public static final int NOT_SET = -1;
034    
035        private int dataFileId = NOT_SET;
036        private int offset = NOT_SET;
037        private int size = NOT_SET;
038        private byte type = NOT_SET_TYPE;
039        private CountDownLatch latch;
040    
041        public Location() {
042        }
043    
044        public Location(Location item) {
045            this.dataFileId = item.dataFileId;
046            this.offset = item.offset;
047            this.size = item.size;
048            this.type = item.type;
049        }
050    
051        public Location(int dataFileId, int offset) {
052            this.dataFileId=dataFileId;
053            this.offset=offset;
054        }
055    
056        boolean isValid() {
057            return dataFileId != NOT_SET;
058        }
059    
060        /**
061         * @return the size of the data record including the header.
062         */
063        public int getSize() {
064            return size;
065        }
066    
067        /**
068         * @param size the size of the data record including the header.
069         */
070        public void setSize(int size) {
071            this.size = size;
072        }
073    
074        public int getOffset() {
075            return offset;
076        }
077    
078        public void setOffset(int offset) {
079            this.offset = offset;
080        }
081    
082        public int getDataFileId() {
083            return dataFileId;
084        }
085    
086        public void setDataFileId(int file) {
087            this.dataFileId = file;
088        }
089    
090        public byte getType() {
091            return type;
092        }
093    
094        public void setType(byte type) {
095            this.type = type;
096        }
097    
098        public String toString() {
099            return dataFileId+":"+offset;
100        }
101    
102        public void writeExternal(DataOutput dos) throws IOException {
103            dos.writeInt(dataFileId);
104            dos.writeInt(offset);
105            dos.writeInt(size);
106            dos.writeByte(type);
107        }
108    
109        public void readExternal(DataInput dis) throws IOException {
110            dataFileId = dis.readInt();
111            offset = dis.readInt();
112            size = dis.readInt();
113            type = dis.readByte();
114        }
115    
116        public CountDownLatch getLatch() {
117            return latch;
118        }
119    
120        public void setLatch(CountDownLatch latch) {
121            this.latch = latch;
122        }
123    
124        public int compareTo(Location o) {
125            Location l = (Location)o;
126            if (dataFileId == l.dataFileId) {
127                int rc = offset - l.offset;
128                return rc;
129            }
130            return dataFileId - l.dataFileId;
131        }
132    
133        public boolean equals(Object o) {
134            boolean result = false;
135            if (o instanceof Location) {
136                result = compareTo((Location)o) == 0;
137            }
138            return result;
139        }
140    
141        public int hashCode() {
142            return dataFileId ^ offset;
143        }
144    
145    }