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1
18 package org.apache.activemq.kaha.impl.async;
19
20 import java.io.IOException  ;
21 import java.io.RandomAccessFile ;
22 import java.util.concurrent.ConcurrentHashMap ;
23
24 import org.apache.activemq.kaha.impl.async.DataFileAppender.WriteCommand;
25 import org.apache.activemq.kaha.impl.async.DataFileAppender.WriteKey;
26 import org.apache.activemq.util.ByteSequence;
27
33 final class DataFileAccessor {
34
35 private final DataFile dataFile;
36 private final ConcurrentHashMap <WriteKey, WriteCommand> inflightWrites;
37 private final RandomAccessFile file;
38 private boolean disposed;
39
40
46 public DataFileAccessor(AsyncDataManager dataManager, DataFile dataFile) throws IOException {
47 this.dataFile = dataFile;
48 this.inflightWrites = dataManager.getInflightWrites();
49 this.file = dataFile.openRandomAccessFile(false);
50 }
51
52 public DataFile getDataFile() {
53 return dataFile;
54 }
55
56 public void dispose() {
57 if( disposed )
58 return;
59 disposed=true;
60 try {
61 dataFile.closeRandomAccessFile(file);
62 } catch (IOException e) {
63 e.printStackTrace();
64 }
65 }
66
67 public ByteSequence readRecord(Location location) throws IOException {
68
69 if( !location.isValid() )
70 throw new IOException ("Invalid location: "+location);
71
72 WriteCommand asyncWrite = (WriteCommand) inflightWrites.get(new WriteKey(location));
73 if( asyncWrite!= null ) {
74 return asyncWrite.data;
75 }
76
77 try {
78
79 if( location.getSize()==Location.NOT_SET ) {
80 file.seek(location.getOffset());
81 location.setSize(file.readInt());
82 file.seek(location.getOffset()+AsyncDataManager.ITEM_HEAD_SPACE);
83 } else {
84 file.seek(location.getOffset()+AsyncDataManager.ITEM_HEAD_SPACE);
85 }
86
87 byte[] data=new byte[location.getSize()-AsyncDataManager.ITEM_HEAD_FOOT_SPACE];
88 file.readFully(data);
89 return new ByteSequence(data, 0, data.length);
90
91 } catch (RuntimeException e) {
92 throw new IOException ("Invalid location: "+location+", : "+e);
93 }
94 }
95
96 public void readLocationDetails(Location location) throws IOException {
97 WriteCommand asyncWrite = (WriteCommand) inflightWrites.get(new WriteKey(location));
98 if( asyncWrite!= null ) {
99 location.setSize(asyncWrite.location.getSize());
100 location.setType(asyncWrite.location.getType());
101 } else {
102 file.seek(location.getOffset());
103 location.setSize(file.readInt());
104 location.setType(file.readByte());
105 }
106 }
107
108 public boolean readLocationDetailsAndValidate(Location location) {
109 try {
110 WriteCommand asyncWrite = (WriteCommand) inflightWrites.get(new WriteKey(location));
111 if( asyncWrite!= null ) {
112 location.setSize(asyncWrite.location.getSize());
113 location.setType(asyncWrite.location.getType());
114 } else {
115 file.seek(location.getOffset());
116 location.setSize(file.readInt());
117 location.setType(file.readByte());
118
119 byte data[] = new byte[3];
120 file.seek(location.getOffset()+AsyncDataManager.ITEM_HEAD_OFFSET_TO_SOR);
121 file.readFully(data);
122 if( data[0] != AsyncDataManager.ITEM_HEAD_SOR[0] ||
123 data[1] != AsyncDataManager.ITEM_HEAD_SOR[1] ||
124 data[2] != AsyncDataManager.ITEM_HEAD_SOR[2] ) {
125 return false;
126 }
127 file.seek(location.getOffset()+location.getSize()-AsyncDataManager.ITEM_FOOT_SPACE);
128 file.readFully(data);
129 if( data[0] != AsyncDataManager.ITEM_HEAD_EOR[0] ||
130 data[1] != AsyncDataManager.ITEM_HEAD_EOR[1] ||
131 data[2] != AsyncDataManager.ITEM_HEAD_EOR[2] ) {
132 return false;
133 }
134 }
135 } catch (IOException e) {
136 return false;
137 }
138 return true;
139 }
140
141 public void updateRecord(Location location, ByteSequence data, boolean sync) throws IOException {
142
143 file.seek(location.getOffset()+AsyncDataManager.ITEM_HEAD_SPACE);
144 int size = Math.min(data.getLength(), location.getSize());
145 file.write(data.getData(), data.getOffset(), size);
146 if( sync ) {
147 file.getFD().sync();
148 }
149
150 }
151
152 }
153 |
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