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1
21 package com.db4o.header;
22
23 import java.io.*;
24
25 import com.db4o.*;
26
27
28
31 public class FileHeader1 extends FileHeader {
32
33
35
50 private static final byte[] SIGNATURE = {(byte)'d', (byte)'b', (byte)'4', (byte)'o'};
51
52 private static byte VERSION = 1;
53
54 private static final int HEADER_LOCK_OFFSET = SIGNATURE.length + 1;
55 private static final int OPEN_TIME_OFFSET = HEADER_LOCK_OFFSET + YapConst.INT_LENGTH;
56 private static final int ACCESS_TIME_OFFSET = OPEN_TIME_OFFSET + YapConst.LONG_LENGTH;
57 private static final int TRANSACTION_POINTER_OFFSET = ACCESS_TIME_OFFSET + YapConst.LONG_LENGTH;
58
59 static final int LENGTH = TRANSACTION_POINTER_OFFSET + (YapConst.INT_LENGTH * 6);
60
61 private TimerFileLock _timerFileLock;
62
63 private Transaction _interruptedTransaction;
64
65 private FileHeaderVariablePart1 _variablePart;
66
67 public void close() throws IOException {
68 _timerFileLock.close();
69 }
70
71 public void initNew(YapFile file) throws IOException {
72 commonTasksForNewAndRead(file);
73 _variablePart = new FileHeaderVariablePart1(0, file.systemData());
74 writeVariablePart(file, 0);
75 }
76
77 protected FileHeader newOnSignatureMatch(YapFile file, YapReader reader) {
78 if(signatureMatches(reader, SIGNATURE, VERSION)){
79 return new FileHeader1();
80 }
81 return null;
82 }
83
84 private void newTimerFileLock(YapFile file) {
85 _timerFileLock = TimerFileLock.forFile(file);
86 }
87
88 public Transaction interruptedTransaction() {
89 return _interruptedTransaction;
90 }
91
92 public int length() {
93 return LENGTH;
94 }
95
96 protected void readFixedPart(YapFile file, YapReader reader) throws IOException {
97 commonTasksForNewAndRead(file);
98 reader.seek(TRANSACTION_POINTER_OFFSET);
99 _interruptedTransaction = Transaction.readInterruptedTransaction(file, reader);
100 file.blockSizeReadFromFile(reader.readInt());
101 readClassCollectionAndFreeSpace(file, reader);
102 _variablePart = new FileHeaderVariablePart1(reader.readInt(), file.systemData());
103 }
104
105 private void commonTasksForNewAndRead(YapFile file){
106 newTimerFileLock(file);
107 file.i_handlers.oldEncryptionOff();
108 }
109
110 public void readVariablePart(YapFile file) {
111 _variablePart.read(file.getSystemTransaction());
112 }
113
114 public void writeFixedPart(
115 YapFile file, boolean shuttingDown, YapWriter writer, int blockSize, int freespaceID) {
116 writer.append(SIGNATURE);
117 writer.append(VERSION);
118 writer.writeInt((int)timeToWrite(_timerFileLock.openTime(), shuttingDown));
119 writer.writeLong(timeToWrite(_timerFileLock.openTime(), shuttingDown));
120 writer.writeLong(timeToWrite(System.currentTimeMillis(), shuttingDown));
121 writer.writeInt(0);
122 writer.writeInt(0);
123 writer.writeInt(blockSize);
124 writer.writeInt(file.systemData().classCollectionID());
125 writer.writeInt(freespaceID);
126 writer.writeInt(_variablePart.getID());
127 writer.noXByteCheck();
128 writer.write();
129 }
130
131 public void writeTransactionPointer(Transaction systemTransaction, int transactionAddress) {
132 writeTransactionPointer(systemTransaction, transactionAddress, 0, TRANSACTION_POINTER_OFFSET);
133 }
134
135 public void writeVariablePart(YapFile file, int part) {
136 _variablePart.setStateDirty();
137 _variablePart.write(file.getSystemTransaction());
138 }
139
140 }
141 |
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