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20 package org.apache.directory.mavibot.btree;
21
22 import java.util.HashMap;
23 import java.util.Map;
24 import java.util.concurrent.locks.Lock;
25 import java.util.concurrent.locks.ReadWriteLock;
26 import java.util.concurrent.locks.ReentrantLock;
27 import java.util.concurrent.locks.ReentrantReadWriteLock;
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34 public class InMemoryTransactionManager extends AbstractTransactionManager
35 {
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37 private Lock transactionLock = new ReentrantLock();
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40 private static final ThreadLocal<Integer> context = new ThreadLocal<Integer>();
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43 private Map<String, BTreeHeader<?, ?>> currentBTreeHeaders = new HashMap<String, BTreeHeader<?, ?>>();
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46 private Map<String, BTreeHeader<?, ?>> newBTreeHeaders = new HashMap<String, BTreeHeader<?, ?>>();
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49 private ReadWriteLock btreeHeadersLock = new ReentrantReadWriteLock();
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54 @Override
55 public void beginTransaction()
56 {
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58 transactionLock.lock();
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61 Integer nbTxnLevel = context.get();
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63 if ( nbTxnLevel == null )
64 {
65 context.set( 1 );
66 }
67 else
68 {
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70 context.set( nbTxnLevel + 1 );
71 }
72 }
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78 @Override
79 public void commit()
80 {
81 int nbTxnStarted = context.get();
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83 if ( nbTxnStarted == 0 )
84 {
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86 transactionLock.unlock();
87
88 return;
89 }
90 else
91 {
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94 context.set( nbTxnStarted - 1 );
95 }
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98 transactionLock.unlock();
99 }
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105 @Override
106 public void rollback()
107 {
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109 context.set( 0 );
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112 transactionLock.unlock();
113 }
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119 public BTreeHeader getBTreeHeader( String name )
120 {
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122 btreeHeadersLock.readLock().lock();
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125 BTreeHeader<?, ?> btreeHeader = currentBTreeHeaders.get( name );
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128 btreeHeadersLock.readLock().unlock();
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130 return btreeHeader;
131 }
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139 public void updateNewBTreeHeaders( BTreeHeader btreeHeader )
140 {
141 newBTreeHeaders.put( btreeHeader.getBtree().getName(), btreeHeader );
142 }
143 }