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18 package org.apache.activemq.kaha.impl.async;
19
20 import java.io.IOException  ;
21 import java.util.ArrayList ;
22 import java.util.HashMap ;
23 import java.util.Iterator ;
24
25
30 public class DataFileAccessorPool {
31
32 private final AsyncDataManager dataManager;
33 private final HashMap <Integer , Pool> pools = new HashMap <Integer , Pool>();
34 private boolean closed=false;
35
36 int MAX_OPEN_READERS_PER_FILE=5;
37
38 class Pool {
39
40 private final DataFile file;
41 private final ArrayList <DataFileAccessor> pool = new ArrayList <DataFileAccessor>();
42 private boolean used;
43 private int openCounter;
44 private boolean disposed;
45
46 public Pool(DataFile file) {
47 this.file = file;
48 }
49
50 public DataFileAccessor openDataFileReader() throws IOException {
51 DataFileAccessor rc=null;
52 if( pool.isEmpty() ) {
53 rc = new DataFileAccessor(dataManager, file);
54 } else {
55 rc = (DataFileAccessor) pool.remove(pool.size()-1);
56 }
57 used=true;
58 openCounter++;
59 return rc;
60 }
61
62 public void closeDataFileReader(DataFileAccessor reader) {
63 openCounter--;
64 used=true;
65 if(pool.size() >= MAX_OPEN_READERS_PER_FILE || disposed) {
66 reader.dispose();
67 } else {
68 pool.add(reader);
69 }
70 }
71
72 public void clearUsedMark() {
73 used=false;
74 }
75
76 public boolean isUsed() {
77 return used;
78 }
79
80 public void dispose() {
81 for (DataFileAccessor reader : pool) {
82 reader.dispose();
83 }
84 pool.clear();
85 disposed=true;
86 }
87
88 public int getOpenCounter() {
89 return openCounter;
90 }
91
92 }
93
94 public DataFileAccessorPool(AsyncDataManager dataManager){
95 this.dataManager=dataManager;
96 }
97
98 synchronized void clearUsedMark() {
99 for (Iterator iter = pools.values().iterator(); iter.hasNext();) {
100 Pool pool = (Pool) iter.next();
101 pool.clearUsedMark();
102 }
103 }
104
105 synchronized void disposeUnused() {
106 for (Iterator <Pool> iter = pools.values().iterator(); iter.hasNext();) {
107 Pool pool = iter.next();
108 if( !pool.isUsed() ) {
109 pool.dispose();
110 iter.remove();
111 }
112 }
113 }
114
115 synchronized void disposeDataFileAccessors(DataFile dataFile) {
116 if( closed ) {
117 throw new IllegalStateException ("Closed.");
118 }
119 Pool pool = pools.get(dataFile.getDataFileId());
120 if( pool != null ) {
121 if( pool.getOpenCounter()==0 ) {
122 pool.dispose();
123 pools.remove(dataFile.getDataFileId());
124 } else {
125 throw new IllegalStateException ("The data file is still in use: "+dataFile+", use count: "+pool.getOpenCounter());
126 }
127 }
128 }
129
130 synchronized DataFileAccessor openDataFileAccessor(DataFile dataFile) throws IOException {
131 if( closed ) {
132 throw new IOException ("Closed.");
133 }
134
135 Pool pool = pools.get(dataFile.getDataFileId());
136 if( pool == null ) {
137 pool = new Pool(dataFile);
138 pools.put(dataFile.getDataFileId(), pool);
139 }
140 return pool.openDataFileReader();
141 }
142
143 synchronized void closeDataFileAccessor(DataFileAccessor reader) {
144 Pool pool = pools.get(reader.getDataFile().getDataFileId());
145 if( pool == null || closed ) {
146 reader.dispose();
147 } else {
148 pool.closeDataFileReader(reader);
149 }
150 }
151
152 synchronized public void close() {
153 if(closed)
154 return;
155 closed=true;
156 for (Iterator <Pool> iter = pools.values().iterator(); iter.hasNext();) {
157 Pool pool = iter.next();
158 pool.dispose();
159 }
160 pools.clear();
161 }
162
163 }
164 |
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