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8 package org.ozoneDB.core.storage.gammaStore;
9
10 import java.io.ByteArrayInputStream  ;
11 import java.io.ByteArrayOutputStream ;
12 import java.io.IOException ;
13 import java.io.ObjectInputStream ;
14 import java.util.Iterator ;
15 import java.util.LinkedHashMap ;
16 import java.util.Map ;
17 import java.util.Set ;
18 import org.ozoneDB.OzoneInternalException;
19
20
24 public class DataFileManager {
25
26 private static final String DATAFILEPREFIX = "";
27 private static final String DATAFILEPOSTFIX = ".datafile";
28
29
38 private static final int NAMECONVERTRADIX = 16;
39
40 private LinkedHashMap dataFiles = new LinkedHashMap () {
41
42 public boolean removeEldestEntry(Map.Entry entry) {
43 if (size() > getMaxOpenDataFiles()) {
44 Storage dataFile = (Storage) entry.getValue();
45 try {
46 dataFile.close();
47 } catch (IOException e) {
48 throw new OzoneInternalException(e);
49 }
50 }
51 return false;
52 }
53
54 };
55
56 private int maxOpenDataFiles;
57
58 private StorageFactory dataFileFactory;
59
60 private ObjectStreamClasses objectStreamClasses;
61
62 public DataFileManager() {
63 }
64
65 public void setObjectStreamClasses(ObjectStreamClasses objectStreamClasses) {
66 this.objectStreamClasses = objectStreamClasses;
67 }
68
69 public ObjectStreamClasses getObjectStreamClasses() {
70 return objectStreamClasses;
71 }
72
73 private Map getDataFiles() {
74 return dataFiles;
75 }
76
77 private static String dataFileIdToStorageName(int dataFileId) {
78 return DATAFILEPREFIX + Integer.toString(dataFileId, NAMECONVERTRADIX) + DATAFILEPOSTFIX;
79 }
80
81 private Storage getDataFile(int dataFileId) {
82 Storage result = (Storage) getDataFiles().get(new Integer (dataFileId));
83 if (result == null) {
84 try {
85 result = dataFileFactory.createStorage(dataFileIdToStorageName(dataFileId));
86 } catch (IOException e) {
87 throw new OzoneInternalException(e);
88 }
89 dataFiles.put(new Integer (dataFileId), result);
90 }
91 return result;
92 }
93
94 public GammaContainer getContainer(ContainerLocation containerLocation) throws ClassNotFoundException {
95 try {
96 Storage dataFile = getDataFile(containerLocation.getDataFileId());
97 dataFile.seek(containerLocation.getPosition());
98 long id = dataFile.readLong();
99 int size = dataFile.readInt();
100 byte[] buf = new byte[size];
101 dataFile.readFully(buf);
102 GammaObjectInputStream in = new GammaObjectInputStream(new ByteArrayInputStream (buf), getObjectStreamClasses());
103 GammaContainer result = (GammaContainer) in.readObject();
104 return result;
105 } catch (IOException e) {
106 throw new OzoneInternalException(e);
107 }
108 }
109
110 public void saveContainer(ContainerLocation containerLocation, GammaContainer container, int freeSize) {
111 try {
112 Storage dataFile = getDataFile(containerLocation.getDataFileId());
113 dataFile.seek(containerLocation.getPosition());
114 dataFile.writeLong(container.getObjectId().value());
115 dataFile.writeInt(freeSize);
116 ByteArrayOutputStream buf = new ByteArrayOutputStream ();
117 GammaObjectOutputStream out = new GammaObjectOutputStream(buf, getObjectStreamClasses());
118 out.writeObject(container);
119 dataFile.write(buf.toByteArray());
120 } catch (IOException e) {
121 throw new OzoneInternalException(e);
122 }
123 }
124
125 public int getMaxOpenDataFiles() {
126 return maxOpenDataFiles;
127 }
128
129 public void setMaxOpenDataFiles(int maxOpenDataFiles) {
130 this.maxOpenDataFiles = maxOpenDataFiles;
131 if (getDataFiles().size() > getMaxOpenDataFiles()) {
132 Iterator i = getDataFiles().values().iterator();
133 for (int cnt = 0; cnt < getDataFiles().size(); cnt++) {
134 i.next();
135 }
136 while (i.hasNext()) {
137 Storage dataFile = (Storage) i.next();
138 try {
139 dataFile.close();
140 } catch (IOException e) {
141 throw new OzoneInternalException(e);
142 }
143 i.remove();
144 }
145 }
146 }
147
148 }
149 |
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