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1
8 package org.ozoneDB.core.storage.gammaStore;
9
10 import java.util.Collection  ;
11 import java.util.HashSet ;
12 import java.util.LinkedList ;
13 import java.util.Properties ;
14 import java.util.SortedSet ;
15 import java.util.TreeSet ;
16 import org.ozoneDB.core.ConfigurationException;
17 import org.ozoneDB.core.storage.PropertyConfigurable;
18 import org.ozoneDB.core.storage.PropertyInfo;
19
20 public final class FreeSpaceManager implements PropertyConfigurable {
21
22 public static final PropertyInfo MAXFREESPACESIZEDIFFERENCE = new PropertyInfo(
23 ".maxFreeSpaceSizeDifference",
24 "int",
25 "8",
26 "Maximum difference in size (bytes) when searching for free space.",
27 new String [] { "0", "5", "28" }
28 );
29
30 public static final PropertyInfo MAXSIZE = new PropertyInfo(
31 ".maxSize",
32 "int",
33 "1000",
34 "If the number of free space entries becomes higher than this value, " +
35 "TODO: what exactly?",
36 new String [] { "100", "1000" }
37 );
38
39 private TreeSet freeSpaces;
40
41 private int maxSizeDifference;
42
43 private int maxSize;
44
45 private String prefix;
46
47 public FreeSpaceManager() {
48 }
49
50
53 public FreeSpaceManager(Properties properties, String prefix) {
54 this.prefix = prefix;
55 try {
56 setMaxFreeSpaceSizeDifference(Integer.parseInt(properties.getProperty(prefix + MAXFREESPACESIZEDIFFERENCE.getKey(), MAXFREESPACESIZEDIFFERENCE.getDefaultValue())));
57 setMaxSize(Integer.parseInt(properties.getProperty(prefix + MAXSIZE.getKey(), MAXSIZE.getDefaultValue())));
58 } catch (NumberFormatException e) {
59 throw new ConfigurationException("invalid value", e);
60 }
61 }
62
63
72 public synchronized FreeSpace findFreeSpace(int size) {
73 FreeSpace searchKey = new FreeSpace(0, 0, size);
74 SortedSet found = freeSpaces.tailSet(searchKey);
75 FreeSpace result = (FreeSpace) found.first();
76 if (result.getSize() <= size + maxSizeDifference) {
77 found.remove(result);
78 size--;
79 } else {
80 result = null;
81 }
82 return result;
83 }
84
85
88 public synchronized void registerFreespace(FreeSpace freeSpace) {
89 freeSpaces.add(freeSpace);
90 }
91
92 public synchronized void registerFreespace(int clusterId, int position, int size) {
93 registerFreespace(new FreeSpace(clusterId, position, size));
94 }
95
96 public int getMaxFreeSpaceSizeDifference() {
97 return maxSizeDifference;
98 }
99
100 public void setMaxFreeSpaceSizeDifference(int maxSizeDifference) {
101 this.maxSizeDifference = maxSizeDifference;
102 }
103
104 public int getMaxSize() {
105 return maxSize;
106 }
107
108 public void setMaxSize(int maxSize) {
109 this.maxSize = maxSize;
110 }
111
112 public Collection getPropertyInfos() {
113 Collection result = new LinkedList ();
114 result.add(MAXFREESPACESIZEDIFFERENCE);
115 result.add(MAXSIZE);
116 return result;
117 }
118
119 public String getPrefix() {
120 return prefix;
121 }
122
123 }
124 |
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