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comparison src/org/dancres/blitz/entry/ci/SimpleCacheLines.java @ 0:3dc0c5604566

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Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
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-1:000000000000 0:3dc0c5604566
1 package org.dancres.blitz.entry.ci;
2
3 import java.util.ArrayList;
4
5 import com.go.trove.util.IntHashMap;
6
7 import org.dancres.blitz.entry.TupleLocator;
8 import org.dancres.blitz.entry.EntrySleeve;
9
10 /**
11 Maintains a set of cache lines (key'd by hashcode) for a particular
12 field of one type of Entry.
13 */
14 class SimpleCacheLines implements CacheLines {
15 private IntHashMap theHashCodes = new IntHashMap();
16 private int theOffset;
17 private String theName;
18
19 SimpleCacheLines(int anOffset, String aName) {
20 theOffset = anOffset;
21 theName = aName;
22 }
23
24 public String getName() {
25 return theName;
26 }
27
28 public TupleLocator getIds(int aHashcode) {
29 CacheLine myEntries = getLine(aHashcode, false);
30
31 if (myEntries == null)
32 return ArrayLocatorImpl.EMPTY_LOCATOR;
33
34 synchronized(myEntries) {
35 return myEntries.getLocator();
36 }
37 }
38
39 /**
40 @return the number of entries under a particular hashcode
41 */
42 public int getSize(int aHashcode) {
43 CacheLine myEntries = getLine(aHashcode, false);
44
45 if (myEntries == null)
46 return 0;
47
48 synchronized(myEntries) {
49 return myEntries.getSize();
50 }
51 }
52
53 /**
54 @return the number of different hashcodes we know about
55 */
56 public int getSize() {
57 synchronized(theHashCodes) {
58 return theHashCodes.size();
59 }
60 }
61
62 public void insert(EntrySleeve aSleeve) {
63 int myKey = getKey(aSleeve);
64
65 synchronized(theHashCodes) {
66 CacheLine myEntries = getLine(myKey, true);
67
68 synchronized(myEntries) {
69 myEntries.insert(aSleeve);
70 }
71 }
72 }
73
74 public void remove(EntrySleeve aSleeve) {
75 int myKey = getKey(aSleeve);
76
77 synchronized(theHashCodes) {
78 CacheLine myEntries = getLine(myKey, false);
79
80 synchronized(myEntries) {
81 myEntries.remove(aSleeve);
82 }
83
84 if (myEntries.getSize() == 0)
85 theHashCodes.remove(myKey);
86 }
87 }
88
89 private int getKey(EntrySleeve aSleeve) {
90 int myHash = aSleeve.getHashCodeForField(theOffset);
91
92 return myHash;
93 }
94
95 private CacheLine getLine(int aKey, boolean doCreate) {
96 CacheLine myEntries;
97
98 synchronized(theHashCodes) {
99 myEntries = (CacheLine) theHashCodes.get(aKey);
100
101 if ((myEntries == null) && doCreate) {
102 myEntries = new CacheLine();
103 theHashCodes.put(aKey, myEntries);
104 }
105 }
106
107 return myEntries;
108 }
109 }