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comparison src/org/dancres/blitz/entry/ci/BitCacheLines.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 com.go.trove.util.IntHashMap;
4
5 import org.dancres.blitz.entry.EntrySleeve;
6
7 import org.dancres.struct.BitIndex;
8
9 /**
10 Maintains a set of cache lines (key'd by hashcode) for a particular
11 field of one type of Entry.
12 */
13 class BitCacheLines {
14 private IntHashMap theHashCodes = new IntHashMap();
15 private int theOffset;
16 private String theName;
17
18 private int theSize;
19
20 BitCacheLines(int anOffset, String aName, int aSize) {
21 theOffset = anOffset;
22 theName = aName;
23 theSize = aSize;
24 }
25
26 String getName() {
27 return theName;
28 }
29
30 BitIndex getHits(int aHashcode) {
31 BitCacheLine myEntries = getLine(aHashcode, false);
32
33 if (myEntries == null)
34 return null;
35
36 return myEntries.getSlots();
37 }
38
39 /**
40 @return the number of entries under a particular hashcode
41 */
42 int getSize(int aHashcode) {
43 BitCacheLine myEntries = getLine(aHashcode, false);
44
45 if (myEntries == null)
46 return 0;
47
48 return myEntries.getSize();
49 }
50
51 /**
52 @return the number of different hashcodes we know about
53 */
54 int getSize() {
55 synchronized(theHashCodes) {
56 return theHashCodes.size();
57 }
58 }
59
60 void insert(EntrySleeve aSleeve, int aSlot) {
61 int myKey = getKey(aSleeve);
62
63 synchronized(theHashCodes) {
64 BitCacheLine myEntries = getLine(myKey, true);
65 myEntries.insert(aSleeve, aSlot);
66 }
67 }
68
69 void remove(EntrySleeve aSleeve, int aSlot) {
70 int myKey = getKey(aSleeve);
71
72 synchronized (theHashCodes) {
73 BitCacheLine myEntries = getLine(myKey, false);
74
75 myEntries.remove(aSleeve, aSlot);
76
77 if (myEntries.getSize() == 0)
78 theHashCodes.remove(myKey);
79 }
80 }
81
82 private int getKey(EntrySleeve aSleeve) {
83 int myHash = aSleeve.getHashCodeForField(theOffset);
84
85 return myHash;
86 }
87
88 private synchronized BitCacheLine getLine(int aKey, boolean doCreate) {
89 BitCacheLine myEntries;
90
91 myEntries = (BitCacheLine) theHashCodes.get(aKey);
92
93 if ((myEntries == null) && doCreate) {
94 myEntries = new BitCacheLine(theSize);
95 theHashCodes.put(aKey, myEntries);
96 }
97
98 return myEntries;
99 }
100 }