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1
5 package org.h2.index;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Session;
10 import org.h2.message.Message;
11 import org.h2.result.Row;
12 import org.h2.result.SearchRow;
13 import org.h2.table.Column;
14 import org.h2.table.TableData;
15 import org.h2.util.IntIntHashMap;
16 import org.h2.util.ValueHashMap;
17 import org.h2.value.Value;
18 import org.h2.value.ValueArray;
19
20
23 public class HashIndex extends Index {
24
25 private ValueHashMap rows;
26 private IntIntHashMap intMap;
27 private TableData tableData;
28
29 public HashIndex(TableData table, int id, String indexName, Column[] columns, IndexType indexType) {
30 super(table, id, indexName, columns, indexType);
31 this.tableData = table;
32 reset();
33 }
34
35 private void reset() {
36 if(columns.length == 1 && columns[0].getType() == Value.INT) {
37 intMap = new IntIntHashMap();
38 } else {
39 rows = new ValueHashMap(table.getDatabase());
40 }
41 }
42
43 public void close(Session session) {
44 }
46
47 public void truncate(Session session) throws SQLException {
48 reset();
49 }
50
51 public void remove(Session session) throws SQLException {
52 }
54
55 public void add(Session session, Row row) throws SQLException {
56 if(intMap!=null) {
57 int key = row.getValue(columns[0].getColumnId()).getInt();
58 intMap.put(key, row.getPos());
59 } else {
60 Value key = getKey(row);
61 Object old = rows.get(key);
62 if (old != null) {
63 throw getDuplicateKeyException();
65 }
66 Integer pos = new Integer (row.getPos());
67 rows.put(getKey(row), pos);
68 }
69 rowCount++;
70 }
71
72 public void remove(Session session, Row row) throws SQLException {
73 if(intMap!=null) {
74 int key = row.getValue(columns[0].getColumnId()).getInt();
75 intMap.remove(key);
76 } else {
77 rows.remove(getKey(row));
78 }
79 rowCount--;
80 }
81
82 private Value getKey(SearchRow row) {
83 if (columns.length == 1) {
84 Column column = columns[0];
85 int index = column.getColumnId();
86 Value v = row.getValue(index);
87 return v;
88 }
89 Value[] list = new Value[columns.length];
90 for (int i = 0; i < columns.length; i++) {
91 Column column = columns[i];
92 int index = column.getColumnId();
93 list[i] = row.getValue(index);
94 }
95 return ValueArray.get(list);
96 }
97
98 public Cursor find(Session session, SearchRow first, SearchRow last) throws SQLException {
99 if(first == null || last == null) {
100 throw Message.getInternalError();
102 }
103 Row result;
104 if(intMap!=null) {
105 int key = first.getValue(columns[0].getColumnId()).getInt();
106 int pos = intMap.get(key);
107 if(pos != IntIntHashMap.NOT_FOUND) {
108 result = tableData.getRow(pos);
109 } else {
110 result = null;
111 }
112 } else {
113 Integer pos = (Integer ) rows.get(getKey(first));
114 if (pos == null) {
115 result = null;
116 } else {
117 result = tableData.getRow(pos.intValue());
118 }
119 }
120 return new HashCursor(result);
121 }
122
123 public int getCost(int[] masks) {
124 for (int i = 0; i < columns.length; i++) {
125 Column column = columns[i];
126 int index = column.getColumnId();
127 int mask = masks[index];
128 if ((mask & IndexCondition.EQUALITY) != IndexCondition.EQUALITY) {
129 return Integer.MAX_VALUE;
130 }
131 }
132 return 2;
133 }
134
135 public void checkRename() throws SQLException {
136 }
138
139 public boolean needRebuild() {
140 return true;
141 }
142
143 public boolean canGetFirstOrLast(boolean first) {
144 return false;
145 }
146
147 public Value findFirstOrLast(Session session, boolean first) throws SQLException {
148 throw Message.getUnsupportedException();
149 }
150
151 }
152 |
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