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1
5 package org.h2.index;
6
7 import java.sql.SQLException  ;
8
9 import org.h2.engine.Constants;
10 import org.h2.engine.Database;
11 import org.h2.engine.Session;
12 import org.h2.message.Message;
13 import org.h2.result.Row;
14 import org.h2.result.SearchRow;
15 import org.h2.store.Storage;
16 import org.h2.table.Column;
17 import org.h2.table.TableData;
18 import org.h2.util.ObjectArray;
19 import org.h2.value.DataType;
20 import org.h2.value.Value;
21 import org.h2.value.ValueLob;
22
23
26 public class ScanIndex extends Index {
27 private int firstFree = -1;
28 private ObjectArray rows = new ObjectArray();
29 private Storage storage;
30 private TableData tableData;
31 private boolean containsLargeObject;
32
33 public ScanIndex(TableData table, int id, Column[] columns, IndexType indexType)
34 throws SQLException {
35 super(table, id, table.getName() + "_TABLE_SCAN", columns, indexType);
36 tableData = table;
37 Database db = table.getDatabase();
38 if(!db.isPersistent() || id < 0) {
39 return;
40 }
41 this.storage = db.getStorage(table, id, true);
42 int count = storage.getRecordCount();
43 rowCount = count;
44 table.setRowCount(count);
45 trace.info("open existing " + table.getName() + " rows: " + count);
46 for(int i=0; i<columns.length; i++) {
47 if(DataType.isLargeObject(columns[i].getType())) {
48 containsLargeObject = true;
49 }
50 }
51 }
52
53 public void remove(Session session) throws SQLException {
54 truncate(session);
55 if(storage != null) {
56 storage.delete(session);
57 }
58 }
59
60 public void truncate(Session session) throws SQLException {
61 if(storage == null) {
62 rows = new ObjectArray();
63 firstFree = -1;
64 } else {
65 storage.truncate(session);
66 }
67 if(containsLargeObject && tableData.isPersistent()) {
68 ValueLob.removeAllForTable(database, table.getId());
69 }
70 tableData.setRowCount(0);
71 rowCount = 0;
72 }
73
74 public String getCreateSQL() {
75 return null;
76 }
77
78 public void close(Session session) throws SQLException {
79 if(storage != null) {
80 storage = null;
81 }
82 }
83
84 public Row getRow(int key) throws SQLException {
85 if(storage != null) {
86 return (Row) storage.getRecord(key);
87 }
88 return (Row) rows.get(key);
89 }
90
91 public void add(Session session, Row row) throws SQLException {
92 if(storage != null) {
93 if(containsLargeObject) {
94 for(int i=0; i<row.getColumnCount(); i++) {
95 Value v = row.getValue(i);
96 Value v2 = v.link(database, getId());
97 session.unlinkAtCommitStop(v2);
98 if(v != v2) {
99 row.setValue(i, v2);
100 }
101 }
102 }
103 storage.addRecord(session, row, Storage.ALLOCATE_POS);
104 } else {
105 if (firstFree == -1) {
106 int key = rows.size();
107 row.setPos(key);
108 rows.add(row);
109 } else {
110 int key = firstFree;
111 Row free = (Row) rows.get(key);
112 firstFree = free.getPos();
113 row.setPos(key);
114 rows.set(key, row);
115 }
116 }
117 rowCount++;
118 }
119
120 public void remove(Session session, Row row) throws SQLException {
121 if(storage != null) {
122 storage.removeRecord(session, row.getPos());
123 if(containsLargeObject) {
124 for(int i=0; i<row.getColumnCount(); i++) {
125 Value v = row.getValue(i);
126 if(v.isLinked()) {
127 session.unlinkAtCommit(v);
128 }
129 }
130 }
131 } else {
132 Row free = new Row();
133 free.setPos(firstFree);
134 int key = row.getPos();
135 rows.set(key, free);
136 firstFree = key;
137 }
138 rowCount--;
139 }
140
141 public Cursor find(Session session, SearchRow first, SearchRow last) throws SQLException {
142 return new ScanCursor(this);
143 }
144
145 public int getCost(int[] masks) throws SQLException {
146 int cost = tableData.getRowCount() + Constants.COST_ROW_OFFSET;
147 if(storage != null) {
148 cost *= 10;
149 }
150 return cost;
151 }
152
153 Row getNextRow(Row row) throws SQLException {
154 if(storage == null) {
155 int key;
156 if (row == null) {
157 key = -1;
158 } else {
159 key = row.getPos();
160 }
161 while (true) {
162 key++;
163 if (key >= rows.size()) {
164 return null;
165 }
166 row = (Row) rows.get(key);
167 if (!row.isEmpty()) {
168 return row;
169 }
170 }
171 }
172 int pos = storage.getNext(row);
173 if (pos < 0) {
174 return null;
175 }
176 return (Row) storage.getRecord(pos);
177 }
178
179 public int getColumnIndex(Column col) {
180 return -1;
182 }
183
184 public void checkRename() throws SQLException {
185 throw Message.getUnsupportedException();
186 }
187
188 public boolean needRebuild() {
189 return false;
190 }
191
192 public boolean canGetFirstOrLast(boolean first) {
193 return false;
194 }
195
196 public Value findFirstOrLast(Session session, boolean first) throws SQLException {
197 throw Message.getUnsupportedException();
198 }
199
200 }
201 |
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