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1 package com.quadcap.sql;
2
3
40
41 import java.io.ByteArrayOutputStream  ;
42 import java.io.Externalizable ;
43 import java.io.IOException ;
44 import java.io.ObjectInput ;
45 import java.io.ObjectOutput ;
46
47 import java.util.Vector ;
48
49 import java.sql.ResultSet ;
50 import java.sql.SQLException ;
51
52 import com.quadcap.sql.file.ByteUtil;
53
54 import com.quadcap.sql.index.Btree;
55 import com.quadcap.sql.index.Comparator;
56
57 import com.quadcap.sql.file.BlockFile;
58
59 import com.quadcap.util.Debug;
60 import com.quadcap.util.Util;
61
62
67 abstract public class IndexConstraint extends Constraint
68 implements Externalizable {
69 Btree index = null;
70 long indexRoot = -1;
71 protected boolean useComparator = true;
72
73
76 public IndexConstraint() {}
77
78
81 public IndexConstraint(String name) {
82 super(name);
83 }
84
85 public IndexConstraint(String name, Vector names) {
86 super(name, names);
87 }
88
89
95 abstract public byte[] makeKey(Session session, Row row, long rowId)
96 throws SQLException
97 ;
98
99
103 abstract public String constraintType();
104
105
108 public void add(Session session) throws SQLException , IOException {
109 index = null;
110 indexRoot = -1;
111 resetColumns();
112 getIndex(session.getDatabase());
113
114 getColumns();
115 IndexCursor c = table.getCursor(session, this);
116 if (c != null) {
117 try {
118 while (c.next()) {
119 Row row = c.getRow();
120 long rowId = c.getRowId();
121 byte[] key = makeKey(session, row, rowId);
122 if (index.get(key) != null) {
123 throw new SQLException (constraintType() +
124 " constraint violated");
125 }
126 if (session.getConnection().inRecovery()) {
127 rowId = session.getLog().getRowMap(rowId);
128 }
129 index.set(key, key.length, session.getBuf8(rowId), 0, 8);
130 }
131 } finally {
132 c.close();
133 }
134 }
135
136 }
137
138
141 public void delete(Session session) throws IOException {
142 if (indexRoot > 0) {
143 Database db = session.getDatabase();
144 getIndex(db);
145 if (index != null) {
146 index.free();
147 }
148 }
149 }
150
151
154 public void readExternal(ObjectInput in)
155 throws IOException , ClassNotFoundException
156 {
157 super.readExternal(in);
158 indexRoot = in.readLong();
159 useComparator = in.read() == 1;
160 }
161
162
165 public void writeExternal(ObjectOutput out) throws IOException {
166 super.writeExternal(out);
167 out.writeLong(indexRoot);
168 out.write(useComparator ? 1 : 0);
169 }
170
171
174
177 public void checkInsert(Session session, Row row)
178 throws SQLException , IOException
179 {
180 }
181
182 public void checkUpdate(Session session, byte[] oldKey, Row row,
183 Row oldRow, long rowId, Constraint activeIndex)
184 throws SQLException , IOException
185 {
186 }
187
188 public void checkDelete(Session session, Row row, long rowId)
189 throws SQLException , IOException
190 {
191 }
192
193
196
199 public void applyInsert(Session session, Row row, long rowId,
200 Constraint activeIndex)
201 throws SQLException , IOException
202 {
203
204 Database db = session.getDatabase();
205 byte[] key = makeKey(session, row, rowId);
206 AddIndexEntry add = new AddIndexEntry(session, this, key, rowId);
207 if (activeIndex == this) {
208 session.addPendingAction(add);
209 } else {
210 session.doStep(add);
211 }
212 }
213
214 public void applyUpdate(Session session, byte[] oldKey, Row row,
217 Row oldRow, long rowId, Constraint activeIndex)
218 throws SQLException , IOException
219 {
220 byte[] key = makeKey(session, row, rowId);
221 if (activeIndex != this) {
222 oldKey = makeKey(session, oldRow, rowId);
223 }
224 if (Util.compareBytes(key, oldKey) != 0) {
225 UpdateIndex ui =
226 (UpdateIndex)session.getContext(this, isDeferred());
227 if (ui == null) {
228 ui = new UpdateIndex(session, this);
229 session.putContext(this, isDeferred(), ui);
230 }
231 ui.addEntry(key, oldKey, rowId);
232 } else {
233 }
234 }
235
236 public void applyDelete(Session session, Row row, long rowId,
237 Constraint activeIndex)
238 throws SQLException , IOException
239 {
240 Database db = session.getDatabase();
241 byte[] key = makeKey(session, row, rowId);
242
243 if (index == null) getIndex(db);
244 DeleteIndexEntry del = new DeleteIndexEntry(session, this, key);
245 if (activeIndex == this) {
246 session.addPendingAction(del);
247 } else {
248 session.doStep(del);
249 }
250 }
251
252
256 public boolean isUnique() { return true; }
257
258
261 public int getIndexColumnCount() {
262 return getColumnCount();
263 }
264
265
268 public Btree getIndex(Database db) throws IOException {
269 if (index == null) {
270 BlockFile file = db.getFile();
271 boolean create = false;
272 if (indexRoot == -1) {
273 indexRoot = file.newPage();
274 db.updateRelation(table);
275 create = true;
276 }
277 if (useComparator) {
278 Comparator compare = new Key(getIndexColumnCount());
279 index = new Btree(file, compare, indexRoot, create);
280 } else {
281 index = new Btree(file, indexRoot, create);
282 }
283 }
284 return index;
285 }
286
287
290 public String toString() {
291 StringBuffer sb = new StringBuffer ();
292 sb.append(getName());
293 if (table != null) {
294 sb.append("(");
295 try {
296 Vector v = getColumnNames();
297 for (int i = 0; i < v.size(); i++) {
298 if (i > 0) sb.append(',');
299 sb.append(v.elementAt(i).toString());
300 }
301 sb.append(")");
302 } catch (SQLException e) {
303 sb.append("Exception: " + e.toString());
304 }
305 }
306 return sb.toString();
307 }
308 }
309 |
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