Skip to main content
aboutsummaryrefslogtreecommitdiffstats
blob: b4b49c190eadb187287fe458909638c5d821e53c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
/**
 * Copyright (c) 2004 - 2011 Eike Stepper (Berlin, Germany) and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Stefan Winkler - initial API and implementation
 *    Stefan Winkler - bug 249610: [DB] Support external references (Implementation)
 *    Eike Stepper - maintenance
 */
package org.eclipse.emf.cdo.server.internal.db;

import org.eclipse.emf.cdo.common.id.CDOIDExternal;
import org.eclipse.emf.cdo.common.id.CDOIDUtil;
import org.eclipse.emf.cdo.common.protocol.CDODataInput;
import org.eclipse.emf.cdo.common.protocol.CDODataOutput;
import org.eclipse.emf.cdo.server.IStoreAccessor;
import org.eclipse.emf.cdo.server.StoreThreadLocal;
import org.eclipse.emf.cdo.server.db.IDBStore;
import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
import org.eclipse.emf.cdo.server.db.IIDHandler;
import org.eclipse.emf.cdo.server.db.IPreparedStatementCache;
import org.eclipse.emf.cdo.server.db.IPreparedStatementCache.ReuseProbability;
import org.eclipse.emf.cdo.server.internal.db.bundle.OM;

import org.eclipse.net4j.db.DBException;
import org.eclipse.net4j.db.DBType;
import org.eclipse.net4j.db.DBUtil;
import org.eclipse.net4j.db.ddl.IDBField;
import org.eclipse.net4j.db.ddl.IDBIndex;
import org.eclipse.net4j.db.ddl.IDBTable;
import org.eclipse.net4j.util.ReflectUtil.ExcludeFromDump;
import org.eclipse.net4j.util.lifecycle.Lifecycle;
import org.eclipse.net4j.util.om.monitor.OMMonitor;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.concurrent.atomic.AtomicLong;

/**
 * @author Stefan Winkler
 */
public class ExternalReferenceManager extends Lifecycle
{
  private static final int NULL = 0;

  private IDBTable table;

  private IDBField idField;

  private IDBField uriField;

  private IDBField timestampField;

  private final IIDHandler idHandler;

  private AtomicLong lastMappedID = new AtomicLong(NULL);

  @ExcludeFromDump
  private transient String sqlSelectByLongID;

  @ExcludeFromDump
  private transient String sqlSelectByURI;

  @ExcludeFromDump
  private transient String sqlInsert;

  public ExternalReferenceManager(IIDHandler idHandler)
  {
    this.idHandler = idHandler;
  }

  public IIDHandler getIDHandler()
  {
    return idHandler;
  }

  public long mapExternalReference(CDOIDExternal id, long commitTime)
  {
    IDBStoreAccessor accessor = getAccessor();
    return mapURI(accessor, id.getURI(), commitTime);
  }

  public CDOIDExternal unmapExternalReference(long mappedId)
  {
    IDBStoreAccessor accessor = getAccessor();
    return CDOIDUtil.createExternal(unmapURI(accessor, mappedId));
  }

  public long mapURI(IDBStoreAccessor accessor, String uri, long commitTime)
  {
    long result = lookupByURI(accessor, uri);
    if (result < NULL)
    {
      // mapping found
      return result;
    }

    return insertNew(accessor, uri, commitTime);
  }

  public String unmapURI(IDBStoreAccessor accessor, long mappedId)
  {
    IPreparedStatementCache statementCache = accessor.getStatementCache();
    PreparedStatement stmt = null;
    ResultSet resultSet = null;

    try
    {
      stmt = statementCache.getPreparedStatement(sqlSelectByLongID, ReuseProbability.HIGH);
      stmt.setLong(1, mappedId);
      resultSet = stmt.executeQuery();

      if (!resultSet.next())
      {
        OM.LOG.error("External ID " + mappedId + " not found. Database inconsistent!");
        throw new IllegalStateException("External ID " + mappedId + " not found. Database inconsistent!");
      }

      return resultSet.getString(1);
    }
    catch (SQLException e)
    {
      throw new DBException(e);
    }
    finally
    {
      DBUtil.close(resultSet);
      statementCache.releasePreparedStatement(stmt);
    }
  }

  public void rawExport(Connection connection, CDODataOutput out, long fromCommitTime, long toCommitTime)
      throws IOException
  {
    String where = " WHERE " + timestampField + " BETWEEN " + fromCommitTime + " AND " + toCommitTime;
    DBUtil.serializeTable(out, connection, table, null, where);
  }

  public void rawImport(Connection connection, CDODataInput in, long fromCommitTime, long toCommitTime,
      OMMonitor monitor) throws IOException
  {
    DBUtil.deserializeTable(in, connection, table, monitor);
  }

  @Override
  protected void doActivate() throws Exception
  {
    super.doActivate();

    IDBStore store = idHandler.getStore();
    table = store.getDBSchema().addTable("cdo_external_refs"); //$NON-NLS-1$
    idField = table.addField("id", idHandler.getDBType()); //$NON-NLS-1$
    uriField = table.addField("uri", DBType.VARCHAR); //$NON-NLS-1$
    timestampField = table.addField("committime", DBType.BIGINT); //$NON-NLS-1$

    table.addIndex(IDBIndex.Type.PRIMARY_KEY, idField);
    table.addIndex(IDBIndex.Type.NON_UNIQUE, uriField);

    IDBStoreAccessor writer = store.getWriter(null);
    Connection connection = writer.getConnection();
    Statement statement = null;
    ResultSet resultSet = null;

    try
    {
      statement = connection.createStatement();
      store.getDBAdapter().createTable(table, statement);
      connection.commit();

      String sql = "SELECT MIN(" + idField + ") FROM " + table;
      resultSet = statement.executeQuery(sql);

      if (resultSet.next())
      {
        lastMappedID.set(resultSet.getLong(1));
      }

      // else: resultSet is empty => table is empty
      // and lastMappedId stays 0 - as initialized.
    }
    catch (SQLException ex)
    {
      connection.rollback();
      throw new DBException(ex);
    }
    finally
    {
      DBUtil.close(resultSet);
      DBUtil.close(statement);
      writer.release();
    }

    StringBuilder builder = new StringBuilder();
    builder.append("INSERT INTO ");
    builder.append(table);
    builder.append("(");
    builder.append(idField);
    builder.append(",");
    builder.append(uriField);
    builder.append(",");
    builder.append(timestampField);
    builder.append(") VALUES (?, ?, ?)");
    sqlInsert = builder.toString();

    builder = new StringBuilder();
    builder.append("SELECT "); //$NON-NLS-1$
    builder.append(idField);
    builder.append(" FROM "); //$NON-NLS-1$
    builder.append(table);
    builder.append(" WHERE "); //$NON-NLS-1$
    builder.append(uriField);
    builder.append("=?"); //$NON-NLS-1$
    sqlSelectByURI = builder.toString();

    builder = new StringBuilder();
    builder.append("SELECT "); //$NON-NLS-1$
    builder.append(uriField);
    builder.append(" FROM "); //$NON-NLS-1$
    builder.append(table);
    builder.append(" WHERE "); //$NON-NLS-1$
    builder.append(idField);
    builder.append("=?"); //$NON-NLS-1$
    sqlSelectByLongID = builder.toString();
  }

  private long insertNew(IDBStoreAccessor accessor, String uri, long commitTime)
  {
    long newMappedID = lastMappedID.decrementAndGet();

    IPreparedStatementCache statementCache = accessor.getStatementCache();
    PreparedStatement stmt = null;

    try
    {
      stmt = statementCache.getPreparedStatement(sqlInsert, ReuseProbability.MEDIUM);
      stmt.setLong(1, newMappedID);
      stmt.setString(2, uri);
      stmt.setLong(3, commitTime);

      DBUtil.update(stmt, true);
      return newMappedID;
    }
    catch (SQLException e)
    {
      throw new DBException(e);
    }
    finally
    {
      statementCache.releasePreparedStatement(stmt);
    }
  }

  private long lookupByURI(IDBStoreAccessor accessor, String uri)
  {
    IPreparedStatementCache statementCache = accessor.getStatementCache();
    PreparedStatement stmt = null;
    ResultSet resultSet = null;

    try
    {
      stmt = statementCache.getPreparedStatement(sqlSelectByURI, ReuseProbability.HIGH);
      stmt.setString(1, uri);

      resultSet = stmt.executeQuery();

      if (resultSet.next())
      {
        return resultSet.getLong(1);
      }

      // Not found ...
      return NULL;
    }
    catch (SQLException e)
    {
      throw new DBException(e);
    }
    finally
    {
      DBUtil.close(resultSet);
      statementCache.releasePreparedStatement(stmt);
    }
  }

  private static IDBStoreAccessor getAccessor()
  {
    IStoreAccessor accessor = StoreThreadLocal.getAccessor();
    if (accessor == null)
    {
      throw new IllegalStateException("Can only be called from within a valid IDBStoreAccessor context");
    }

    return (IDBStoreAccessor)accessor;
  }
}

Back to the top