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Diffstat (limited to 'plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ExternalReferenceManager.java')
-rw-r--r--plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ExternalReferenceManager.java245
1 files changed, 245 insertions, 0 deletions
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ExternalReferenceManager.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ExternalReferenceManager.java
new file mode 100644
index 0000000000..2bbfcac381
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ExternalReferenceManager.java
@@ -0,0 +1,245 @@
+/**
+ * Copyright (c) 2004 - 2009 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.server.db.CDODBUtil;
+import org.eclipse.emf.cdo.server.db.IDBStore;
+import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
+import org.eclipse.emf.cdo.server.db.IExternalReferenceManager;
+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.DBUtil;
+import org.eclipse.net4j.util.ReflectUtil.ExcludeFromDump;
+import org.eclipse.net4j.util.lifecycle.Lifecycle;
+import org.eclipse.net4j.util.lifecycle.LifecycleUtil;
+
+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 implements IExternalReferenceManager.Internal
+{
+ private IDBStore store;
+
+ private AtomicLong lastMappedId = new AtomicLong(0);
+
+ @ExcludeFromDump
+ private transient String sqlSelectByLongId;
+
+ @ExcludeFromDump
+ private transient String sqlSelectByURI;
+
+ @ExcludeFromDump
+ private transient String sqlInsert;
+
+ public ExternalReferenceManager()
+ {
+ }
+
+ public IDBStore getStore()
+ {
+ return store;
+ }
+
+ public void setStore(IDBStore store)
+ {
+ this.store = store;
+ }
+
+ public long mapExternalReference(IDBStoreAccessor accessor, CDOIDExternal id)
+ {
+ String uri = id.getURI();
+ long result = lookupByID(accessor, uri);
+ if (result < 0)
+ {
+ // mapping found
+ return result;
+ }
+
+ return insertNew(accessor, uri);
+ }
+
+ public CDOIDExternal unmapExternalReference(IDBStoreAccessor accessor, long mappedId)
+ {
+ PreparedStatement stmt = null;
+ ResultSet rs = null;
+
+ try
+ {
+ stmt = accessor.getStatementCache().getPreparedStatement(sqlSelectByLongId, ReuseProbability.HIGH);
+ stmt.setLong(1, mappedId);
+ rs = stmt.executeQuery();
+
+ if (!rs.next())
+ {
+ OM.LOG.error("External ID " + mappedId + " not found. Database inconsistent!");
+ throw new IllegalStateException("External ID " + mappedId + " not found. Database inconsistent!");
+ }
+
+ String uri = rs.getString(1);
+ return CDOIDUtil.createExternal(uri);
+ }
+ catch (SQLException e)
+ {
+ throw new DBException(e);
+ }
+ finally
+ {
+ DBUtil.close(rs);
+ accessor.getStatementCache().releasePreparedStatement(stmt);
+ }
+ }
+
+ @Override
+ protected void doBeforeActivate() throws Exception
+ {
+ super.doBeforeActivate();
+ checkState(store, "Store is not set");
+ }
+
+ @Override
+ protected void doActivate() throws Exception
+ {
+ super.doActivate();
+ IDBStoreAccessor reader = getStore().getReader(null);
+ Connection connection = reader.getConnection();
+ Statement statement = null;
+
+ try
+ {
+ String sql = "SELECT MIN(" + CDODBSchema.EXTERNAL_ID + ") FROM " + CDODBSchema.EXTERNAL_REFS;
+
+ statement = connection.createStatement();
+ ResultSet result = statement.executeQuery(sql);
+
+ if (result.next())
+ {
+ lastMappedId.set(result.getLong(1));
+ }
+
+ // else: resultSet is empty => table is empty
+ // and lastMappedId stays 0 - as initialized.
+ }
+ catch (SQLException ex)
+ {
+ throw new DBException(ex);
+ }
+ finally
+ {
+ DBUtil.close(statement);
+ LifecycleUtil.deactivate(reader); // Don't let the null-context accessor go to the pool!
+ }
+
+ sqlInsert = "INSERT INTO " + CDODBSchema.EXTERNAL_REFS + " VALUES (?,?,?)"; //$NON-NLS-1$ //$NON-NLS-2$
+ StringBuilder builder = new StringBuilder();
+ builder.append("INSERT INTO ");
+ builder.append(CDODBSchema.EXTERNAL_REFS);
+ builder.append("(");
+ builder.append(CDODBSchema.EXTERNAL_ID);
+ builder.append(",");
+ builder.append(CDODBSchema.EXTERNAL_URI);
+ builder.append(") VALUES (?,?)");
+
+ sqlInsert = builder.toString();
+
+ builder = new StringBuilder();
+ builder.append("SELECT "); //$NON-NLS-1$
+ builder.append(CDODBSchema.EXTERNAL_ID);
+ builder.append(" FROM "); //$NON-NLS-1$
+ builder.append(CDODBSchema.EXTERNAL_REFS);
+ builder.append(" WHERE "); //$NON-NLS-1$
+ builder.append(CDODBSchema.EXTERNAL_URI);
+ builder.append(" =? "); //$NON-NLS-1$
+
+ sqlSelectByURI = builder.toString();
+
+ builder = new StringBuilder();
+ builder.append("SELECT "); //$NON-NLS-1$
+ builder.append(CDODBSchema.EXTERNAL_URI);
+ builder.append(" FROM "); //$NON-NLS-1$
+ builder.append(CDODBSchema.EXTERNAL_REFS);
+ builder.append(" WHERE "); //$NON-NLS-1$
+ builder.append(CDODBSchema.EXTERNAL_ID);
+ builder.append(" =? "); //$NON-NLS-1$
+
+ sqlSelectByLongId = builder.toString();
+ }
+
+ private long insertNew(IDBStoreAccessor accessor, String uri)
+ {
+ long newMappedId = lastMappedId.decrementAndGet();
+
+ PreparedStatement stmt = null;
+
+ try
+ {
+ stmt = accessor.getStatementCache().getPreparedStatement(sqlInsert, ReuseProbability.MEDIUM);
+ stmt.setLong(1, newMappedId);
+ stmt.setString(2, uri);
+
+ CDODBUtil.sqlUpdate(stmt, true);
+ return newMappedId;
+ }
+ catch (SQLException e)
+ {
+ throw new DBException(e);
+ }
+ finally
+ {
+ accessor.getStatementCache().releasePreparedStatement(stmt);
+ }
+ }
+
+ private long lookupByID(IDBStoreAccessor accessor, String uri)
+ {
+ PreparedStatement stmt = null;
+ ResultSet rs = null;
+
+ try
+ {
+ stmt = accessor.getStatementCache().getPreparedStatement(sqlSelectByURI, ReuseProbability.HIGH);
+ stmt.setString(1, uri);
+
+ rs = stmt.executeQuery();
+
+ if (rs.next())
+ {
+ return rs.getLong(1);
+ }
+ else
+ {
+ // not found ...
+ return 0;
+ }
+ }
+ catch (SQLException e)
+ {
+ throw new DBException(e);
+ }
+ finally
+ {
+ DBUtil.close(rs);
+ accessor.getStatementCache().releasePreparedStatement(stmt);
+ }
+ }
+}

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