001: /*
002: * $Id: ResolveFromNodeVisitor.java,v 1.4 2005/12/20 18:32:27 ahimanikya Exp $
003: * =======================================================================
004: * Copyright (c) 2004 Axion Development Team. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * 1. Redistributions of source code must retain the above
011: * copyright notice, this list of conditions and the following
012: * disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The names "Tigris", "Axion", nor the names of its contributors may
020: * not be used to endorse or promote products derived from this
021: * software without specific prior written permission.
022: *
023: * 4. Products derived from this software may not be called "Axion", nor
024: * may "Tigris" or "Axion" appear in their names without specific prior
025: * written permission.
026: *
027: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
028: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
029: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
030: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
031: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
032: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
033: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
034: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
035: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
036: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
037: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
038: * =======================================================================
039: */
040: package org.axiondb.engine.visitors;
041:
042: import java.util.List;
043:
044: import org.axiondb.AxionException;
045: import org.axiondb.Database;
046: import org.axiondb.FromNode;
047: import org.axiondb.Table;
048: import org.axiondb.TableIdentifier;
049: import org.axiondb.engine.commands.SelectCommand;
050: import org.axiondb.engine.commands.SubSelectCommand;
051:
052: /**
053: * Resolves a (@link FromNode) for a given (@link Database)
054: *
055: * @author Ahimanikya Satapathy
056: * @author Ritesh Adval
057: */
058: public class ResolveFromNodeVisitor {
059:
060: public void resolveFromNode(FromNode from, Database db)
061: throws AxionException {
062: if (from == null) {
063: return;
064: }
065: resolveFromNode(from, from.getLeft(), db, FromNode.TYPE_LEFT);
066: resolveFromNode(from, from.getRight(), db, FromNode.TYPE_RIGHT);
067: }
068:
069: private void resolveFromNode(FromNode from, Object child,
070: Database db, int type) throws AxionException {
071: if (child instanceof SelectCommand) {
072: SubSelectCommand selCmd = ((SubSelectCommand) child);
073: Table view = selCmd.getTableView(db, null, true);
074: TableIdentifier tid = new TableIdentifier(view.getName(),
075: selCmd.getAlias());
076: if (type == FromNode.TYPE_LEFT) {
077: from.setLeft(tid);
078: } else {
079: from.setRight(tid);
080: }
081: } else if (child instanceof FromNode) {
082: resolveFromNode((FromNode) child, db);
083: }
084: }
085:
086: public void resolveFromNode(FromNode node, Database db,
087: List selected) throws AxionException {
088: if (node == null) {
089: return;
090: }
091:
092: ResolveSelectableVisitor resolveSel = new ResolveSelectableVisitor(
093: db);
094: node.setCondition(resolveSel.visit(node.getCondition(),
095: selected, node.toTableArray()));
096: MaskSelectablesForTablesVisitor filter = new MaskSelectablesForTablesVisitor();
097:
098: Object left = node.getLeft();
099: if (left instanceof FromNode) {
100: FromNode childNode = (FromNode) left;
101: resolveFromNode(childNode, db, filter
102: .maskAliasListForTables(childNode, selected));
103: }
104:
105: Object right = node.getRight();
106: if (right instanceof FromNode) {
107: FromNode childNode = (FromNode) right;
108: resolveFromNode(childNode, db, filter
109: .maskAliasListForTables(childNode, selected));
110: }
111: }
112:
113: }
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