001: package com.quadcap.sql;
002:
003: /* Copyright 1999 - 2003 Quadcap Software. All rights reserved.
004: *
005: * This software is distributed under the Quadcap Free Software License.
006: * This software may be used or modified for any purpose, personal or
007: * commercial. Open Source redistributions are permitted. Commercial
008: * redistribution of larger works derived from, or works which bundle
009: * this software requires a "Commercial Redistribution License"; see
010: * http://www.quadcap.com/purchase.
011: *
012: * Redistributions qualify as "Open Source" under one of the following terms:
013: *
014: * Redistributions are made at no charge beyond the reasonable cost of
015: * materials and delivery.
016: *
017: * Redistributions are accompanied by a copy of the Source Code or by an
018: * irrevocable offer to provide a copy of the Source Code for up to three
019: * years at the cost of materials and delivery. Such redistributions
020: * must allow further use, modification, and redistribution of the Source
021: * Code under substantially the same terms as this license.
022: *
023: * Redistributions of source code must retain the copyright notices as they
024: * appear in each source code file, these license terms, and the
025: * disclaimer/limitation of liability set forth as paragraph 6 below.
026: *
027: * Redistributions in binary form must reproduce this Copyright Notice,
028: * these license terms, and the disclaimer/limitation of liability set
029: * forth as paragraph 6 below, in the documentation and/or other materials
030: * provided with the distribution.
031: *
032: * The Software is provided on an "AS IS" basis. No warranty is
033: * provided that the Software is free of defects, or fit for a
034: * particular purpose.
035: *
036: * Limitation of Liability. Quadcap Software shall not be liable
037: * for any damages suffered by the Licensee or any third party resulting
038: * from use of the Software.
039: */
040:
041: import java.io.Externalizable;
042: import java.io.IOException;
043: import java.io.ObjectInput;
044: import java.io.ObjectOutput;
045:
046: import java.util.Vector;
047:
048: import java.sql.SQLException;
049:
050: import antlr.RecognitionException;
051:
052: import com.quadcap.sql.types.Value;
053:
054: import com.quadcap.util.Debug;
055:
056: /**
057: * This might be a vector (row value constructor) or a cursor (table value
058: * constructor)
059: *
060: * @author Stan Bailes
061: */
062: public class VectorExpression extends TableExpression implements
063: Externalizable {
064: Vector expressions = new Vector();
065: int rank = 1;
066:
067: public VectorExpression() {
068: }
069:
070: public void addElement(Expression expression)
071: throws RecognitionException {
072: if (expressions.size() == 0) {
073: // determine rank
074: rank = expression.rank() + 1;
075: } else {
076: if (expression.rank() != rank - 1) {
077: throw new RecognitionException(
078: "Mismatched ranks in table expression");
079: }
080: }
081: expressions.addElement(expression);
082: }
083:
084: public int rank() {
085: return rank;
086: }
087:
088: public boolean isUpdatable() {
089: return false;
090: }
091:
092: public void getBaseTables(Vector v) {
093: }
094:
095: public int size() {
096: return expressions.size();
097: }
098:
099: public final Expression get(int i) {
100: return (Expression) expressions.get(i);
101: }
102:
103: public Row getValues(Session session, Cursor cursor)
104: throws SQLException {
105: if (rank == 1) {
106: Row values = new Row();
107: for (int i = 0; i < expressions.size(); i++) {
108: Expression e = (Expression) expressions.elementAt(i);
109: values.addElement(e.getValue(session, cursor));
110: }
111: return values;
112: } else if (rank == 2) {
113: Expression e = (Expression) expressions.elementAt(0);
114: return e.getValues(session, cursor);
115: }
116: return null;
117: }
118:
119: public Cursor getCursor(Session session, Cursor cursor)
120: throws SQLException {
121: if (rank == 1) {
122: Vector v = new Vector();
123: v.addElement(getValues(session, cursor));
124: return new StaticCursor(session, v);
125: } else if (rank == 2) {
126: Vector cursorVec = new Vector();
127: for (int i = 0; i < expressions.size(); i++) {
128: Expression e = (Expression) expressions.elementAt(i);
129: cursorVec.addElement(e.getValues(session, cursor));
130: }
131: return new StaticCursor(session, cursorVec);
132: } else {
133: return null;
134: }
135: }
136:
137: public void invert() {
138: throw new RuntimeException("Can't invert vector expression");
139: }
140:
141: public void visitSubExpressions(ExpressionVisitor ev) {
142: for (int i = 0; i < expressions.size(); i++) {
143: Expression ex = (Expression) expressions.elementAt(i);
144: ev.visit(ex);
145: }
146: }
147:
148: public String toString() {
149: StringBuffer sb = new StringBuffer();
150: for (int i = 0; i < expressions.size(); i++) {
151: if (i > 0)
152: sb.append(", ");
153: sb.append(expressions.elementAt(i).toString());
154: }
155: return sb.toString();
156: }
157:
158: public void readExternal(ObjectInput in) throws IOException,
159: ClassNotFoundException {
160: expressions = (Vector) in.readObject();
161: }
162:
163: public void writeExternal(ObjectOutput out) throws IOException {
164: out.writeObject(expressions);
165: }
166:
167: /**
168: * Return the (one-based) parameter from this VectorExpression which
169: * is assumed to be a simple list of parameterized expressions
170: */
171: public Value getParameter(Session session, int pos) {
172: try {
173: if (rank == 2) {
174: VectorExpression v = (VectorExpression) expressions
175: .get(0);
176: Expression e = v.get(pos - 1);
177: return e.getValue(session, null);
178: }
179: } catch (Throwable t) {
180: }
181: return null;
182: }
183:
184: //#ifdef DEBUG
185: public String name() {
186: return "[]";
187: }
188: //#endif
189: }
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