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1 package com.quadcap.sql;
2
3
40
41 import java.io.Externalizable  ;
42 import java.io.IOException ;
43 import java.io.ObjectInput ;
44 import java.io.ObjectOutput ;
45
46 import java.util.Vector ;
47
48 import java.sql.SQLException ;
49
50 import antlr.RecognitionException;
51
52 import com.quadcap.sql.types.Value;
53
54 import com.quadcap.util.Debug;
55
56
62 public class VectorExpression extends TableExpression
63 implements Externalizable
64 {
65 Vector expressions = new Vector ();
66 int rank = 1;
67
68 public VectorExpression() {}
69
70 public void addElement(Expression expression) throws RecognitionException {
71 if (expressions.size() == 0) {
72 rank = expression.rank() + 1;
74 } else {
75 if (expression.rank() != rank-1) {
76 throw new RecognitionException(
77 "Mismatched ranks in table expression");
78 }
79 }
80 expressions.addElement(expression);
81 }
82
83 public int rank() { return rank; }
84
85 public boolean isUpdatable() { return false; }
86
87 public void getBaseTables(Vector v) {}
88
89 public int size() { return expressions.size(); }
90
91 public final Expression get(int i) {
92 return (Expression)expressions.get(i);
93 }
94
95 public Row getValues(Session session, Cursor cursor) throws SQLException {
96 if (rank == 1) {
97 Row values = new Row();
98 for (int i = 0; i < expressions.size(); i++) {
99 Expression e = (Expression)expressions.elementAt(i);
100 values.addElement(e.getValue(session, cursor));
101 }
102 return values;
103 } else if (rank == 2) {
104 Expression e = (Expression)expressions.elementAt(0);
105 return e.getValues(session, cursor);
106 }
107 return null;
108 }
109
110 public Cursor getCursor(Session session, Cursor cursor)
111 throws SQLException
112 {
113 if (rank == 1) {
114 Vector v = new Vector ();
115 v.addElement(getValues(session, cursor));
116 return new StaticCursor(session, v);
117 } else if (rank == 2) {
118 Vector cursorVec = new Vector ();
119 for (int i = 0; i < expressions.size(); i++) {
120 Expression e = (Expression)expressions.elementAt(i);
121 cursorVec.addElement(e.getValues(session, cursor));
122 }
123 return new StaticCursor(session, cursorVec);
124 } else {
125 return null;
126 }
127 }
128
129 public void invert() {
130 throw new RuntimeException ("Can't invert vector expression");
131 }
132
133 public void visitSubExpressions(ExpressionVisitor ev) {
134 for (int i = 0; i < expressions.size(); i++) {
135 Expression ex = (Expression)expressions.elementAt(i);
136 ev.visit(ex);
137 }
138 }
139
140 public String toString() {
141 StringBuffer sb = new StringBuffer ();
142 for (int i = 0; i < expressions.size(); i++) {
143 if (i > 0) sb.append(", ");
144 sb.append(expressions.elementAt(i).toString());
145 }
146 return sb.toString();
147 }
148
149 public void readExternal(ObjectInput in)
150 throws IOException , ClassNotFoundException
151 {
152 expressions = (Vector )in.readObject();
153 }
154
155 public void writeExternal(ObjectOutput out) throws IOException {
156 out.writeObject(expressions);
157 }
158
159
163 public Value getParameter(Session session, int pos) {
164 try {
165 if (rank == 2) {
166 VectorExpression v = (VectorExpression)expressions.get(0);
167 Expression e = v.get(pos-1);
168 return e.getValue(session, null);
169 }
170 } catch (Throwable t) {}
171 return null;
172 }
173
174 public String name() { return "[]"; }
176 }
178 |
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