1 | /* |
2 | * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0, |
3 | * and the EPL 1.0 (http://h2database.com/html/license.html). |
4 | * Initial Developer: H2 Group |
5 | */ |
6 | package org.h2.expression; |
7 | |
8 | import org.h2.command.Parser; |
9 | import org.h2.engine.Constants; |
10 | import org.h2.engine.FunctionAlias; |
11 | import org.h2.engine.Session; |
12 | import org.h2.table.ColumnResolver; |
13 | import org.h2.table.TableFilter; |
14 | import org.h2.util.StatementBuilder; |
15 | import org.h2.value.DataType; |
16 | import org.h2.value.Value; |
17 | import org.h2.value.ValueArray; |
18 | import org.h2.value.ValueNull; |
19 | import org.h2.value.ValueResultSet; |
20 | |
21 | /** |
22 | * This class wraps a user-defined function. |
23 | */ |
24 | public class JavaFunction extends Expression implements FunctionCall { |
25 | |
26 | private final FunctionAlias functionAlias; |
27 | private final FunctionAlias.JavaMethod javaMethod; |
28 | private final Expression[] args; |
29 | |
30 | public JavaFunction(FunctionAlias functionAlias, Expression[] args) { |
31 | this.functionAlias = functionAlias; |
32 | this.javaMethod = functionAlias.findJavaMethod(args); |
33 | this.args = args; |
34 | } |
35 | |
36 | @Override |
37 | public Value getValue(Session session) { |
38 | return javaMethod.getValue(session, args, false); |
39 | } |
40 | |
41 | @Override |
42 | public int getType() { |
43 | return javaMethod.getDataType(); |
44 | } |
45 | |
46 | @Override |
47 | public void mapColumns(ColumnResolver resolver, int level) { |
48 | for (Expression e : args) { |
49 | e.mapColumns(resolver, level); |
50 | } |
51 | } |
52 | |
53 | @Override |
54 | public Expression optimize(Session session) { |
55 | boolean allConst = isDeterministic(); |
56 | for (int i = 0, len = args.length; i < len; i++) { |
57 | Expression e = args[i].optimize(session); |
58 | args[i] = e; |
59 | allConst &= e.isConstant(); |
60 | } |
61 | if (allConst) { |
62 | return ValueExpression.get(getValue(session)); |
63 | } |
64 | return this; |
65 | } |
66 | |
67 | @Override |
68 | public void setEvaluatable(TableFilter tableFilter, boolean b) { |
69 | for (Expression e : args) { |
70 | if (e != null) { |
71 | e.setEvaluatable(tableFilter, b); |
72 | } |
73 | } |
74 | } |
75 | |
76 | @Override |
77 | public int getScale() { |
78 | return DataType.getDataType(getType()).defaultScale; |
79 | } |
80 | |
81 | @Override |
82 | public long getPrecision() { |
83 | return Integer.MAX_VALUE; |
84 | } |
85 | |
86 | @Override |
87 | public int getDisplaySize() { |
88 | return Integer.MAX_VALUE; |
89 | } |
90 | |
91 | @Override |
92 | public String getSQL() { |
93 | StatementBuilder buff = new StatementBuilder(); |
94 | // TODO always append the schema once FUNCTIONS_IN_SCHEMA is enabled |
95 | if (functionAlias.getDatabase().getSettings().functionsInSchema || |
96 | !functionAlias.getSchema().getName().equals(Constants.SCHEMA_MAIN)) { |
97 | buff.append( |
98 | Parser.quoteIdentifier(functionAlias.getSchema().getName())) |
99 | .append('.'); |
100 | } |
101 | buff.append(Parser.quoteIdentifier(functionAlias.getName())).append('('); |
102 | for (Expression e : args) { |
103 | buff.appendExceptFirst(", "); |
104 | buff.append(e.getSQL()); |
105 | } |
106 | return buff.append(')').toString(); |
107 | } |
108 | |
109 | @Override |
110 | public void updateAggregate(Session session) { |
111 | for (Expression e : args) { |
112 | if (e != null) { |
113 | e.updateAggregate(session); |
114 | } |
115 | } |
116 | } |
117 | |
118 | @Override |
119 | public String getName() { |
120 | return functionAlias.getName(); |
121 | } |
122 | |
123 | @Override |
124 | public ValueResultSet getValueForColumnList(Session session, |
125 | Expression[] argList) { |
126 | Value v = javaMethod.getValue(session, argList, true); |
127 | return v == ValueNull.INSTANCE ? null : (ValueResultSet) v; |
128 | } |
129 | |
130 | @Override |
131 | public Expression[] getArgs() { |
132 | return args; |
133 | } |
134 | |
135 | @Override |
136 | public boolean isEverything(ExpressionVisitor visitor) { |
137 | switch(visitor.getType()) { |
138 | case ExpressionVisitor.DETERMINISTIC: |
139 | if (!isDeterministic()) { |
140 | return false; |
141 | } |
142 | // only if all parameters are deterministic as well |
143 | break; |
144 | case ExpressionVisitor.GET_DEPENDENCIES: |
145 | visitor.addDependency(functionAlias); |
146 | break; |
147 | default: |
148 | } |
149 | for (Expression e : args) { |
150 | if (e != null && !e.isEverything(visitor)) { |
151 | return false; |
152 | } |
153 | } |
154 | return true; |
155 | } |
156 | |
157 | @Override |
158 | public int getCost() { |
159 | int cost = javaMethod.hasConnectionParam() ? 25 : 5; |
160 | for (Expression e : args) { |
161 | cost += e.getCost(); |
162 | } |
163 | return cost; |
164 | } |
165 | |
166 | @Override |
167 | public boolean isDeterministic() { |
168 | return functionAlias.isDeterministic(); |
169 | } |
170 | |
171 | @Override |
172 | public Expression[] getExpressionColumns(Session session) { |
173 | switch (getType()) { |
174 | case Value.RESULT_SET: |
175 | ValueResultSet rs = getValueForColumnList(session, getArgs()); |
176 | return getExpressionColumns(session, rs.getResultSet()); |
177 | case Value.ARRAY: |
178 | return getExpressionColumns(session, (ValueArray) getValue(session)); |
179 | } |
180 | return super.getExpressionColumns(session); |
181 | } |
182 | |
183 | @Override |
184 | public boolean isBufferResultSetToLocalTemp() { |
185 | return functionAlias.isBufferResultSetToLocalTemp(); |
186 | } |
187 | |
188 | } |