1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the  "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 /*
19  * $Id: FunctionMultiArgs.java 468655 2006-10-28 07:12:06Z minchau $
20  */
21 package org.apache.xpath.functions;
22 
23 import org.apache.xalan.res.XSLMessages;
24 import org.apache.xpath.Expression;
25 import org.apache.xpath.ExpressionOwner;
26 import org.apache.xpath.XPathVisitor;
27 import org.apache.xpath.res.XPATHErrorResources;
28 
29 /**
30  * Base class for functions that accept an undetermined number of multiple
31  * arguments.
32  * @xsl.usage advanced
33  */
34 public class FunctionMultiArgs extends Function3Args
35 {
36     static final long serialVersionUID = 7117257746138417181L;
37 
38   /** Argument expressions that are at index 3 or greater.
39    *  @serial */
40   Expression[] m_args;
41 
42   /**
43    * Return an expression array containing arguments at index 3 or greater.
44    *
45    * @return An array that contains the arguments at index 3 or greater.
46    */
getArgs()47   public Expression[] getArgs()
48   {
49     return m_args;
50   }
51 
52   /**
53    * Set an argument expression for a function.  This method is called by the
54    * XPath compiler.
55    *
56    * @param arg non-null expression that represents the argument.
57    * @param argNum The argument number index.
58    *
59    * @throws WrongNumberArgsException If a derived class determines that the
60    * number of arguments is incorrect.
61    */
setArg(Expression arg, int argNum)62   public void setArg(Expression arg, int argNum)
63           throws WrongNumberArgsException
64   {
65 
66     if (argNum < 3)
67       super.setArg(arg, argNum);
68     else
69     {
70       if (null == m_args)
71       {
72         m_args = new Expression[1];
73         m_args[0] = arg;
74       }
75       else
76       {
77 
78         // Slow but space conservative.
79         Expression[] args = new Expression[m_args.length + 1];
80 
81         System.arraycopy(m_args, 0, args, 0, m_args.length);
82 
83         args[m_args.length] = arg;
84         m_args = args;
85       }
86       arg.exprSetParent(this);
87     }
88   }
89 
90   /**
91    * This function is used to fixup variables from QNames to stack frame
92    * indexes at stylesheet build time.
93    * @param vars List of QNames that correspond to variables.  This list
94    * should be searched backwards for the first qualified name that
95    * corresponds to the variable reference qname.  The position of the
96    * QName in the vector from the start of the vector will be its position
97    * in the stack frame (but variables above the globalsTop value will need
98    * to be offset to the current stack frame).
99    */
fixupVariables(java.util.Vector vars, int globalsSize)100   public void fixupVariables(java.util.Vector vars, int globalsSize)
101   {
102     super.fixupVariables(vars, globalsSize);
103     if(null != m_args)
104     {
105       for (int i = 0; i < m_args.length; i++)
106       {
107         m_args[i].fixupVariables(vars, globalsSize);
108       }
109     }
110   }
111 
112   /**
113    * Check that the number of arguments passed to this function is correct.
114    *
115    *
116    * @param argNum The number of arguments that is being passed to the function.
117    *
118    * @throws WrongNumberArgsException
119    */
checkNumberArgs(int argNum)120   public void checkNumberArgs(int argNum) throws WrongNumberArgsException{}
121 
122   /**
123    * Constructs and throws a WrongNumberArgException with the appropriate
124    * message for this function object.  This class supports an arbitrary
125    * number of arguments, so this method must never be called.
126    *
127    * @throws WrongNumberArgsException
128    */
reportWrongNumberArgs()129   protected void reportWrongNumberArgs() throws WrongNumberArgsException {
130     String fMsg = XSLMessages.createXPATHMessage(
131         XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
132         new Object[]{ "Programmer's assertion:  the method FunctionMultiArgs.reportWrongNumberArgs() should never be called." });
133 
134     throw new RuntimeException(fMsg);
135   }
136 
137   /**
138    * Tell if this expression or it's subexpressions can traverse outside
139    * the current subtree.
140    *
141    * @return true if traversal outside the context node's subtree can occur.
142    */
canTraverseOutsideSubtree()143   public boolean canTraverseOutsideSubtree()
144   {
145 
146     if (super.canTraverseOutsideSubtree())
147       return true;
148     else
149     {
150       int n = m_args.length;
151 
152       for (int i = 0; i < n; i++)
153       {
154         if (m_args[i].canTraverseOutsideSubtree())
155           return true;
156       }
157 
158       return false;
159     }
160   }
161 
162   class ArgMultiOwner implements ExpressionOwner
163   {
164   	int m_argIndex;
165 
ArgMultiOwner(int index)166   	ArgMultiOwner(int index)
167   	{
168   		m_argIndex = index;
169   	}
170 
171     /**
172      * @see ExpressionOwner#getExpression()
173      */
getExpression()174     public Expression getExpression()
175     {
176       return m_args[m_argIndex];
177     }
178 
179 
180     /**
181      * @see ExpressionOwner#setExpression(Expression)
182      */
setExpression(Expression exp)183     public void setExpression(Expression exp)
184     {
185     	exp.exprSetParent(FunctionMultiArgs.this);
186     	m_args[m_argIndex] = exp;
187     }
188   }
189 
190 
191     /**
192      * @see org.apache.xpath.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
193      */
callArgVisitors(XPathVisitor visitor)194     public void callArgVisitors(XPathVisitor visitor)
195     {
196       super.callArgVisitors(visitor);
197       if (null != m_args)
198       {
199         int n = m_args.length;
200         for (int i = 0; i < n; i++)
201         {
202           m_args[i].callVisitors(new ArgMultiOwner(i), visitor);
203         }
204       }
205     }
206 
207     /**
208      * @see Expression#deepEquals(Expression)
209      */
deepEquals(Expression expr)210     public boolean deepEquals(Expression expr)
211     {
212       if (!super.deepEquals(expr))
213             return false;
214 
215       FunctionMultiArgs fma = (FunctionMultiArgs) expr;
216       if (null != m_args)
217       {
218         int n = m_args.length;
219         if ((null == fma) || (fma.m_args.length != n))
220               return false;
221 
222         for (int i = 0; i < n; i++)
223         {
224           if (!m_args[i].deepEquals(fma.m_args[i]))
225                 return false;
226         }
227 
228       }
229       else if (null != fma.m_args)
230       {
231           return false;
232       }
233 
234       return true;
235     }
236 }
237