org.exist.xquery.UserDefinedFunction Maven / Gradle / Ivy
/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-06 Wolfgang M. Meier
* [email protected]
* http://exist.sourceforge.net
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id$
*/
package org.exist.xquery;
import org.exist.dom.persistent.DocumentSet;
import org.exist.dom.QName;
import org.exist.xquery.util.ExpressionDumper;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import java.util.ArrayList;
import java.util.List;
/**
* @author wolf
*/
public class UserDefinedFunction extends Function implements Cloneable {
private Expression body;
private List parameters = new ArrayList(5);
private Sequence[] currentArguments = null;
private DocumentSet[] contextDocs = null;
private boolean bodyAnalyzed = false;
private FunctionCall call;
private boolean hasBeenReset = false;
protected boolean visited = false;
private List closureVariables = null;
public UserDefinedFunction(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
public void setFunctionBody(Expression body) {
this.body = body.simplify();
}
public Expression getFunctionBody() {
return body;
}
public void addVariable(final String varName) throws XPathException {
try {
final QName qname = QName.parse(context, varName, null);
addVariable(qname);
} catch (final QName.IllegalQNameException e) {
throw new XPathException(ErrorCodes.XPST0081, "No namespace defined for prefix " + varName);
}
}
public void addVariable(QName varName) throws XPathException {
if (parameters.contains(varName))
{throw new XPathException("XQST0039: function " + getName() + " is already have parameter with the name "+varName);}
parameters.add(varName);
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#setArguments(java.util.List)
*/
public void setArguments(Sequence[] args, DocumentSet[] contextDocs) throws XPathException {
this.currentArguments = args;
this.contextDocs = contextDocs;
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#analyze(org.exist.xquery.AnalyzeContextInfo)
*/
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
hasBeenReset = false;
if(call != null && !call.isRecursive()) {
// Save the local variable stack
final LocalVariable mark = context.markLocalVariables(true);
if (closureVariables != null)
// if this is a inline function, context variables are known
{context.restoreStack(closureVariables);}
try {
LocalVariable var;
for(final QName varName : parameters) {
var = new LocalVariable(varName);
context.declareVariableBinding(var);
}
final AnalyzeContextInfo newContextInfo = new AnalyzeContextInfo(contextInfo);
newContextInfo.setParent(this);
if (!bodyAnalyzed) {
if(body != null) {
body.analyze(newContextInfo);
}
bodyAnalyzed = true;
}
} finally {
// restore the local variable stack
context.popLocalVariables(mark);
}
}
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#eval(org.exist.dom.persistent.DocumentSet, org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
*/
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
// context.expressionStart(this);
context.stackEnter(this);
// make sure reset state is called after query has finished
hasBeenReset = false;
// Save the local variable stack
final LocalVariable mark = context.markLocalVariables(true);
if (closureVariables != null)
{context.restoreStack(closureVariables);}
Sequence result = null;
try {
QName varName;
LocalVariable var;
int j = 0;
for (int i = 0; i < parameters.size(); i++, j++) {
varName = parameters.get(i);
var = new LocalVariable(varName);
var.setValue(currentArguments[j]);
if (contextDocs != null)
{var.setContextDocs(contextDocs[i]);}
context.declareVariableBinding(var);
int actualCardinality;
if (currentArguments[j].isEmpty()) {actualCardinality = Cardinality.EMPTY;}
else if (currentArguments[j].hasMany()) {actualCardinality = Cardinality.MANY;}
else {actualCardinality = Cardinality.ONE;}
if (!Cardinality.checkCardinality(getSignature().getArgumentTypes()[j].getCardinality(), actualCardinality))
{throw new XPathException(this, ErrorCodes.XPTY0004, "Invalid cardinality for parameter $" + varName +
". Expected " + Cardinality.getDescription(getSignature().getArgumentTypes()[j].getCardinality()) +
", got " + currentArguments[j].getItemCount());}
}
result = body.eval(contextSequence, contextItem);
return result;
} finally {
// restore the local variable stack
context.popLocalVariables(mark, result);
context.stackLeave(this);
// context.expressionEnd(this);
}
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#dump(org.exist.xquery.util.ExpressionDumper)
*/
public void dump(ExpressionDumper dumper) {
final FunctionSignature signature = getSignature();
if (signature.getName() != null)
{dumper.display(signature.getName());}
dumper.display('(');
for(int i = 0; i < signature.getArgumentTypes().length; i++) {
if(i > 0)
{dumper.display(", ");}
dumper.display(signature.getArgumentTypes()[i]);
}
dumper.display(") ");
dumper.display(signature.getReturnType().toString());
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
public String toString() {
final FunctionSignature signature = getSignature();
final StringBuilder buf = new StringBuilder();
if (signature.getName() != null)
{buf.append(signature.getName());}
buf.append('(');
for(int i = 0; i < signature.getArgumentTypes().length; i++) {
if(i > 0)
{buf.append(", ");}
buf.append(signature.getArgumentTypes()[i]);
}
buf.append(')');
return buf.toString();
}
/* (non-Javadoc)
* @see org.exist.xquery.functions.Function#getDependencies()
*/
public int getDependencies() {
return Dependency.CONTEXT_SET + Dependency.CONTEXT_ITEM
+ Dependency.CONTEXT_POSITION;
}
/* (non-Javadoc)
* @see org.exist.xquery.PathExpr#resetState()
*/
public void resetState(boolean postOptimization) {
if (hasBeenReset) {
return;
}
hasBeenReset = true;
super.resetState(postOptimization);
// Question: understand this test. Why not reset even is not in recursion ?
// Answer: would lead to an infinite loop if the function is recursive.
bodyAnalyzed = false;
if(body != null) {
body.resetState(postOptimization);
}
if (!postOptimization) {
currentArguments = null;
contextDocs = null;
}
}
public void accept(ExpressionVisitor visitor) {
if (visited)
{return;}
visited = true;
visitor.visitUserFunction(this);
}
/**
* Return the functions parameters list
*
* @return List of function parameters
*/
public List getParameters()
{
return parameters;
}
public synchronized Object clone() {
try {
final UserDefinedFunction clone = (UserDefinedFunction) super.clone();
clone.currentArguments = null;
clone.contextDocs = null;
clone.body = this.body; // so body will be analyzed and optimized for all calls of such functions in recursion.
return clone;
} catch (final CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
public FunctionCall getCaller(){
return call;
}
public void setCaller(FunctionCall call){
this.call = call;
}
public void setClosureVariables(List vars) {
this.closureVariables = vars;
if (vars != null) {
// register the closure with the context so it gets cleared after execution
context.pushClosure(this);
}
}
public List getClosureVariables() {
return closureVariables;
}
protected Sequence[] getCurrentArguments() {
return currentArguments;
}
}
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