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eXist-db NoSQL Database Core
/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-2012 The eXist Project
* http://exist-db.org
*
* 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* $Id$
*/
package org.exist.xquery;
import java.util.Arrays;
import java.util.List;
import org.exist.dom.persistent.DocumentSet;
import org.exist.dom.QName;
import org.exist.dom.persistent.VirtualNodeSet;
import org.exist.xquery.util.Error;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
/**
* Represents a call to a user-defined function
* {@link org.exist.xquery.UserDefinedFunction}.
*
* FunctionCall wraps around a user-defined function. It makes sure that all function parameters
* are checked against the signature of the function.
*
* @author wolf
*/
public class FunctionCall extends Function {
protected UserDefinedFunction functionDef;
protected Expression expression;
// the name of the function. Used for forward references.
protected QName name = null;
protected List arguments = null;
private boolean recursive = false;
protected VariableReference varDeps[];
public FunctionCall(XQueryContext context, QName name, List arguments) {
super(context);
this.name = name;
this.arguments = arguments;
}
public FunctionCall(XQueryContext context, UserDefinedFunction functionDef) {
super(context);
setFunction(functionDef);
}
public FunctionCall(FunctionCall other) {
super(other.getContext());
this.name = other.name;
this.recursive = other.recursive;
this.functionDef = other.functionDef;
this.expression = other.expression;
this.mySignature = other.mySignature;
}
private void setFunction(UserDefinedFunction functionDef) {
this.functionDef = (UserDefinedFunction) functionDef.clone();
this.mySignature = this.functionDef.getSignature();
this.expression = this.functionDef;
this.functionDef.setCaller(this);
final SequenceType returnType = this.functionDef.getSignature().getReturnType();
// add return type checks
if(returnType.getCardinality() != Cardinality.ZERO_OR_MORE) {
expression = new DynamicCardinalityCheck(context, returnType.getCardinality(), expression, new Error(Error.FUNC_RETURN_CARDINALITY));
}
if(Type.subTypeOf(returnType.getPrimaryType(), Type.ATOMIC)) {
expression = new Atomize(context, expression);
}
if(Type.subTypeOf(returnType.getPrimaryType(), Type.NUMBER)) {
expression = new UntypedValueCheck(context, returnType.getPrimaryType(), expression, new Error(Error.FUNC_RETURN_TYPE));
} else if(returnType.getPrimaryType() != Type.ITEM) {
expression = new DynamicTypeCheck(context, returnType.getPrimaryType(), expression);
}
}
public UserDefinedFunction getFunction() {
return functionDef;
}
/**
* For calls to functions in external modules, check that the instance of the function we were
* bound to matches the current implementation of the module bound to our context. If not,
* rebind to the correct instance, but don't bother resetting the signature since it's guaranteed
* (I hope!) to be the same.
* @throws XPathException
*/
private void updateFunction() throws XPathException {
if (functionDef.getContext() instanceof ModuleContext) {
final ModuleContext modContext = (ModuleContext) functionDef.getContext();
// util:eval will stuff non-module function declarations into a module context sometimes,
// so watch out for those and ignore them.
if (functionDef.getName() != null &&
functionDef.getName().getNamespaceURI().equals(modContext.getModuleNamespace()) &&
modContext.getRootContext() != context.getRootContext()) {
final ExternalModule rootModule = (ExternalModule) context.getRootModule(functionDef.getName().getNamespaceURI());
if (rootModule != null) {
final UserDefinedFunction replacementFunctionDef =
rootModule.getFunction(functionDef.getName(), getArgumentCount(), modContext);
if (replacementFunctionDef != null) {
expression = functionDef = (UserDefinedFunction) replacementFunctionDef.clone();
mySignature = functionDef.getSignature();
functionDef.setCaller(this);
}
}
}
}
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#analyze(org.exist.xquery.AnalyzeContextInfo)
*/
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
//updateFunction();
final AnalyzeContextInfo newContextInfo = new AnalyzeContextInfo(contextInfo);
newContextInfo.setParent(this);
newContextInfo.removeFlag(IN_NODE_CONSTRUCTOR);
super.analyze(newContextInfo);
if (context.tailRecursiveCall(functionDef.getSignature())) {
setRecursive(true);
}
context.functionStart(functionDef.getSignature());
try {
expression.analyze(newContextInfo);
} finally {
context.functionEnd();
}
varDeps = new VariableReference[getArgumentCount()];
for(int i = 0; i < getArgumentCount(); i++) {
final Expression arg = getArgument(i);
final VariableReference varRef = BasicExpressionVisitor.findVariableRef(arg);
if(varRef != null) {
varDeps[i] = varRef;
}
}
}
/**
* Called by {@link XQueryContext} to resolve a call to a function that has not
* yet been declared. XQueryContext remembers all calls to undeclared functions
* and tries to resolve them after parsing has completed.
*
* @param functionDef the function definition to resolve
* @throws XPathException if an error occurs resolving the forward reference
*/
public void resolveForwardReference(UserDefinedFunction functionDef) throws XPathException {
setFunction(functionDef);
setArguments(arguments);
arguments = null;
name = null;
}
@Override
public int getArgumentCount() {
if(arguments == null) {
return super.getArgumentCount();
}
return arguments.size();
}
public QName getQName() {
return name;
}
/**
* Evaluates all arguments, then forwards them to the user-defined function.
*
* The return value of the user-defined function will be checked against the
* provided function signature.
*
* @see org.exist.xquery.Expression#eval(Sequence, Item)
*/
@Override
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
final Sequence[] seq = new Sequence[getArgumentCount()];
final DocumentSet[] contextDocs = new DocumentSet[getArgumentCount()];
for(int i = 0; i < getArgumentCount(); i++) {
try {
seq[i] = getArgument(i).eval(contextSequence, contextItem);
if(varDeps != null && varDeps[i] != null) {
final Variable var = varDeps[i].getVariable();
if(var != null) {
contextDocs[i] = var.getContextDocs();
}
}
//System.out.println("found " + seq[i].getLength() + " for " + getArgument(i).pprint());
} catch(final XPathException e) {
if(e.getLine() <= 0) {
e.setLocation(line, column, getSource());
}
// append location of the function call to the exception message:
e.addFunctionCall(functionDef, this);
throw e;
}
}
final Sequence result = evalFunction(contextSequence, contextItem, seq, contextDocs);
try {
//Don't check deferred calls : it would result in a stack overflow
//TODO : find a solution or... is it already here ?
//Don't test on empty sequences since they can have several types
//TODO : add a prior cardinality check on wether an empty result is allowed or not
//TODO : should we introduce a deffered type check on VirtualNodeSet
// and trigger it when the nodeSet is realized ?
if(!(result instanceof DeferredFunctionCall) && !(result instanceof VirtualNodeSet) && !result.isEmpty()) {
getSignature().getReturnType().checkType(result.getItemType());
}
} catch(final XPathException e) {
throw new XPathException(this, ErrorCodes.XPTY0004, "Return type of function '" + getSignature().getName() + "'. " + e.getMessage(), Sequence.EMPTY_SEQUENCE, e);
}
//Annotation Triggers are bad design, disabled as breaks RESTXQ - Adam.
/*for (Annotation ann : functionDef.getSignature().getAnnotations()) {
AnnotationTrigger trigger = ann.getTrigger();
if (trigger instanceof AnnotationTriggerOnResult) {
try {
((AnnotationTriggerOnResult) trigger).trigger(result);
} catch (Throwable e) {
throw new XPathException(this, "function '" + getSignature().getName() + "'. " + e.getMessage(), e);
}
}
}*/
return result;
}
/**
* Evaluate the function.
*
* @param contextSequence the context sequence
* @param contextItem the context item
* @param seq the sequence
* @throws XPathException if an error occurs whilst evaluation the function.
* @return the evaluation result
*/
public Sequence evalFunction(Sequence contextSequence, Item contextItem, Sequence[] seq) throws XPathException {
return evalFunction(contextSequence, contextItem, seq, null);
}
public Sequence evalFunction(Sequence contextSequence, Item contextItem, Sequence[] seq, DocumentSet[] contextDocs) throws XPathException {
context.proceed(this);
if(context.isProfilingEnabled()) {
context.getProfiler().start(this);
context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
if(contextSequence != null) {
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);
}
if(contextItem != null) {
context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());
}
}
functionDef.setArguments(seq, contextDocs);
if(isRecursive()) {
//LOG.warn("Tail recursive function: " + functionDef.getSignature().toString());
return new DeferredFunctionCallImpl(this, contextSequence, contextItem, seq, contextDocs);
} else {
//XXX: should we have it? org.exist.xquery.UserDefinedFunction do a call -shabanovd
context.stackEnter(this);
long start = System.currentTimeMillis();
if(context.getProfiler().traceFunctions()) {
if (context.tailRecursiveCall(getSignature()))
{start = -1;}
context.getProfiler().traceFunctionStart(this);
}
context.functionStart(functionDef.getSignature());
final LocalVariable mark = context.markLocalVariables(true);
context.pushInScopeNamespaces(false);
Sequence returnSeq = null;
try {
returnSeq = expression.eval(contextSequence, contextItem);
while(returnSeq instanceof DeferredFunctionCall &&
functionDef.getSignature().equals(((DeferredFunctionCall)returnSeq).getSignature())) {
if (LOG.isTraceEnabled()) {
LOG.trace("Executing function: " + functionDef.getSignature());
}
returnSeq = ((DeferredFunctionCall) returnSeq).execute();
}
if(context.getProfiler().traceFunctions()) {
context.getProfiler().traceFunctionEnd(this, start < 0 ? 0 : System.currentTimeMillis() - start);
}
if(context.isProfilingEnabled()) {
context.getProfiler().end(this, "", returnSeq);
}
return returnSeq;
} catch(final XPathException e) {
// append location of the function call to the exception message:
if(e.getLine() <= 0) {
e.setLocation(expression.getLine(), expression.getColumn());
}
e.addFunctionCall(functionDef, this);
throw e;
} finally {
context.popInScopeNamespaces();
context.popLocalVariables(mark, returnSeq);
context.functionEnd();
context.stackLeave(this);
}
}
}
/**
* @see org.exist.xquery.PathExpr#resetState(boolean)
*/
@Override
public void resetState(boolean postOptimization) {
super.resetState(postOptimization);
if(expression.needsReset() || postOptimization) {
expression.resetState(postOptimization);
}
}
/**
* @see org.exist.xquery.Expression#setContextDocSet(org.exist.dom.persistent.DocumentSet)
*/
@Override
public void setContextDocSet(DocumentSet contextSet) {
super.setContextDocSet(contextSet);
functionDef.setContextDocSet(contextSet);
}
@Override
public void accept(ExpressionVisitor visitor) {
visitor.visitFunctionCall(this);
}
private static class DeferredFunctionCallImpl extends DeferredFunctionCall {
private final FunctionCall call;
private UserDefinedFunction functionDef;
private Expression expression;
private Sequence contextSequence;
private Item contextItem;
private final Sequence[] seq;
private final DocumentSet[] contextDocs;
private DeferredFunctionCallImpl(FunctionCall call, Sequence contextSequence, Item contextItem, Sequence[] seq, DocumentSet[] contextDocs) {
super(call.mySignature);
this.contextSequence = contextSequence;
this.contextItem = contextItem;
if (seq != null) {
// copy the sequence of arguments to make sure it is not overwritten by caller
this.seq = Arrays.copyOf(seq, seq.length);
} else {
this.seq = null;
}
this.contextDocs = contextDocs;
this.call = call;
setup();
}
private void setup() {
this.functionDef = (UserDefinedFunction) call.functionDef.clone();
//this.mySignature = this.functionDef.getSignature();
this.expression = this.functionDef;
this.functionDef.setCaller(call);
final SequenceType returnType = this.functionDef.getSignature().getReturnType();
final XQueryContext context = call.context;
// add return type checks
if(returnType.getCardinality() != Cardinality.ZERO_OR_MORE) {
expression = new DynamicCardinalityCheck(context, returnType.getCardinality(), expression, new Error(Error.FUNC_RETURN_CARDINALITY));
}
if(Type.subTypeOf(returnType.getPrimaryType(), Type.ATOMIC)) {
expression = new Atomize(context, expression);
}
if(Type.subTypeOf(returnType.getPrimaryType(), Type.NUMBER)) {
expression = new UntypedValueCheck(context, returnType.getPrimaryType(), expression, new Error(Error.FUNC_RETURN_TYPE));
} else if(returnType.getPrimaryType() != Type.ITEM) {
expression = new DynamicTypeCheck(context, returnType.getPrimaryType(), expression);
}
}
@Override
protected Sequence execute() throws XPathException {
final XQueryContext context = call.context;
context.pushDocumentContext();
//context.stackEnter(expression);
context.functionStart(functionDef.getSignature());
final LocalVariable mark = context.markLocalVariables(true);
Sequence returnSeq = null;
try {
/*
Ensure that the arguments are set for a deferred function
as reset may alreay have been called before our deferred execution
*/
functionDef.setArguments(seq, contextDocs);
returnSeq = expression.eval(contextSequence, contextItem);
LOG.trace("Returning from execute()");
return returnSeq;
} catch(final XPathException e) {
// append location of the function call to the exception message:
if(e.getLine() == 0) {
e.setLocation(call.line, call.column);
}
e.addFunctionCall(functionDef, call);
throw e;
} finally {
context.popLocalVariables(mark, returnSeq);
context.functionEnd();
//context.stackLeave(expression);
context.popDocumentContext();
}
}
}
protected void setRecursive(boolean recursive) {
this.recursive = recursive;
}
public boolean isRecursive(){
return recursive;
}
}
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