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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2013 Saxonica Limited.
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.query;
import net.sf.saxon.Configuration;
import net.sf.saxon.expr.*;
import net.sf.saxon.expr.instruct.UserFunction;
import net.sf.saxon.expr.parser.ExpressionVisitor;
import net.sf.saxon.functions.FunctionLibrary;
import net.sf.saxon.om.FunctionItem;
import net.sf.saxon.om.Sequence;
import net.sf.saxon.om.StructuredQName;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.FunctionItemType;
import net.sf.saxon.value.SequenceExtent;
import java.util.HashMap;
import java.util.Iterator;
/**
* An XQueryFunctionLibrary is a function library containing all the user-defined functions available for use within a
* particular XQuery module: that is, the functions declared in that module, and the functions imported from other
* modules. It also contains (transiently during compilation) a list of function calls within the module that have not
* yet been bound to a specific function declaration.
*/
public class XQueryFunctionLibrary implements FunctionLibrary, XQueryFunctionBinder {
private Configuration config;
// The functions in this library are represented using a HashMap
// The key of the hashmap is a String that encodes the QName of the function and its arity
// The value in the hashmap is an XQueryFunction
/*@NotNull*/ private HashMap functions =
new HashMap(20);
/**
* Create an XQueryFunctionLibrary
* @param config the Saxon configuration
*/
public XQueryFunctionLibrary(Configuration config) {
this.config = config;
}
/**
* Set the Configuration options
* @param config the Saxon configuration
*/
public void setConfiguration(Configuration config) {
this.config = config;
}
/**
* Get the Configuration options
* @return the Saxon configuration
*/
public Configuration getConfiguration() {
return config;
}
/**
* Register a user-defined XQuery function
* @param function the function to be registered
* @throws XPathException if there is an existing function with the same name and arity
*/
public void declareFunction(/*@NotNull*/ XQueryFunction function) throws XPathException {
String keyObj = function.getIdentificationKey();
XQueryFunction existing = functions.get(keyObj);
if (existing == function) {
return;
}
if (existing != null) {
XPathException err = new XPathException("Duplicate definition of function " +
function.getDisplayName() +
" (see line " + existing.getLineNumber() + " in " + existing.getSystemId() + ')');
err.setErrorCode("XQST0034");
err.setIsStaticError(true);
err.setLocator(function);
throw err;
}
functions.put(keyObj, function);
}
/**
* Test whether a function with a given name and arity is available
* This supports the function-available() function in XSLT.
*
* @param functionName the qualified name of the function being called
* @param arity The number of arguments.
* @return true if a function of this name and arity is available for calling
*/
public boolean isAvailable(StructuredQName functionName, int arity) {
String functionKey = XQueryFunction.getIdentificationKey(functionName, arity);
return functions.get(functionKey) != null;
}
/**
* Inner class containing information about a reference to a function whose declaration
* has not yet been encountered. The references gets fixed up later, once information
* about all user-declared functions is available.
*/
public static class UnresolvedCallable implements UserFunctionReference, Callable {
StructuredQName name;
int arity;
UserFunction function;
//CallableFunctionItem functionItem;
public UnresolvedCallable(StructuredQName name, int arity) {
this.name = name;
this.arity = arity;
}
public StructuredQName getFunctionName() {
return name;
}
public int getArity() {
return arity;
}
//public void setFunctionItem(CallableFunctionItem fi) {
// this.functionItem = fi;
//}
/**
* Evaluate the expression
*
* @param context the dynamic evaluation context
* @param arguments the values of the arguments, supplied as Sequences
* @return the result of the evaluation, in the form of a Sequence
* @throws net.sf.saxon.trans.XPathException
* if a dynamic error occurs during the evaluation of the expression
*/
public Sequence call(XPathContext context, Sequence[] arguments) throws XPathException {
if (function == null) {
throw new XPathException("Forwards reference to XQuery function has not been resolved");
}
Sequence[] args = new Sequence[arguments.length];
for (int i=0; iNote that a function call may appear earlier in the query than the definition
* of the function to which it is bound. Unlike XSLT, we cannot search forwards to
* find the function definition. Binding of function calls is therefore a two-stage
* process; at the time the function call is parsed, we simply register it as
* pending; subsequently at the end of query parsing all the pending function
* calls are resolved. Another consequence of this is that we cannot tell at the time
* a function call is parsed whether it is a call to an internal (XSLT or XQuery)
* function or to an extension function written in Java.
* @return an Expression representing the function call. This will normally be
* a FunctionCall, but it may be rewritten as some other expression.
* @throws XPathException if the function call is invalid, either because it is
* an unprefixed call to a non-system function, or because it is calling a system
* function that is available in XSLT only. A prefixed function call that cannot
* be recognized at this stage is assumed to be a forwards reference, and is bound
* later when bindUnboundFunctionCalls() is called.
*/
/*@Nullable*/ public Expression bind(/*@NotNull*/ StructuredQName functionName, /*@NotNull*/ int arity, Expression[] arguments, StaticContext env, Container container) throws XPathException {
String functionKey = XQueryFunction.getIdentificationKey(
functionName, arguments.length);
XQueryFunction fd = functions.get(functionKey);
if (fd != null) {
if (fd.isPrivate() && fd.getStaticContext() != env) {
throw new XPathException("Cannot call the private function " +
functionName.getDisplayName() + " from outside its module", "XPST0017");
}
UserFunctionCall ufc = new UserFunctionCall();
ufc.setFunctionName(fd.getFunctionName());
ufc.setArguments(arguments);
ufc.setStaticType(fd.getResultType());
UserFunction fn = fd.getUserFunction();
if (fn == null) {
// not yet compiled
fd.registerReference(ufc);
} else {
ufc.setFunction(fn);
ExpressionVisitor visitor = ExpressionVisitor.make(fd.getStaticContext(), fd.getExecutable());
ufc.checkFunctionCall(fn, visitor);
}
return ufc;
} else {
return null;
}
}
/**
* Get the function declaration corresponding to a given function name and arity
* @return the XQueryFunction if there is one, or null if not.
*/
public XQueryFunction getDeclaration(/*@NotNull*/ StructuredQName functionName, /*@NotNull*/ Expression[] staticArgs) {
String functionKey = XQueryFunction.getIdentificationKey(
functionName, staticArgs.length);
return functions.get(functionKey);
}
/**
* Get the function declaration corresponding to a given function name and arity, supplied
* in the form "{uri}local/arity"
* @param functionKey a string in the form "{uri}local/arity" identifying the required function
* @return the XQueryFunction if there is one, or null if not.
*/
public XQueryFunction getDeclarationByKey(String functionKey) {
return functions.get(functionKey);
}
/**
* Get an iterator over the Functions defined in this module
* @return an Iterator, whose items are {@link XQueryFunction} objects. It returns
* all function known to this module including those imported from elsewhere; they
* can be distinguished by their namespace.
*/
public Iterator getFunctionDefinitions() {
return functions.values().iterator();
}
/**
* Fixup all references to global functions. This method is called
* on completion of query parsing. Each XQueryFunction is required to
* bind all references to that function to the object representing the run-time
* executable code of the function.
*
* This method is for internal use.
* @param env the static context for the main query body.
* @throws net.sf.saxon.trans.XPathException if an error occurs
*/
protected void fixupGlobalFunctions(/*@NotNull*/ QueryModule env) throws XPathException {
ExpressionVisitor visitor = ExpressionVisitor.make(env, env.getExecutable());
for (XQueryFunction fn : functions.values()) {
fn.compile();
}
for (XQueryFunction fn : functions.values()) {
visitor.setExecutable(fn.getExecutable());
fn.checkReferences(visitor);
}
}
/**
* Optimize the body of all global functions. This may involve inlining functions calls
* @throws net.sf.saxon.trans.XPathException if an error occurs
*/
protected void optimizeGlobalFunctions() throws XPathException {
for (XQueryFunction fn : functions.values()) {
fn.optimize();
}
}
/**
* Output "explain" information about each declared function
* @param out the ExpressionPresenter that renders the output
*/
public void explainGlobalFunctions(/*@NotNull*/ ExpressionPresenter out) {
for (XQueryFunction fn : functions.values()) {
fn.explain(out);
}
}
/**
* Get the function with a given name and arity. This method is provided so that XQuery functions
* can be called directly from a Java application. Note that there is no type checking or conversion
* of arguments when this is done: the arguments must be provided in exactly the form that the function
* signature declares them.
* @param uri the uri of the function name
* @param localName the local part of the function name
* @param arity the number of arguments.
* @return the function identified by the URI, local name, and arity; or null if there is no such function
*/
/*@Nullable*/ public UserFunction getUserDefinedFunction(/*@NotNull*/ String uri, /*@NotNull*/ String localName, int arity) {
String functionKey = XQueryFunction.getIdentificationKey(uri, localName, arity);
XQueryFunction fd = functions.get(functionKey);
if (fd==null) {
return null;
}
return fd.getUserFunction();
}
/**
* This method creates a copy of a FunctionLibrary: if the original FunctionLibrary allows
* new functions to be added, then additions to this copy will not affect the original, or
* vice versa.
*
* @return a copy of this function library. This must be an instance of the original class.
*/
/*@NotNull*/ public FunctionLibrary copy() {
XQueryFunctionLibrary qfl = new XQueryFunctionLibrary(config);
qfl.functions = new HashMap(functions);
return qfl;
}
}