/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-09 Wolfgang M. Meier
* wolfgang@exist-db.org
* 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.functions;
import org.exist.EXistException;
import org.exist.dom.DocumentSet;
import org.exist.dom.ExtArrayNodeSet;
import org.exist.dom.NodeProxy;
import org.exist.dom.NodeSet;
import org.exist.dom.QName;
import org.exist.storage.DBBroker;
import org.exist.storage.ElementValue;
import org.exist.storage.NativeValueIndex;
import org.exist.xquery.pragmas.Optimize;
import org.exist.xquery.*;
import org.exist.xquery.util.Error;
import org.exist.xquery.util.RegexTranslator;
import org.exist.xquery.util.RegexTranslator.RegexSyntaxException;
import org.exist.xquery.value.BooleanValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
/**
* Implements the fn:matches() function.
*
* Based on the java.util.regex package for regular expression support.
*
* @author Wolfgang Meier (wolfgang@exist-db.org)
*/
public class FunMatches extends Function implements Optimizable, IndexUseReporter {
protected static final String FUNCTION_DESCRIPTION_1_PARAM =
"The function returns true if $input matches the regular expression " +
"supplied as $pattern, if present; otherwise, it returns false.\n\n";
protected static final String FUNCTION_DESCRIPTION_2_PARAM =
"The function returns true if $input matches the regular expression " +
"supplied as $pattern as influenced by the value of $flags, if present; " +
"otherwise, it returns false.\n\n" +
"The effect of calling this version of the function with the $flags argument set to a zero-length string is the same as using the other two argument version. " +
"Flags are defined in 7.6.1.1 Flags.\n\n";
protected static final String FUNCTION_DESCRIPTION_COMMON =
"If $input is the empty sequence, it is interpreted as the zero-length string.\n\n" +
"Unless the metacharacters ^ and $ are used as anchors, the string is considered " +
"to match the pattern if any substring matches the pattern. But if anchors are used, " +
"the anchors must match the start/end of the string (in string mode), or the " +
"start/end of a line (in multiline mode).\n\n" +
"Note:\n\n" +
"This is different from the behavior of patterns in [XML Schema Part 2: Datatypes " +
"Second Edition], where regular expressions are implicitly anchored.\n\n" +
"Please note that - in contrast - with the " +
"specification - this method allows zero or more items for the string argument.\n\n" +
"An error is raised [err:FORX0002] if the value of $pattern is invalid " +
"according to the rules described in section 7.6.1 Regular Expression Syntax.\n\n";
protected static final String FUNCTION_DESCRIPTION_2_PARAM_2 =
"An error is raised [err:FORX0001] if the value of $flags is invalid " +
"according to the rules described in section 7.6.1 Regular Expression Syntax.";
protected static final FunctionParameterSequenceType INPUT_ARG = new FunctionParameterSequenceType("input", Type.STRING, Cardinality.ZERO_OR_MORE, "The input string");
protected static final FunctionParameterSequenceType PATTERN_ARG = new FunctionParameterSequenceType("pattern", Type.STRING, Cardinality.EXACTLY_ONE, "The pattern");
protected static final FunctionParameterSequenceType FLAGS_ARG = new FunctionParameterSequenceType("flags", Type.STRING, Cardinality.EXACTLY_ONE, "The flags");
public final static FunctionSignature signatures[] = {
new FunctionSignature(
new QName("matches", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_1_PARAM + FUNCTION_DESCRIPTION_COMMON,
new SequenceType[] { INPUT_ARG, PATTERN_ARG },
new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE, "true if the pattern is a match, false otherwise")
),
new FunctionSignature(
new QName("matches", Function.BUILTIN_FUNCTION_NS),
FUNCTION_DESCRIPTION_2_PARAM + FUNCTION_DESCRIPTION_COMMON +
FUNCTION_DESCRIPTION_2_PARAM_2,
new SequenceType[] { INPUT_ARG, PATTERN_ARG, FLAGS_ARG },
new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE, "true if the pattern is a match, false otherwise")
)
};
protected Matcher matcher = null;
protected Pattern pat = null;
protected boolean hasUsedIndex = false;
private LocationStep contextStep = null;
private QName contextQName = null;
private int axis = Constants.UNKNOWN_AXIS;
private NodeSet preselectResult = null;
private GeneralComparison.IndexFlags idxflags = new GeneralComparison.IndexFlags();
/**
* @param context
*/
public FunMatches(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#setArguments(java.util.List)
*/
public void setArguments(List arguments) throws XPathException {
Expression path = (Expression) arguments.get(0);
steps.add(path);
Expression arg = (Expression) arguments.get(1);
arg = new DynamicCardinalityCheck(context, Cardinality.EXACTLY_ONE, arg,
new Error(Error.FUNC_PARAM_CARDINALITY, "2", mySignature));
if(!Type.subTypeOf(arg.returnsType(), Type.ATOMIC))
arg = new Atomize(context, arg);
steps.add(arg);
if (arguments.size() == 3) {
arg = (Expression) arguments.get(2);
arg = new DynamicCardinalityCheck(context, Cardinality.EXACTLY_ONE, arg,
new Error(Error.FUNC_PARAM_CARDINALITY, "3", mySignature));
if(!Type.subTypeOf(arg.returnsType(), Type.ATOMIC))
arg = new Atomize(context, arg);
steps.add(arg);
}
List steps = BasicExpressionVisitor.findLocationSteps(path);
if (!steps.isEmpty()) {
LocationStep firstStep = (LocationStep) steps.get(0);
LocationStep lastStep = (LocationStep) steps.get(steps.size() - 1);
NodeTest test = lastStep.getTest();
if (!test.isWildcardTest() && test.getName() != null) {
contextQName = new QName(test.getName());
if (lastStep.getAxis() == Constants.ATTRIBUTE_AXIS || lastStep.getAxis() == Constants.DESCENDANT_ATTRIBUTE_AXIS)
contextQName.setNameType(ElementValue.ATTRIBUTE);
contextStep = lastStep;
axis = firstStep.getAxis();
if (axis == Constants.SELF_AXIS && steps.size() > 1)
axis = ((LocationStep) steps.get(1)).getAxis();
}
}
}
public boolean canOptimize(Sequence contextSequence) {
if (contextQName == null)
return false;
return Type.subTypeOf(Optimize.getQNameIndexType(context, contextSequence, contextQName), Type.STRING);
}
public boolean optimizeOnSelf() {
return false;
}
public int getOptimizeAxis() {
return axis;
}
public NodeSet preSelect(Sequence contextSequence, boolean useContext) throws XPathException {
long start = System.currentTimeMillis();
// the expression can be called multiple times, so we need to clear the previous preselectResult
preselectResult = null;
int indexType = Optimize.getQNameIndexType(context, contextSequence, contextQName);
if (LOG.isTraceEnabled())
LOG.trace("Using QName index on type " + Type.getTypeName(indexType));
String pattern = translateRegexp(getArgument(1).eval(contextSequence).getStringValue());
boolean caseSensitive = true;
int flags = 0;
if(getSignature().getArgumentCount() == 3) {
String flagsArg = getArgument(2).eval(contextSequence).getStringValue();
caseSensitive = (flagsArg.indexOf('i') == Constants.STRING_NOT_FOUND);
flags = parseFlags(flagsArg);
}
try {
preselectResult = context.getBroker().getValueIndex().match(contextSequence.getDocumentSet(),
useContext ? contextSequence.toNodeSet() : null, NodeSet.DESCENDANT, pattern,
contextQName, DBBroker.MATCH_REGEXP, flags, caseSensitive);
hasUsedIndex = true;
} catch (EXistException e) {
throw new XPathException(this, "Error during index lookup: " + e.getMessage(), e);
}
if (context.getProfiler().traceFunctions())
context.getProfiler().traceIndexUsage(context, PerformanceStats.RANGE_IDX_TYPE, this,
PerformanceStats.OPTIMIZED_INDEX, System.currentTimeMillis() - start);
return preselectResult;
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#getDependencies()
*/
public int getDependencies() {
final Expression stringArg = getArgument(0);
final Expression patternArg = getArgument(1);
if (Type.subTypeOf(stringArg.returnsType(), Type.NODE) &&
!Dependency.dependsOn(stringArg, Dependency.CONTEXT_ITEM) &&
!Dependency.dependsOn(patternArg, Dependency.CONTEXT_ITEM)) {
return Dependency.CONTEXT_SET;
} else {
return Dependency.CONTEXT_SET + Dependency.CONTEXT_ITEM;
}
}
/* (non-Javadoc)
* @see org.exist.xquery.Function#returnsType()
*/
public int returnsType() {
if (inPredicate && (getDependencies() & Dependency.CONTEXT_ITEM) == 0) {
/* If one argument is a node set we directly
* return the matching nodes from the context set. This works
* only inside predicates.
*/
return Type.NODE;
}
// In all other cases, we return boolean
return Type.BOOLEAN;
}
public boolean hasUsedIndex() {
return hasUsedIndex;
}
public void analyze(AnalyzeContextInfo contextInfo) throws XPathException {
AnalyzeContextInfo newContextInfo = new AnalyzeContextInfo(contextInfo);
newContextInfo.setParent(this);
// call analyze for each argument
inPredicate = (newContextInfo.getFlags() & IN_PREDICATE) > 0;
for (int i = 0; i < getArgumentCount(); i++) {
getArgument(i).analyze(newContextInfo);
}
}
/* (non-Javadoc)
* @see org.exist.xquery.Expression#eval(org.exist.dom.DocumentSet, org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
*/
public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
long start = System.currentTimeMillis();
if (context.getProfiler().isEnabled()) {
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());
}
// if we were optimizing and the preselect did not return anything,
// we won't have any matches and can return
if (preselectResult != null && preselectResult.isEmpty())
return Sequence.EMPTY_SEQUENCE;
if (contextItem != null)
contextSequence = contextItem.toSequence();
Sequence result;
if (contextStep == null || preselectResult == null) {
Sequence input = getArgument(0).eval(contextSequence, contextItem);
if (input.isEmpty())
result = Sequence.EMPTY_SEQUENCE;
else if (input.isPersistentSet() && inPredicate && !Dependency.dependsOn(this, Dependency.CONTEXT_ITEM)) {
if (context.isProfilingEnabled())
context.getProfiler().message(this, Profiler.OPTIMIZATION_FLAGS, "", "Index evaluation");
result = evalWithIndex(contextSequence, contextItem, input);
if (context.getProfiler().traceFunctions())
context.getProfiler().traceIndexUsage(context, PerformanceStats.RANGE_IDX_TYPE, this,
PerformanceStats.BASIC_INDEX, System.currentTimeMillis() - start);
} else {
if (context.isProfilingEnabled())
context.getProfiler().message(this, Profiler.OPTIMIZATION_FLAGS, "", "Generic evaluation");
result = evalGeneric(contextSequence, contextItem, input);
if (context.getProfiler().traceFunctions())
context.getProfiler().traceIndexUsage(context, PerformanceStats.RANGE_IDX_TYPE, this,
PerformanceStats.NO_INDEX, System.currentTimeMillis() - start);
}
} else {
contextStep.setPreloadedData(contextSequence.getDocumentSet(), preselectResult);
result = getArgument(0).eval(contextSequence).toNodeSet();
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
/**
* @param contextSequence
* @param contextItem
* @param input
* @return The resulting sequence
* @throws XPathException
*/
private Sequence evalWithIndex(Sequence contextSequence, Item contextItem, Sequence input) throws XPathException {
if (context.getProfiler().isEnabled()) {
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());
}
boolean caseSensitive = true;
int flags = 0;
if(getSignature().getArgumentCount() == 3) {
String flagsArg = getArgument(2).eval(contextSequence, contextItem).getStringValue();
caseSensitive = (flagsArg.indexOf('i') == Constants.STRING_NOT_FOUND);
flags = parseFlags(flagsArg);
}
Sequence result = null;
String pattern = translateRegexp(getArgument(1).eval(contextSequence, contextItem).getStringValue());
NodeSet nodes = input.toNodeSet();
// get the type of a possible index
int indexType = nodes.getIndexType();
if (LOG.isTraceEnabled())
LOG.trace("found an index of type: " + Type.getTypeName(indexType));
if(Type.subTypeOf(indexType, Type.STRING)) {
boolean indexScan = false;
if (contextSequence != null) {
GeneralComparison.IndexFlags iflags = GeneralComparison.checkForQNameIndex(idxflags, context, contextSequence, contextQName);
boolean indexFound = false;
if (!iflags.indexOnQName()) {
// if contextQName != null and no index is defined on
// contextQName, we don't need to scan other QName indexes
// and can just use the generic range index
indexFound = contextQName != null;
// set contextQName to null so the index lookup below is not
// restricted to that QName
contextQName = null;
}
if (!indexFound && contextQName == null) {
// if there are some indexes defined on a qname,
// we need to check them all
if (iflags.hasIndexOnQNames())
indexScan = true;
// else use range index defined on path by default
}
} else
result = evalFallback(nodes, pattern, flags, indexType);
if (result == null) {
DocumentSet docs = nodes.getDocumentSet();
try {
NativeValueIndex index = context.getBroker().getValueIndex();
hasUsedIndex = true;
//TODO : check index' case compatibility with flags' one ? -pb
if (context.isProfilingEnabled())
context.getProfiler().message(this, Profiler.OPTIMIZATIONS, "Using vlaue index '" + index.toString() + "'", "Regex: " + pattern);
if (LOG.isTraceEnabled())
LOG.trace("Using range index for fn:matches expression: " + pattern);
if (indexScan)
result = index.matchAll(docs, nodes, NodeSet.ANCESTOR, pattern, DBBroker.MATCH_REGEXP, flags, caseSensitive);
else
result = index.match(docs, nodes, NodeSet.ANCESTOR, pattern, contextQName, DBBroker.MATCH_REGEXP, flags, caseSensitive);
} catch (EXistException e) {
throw new XPathException(this, e.getMessage(), e);
}
}
} else {
result = evalFallback(nodes, pattern, flags, indexType);
}
if (context.getProfiler().isEnabled())
context.getProfiler().end(this, "", result);
return result;
}
private Sequence evalFallback(NodeSet nodes, String pattern, int flags, int indexType) throws XPathException {
Sequence result;
if (LOG.isTraceEnabled())
LOG.trace("fn:matches: can't use existing range index of type " + Type.getTypeName(indexType) + ". Need a string index.");
result = new ExtArrayNodeSet();
for(Iterator i = nodes.iterator(); i.hasNext(); ) {
NodeProxy node = (NodeProxy) i.next();
if (match(node.getStringValue(), pattern, flags))
result.add(node);
}
return result;
}
/**
* Translates the regular expression from XPath2 syntax to java regex
* syntax.
*
* @param pattern
* @return The translated regexp
* @throws XPathException
*/
protected String translateRegexp(String pattern) throws XPathException {
// convert pattern to Java regex syntax
try {
pattern = RegexTranslator.translate(pattern, true);
} catch (RegexSyntaxException e) {
throw new XPathException(this, "Conversion from XPath2 to Java regular expression " +
"syntax failed: " + e.getMessage(), e);
}
return pattern;
}
/**
* @param contextSequence
* @param contextItem
* @param stringArg
* @return The resulting sequence
* @throws XPathException
*/
private Sequence evalGeneric(Sequence contextSequence, Item contextItem, Sequence stringArg) throws XPathException {
String string = stringArg.getStringValue();
String pattern = translateRegexp(getArgument(1).eval(contextSequence, contextItem).getStringValue());
int flags = 0;
if(getSignature().getArgumentCount() == 3)
flags = parseFlags(getArgument(2).eval(contextSequence, contextItem).getStringValue());
return BooleanValue.valueOf(match(string, pattern, flags));
}
/**
* @param string
* @param pattern
* @param flags
* @return Whether or not the string matches the given pattern with the given flags
* @throws XPathException
*/
private boolean match(String string, String pattern, int flags) throws XPathException {
try {
if(pat == null || (!pattern.equals(pat.pattern())) || flags != pat.flags()) {
pat = Pattern.compile(pattern, flags);
//TODO : make matches('K', '[A-Z]', 'i') work !
matcher = pat.matcher(string);
} else {
matcher.reset(string);
}
return matcher.find();
} catch (PatternSyntaxException e) {
throw new XPathException(this, "Invalid regular expression: " + e.getMessage(), e);
}
}
protected final static int parseFlags(String s) throws XPathException {
int flags = 0;
for(int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
switch(ch) {
case 'm':
flags |= Pattern.MULTILINE;
break;
case 'i':
flags = flags | Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE;
break;
case 'x':
flags |= Pattern.COMMENTS;
break;
case 's':
flags |= Pattern.DOTALL;
break;
default:
throw new XPathException("Invalid regular expression flag: " + ch);
}
}
return flags;
}
public void reset() {
super.reset();
hasUsedIndex = false;
}
/*
* (non-Javadoc)
*
* @see org.exist.xquery.AbstractExpression#resetState()
*/
public void resetState(boolean postOptimization) {
super.resetState(postOptimization);
if (!postOptimization)
preselectResult = null;
}
}