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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2023 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.style;
import net.sf.saxon.Configuration;
import net.sf.saxon.Version;
import net.sf.saxon.expr.*;
import net.sf.saxon.expr.instruct.Actor;
import net.sf.saxon.expr.instruct.ApplyTemplates;
import net.sf.saxon.expr.instruct.CallTemplate;
import net.sf.saxon.expr.instruct.SlotManager;
import net.sf.saxon.expr.parser.*;
import net.sf.saxon.expr.sort.CodepointCollator;
import net.sf.saxon.lib.StringCollator;
import net.sf.saxon.om.*;
import net.sf.saxon.pattern.NodeTestPattern;
import net.sf.saxon.pattern.Pattern;
import net.sf.saxon.trans.*;
import net.sf.saxon.type.BuiltInAtomicType;
import net.sf.saxon.type.ErrorType;
import net.sf.saxon.type.ItemType;
import net.sf.saxon.value.SequenceType;
import net.sf.saxon.value.Whitespace;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.function.Predicate;
import java.util.function.Supplier;
/**
* Handler for xsl:key elements in stylesheet.
*/
public class XSLKey extends StyleElement implements StylesheetComponent {
private Pattern match;
private Expression use;
private String collationName;
private StructuredQName keyName;
private SlotManager stackFrameMap;
private boolean rangeKey;
private boolean composite = false;
private KeyDefinition keyDefinition;
/**
* Get the corresponding Actor object that results from the compilation of this
* StylesheetComponent
*
* @return the compiled ComponentCode
* @throws UnsupportedOperationException for second-class components such as keys that support outwards references
* but not inwards references
*/
@Override
public Actor getActor() {
throw new UnsupportedOperationException();
}
@Override
public SymbolicName getSymbolicName() {
return null;
}
@Override
public void checkCompatibility(Component component) {
// no action: keys cannot be overridden
}
@Override
public boolean isDeclaration() {
return true;
}
/**
* Determine whether this type of element is allowed to contain a sequence constructor
*
* @return true: yes, it may contain a sequence constructor
*/
@Override
protected boolean mayContainSequenceConstructor() {
return true;
}
/**
* Get the Procedure object that looks after any local variables declared in the content constructor
*/
@Override
public SlotManager getSlotManager() {
return stackFrameMap;
}
@Override
protected void prepareAttributes() {
String nameAtt = null;
String matchAtt = null;
String useAtt;
for (AttributeInfo att : attributes()) {
NodeName attName = att.getNodeName();
String value = att.getValue();
NamespaceUri uri = attName.getNamespaceUri();
String local = attName.getLocalPart();
if (uri.isEmpty()) {
switch (local) {
case "name":
nameAtt = Whitespace.trim(value);
break;
case "use":
useAtt = value;
use = makeExpression(useAtt, att);
break;
case "match":
matchAtt = value;
break;
case "collation":
collationName = Whitespace.trim(value);
break;
case "composite":
composite = processBooleanAttribute("composite", value);
break;
default:
checkUnknownAttribute(attName);
break;
}
} else if (local.equals("range-key") && uri.equals(NamespaceUri.SAXON)) {
if (Version.platform.isDotNet()) {
compileError("saxon:range-key is not supported in SaxonCS");
}
rangeKey = processBooleanAttribute("range-key", value);
} else {
checkUnknownAttribute(attName);
}
}
if (nameAtt == null) {
reportAbsence("name");
nameAtt = "_dummy_key_name";
}
keyName = makeQName(nameAtt, null, "name");
setObjectName(keyName);
if (matchAtt == null) {
reportAbsence("match");
matchAtt = "*";
}
match = makePattern(matchAtt, "match");
if (match == null) {
// error has been reported
match = new NodeTestPattern(ErrorType.getInstance());
}
}
public StructuredQName getKeyName() {
//We use null to mean "not yet evaluated"
if (getObjectName() == null) {
// allow for forwards references
String nameAtt = getAttributeValue(NamespaceUri.NULL, "name");
if (nameAtt != null) {
setObjectName(makeQName(nameAtt, null, "name"));
}
}
return getObjectName();
}
@Override
public void validate(ComponentDeclaration decl) throws XPathException {
Configuration config = getConfiguration();
stackFrameMap = config.makeSlotManager();
checkTopLevel("XTSE0010", false);
if (use != null) {
// the value can be supplied as a content constructor in place of a use expression
if (hasChildNodes()) {
compileError("An xsl:key element with a @use attribute must be empty", "XTSE1205");
}
try {
Supplier role = () ->
new RoleDiagnostic(RoleDiagnostic.INSTRUCTION, "xsl:key/use", 0);
use = config.getTypeChecker(false).staticTypeCheck(
use,
SequenceType.ATOMIC_SEQUENCE,
role, makeExpressionVisitor());
} catch (XPathException err) {
compileError(err);
}
} else {
if (!hasChildNodes()) {
compileError("An xsl:key element must either have a @use attribute or have content", "XTSE1205");
}
}
use = typeCheck("use", use);
match = typeCheck("match", match);
// Do a further check that the use expression makes sense in the context of the match pattern
if (use != null) {
use = use.typeCheck(makeExpressionVisitor(), config.makeContextItemStaticInfo(match.getItemType(), false));
}
if (collationName != null) {
URI collationURI;
try {
collationURI = new URI(collationName);
if (!collationURI.isAbsolute()) {
URI base = new URI(getBaseURI());
collationURI = base.resolve(collationURI);
collationName = collationURI.toString();
}
} catch (URISyntaxException err) {
compileError("Collation name '" + collationName + "' is not a valid URI");
//collationName = NamespaceConstant.CODEPOINT_COLLATION_URI;
}
} else {
collationName = getDefaultCollationName();
}
}
private static final Predicate containsGlobalVariable = e -> (
e instanceof GlobalVariableReference ||
e instanceof UserFunctionCall ||
e instanceof CallTemplate ||
e instanceof ApplyTemplates);
@Override
public void index(ComponentDeclaration decl, PrincipalStylesheetModule top) {
StructuredQName keyName = getKeyName();
if (keyName != null) {
top.getKeyManager().preRegisterKeyDefinition(keyName);
}
}
@Override
public void compileDeclaration(Compilation compilation, ComponentDeclaration decl) throws XPathException {
StaticContext env = getStaticContext();
Configuration config = env.getConfiguration();
StringCollator collator = null;
if (collationName != null) {
collator = findCollation(collationName, getBaseURI());
if (collator == null) {
compileError("The collation name " + Err.wrap(collationName, Err.URI) + " is not recognized", "XTSE1210");
collator = CodepointCollator.getInstance();
}
if (collator instanceof CodepointCollator) {
// if the user explicitly asks for the codepoint collation, treat it as if they hadn't asked
collator = null;
collationName = null;
} else if (!Version.platform.canReturnCollationKeys(collator)) {
compileError("The collation used for xsl:key must be capable of generating collation keys", "XTSE1210");
}
}
if (use == null) {
Expression body = compileSequenceConstructor(compilation, decl, true);
try {
use = Atomizer.makeAtomizer(body, null);
use = use.simplify();
} catch (XPathException e) {
compileError(e);
}
try {
Supplier role = () ->
new RoleDiagnostic(RoleDiagnostic.INSTRUCTION, "xsl:key/use", 0);
use = config.getTypeChecker(false).staticTypeCheck(
use,
SequenceType.ATOMIC_SEQUENCE,
role, makeExpressionVisitor());
// Do a further check that the use expression makes sense in the context of the match pattern
assert match != null;
use = use.typeCheck(makeExpressionVisitor(), config.makeContextItemStaticInfo(match.getItemType(), false));
} catch (XPathException err) {
compileError(err);
}
}
ItemType useItemType = use.getItemType();
if (useItemType == ErrorType.getInstance()) {
useItemType = BuiltInAtomicType.STRING; // corner case, prevents crashing
}
BuiltInAtomicType useType = (BuiltInAtomicType) useItemType.getPrimitiveItemType();
if (xPath10ModeIsEnabled()) {
if (!useType.equals(BuiltInAtomicType.STRING) && !useType.equals(BuiltInAtomicType.UNTYPED_ATOMIC)) {
use = new AtomicSequenceConverter(use, BuiltInAtomicType.STRING);
((AtomicSequenceConverter) use).allocateConverter(config, false);
useType = BuiltInAtomicType.STRING;
}
}
// first slot in pattern is reserved for current()
int nextFree = 0;
if ((match.getDependencies() & StaticProperty.DEPENDS_ON_CURRENT_ITEM) != 0) {
nextFree = 1;
}
match.allocateSlots(stackFrameMap, nextFree);
// If either the match pattern or the use expression references a global variable or parameter,
// or a call on a function or template that might reference one, then
// the key indexes cannot be reused across multiple transformations. See Saxon bug 1968.
boolean sensitive =
ExpressionTool.contains(use, false, containsGlobalVariable) ||
ExpressionTool.contains(match, false, containsGlobalVariable);
KeyManager km = getCompilation().getPrincipalStylesheetModule().getKeyManager();
SymbolicName symbolicName = new SymbolicName(StandardNames.XSL_KEY, keyName);
KeyDefinition keydef = new KeyDefinition(symbolicName, match, use, collationName, collator);
keydef.setPackageData(getCompilation().getPackageData());
keydef.setRangeKey(rangeKey);
keydef.setIndexedItemType(useType);
keydef.setStackFrameMap(stackFrameMap);
keydef.setLocation(this);
keydef.setBackwardsCompatible(xPath10ModeIsEnabled());
keydef.setComposite(composite);
keydef.obtainDeclaringComponent(this);
try {
km.addKeyDefinition(keyName, keydef, !sensitive, compilation.getConfiguration());
} catch (XPathException err) {
compileError(err);
}
keyDefinition = keydef;
}
/**
* Optimize the stylesheet construct
*
* @param declaration this xsl:key declaration
*/
@Override
public void optimize(ComponentDeclaration declaration) throws XPathException {
ExpressionVisitor visitor = makeExpressionVisitor();
ContextItemStaticInfo contextItemType = getConfiguration().makeContextItemStaticInfo(match.getItemType(), false);
Expression useExp = keyDefinition.getUse();
useExp = useExp.optimize(visitor, contextItemType);
allocateLocalSlots(useExp);
keyDefinition.setBody(useExp);
}
}