[bugfix] New implementation of the fn:doc-available#1 XPath function

Closes eXist-db/exist#5220

Author: adamretter

exist-core/pom.xml

@@ -753,6 +753,7 @@
                                 <include>src/main/java/org/exist/util/JREUtil.java</include>
                                 <include>src/main/java/org/exist/util/OSUtil.java</include>
                                 <include>src/main/java/org/exist/util/StringUtil.java</include>
+                                <include>src/main/java/org/exist/xquery/functions/fn/FunDocAvailable.java</include>
                                 <include>src/test/java/org/exist/xquery/ImportFromPkgTest.java</include>
                                 <include>src/test/java/org/exist/xquery/WatchdogTest.java</include>
                                 <include>src/test/java/org/exist/xquery/value/DateTimeTypesTest.java</include>
@@ -943,6 +944,8 @@
                                 <include>src/main/java/org/exist/management/impl/JMXAgent.java</include>
                                 <include>src/test/java/org/exist/xmldb/CreateCollectionsTest.java</include>
                                 <include>src/test/java/org/exist/xquery/XQueryFunctionsTest.java</include>
+                                <include>src/test/java/org/exist/xquery/functions/fn/DocTest.java</include>
+                                <include>src/main/java/org/exist/xquery/functions/fn/FnModule.java</include>
                                 <include>src/main/java/org/exist/xquery/functions/fn/FunBaseURI.java</include>
                                 <include>src/main/java/org/exist/xquery/functions/fn/FunParseIetfDate.java</include>
                                 <include>src/main/java/org/exist/xquery/functions/fn/FunTrace.java</include>
@@ -1127,7 +1130,9 @@
                                 <exclude>src/main/java/org/exist/xquery/UserDefinedFunction.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/WatchdogTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/XQueryContext.java</exclude>
+                                <exclude>src/main/java/org/exist/xquery/functions/fn/FnModule.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/functions/fn/FunDeepEqual.java</exclude>
+                                <exclude>src/main/java/org/exist/xquery/functions/fn/FunDocAvailable.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/functions/fn/FunUriCollection.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/functions/fn/FunBaseURI.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/functions/fn/FunParseIetfDate.java</exclude>
@@ -1251,6 +1256,7 @@
                                 <exclude>src/test/java/org/exist/xquery/ImportModuleTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/Materializable.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/XQueryContextAttributesTest.java</exclude>
+                                <exclude>src/test/java/org/exist/xquery/functions/fn/DocTest.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/functions/map/MapType.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/functions/session/AbstractSessionTest.java</exclude>
                                 <exclude>src/test/java/org/exist/xquery/functions/xmldb/AbstractXMLDBTest.java</exclude>

exist-core/src/main/java/org/exist/xquery/functions/fn/FnModule.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library 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; version 2.1.
+ *
+ * This library 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 Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -33,6 +57,7 @@
 /**
  * Module function definitions for xpath-functions module.
  *
+ * @author <a href="mailto:[email protected]">Adam Retter</a>
  * @author <a href="mailto:[email protected]">Wolfgang Meier</a>
  * @author ljo
  */
@@ -73,7 +98,7 @@ public class FnModule extends AbstractInternalModule {
         new FunctionDef(FunDistinctValues.signatures[0], FunDistinctValues.class),
         new FunctionDef(FunDistinctValues.signatures[1], FunDistinctValues.class),
         new FunctionDef(FunDoc.signature, FunDoc.class),
-        new FunctionDef(FunDocAvailable.signature, FunDocAvailable.class),
+        new FunctionDef(FunDocAvailable.FS_DOC_AVAILABLE, FunDocAvailable.class),
         new FunctionDef(FunDocumentURI.FS_DOCUMENT_URI_0, FunDocumentURI.class),
         new FunctionDef(FunDocumentURI.FS_DOCUMENT_URI_1, FunDocumentURI.class),
         new FunctionDef(FunElementWithId.FS_ELEMENT_WITH_ID_SIGNATURES[0], FunElementWithId.class),

exist-core/src/main/java/org/exist/xquery/functions/fn/FunDocAvailable.java

@@ -1,14 +1,13 @@
 /*
- * eXist-db Open Source Native XML Database
- * Copyright (C) 2001 The eXist-db Authors
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
  *
- * [email protected]
- * http://www.exist-db.org
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
  *
  * This library 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 2.1 of the License, or (at your option) any later version.
+ * License as published by the Free Software Foundation; version 2.1.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -21,101 +20,66 @@
  */
 package org.exist.xquery.functions.fn;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-
-import org.exist.dom.QName;
-import org.exist.xquery.*;
-import org.exist.xquery.functions.xmldb.XMLDBModule;
+import org.exist.xquery.BasicFunction;
+import org.exist.xquery.ErrorCodes;
+import org.exist.xquery.FunctionSignature;
+import org.exist.xquery.XPathException;
+import org.exist.xquery.XQueryContext;
 import org.exist.xquery.util.DocUtils;
 import org.exist.xquery.value.BooleanValue;
-import org.exist.xquery.value.FunctionReturnSequenceType;
-import org.exist.xquery.value.FunctionParameterSequenceType;
-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.net.URI;
 import java.net.URISyntaxException;
 
+import static org.exist.xquery.FunctionDSL.optParam;
+import static org.exist.xquery.FunctionDSL.returns;
+import static org.exist.xquery.functions.fn.FnModule.functionSignature;
+
 /**
- * Implements the XQuery's fn:doc-available() function.
+ * Implementation of the XPath fn:doc-available() function.
+ * See <a href="https://www.w3.org/TR/xpath-functions-31/#func-doc-available">14.6.2 fn:doc-available</a> in the
+ * W3C XPath and XQuery Functions and Operators 3.1 specification.
  *
- * @author <a href="mailto:[email protected]">Pierrick Brihaye</a>
- * @author wolf
+ * @author <a href="mailto:[email protected]">Adam Retter</a>
  */
-public class FunDocAvailable extends Function {
+public class FunDocAvailable extends BasicFunction {
 
-    protected static final Logger logger = LogManager.getLogger(FunDocAvailable.class);
+    public static final FunctionSignature FS_DOC_AVAILABLE = functionSignature(
+        "doc-available",
+        "The function returns true if and only if the function call fn:doc($uri) would return a document node.",
+        returns(Type.BOOLEAN, "If a call on fn:doc($uri) would return a document node, this function returns true. In all other cases this function returns false."),
+        optParam("uri", Type.STRING, "The URI to check for a document.")
+    );
 
-    public static final FunctionSignature signature =
-            new FunctionSignature(
-                    new QName("doc-available", Function.BUILTIN_FUNCTION_NS),
-                    "Returns whether or not the document, $document-uri, " +
-                            "specified in the input sequence is available. " +
-                            XMLDBModule.ANY_URI,
-                    new SequenceType[]{
-                            new FunctionParameterSequenceType("document-uri", Type.STRING,
-                                    Cardinality.ZERO_OR_ONE, "The document URI")
-                    },
-                    new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE,
-                            "true() if the document is available, false() otherwise"));
-
-    public FunDocAvailable(final XQueryContext context) {
+    public FunDocAvailable(final XQueryContext context, final FunctionSignature signature) {
         super(context, signature);
     }
 
     @Override
-    public int getDependencies() {
-        return Dependency.CONTEXT_SET;
-    }
-
-    @Override
-    public Sequence eval(final Sequence contextSequence, final Item contextItem)
-            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());
-            }
+    public Sequence eval(final Sequence[] args, final Sequence contextSequence) throws XPathException {
+        if (args.length == 0) {
+            return BooleanValue.FALSE;
         }
 
-        Sequence result = BooleanValue.FALSE;
-        final Sequence arg = getArgument(0).eval(contextSequence, contextItem);
-        if (!arg.isEmpty()) {
-            final String path = arg.itemAt(0).getStringValue();
-
-            try {
-                new URI(path);
-            } catch (final URISyntaxException e) {
-                throw new XPathException(this, ErrorCodes.FODC0005, e.getMessage(), arg, e);
-            }
-
-            try {
-                result = BooleanValue.valueOf(DocUtils.isDocumentAvailable(this.context, path, this));
-            } catch (final XPathException e) {
-                result = BooleanValue.FALSE;
+        final String uri = args[0].getStringValue();
+        try {
+            new URI(uri);
+        } catch (final URISyntaxException e) {
+            if (context.getXQueryVersion() == 31) {
+                // XPath 3.1
+                return BooleanValue.FALSE;
+            } else {
+                // XPath 2.0 and 3.0
+                throw new XPathException(this, ErrorCodes.FODC0005, e.getMessage(), args[0], e);
             }
         }
 
-        if (context.getProfiler().isEnabled()) {
-            context.getProfiler().end(this, "", result);
+        try {
+            return BooleanValue.valueOf(DocUtils.isDocumentAvailable(this.context, uri, this));
+        } catch (final XPathException e) {
+            return BooleanValue.FALSE;
         }
-
-        return result;
-    }
-
-    @Override
-    public void resetState(final boolean postOptimization) {
-        super.resetState(postOptimization);
-        getArgument(0).resetState(postOptimization);
     }
 }

exist-core/src/test/java/org/exist/xquery/functions/fn/DocTest.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library 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; version 2.1.
+ *
+ * This library 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 Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -68,10 +92,9 @@
 import java.net.URISyntaxException;
 
 /**
- *
+ * @author <a href="mailto:[email protected]">Adam Retter</a>
  * @author Joe Wicentowski
  * @author <a href="mailto:[email protected]">Dmitriy Shabanov</a>
- * @author Adam Retter
  */
 public class DocTest {
 
@@ -260,6 +283,25 @@ public void docAvailable_dynamicallyAvailableDocument_relativeUri() throws XPath
         }
     }
 
+    @Test
+    public void docAvailableInPredicate() throws XPathException, EXistException, PermissionDeniedException {
+        final BrokerPool pool = BrokerPool.getInstance();
+        final String query = "('/db/test.xml', '/db/test/test.xml', '/db/non-existent.xml')[fn:doc-available(.)]";
+
+        try (final DBBroker broker = pool.getBroker()) {
+            final XQueryContext context = new XQueryContext(pool);
+
+            final XQuery xqueryService = pool.getXQueryService();
+            final CompiledXQuery compiled = xqueryService.compile(context, query);
+            final Sequence result = xqueryService.execute(broker, compiled, null);
+
+            assertFalse(result.isEmpty());
+            assertEquals(2, result.getItemCount());
+            assertEquals("/db/test.xml", result.itemAt(0).getStringValue());
+            assertEquals("/db/test/test.xml", result.itemAt(1).getStringValue());
+        }
+    }
+
     private Either<DocumentImpl, org.exist.dom.persistent.DocumentImpl> asInMemoryDocument(final String doc) throws XPathException {
         try {
             final SAXAdapter saxAdapter = new SAXAdapter();