Merge pull request #4483 from evolvedbinary/feature/fn-uri-collection#0,#1

[feature] Implement the fn:uri-collection function

Author: adamretter

exist-core/src/main/java/org/exist/xquery/ErrorCodes.java

@@ -150,7 +150,7 @@ public class ErrorCodes {
     public static final ErrorCode FODC0001 = new W3CErrorCode("FODC0001", "No context document.");
     public static final ErrorCode FODC0002 = new W3CErrorCode("FODC0002", "Error retrieving resource.");
     public static final ErrorCode FODC0003 = new W3CErrorCode("FODC0003", "Function stability not defined.");
-    public static final ErrorCode FODC0004 = new W3CErrorCode("FODC0004", "Invalid argument to fn:collection.");
+    public static final ErrorCode FODC0004 = new W3CErrorCode("FODC0004", "Invalid argument to fn:collection or fn:uri-collection.");
     public static final ErrorCode FODC0005 = new W3CErrorCode("FODC0005", "Invalid argument to fn:doc or fn:doc-available.");
     public static final ErrorCode FODT0001 = new W3CErrorCode("FODT0001", "Overflow/underflow in date/time operation.");
     public static final ErrorCode FODT0002 = new W3CErrorCode("FODT0002", "Overflow/underflow in duration operation.");

exist-core/src/main/java/org/exist/xquery/XQueryContext.java

@@ -203,6 +203,8 @@ public class XQueryContext implements BinaryValueManager, Context {
     private XMLGregorianCalendar calendar = null;
     private TimeZone implicitTimeZone = null;
 
+    private final Map<String, Sequence> cachedUriCollectionResults = new HashMap<>();
+
     /**
      * the watchdog object assigned to this query.
      */
@@ -1403,6 +1405,8 @@ public void reset(final boolean keepGlobals) {
         callStack.clear();
         protectedDocuments = null;
 
+        cachedUriCollectionResults.clear();
+
         if (!keepGlobals) {
             globalVariables.clear();
         }
@@ -2790,6 +2794,10 @@ public void setStaticDecimalFormat(final QName qnDecimalFormat, final DecimalFor
         staticDecimalFormats.put(qnDecimalFormat, decimalFormat);
     }
 
+    public Map<String, Sequence> getCachedUriCollectionResults() {
+        return cachedUriCollectionResults;
+    }
+
     /**
      * Save state
      */

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

@@ -223,6 +223,8 @@ public class FnModule extends AbstractInternalModule {
         new FunctionDef(FunTrueOrFalse.fnFalse, FunTrueOrFalse.class),
         new FunctionDef(FunUpperOrLowerCase.fnLowerCase, FunUpperOrLowerCase.class),
         new FunctionDef(FunUpperOrLowerCase.fnUpperCase, FunUpperOrLowerCase.class),
+        new FunctionDef(FunUriCollection.FS_URI_COLLECTION_SIGNATURES[0], FunUriCollection.class),
+        new FunctionDef(FunUriCollection.FS_URI_COLLECTION_SIGNATURES[1], FunUriCollection.class),
         new FunctionDef(FunXmlToJson.FS_XML_TO_JSON[0], FunXmlToJson.class),
         new FunctionDef(FunXmlToJson.FS_XML_TO_JSON[1], FunXmlToJson.class),
         new FunctionDef(FunZeroOrOne.signature, FunZeroOrOne.class),

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

@@ -0,0 +1,240 @@
+/*
+ * eXist-db Open Source Native XML Database
+ * Copyright (C) 2001 The eXist-db Authors
+ *
+ * [email protected]
+ * http://www.exist-db.org
+ *
+ * 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.
+ *
+ * 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
+ */
+
+package org.exist.xquery.functions.fn;
+
+import org.exist.collections.Collection;
+import org.exist.dom.persistent.BinaryDocument;
+import org.exist.dom.persistent.DocumentImpl;
+import org.exist.security.PermissionDeniedException;
+import org.exist.storage.lock.Lock;
+import org.exist.util.LockException;
+import org.exist.util.PatternFactory;
+import org.exist.xmldb.XmldbURI;
+import org.exist.xquery.*;
+import org.exist.xquery.value.*;
+
+import java.net.URISyntaxException;
+import java.util.*;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import static org.exist.xquery.FunctionDSL.*;
+import static org.exist.xquery.functions.fn.FnModule.functionSignatures;
+
+public class FunUriCollection extends BasicFunction {
+
+    private static final String FN_NAME = "uri-collection";
+    private static final String FN_DESCRIPTION = "Returns a sequence of xs:anyURI values that represent the URIs in a URI collection.";
+    private static final FunctionReturnSequenceType FN_RETURN = returnsOptMany(Type.ANY_URI,
+            "the default URI collection, if $arg is not specified or is an empty sequence, " +
+                    "or the sequence of URIs that correspond to the supplied URI");
+    private static final FunctionParameterSequenceType ARG = optParam("arg", Type.STRING,
+            "An xs:string identifying a URI Collection. " +
+                    "The argument is interpreted as either an absolute xs:anyURI, or a relative xs:anyURI resolved " +
+                    "against the base-URI property from the static context. In eXist-db this function consults the " +
+                    "query hierarchy of the database. Query String parameters may be provided to " +
+                    "control the URIs returned by this function. " +
+                    "The parameter `match` may be used to provide a Regular Expression against which the result " +
+                    "sequence of URIs are filtered. " +
+                    "The parameter `content-type` may be used to determine the Internet Media Type (or generally " +
+                    "whether XML, Binary, and/or (Sub) Collection) URIs that are returned in the result sequence; " +
+                    "the special values: 'application/vnd.existdb.collection' includes (Sub) Collections, " +
+                    "'application/vnd.existdb.document' includes any document, " +
+                    "'application/vnd.existdb.document+xml' includes only XML documents, and " +
+                    "'application/vnd.existdb.document+binary' includes only Binary documents. By default, " +
+                    "`content-type=application/vnd.existdb.collection,application/vnd.existdb.document` " +
+                    "(i.e. all Collections and Documents). " +
+                    "The parameter `stable` may be used to determine if the function is deterministic. " +
+                    "By default `stable=yes` to ensure that the same results are returned by each call within the same " +
+                    "query."
+    );
+    public static final FunctionSignature[] FS_URI_COLLECTION_SIGNATURES = functionSignatures(
+            FN_NAME,
+            FN_DESCRIPTION,
+            FN_RETURN,
+            arities(
+                    arity(),
+                    arity(ARG)
+            )
+        );
+
+    private static final String KEY_CONTENT_TYPE = "content-type";
+    private static final String VALUE_CONTENT_TYPE_DOCUMENT = "application/vnd.existdb.document";
+    private static final String VALUE_CONTENT_TYPE_DOCUMENT_BINARY = "application/vnd.existdb.document+binary";
+    private static final String VALUE_CONTENT_TYPE_DOCUMENT_XML = "application/vnd.existdb.document+xml";
+    private static final String VALUE_CONTENT_TYPE_SUBCOLLECTION = "application/vnd.existdb.collection";
+    private static final String[] VALUE_CONTENT_TYPES = {
+            VALUE_CONTENT_TYPE_DOCUMENT,
+            VALUE_CONTENT_TYPE_DOCUMENT_BINARY,
+            VALUE_CONTENT_TYPE_DOCUMENT_XML,
+            VALUE_CONTENT_TYPE_SUBCOLLECTION
+    };
+
+    private static final String KEY_STABLE = "stable";
+    private static final String VALUE_STABLE_NO = "no";
+    private static final String VALUE_STABLE_YES = "yes";
+    private static final String[] VALUE_STABLES = {
+            VALUE_STABLE_NO,
+            VALUE_STABLE_YES
+    };
+
+    private static final String KEY_MATCH = "match";
+
+    public FunUriCollection(final XQueryContext context, final FunctionSignature signature) {
+        super(context, signature);
+    }
+
+    public Sequence eval(final Sequence[] args, final Sequence contextSequence) throws XPathException {
+        final Sequence result;
+        if (args.length == 0 || args[0].isEmpty() || args[0].toString().isEmpty()) {
+            result = new AnyURIValue(XmldbURI.ROOT_COLLECTION);
+        } else {
+            final List<String> resultUris = new ArrayList<>();
+
+            final String uriWithQueryString = args[0].toString();
+            final int queryStringIndex = uriWithQueryString.indexOf('?');
+            final String uriWithoutQueryString = (queryStringIndex >= 0) ? uriWithQueryString.substring(0, queryStringIndex) : uriWithQueryString;
+            String uriWithoutStableQueryString = uriWithQueryString.replaceAll(String.format("%s\\s*=\\s*\\byes|no\\b\\s*&+", KEY_STABLE), "");
+            if (uriWithoutStableQueryString.endsWith("?")) {
+                uriWithoutStableQueryString = uriWithoutStableQueryString.substring(0, uriWithoutStableQueryString.length() - 1);
+            }
+
+            final XmldbURI uri;
+            try {
+                uri = XmldbURI.xmldbUriFor(uriWithoutQueryString);
+            } catch (URISyntaxException e) {
+                throw new XPathException(this, ErrorCodes.FODC0004, String.format("\"%s\" is not a valid URI.", args[0].toString()));
+            }
+
+            final Map<String, String> queryStringMap = parseQueryString(uriWithQueryString);
+            checkQueryStringMap(queryStringMap);
+
+            if ((!queryStringMap.containsKey(KEY_STABLE) || queryStringMap.get(KEY_STABLE).equals(VALUE_STABLE_YES)) &&
+                    context.getCachedUriCollectionResults().containsKey(uriWithoutStableQueryString)) {
+                result = context.getCachedUriCollectionResults().get(uriWithoutStableQueryString);
+            } else {
+                final boolean binaryUrisIncluded = !queryStringMap.containsKey(KEY_CONTENT_TYPE) ||
+                        (queryStringMap.get(KEY_CONTENT_TYPE).equals(VALUE_CONTENT_TYPE_DOCUMENT) ||
+                         queryStringMap.get(KEY_CONTENT_TYPE).equals(VALUE_CONTENT_TYPE_DOCUMENT_BINARY));
+                final boolean subcollectionUrisIncluded = !queryStringMap.containsKey(KEY_CONTENT_TYPE) ||
+                        queryStringMap.get(KEY_CONTENT_TYPE).equals(VALUE_CONTENT_TYPE_SUBCOLLECTION);
+                final boolean xmlUrisIncluded = !queryStringMap.containsKey(KEY_CONTENT_TYPE) ||
+                        (queryStringMap.get(KEY_CONTENT_TYPE).equals(VALUE_CONTENT_TYPE_DOCUMENT) ||
+                                queryStringMap.get(KEY_CONTENT_TYPE).equals(VALUE_CONTENT_TYPE_DOCUMENT_XML));
+
+                try (final Collection collection = context.getBroker().openCollection(uri, Lock.LockMode.READ_LOCK)) {
+                    if (collection != null) {
+                        if (binaryUrisIncluded || xmlUrisIncluded) {
+                            final Iterator<DocumentImpl> documentIterator = collection.iterator(context.getBroker());
+                            while (documentIterator.hasNext()) {
+                                final DocumentImpl document = documentIterator.next();
+                                if ((xmlUrisIncluded && !(document instanceof BinaryDocument)) ||
+                                        (binaryUrisIncluded && document instanceof BinaryDocument)) {
+                                    resultUris.add(document.getURI().toString());
+                                }
+                            }
+                        }
+
+                        if (subcollectionUrisIncluded) {
+                            final Iterator<XmldbURI> collectionsIterator = collection.collectionIterator(context.getBroker());
+                            while (collectionsIterator.hasNext()) {
+                                resultUris.add(uri.append(collectionsIterator.next()).toString());
+                            }
+                        }
+                    } else {
+                        throw new XPathException(this, ErrorCodes.FODC0002, String.format("Collection \"%s\" not found.", uri));
+                    }
+                } catch (final LockException | PermissionDeniedException e) {
+                    throw new XPathException(this, ErrorCodes.FODC0002, e);
+                }
+
+                if (queryStringMap.containsKey(KEY_MATCH) && queryStringMap.get(KEY_MATCH).length() > 0) {
+                    final Pattern pattern = PatternFactory.getInstance().getPattern(queryStringMap.get(KEY_MATCH));
+                    final List<String> matchedResultUris = resultUris.stream().filter(resultUri -> pattern.matcher(resultUri).find()).collect(Collectors.toList());
+                    if (matchedResultUris.isEmpty()) {
+                        result = Sequence.EMPTY_SEQUENCE;
+                    } else {
+                        result = new ValueSequence();
+                        for (String resultUri : matchedResultUris) {
+                            result.add(new AnyURIValue(resultUri));
+                        }
+                    }
+                } else {
+                    result = new ValueSequence();
+                    for (String resultUri : resultUris) {
+                        result.add(new AnyURIValue(resultUri));
+                    }
+                }
+
+                // only store the result if they were not previously stored - otherwise we loose stability!
+                if (!context.getCachedUriCollectionResults().containsKey(uriWithoutStableQueryString)) {
+                    context.getCachedUriCollectionResults().put(uriWithoutStableQueryString, result);
+                }
+            }
+        }
+
+        return result;
+    }
+
+    private static Map<String, String> parseQueryString(final String uri) {
+        final Map<String, String> map = new HashMap<>();
+        if (uri != null) {
+            final int questionMarkIndex = uri.indexOf('?');
+            if (questionMarkIndex >= 0 && questionMarkIndex + 1 < uri.length()) {
+                String[] keyValuePairs = uri.substring(questionMarkIndex + 1).split("&");
+                for (String keyValuePair : keyValuePairs) {
+                    int equalIndex = keyValuePair.indexOf('=');
+                    if (equalIndex >= 0) {
+                        if (equalIndex + 1 < uri.length()) {
+                            map.put(keyValuePair.substring(0, equalIndex).trim(), keyValuePair.substring(equalIndex + 1).trim());
+                        } else {
+                            map.put(keyValuePair.substring(0, equalIndex).trim(), "");
+                        }
+                    } else {
+                        map.put(keyValuePair.trim(), "");
+                    }
+                }
+            }
+        }
+
+        return map;
+    }
+
+    private void checkQueryStringMap(final Map<String, String> queryStringMap) throws XPathException {
+        for (Map.Entry<String, String> queryStringEntry : queryStringMap.entrySet()) {
+            final String key = queryStringEntry.getKey();
+            final String value = queryStringEntry.getValue();
+            if (key.equals(KEY_CONTENT_TYPE)) {
+                if (Arrays.stream(VALUE_CONTENT_TYPES).noneMatch(contentTypeValue -> contentTypeValue.equals(value))) {
+                    throw new XPathException(this, ErrorCodes.FODC0004, String.format("Invalid query-string value \"%s\".", queryStringEntry));
+                }
+            } else if (key.equals(KEY_STABLE)) {
+                if (Arrays.stream(VALUE_STABLES).noneMatch(stableValue -> stableValue.equals(value))) {
+                    throw new XPathException(this, ErrorCodes.FODC0004, String.format("Invalid query-string value \"%s\".", queryStringEntry));
+                }
+            } else if (!key.equals(KEY_MATCH)) {
+                throw new XPathException(this, ErrorCodes.FODC0004, String.format("Unexpected query string \"%s\".", queryStringEntry));
+            }
+        }
+    }
+}