afs commented on code in PR #1752: URL: https://github.com/apache/jena/pull/1752#discussion_r1105070057
########## jena-arq/src/main/java/org/apache/jena/system/buffering/BufferingPrefixMapping.java: ########## @@ -0,0 +1,94 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.jena.system.buffering; + +import java.util.HashSet; +import java.util.Set; + +import org.apache.jena.shared.PrefixMapping; +import org.apache.jena.shared.impl.PrefixMappingImpl; + +/** A {@link PrefixMapping} that buffers changes until {@link #flush()} is called. */ +public class BufferingPrefixMapping extends PrefixMappingImpl implements BufferingCtl { + + private static final boolean CHECK = false; + // Depends on the fact that PrefixMappingImpl maps everything get/set/remove. + private final PrefixMapping added = new PrefixMappingImpl(); + private final Set<String> deleted = new HashSet<>(); + private final PrefixMapping other; + + public BufferingPrefixMapping(PrefixMapping other) { + this.other = other; + } + + public PrefixMapping base() { return other; } + + @Override + public void flush() { + deleted.forEach(prefix->other.removeNsPrefix(prefix)); + other.setNsPrefixes(added); + + deleted.clear(); + added.clearNsPrefixMap(); + } + + public PrefixMapping getAdded() { + return added; + } + + public Set<String> getDeleted() { + return deleted; + } + + @Override + protected void set(String prefix, String uri) { + if ( CHECK ) { + String u = other.getNsPrefixURI(prefix); + if ( uri.equals(u) ) + return; + } + added.setNsPrefix(prefix, uri); + } + + @Override + protected String get(String prefix) { + if ( deleted.contains(prefix) ) + return null; + String uri = added.getNsPrefixURI(prefix); + if ( uri != null ) + return uri; + return other.getNsPrefixURI(prefix); + } + + @Override + protected void remove(String prefix) { + deleted.add(prefix); + added.removeNsPrefix(prefix); + } + + @Override + public int numPrefixes() { + return added.numPrefixes() - deleted.size() + other.numPrefixes(); Review Comment: All classes `Buffering*` are not thread safe. The idea is a thread wraps a graph/dataset to store up changes. graph support isn't transaction aware - dataset support is. If anything more, then multithreaded apps need to use the base dataset properly! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
