| package org.apache.rya.accumulo.query; |
| |
| /* |
| * 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. |
| */ |
| |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| import org.apache.accumulo.core.data.Key; |
| import org.apache.accumulo.core.data.Value; |
| import org.apache.rya.api.RdfCloudTripleStoreConstants.TABLE_LAYOUT; |
| import org.apache.rya.api.domain.RyaStatement; |
| import org.apache.rya.api.persist.RyaDAOException; |
| import org.apache.rya.api.resolver.RyaTripleContext; |
| import org.apache.rya.api.resolver.triple.TripleRow; |
| import org.apache.rya.api.resolver.triple.TripleRowResolverException; |
| import org.eclipse.rdf4j.common.iteration.CloseableIteration; |
| |
| /** |
| * Date: 7/17/12 |
| * Time: 11:48 AM |
| */ |
| public class RyaStatementKeyValueIterator implements CloseableIteration<RyaStatement, RyaDAOException> { |
| private Iterator<Map.Entry<Key, Value>> dataIterator; |
| private TABLE_LAYOUT tableLayout; |
| private Long maxResults = -1L; |
| private RyaTripleContext context; |
| |
| public RyaStatementKeyValueIterator(TABLE_LAYOUT tableLayout, RyaTripleContext context, Iterator<Map.Entry<Key, Value>> dataIterator) { |
| this.tableLayout = tableLayout; |
| this.dataIterator = dataIterator; |
| this.context = context; |
| } |
| |
| @Override |
| public void close() throws RyaDAOException { |
| dataIterator = null; |
| } |
| |
| public boolean isClosed() throws RyaDAOException { |
| return dataIterator == null; |
| } |
| |
| @Override |
| public boolean hasNext() throws RyaDAOException { |
| if (isClosed()) { |
| throw new RyaDAOException("Closed Iterator"); |
| } |
| return maxResults != 0 && dataIterator.hasNext(); |
| } |
| |
| @Override |
| public RyaStatement next() throws RyaDAOException { |
| if (!hasNext()) { |
| return null; |
| } |
| |
| try { |
| Map.Entry<Key, Value> next = dataIterator.next(); |
| Key key = next.getKey(); |
| RyaStatement statement = context.deserializeTriple(tableLayout, |
| new TripleRow(key.getRowData().toArray(), key.getColumnFamilyData().toArray(), key.getColumnQualifierData().toArray(), |
| key.getTimestamp(), key.getColumnVisibilityData().toArray(), next.getValue().get())); |
| if (next.getValue() != null) { |
| statement.setValue(next.getValue().get()); |
| } |
| maxResults--; |
| return statement; |
| } catch (TripleRowResolverException e) { |
| throw new RyaDAOException(e); |
| } |
| } |
| |
| @Override |
| public void remove() throws RyaDAOException { |
| next(); |
| } |
| |
| public Long getMaxResults() { |
| return maxResults; |
| } |
| |
| public void setMaxResults(Long maxResults) { |
| this.maxResults = maxResults; |
| } |
| } |