/*
* 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.accumulo.core.iterators.system;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import org.apache.accumulo.core.data.ArrayByteSequence;
import org.apache.accumulo.core.data.ByteSequence;
import org.apache.accumulo.core.data.Column;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.Filter;
import org.apache.accumulo.core.iterators.IteratorEnvironment;
import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
public class ColumnQualifierFilter extends Filter {
private boolean scanColumns;
private HashSet<ByteSequence> columnFamilies;
private HashMap<ByteSequence,HashSet<ByteSequence>> columnsQualifiers;
public ColumnQualifierFilter() {}
public ColumnQualifierFilter(SortedKeyValueIterator<Key,Value> iterator, Set<Column> columns) {
setSource(iterator);
init(columns);
}
public ColumnQualifierFilter(SortedKeyValueIterator<Key,Value> iterator, HashSet<ByteSequence> columnFamilies,
HashMap<ByteSequence,HashSet<ByteSequence>> columnsQualifiers, boolean scanColumns) {
setSource(iterator);
this.columnFamilies = columnFamilies;
this.columnsQualifiers = columnsQualifiers;
this.scanColumns = scanColumns;
}
public boolean accept(Key key, Value v) {
if (!scanColumns)
return true;
if (columnFamilies.contains(key.getColumnFamilyData()))
return true;
HashSet<ByteSequence> cfset = columnsQualifiers.get(key.getColumnQualifierData());
// ensure the columm qualifier goes with a paired column family,
// it is possible that a column qualifier could occur with a
// column family it was not paired with
return cfset != null && cfset.contains(key.getColumnFamilyData());
}
public void init(Set<Column> columns) {
this.columnFamilies = new HashSet<ByteSequence>();
this.columnsQualifiers = new HashMap<ByteSequence,HashSet<ByteSequence>>();
for (Iterator<Column> iter = columns.iterator(); iter.hasNext();) {
Column col = iter.next();
if (col.columnQualifier != null) {
ArrayByteSequence cq = new ArrayByteSequence(col.columnQualifier);
HashSet<ByteSequence> cfset = this.columnsQualifiers.get(cq);
if (cfset == null) {
cfset = new HashSet<ByteSequence>();
this.columnsQualifiers.put(cq, cfset);
}
cfset.add(new ArrayByteSequence(col.columnFamily));
} else {
// this whole column family should pass
columnFamilies.add(new ArrayByteSequence(col.columnFamily));
}
}
// only take action when column qualifies are present
scanColumns = this.columnsQualifiers.size() > 0;
}
@Override
public SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env) {
return new ColumnQualifierFilter(getSource().deepCopy(env), columnFamilies, columnsQualifiers, scanColumns);
}
}