/*
* Copyright 2012 NGDATA nv
*
* Licensed 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.lilyproject.hbaseindex.filter;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.List;
import com.gotometrics.orderly.StructIterator;
import com.gotometrics.orderly.StructRowKey;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.filter.FilterBase;
import org.lilyproject.hbaseindex.IndexDefinition;
import org.lilyproject.hbaseindex.IndexFieldDefinition;
/**
* Actual implementation of {@link IndexFilter} as an HBase filter.
*
*
*/
public class IndexFilterHbaseImpl extends FilterBase {
private IndexFilter indexFilter;
private IndexDefinition indexDefinition;
public IndexFilterHbaseImpl(IndexFilter indexFilter, IndexDefinition indexDefinition) {
this.indexFilter = indexFilter;
this.indexDefinition = indexDefinition;
}
public IndexFilterHbaseImpl() {
// for hbase readFields
}
@Override
public ReturnCode filterKeyValue(KeyValue keyValue) {
// for all data qualifiers that we are interested in
for (byte[] dataQualifier : indexFilter.getFilteredDataQualifiers()) {
// check if the key value is about one of those data qualifiers
if (keyValue.matchingColumn(IndexDefinition.DATA_FAMILY, dataQualifier)) {
// if it is, apply the filter
if (indexFilter.filterData(dataQualifier, keyValue.getBuffer(), keyValue.getValueOffset(),
keyValue.getValueLength())) {
return ReturnCode.NEXT_ROW; // this result is ignored
}
}
}
return ReturnCode.INCLUDE; // not skipped
}
@Override
public boolean filterRowKey(byte[] buffer, int offset, int length) {
final StructRowKey structRowKey = indexDefinition.asStructRowKey();
structRowKey.iterateOver(buffer, offset);
final StructIterator fieldsIterator = structRowKey.iterator();
final List<IndexFieldDefinition> fieldDefinitions = indexDefinition.getFields();
// for all defined field definitions
for (IndexFieldDefinition field : fieldDefinitions) {
// check if the field should be filtered
if (indexFilter.getFields().contains(field.getName())) {
final Object nextField = fieldsIterator.next();
if (indexFilter.filterField(field.getName(), nextField)) {
return true; // this result is ignored
}
} else {
try {
fieldsIterator.skip();
} catch (IOException e) {
throw new RuntimeException("failed to skip, index inconsistency?", e);
}
}
}
return false; // nothing was skipped
}
@Override
public void write(DataOutput out) throws IOException {
out.writeUTF(indexDefinition.getClass().getName());
indexDefinition.write(out);
out.writeUTF(indexFilter.getClass().getName());
indexFilter.write(out);
}
@Override
public void readFields(DataInput in) throws IOException {
final String indexDefinitionClassName = in.readUTF();
indexDefinition = (IndexDefinition) tryInstantiateClass(indexDefinitionClassName);
indexDefinition.readFields(in);
final String indexFilterClassName = in.readUTF();
indexFilter = (IndexFilter) tryInstantiateClass(indexFilterClassName);
indexFilter.readFields(in);
}
private Object tryInstantiateClass(String className) throws IOException {
try {
return Class.forName(className).newInstance();
} catch (InstantiationException e) {
throw new IOException(e);
} catch (IllegalAccessException e) {
throw new IOException(e);
} catch (ClassNotFoundException e) {
throw new IOException(e);
}
}
}