/*
* 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.hadoop.hbase.filter;
import com.google.protobuf.ByteString;
import com.google.protobuf.InvalidProtocolBufferException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.hbase.DeserializationException;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
import org.apache.hadoop.hbase.util.Bytes;
import java.util.Set;
import java.util.TreeSet;
/**
* The filter looks for the given columns in KeyValue. Once there is a match for
* any one of the columns, it returns ReturnCode.NEXT_ROW for remaining
* KeyValues in the row.
* <p>
* Note : It may emit KVs which do not have the given columns in them, if
* these KVs happen to occur before a KV which does have a match. Given this
* caveat, this filter is only useful for special cases
* like {@link org.apache.hadoop.hbase.mapreduce.RowCounter}.
* <p>
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class FirstKeyValueMatchingQualifiersFilter extends FirstKeyOnlyFilter {
private Set<byte []> qualifiers;
/**
* Constructor which takes a set of columns. As soon as first KeyValue
* matching any of these columns is found, filter moves to next row.
*
* @param qualifiers the set of columns to me matched.
*/
public FirstKeyValueMatchingQualifiersFilter(Set<byte []> qualifiers) {
this.qualifiers = qualifiers;
}
public ReturnCode filterKeyValue(KeyValue v) {
if (hasFoundKV()) {
return ReturnCode.NEXT_ROW;
} else if (hasOneMatchingQualifier(v)) {
setFoundKV(true);
}
return ReturnCode.INCLUDE;
}
private boolean hasOneMatchingQualifier(KeyValue v) {
for (byte[] q : qualifiers) {
if (v.matchingQualifier(q)) {
return true;
}
}
return false;
}
/**
* @return The filter serialized using pb
*/
public byte [] toByteArray() {
FilterProtos.FirstKeyValueMatchingQualifiersFilter.Builder builder =
FilterProtos.FirstKeyValueMatchingQualifiersFilter.newBuilder();
for (byte[] qualifier : qualifiers) {
if (qualifier != null) builder.addQualifiers(ByteString.copyFrom(qualifier));
}
return builder.build().toByteArray();
}
/**
* @param pbBytes A pb serialized {@link FirstKeyValueMatchingQualifiersFilter} instance
* @return An instance of {@link FirstKeyValueMatchingQualifiersFilter} made from <code>bytes</code>
* @throws DeserializationException
* @see #toByteArray
*/
public static FirstKeyValueMatchingQualifiersFilter parseFrom(final byte [] pbBytes)
throws DeserializationException {
FilterProtos.FirstKeyValueMatchingQualifiersFilter proto;
try {
proto = FilterProtos.FirstKeyValueMatchingQualifiersFilter.parseFrom(pbBytes);
} catch (InvalidProtocolBufferException e) {
throw new DeserializationException(e);
}
TreeSet<byte []> qualifiers = new TreeSet<byte []>(Bytes.BYTES_COMPARATOR);
for (ByteString qualifier : proto.getQualifiersList()) {
qualifiers.add(qualifier.toByteArray());
}
return new FirstKeyValueMatchingQualifiersFilter(qualifiers);
}
/**
* @param other
* @return true if and only if the fields of the filter that are serialized
* are equal to the corresponding fields in other. Used for testing.
*/
boolean areSerializedFieldsEqual(Filter o) {
if (o == this) return true;
if (!(o instanceof FirstKeyValueMatchingQualifiersFilter)) return false;
FirstKeyValueMatchingQualifiersFilter other = (FirstKeyValueMatchingQualifiersFilter)o;
return this.qualifiers.equals(other.qualifiers);
}
}