/*
*
* 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 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.ProtobufUtil;
import org.apache.hadoop.hbase.protobuf.generated.FilterProtos;
import com.google.protobuf.InvalidProtocolBufferException;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.List;
/**
* A wrapper filter that filters an entire row if any of the KeyValue checks do
* not pass.
* <p>
* For example, if all columns in a row represent weights of different things,
* with the values being the actual weights, and we want to filter out the
* entire row if any of its weights are zero. In this case, we want to prevent
* rows from being emitted if a single key is filtered. Combine this filter
* with a {@link ValueFilter}:
* <p>
* <pre>
* scan.setFilter(new SkipFilter(new ValueFilter(CompareOp.NOT_EQUAL,
* new BinaryComparator(Bytes.toBytes(0))));
* </code>
* Any row which contained a column whose value was 0 will be filtered out
* (since ValueFilter will not pass that KeyValue).
* Without this filter, the other non-zero valued columns in the row would still
* be emitted.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class SkipFilter extends FilterBase {
private boolean filterRow = false;
private Filter filter;
public SkipFilter(Filter filter) {
this.filter = filter;
}
public Filter getFilter() {
return filter;
}
public void reset() {
filter.reset();
filterRow = false;
}
private void changeFR(boolean value) {
filterRow = filterRow || value;
}
public ReturnCode filterKeyValue(KeyValue v) {
ReturnCode c = filter.filterKeyValue(v);
changeFR(c != ReturnCode.INCLUDE);
return c;
}
@Override
public KeyValue transform(KeyValue v) {
return filter.transform(v);
}
public boolean filterRow() {
return filterRow;
}
public boolean hasFilterRow() {
return true;
}
/**
* @return The filter serialized using pb
*/
public byte [] toByteArray() {
FilterProtos.SkipFilter.Builder builder =
FilterProtos.SkipFilter.newBuilder();
builder.setFilter(ProtobufUtil.toFilter(this.filter));
return builder.build().toByteArray();
}
/**
* @param pbBytes A pb serialized {@link SkipFilter} instance
* @return An instance of {@link SkipFilter} made from <code>bytes</code>
* @throws DeserializationException
* @see #toByteArray
*/
public static SkipFilter parseFrom(final byte [] pbBytes)
throws DeserializationException {
FilterProtos.SkipFilter proto;
try {
proto = FilterProtos.SkipFilter.parseFrom(pbBytes);
} catch (InvalidProtocolBufferException e) {
throw new DeserializationException(e);
}
try {
return new SkipFilter(ProtobufUtil.toFilter(proto.getFilter()));
} catch (IOException ioe) {
throw new DeserializationException(ioe);
}
}
/**
* @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 SkipFilter)) return false;
SkipFilter other = (SkipFilter)o;
return getFilter().areSerializedFieldsEqual(other.getFilter());
}
public boolean isFamilyEssential(byte[] name) {
return filter.isFamilyEssential(name);
}
@Override
public String toString() {
return this.getClass().getSimpleName() + " " + this.filter.toString();
}
}