/*
* Copyright 2010 The Apache Software Foundation
*
* 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.hbase.KeyValue;
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.EQUAL,
* new BinaryComparator(Bytes.toBytes(0))));
* </code>
* Any row which contained a column whose value was 0 will be filtered out.
* Without this filter, the other non-zero valued columns in the row would still
* be emitted.
*/
public class SkipFilter extends FilterBase {
private boolean filterRow = false;
private Filter filter;
public SkipFilter() {
super();
}
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 void write(DataOutput out) throws IOException {
out.writeUTF(this.filter.getClass().getName());
this.filter.write(out);
}
public void readFields(DataInput in) throws IOException {
String className = in.readUTF();
try {
this.filter = (Filter)(Class.forName(className).newInstance());
this.filter.readFields(in);
} catch (InstantiationException e) {
throw new RuntimeException("Failed deserialize.", e);
} catch (IllegalAccessException e) {
throw new RuntimeException("Failed deserialize.", e);
} catch (ClassNotFoundException e) {
throw new RuntimeException("Failed deserialize.", e);
}
}
}