/**
* Licensed to Cloudera, Inc. under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Cloudera, Inc. 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 com.cloudera.flume.core;
import java.io.IOException;
import com.cloudera.flume.conf.Context;
import com.cloudera.flume.conf.SinkFactory.SinkDecoBuilder;
import com.google.common.base.Preconditions;
/**
* This decorator 'masks' attributes from an event by propagates all attributes
* except for the attributes specified. This corresponds to project complement
* operation in relational calculus, (there is no sql equivalent).
*/
public class MaskDecorator<S extends EventSink> extends EventSinkDecorator<S> {
String[] attrs;
public MaskDecorator(S s, String... attrs) {
super(s);
this.attrs = attrs;
}
@Override
public void append(Event e) throws IOException, InterruptedException {
Event e2 = EventImpl.unselect(e, attrs);
super.append(e2);
}
public static SinkDecoBuilder builder() {
return new SinkDecoBuilder() {
@Override
public EventSinkDecorator<EventSink> build(Context context,
String... argv) {
Preconditions.checkArgument(argv.length >= 1, "usage: mask(attr1,...)");
return new MaskDecorator<EventSink>(null, argv);
}
};
}
}