| /* |
| * 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.pig.backend.hadoop.executionengine.mapReduceLayer; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POStore; |
| import org.apache.pig.classification.InterfaceAudience; |
| import org.apache.pig.classification.InterfaceStability; |
| |
| /** |
| * Interface to implement when you want to customize the way of computing the |
| * size of output in PigStats. Since not every storage is file-based (e.g. |
| * HBaseStorage), the output size cannot always be computed as the total size of |
| * output files. |
| * |
| * @see FileBasedOutputSizeReader |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public interface PigStatsOutputSizeReader { |
| |
| static final String OUTPUT_SIZE_READER_KEY = "pig.stats.output.size.reader"; |
| static final String OUTPUT_SIZE_READER_UNSUPPORTED = "pig.stats.output.size.reader.unsupported"; |
| |
| /** |
| * Returns whether the given PSStore is supported by this output size reader |
| * or not. |
| * @param sto POStore |
| * @param conf Configuration |
| */ |
| public boolean supports(POStore sto, Configuration conf); |
| |
| /** |
| * Returns the size of output in bytes. If the size of output cannot be |
| * computed for any reason, -1 should be returned. |
| * @param sto POStore |
| * @param conf configuration |
| */ |
| public long getOutputSize(POStore sto, Configuration conf) throws IOException; |
| } |