/**
* 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.hive.metastore;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.List;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.metastore.Metastore.SplitInfos;
import org.apache.hadoop.hive.ql.io.sarg.SearchArgument;
/**
* Same as PartitionExpressionProxy, but for file format specific methods for metadata cache.
*/
public interface FileFormatProxy {
/**
* Applies SARG to file metadata, and produces some result for this file.
* @param sarg SARG
* @param fileMetadata File metadata from metastore cache.
* @return The result to return to client for this file, or null if file is eliminated.
*/
SplitInfos applySargToMetadata(SearchArgument sarg, ByteBuffer fileMetadata) throws IOException;
/**
* @param fs The filesystem of the file.
* @param path The file path.
* @param addedVals Output parameter; additional column values for columns returned by
* getAddedColumnsToCache to cache in MS.
* @return The ORC file metadata for a given file.
*/
ByteBuffer getMetadataToCache(
FileSystem fs, Path path, ByteBuffer[] addedVals) throws IOException;
/**
* @return Additional column names to cache in MS for this format.
*/
ByteBuffer[] getAddedColumnsToCache();
/**
* @param metadata File metadatas.
* @return Additional values for columns returned by getAddedColumnsToCache to cache in MS
* for respective metadatas.
*/
ByteBuffer[][] getAddedValuesToCache(List<ByteBuffer> metadata);
}