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Common functionality for HBase

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/*
 * 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.io.encoding;

import java.io.IOException;
import org.apache.hadoop.hbase.io.hfile.BlockType;
import org.apache.hadoop.hbase.io.hfile.HFileContext;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.yetus.audience.InterfaceAudience;

/**
 * An encoding context that is created by a writer's encoder, and is shared across the writer's
 * whole lifetime.
 * @see HFileBlockDecodingContext for decoding
 */
@InterfaceAudience.Private
public interface HFileBlockEncodingContext {

  /** Returns the block type after encoding */
  BlockType getBlockType();

  /** Returns the {@link DataBlockEncoding} encoding used */
  DataBlockEncoding getDataBlockEncoding();

  /**
   * Do any action that needs to be performed after the encoding. Compression is also included if a
   * non-null compression algorithm is used
   */
  void postEncoding(BlockType blockType) throws IOException;

  /** Releases the resources used. */
  void close();

  /** Returns HFile context information */
  HFileContext getHFileContext();

  /** Sets the encoding state. */
  void setEncodingState(EncodingState state);

  /** Returns the encoding state */
  EncodingState getEncodingState();

  /**
   * Compress and encrypt the supplied encoded block data with header.
   * @param data   encoded bytes with header
   * @param offset the offset in encoded data to start at
   * @param length the number of encoded bytes
   * @return Bytes with header which are ready to write out to disk. This is compressed and
   *         encrypted bytes applying the set compression algorithm and encryption. The bytes may be
   *         changed. If need a Bytes reference for later use, clone the bytes and use that. Null if
   *         the data doesn't need to be compressed and encrypted.
   */
  Bytes compressAndEncrypt(byte[] data, int offset, int length) throws IOException;
}