001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.io.encoding;
019
020import java.io.DataInputStream;
021import java.io.DataOutputStream;
022import java.io.IOException;
023import java.nio.ByteBuffer;
024import org.apache.hadoop.hbase.Cell;
025import org.apache.hadoop.hbase.nio.ByteBuff;
026import org.apache.hadoop.hbase.util.ByteBufferUtils;
027import org.apache.hadoop.hbase.util.Bytes;
028import org.apache.yetus.audience.InterfaceAudience;
029
030/**
031 * Just copy data, do not do any kind of compression. Use for comparison and benchmarking.
032 */
033@InterfaceAudience.Private
034public class CopyKeyDataBlockEncoder extends BufferedDataBlockEncoder {
035
036  private static class CopyKeyEncodingState extends EncodingState {
037    NoneEncoder encoder = null;
038  }
039
040  @Override
041  public void startBlockEncoding(HFileBlockEncodingContext blkEncodingCtx, DataOutputStream out)
042    throws IOException {
043    if (blkEncodingCtx.getClass() != HFileBlockDefaultEncodingContext.class) {
044      throw new IOException(this.getClass().getName() + " only accepts "
045        + HFileBlockDefaultEncodingContext.class.getName() + " as the " + "encoding context.");
046    }
047
048    HFileBlockDefaultEncodingContext encodingCtx =
049      (HFileBlockDefaultEncodingContext) blkEncodingCtx;
050    encodingCtx.prepareEncoding(out);
051
052    NoneEncoder encoder = new NoneEncoder(out, encodingCtx);
053    CopyKeyEncodingState state = new CopyKeyEncodingState();
054    state.encoder = encoder;
055    blkEncodingCtx.setEncodingState(state);
056  }
057
058  @Override
059  public int internalEncode(Cell cell, HFileBlockDefaultEncodingContext encodingContext,
060    DataOutputStream out) throws IOException {
061    CopyKeyEncodingState state = (CopyKeyEncodingState) encodingContext.getEncodingState();
062    NoneEncoder encoder = state.encoder;
063    return encoder.write(cell);
064  }
065
066  @Override
067  public Cell getFirstKeyCellInBlock(ByteBuff block) {
068    int keyLength = block.getIntAfterPosition(Bytes.SIZEOF_INT);
069    int pos = 3 * Bytes.SIZEOF_INT;
070    ByteBuffer key = block.asSubByteBuffer(pos + keyLength).duplicate();
071    return createFirstKeyCell(key, keyLength);
072  }
073
074  @Override
075  public String toString() {
076    return CopyKeyDataBlockEncoder.class.getSimpleName();
077  }
078
079  @Override
080  public EncodedSeeker createSeeker(final HFileBlockDecodingContext decodingCtx) {
081    return new SeekerStateBufferedEncodedSeeker(decodingCtx);
082  }
083
084  @Override
085  protected ByteBuffer internalDecodeKeyValues(DataInputStream source, int allocateHeaderLength,
086    int skipLastBytes, HFileBlockDefaultDecodingContext decodingCtx) throws IOException {
087    int decompressedSize = source.readInt();
088    ByteBuffer buffer = ByteBuffer.allocate(decompressedSize + allocateHeaderLength);
089    buffer.position(allocateHeaderLength);
090    ByteBufferUtils.copyFromStreamToBuffer(buffer, source, decompressedSize);
091
092    return buffer;
093  }
094
095  private static class SeekerStateBufferedEncodedSeeker extends BufferedEncodedSeeker<SeekerState> {
096
097    private SeekerStateBufferedEncodedSeeker(HFileBlockDecodingContext decodingCtx) {
098      super(decodingCtx);
099    }
100
101    @Override
102    protected void decodeNext() {
103      current.keyLength = currentBuffer.getInt();
104      current.valueLength = currentBuffer.getInt();
105      current.ensureSpaceForKey();
106      currentBuffer.get(current.keyBuffer, 0, current.keyLength);
107      current.valueOffset = currentBuffer.position();
108      currentBuffer.skip(current.valueLength);
109      if (includesTags()) {
110        // Read short as unsigned, high byte first
111        current.tagsLength = ((currentBuffer.get() & 0xff) << 8) ^ (currentBuffer.get() & 0xff);
112        currentBuffer.skip(current.tagsLength);
113      }
114      if (includesMvcc()) {
115        current.memstoreTS = ByteBufferUtils.readVLong(currentBuffer);
116      } else {
117        current.memstoreTS = 0;
118      }
119      current.nextKvOffset = currentBuffer.position();
120    }
121
122    @Override
123    protected void decodeFirst() {
124      currentBuffer.skip(Bytes.SIZEOF_INT);
125      current.lastCommonPrefix = 0;
126      decodeNext();
127    }
128  }
129
130}