/*
* 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.hfile;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.io.encoding.DataBlockEncoder;
import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDecodingContext;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultDecodingContext;
import org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultEncodingContext;
import org.apache.hadoop.hbase.io.encoding.HFileBlockEncodingContext;
import org.apache.hadoop.hbase.io.hfile.HFile.FileInfo;
import org.apache.hadoop.hbase.util.Bytes;
/**
* Do different kinds of data block encoding according to column family
* options.
*/
@InterfaceAudience.Private
public class HFileDataBlockEncoderImpl implements HFileDataBlockEncoder {
private final DataBlockEncoding encoding;
/**
* Do data block encoding with specified options.
* @param encoding What kind of data block encoding will be used.
*/
public HFileDataBlockEncoderImpl(DataBlockEncoding encoding) {
this.encoding = encoding != null ? encoding : DataBlockEncoding.NONE;
}
public static HFileDataBlockEncoder createFromFileInfo(
FileInfo fileInfo) throws IOException {
DataBlockEncoding encoding = DataBlockEncoding.NONE;
byte[] dataBlockEncodingType = fileInfo.get(DATA_BLOCK_ENCODING);
if (dataBlockEncodingType != null) {
String dataBlockEncodingStr = Bytes.toString(dataBlockEncodingType);
try {
encoding = DataBlockEncoding.valueOf(dataBlockEncodingStr);
} catch (IllegalArgumentException ex) {
throw new IOException("Invalid data block encoding type in file info: "
+ dataBlockEncodingStr, ex);
}
}
if (encoding == DataBlockEncoding.NONE) {
return NoOpDataBlockEncoder.INSTANCE;
}
return new HFileDataBlockEncoderImpl(encoding);
}
@Override
public void saveMetadata(HFile.Writer writer) throws IOException {
writer.appendFileInfo(DATA_BLOCK_ENCODING, encoding.getNameInBytes());
}
@Override
public DataBlockEncoding getDataBlockEncoding() {
return encoding;
}
/**
* Precondition: a non-encoded buffer. Postcondition: on-disk encoding.
*
* The encoded results can be stored in {@link HFileBlockEncodingContext}.
*
* @throws IOException
*/
@Override
public void beforeWriteToDisk(ByteBuffer in,
HFileBlockEncodingContext encodeCtx,
BlockType blockType) throws IOException {
if (encoding == DataBlockEncoding.NONE) {
// there is no need to encode the block before writing it to disk
((HFileBlockDefaultEncodingContext) encodeCtx).compressAfterEncodingWithBlockType(
in.array(), blockType);
return;
}
encodeBufferToHFileBlockBuffer(in, encoding, encodeCtx);
}
@Override
public boolean useEncodedScanner() {
return encoding != DataBlockEncoding.NONE;
}
/**
* Encode a block of key value pairs.
*
* @param in input data to encode
* @param algo encoding algorithm
* @param encodeCtx where will the output data be stored
*/
private void encodeBufferToHFileBlockBuffer(ByteBuffer in, DataBlockEncoding algo,
HFileBlockEncodingContext encodeCtx) {
DataBlockEncoder encoder = algo.getEncoder();
try {
encoder.encodeKeyValues(in, encodeCtx);
} catch (IOException e) {
throw new RuntimeException(String.format(
"Bug in data block encoder "
+ "'%s', it probably requested too much data, " +
"exception message: %s.",
algo.toString(), e.getMessage()), e);
}
}
@Override
public String toString() {
return getClass().getSimpleName() + "(encoding=" + encoding + ")";
}
@Override
public HFileBlockEncodingContext newDataBlockEncodingContext(
byte[] dummyHeader, HFileContext fileContext) {
DataBlockEncoder encoder = encoding.getEncoder();
if (encoder != null) {
return encoder.newDataBlockEncodingContext(encoding, dummyHeader, fileContext);
}
return new HFileBlockDefaultEncodingContext(null, dummyHeader, fileContext);
}
@Override
public HFileBlockDecodingContext newDataBlockDecodingContext(HFileContext fileContext) {
DataBlockEncoder encoder = encoding.getEncoder();
if (encoder != null) {
return encoder.newDataBlockDecodingContext(fileContext);
}
return new HFileBlockDefaultDecodingContext(fileContext);
}
}