/*
* 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.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.KeyValue.KeyComparator;
import org.apache.hadoop.hbase.io.compress.Compression;
import org.apache.hadoop.hbase.io.hfile.HFile.FileInfo;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.FSUtils;
import org.apache.hadoop.io.RawComparator;
import org.apache.hadoop.io.Writable;
/**
* Common functionality needed by all versions of {@link HFile} writers.
*/
@InterfaceAudience.Private
public abstract class AbstractHFileWriter implements HFile.Writer {
/** Key previously appended. Becomes the last key in the file. */
protected byte[] lastKeyBuffer = null;
protected int lastKeyOffset = -1;
protected int lastKeyLength = -1;
/** FileSystem stream to write into. */
protected FSDataOutputStream outputStream;
/** True if we opened the <code>outputStream</code> (and so will close it). */
protected final boolean closeOutputStream;
/** A "file info" block: a key-value map of file-wide metadata. */
protected FileInfo fileInfo = new HFile.FileInfo();
/** Number of uncompressed bytes we allow per block. */
protected final int blockSize;
/** Total # of key/value entries, i.e. how many times add() was called. */
protected long entryCount = 0;
/** Used for calculating the average key length. */
protected long totalKeyLength = 0;
/** Used for calculating the average value length. */
protected long totalValueLength = 0;
/** Total uncompressed bytes, maybe calculate a compression ratio later. */
protected long totalUncompressedBytes = 0;
/** Key comparator. Used to ensure we write in order. */
protected final RawComparator<byte[]> comparator;
/** Meta block names. */
protected List<byte[]> metaNames = new ArrayList<byte[]>();
/** {@link Writable}s representing meta block data. */
protected List<Writable> metaData = new ArrayList<Writable>();
/** The compression algorithm used. NONE if no compression. */
protected final Compression.Algorithm compressAlgo;
/**
* The data block encoding which will be used.
* {@link NoOpDataBlockEncoder#INSTANCE} if there is no encoding.
*/
protected final HFileDataBlockEncoder blockEncoder;
/** First key in a block. */
protected byte[] firstKeyInBlock = null;
/** May be null if we were passed a stream. */
protected final Path path;
/** Cache configuration for caching data on write. */
protected final CacheConfig cacheConf;
/**
* Name for this object used when logging or in toString. Is either
* the result of a toString on stream or else name of passed file Path.
*/
protected final String name;
public AbstractHFileWriter(CacheConfig cacheConf,
FSDataOutputStream outputStream, Path path, int blockSize,
Compression.Algorithm compressAlgo,
HFileDataBlockEncoder dataBlockEncoder,
KeyComparator comparator) {
this.outputStream = outputStream;
this.path = path;
this.name = path != null ? path.getName() : outputStream.toString();
this.blockSize = blockSize;
this.compressAlgo = compressAlgo == null
? HFile.DEFAULT_COMPRESSION_ALGORITHM : compressAlgo;
this.blockEncoder = dataBlockEncoder != null
? dataBlockEncoder : NoOpDataBlockEncoder.INSTANCE;
this.comparator = comparator != null ? comparator
: Bytes.BYTES_RAWCOMPARATOR;
closeOutputStream = path != null;
this.cacheConf = cacheConf;
}
/**
* Add last bits of metadata to file info before it is written out.
*/
protected void finishFileInfo() throws IOException {
if (lastKeyBuffer != null) {
// Make a copy. The copy is stuffed into HMapWritable. Needs a clean
// byte buffer. Won't take a tuple.
fileInfo.append(FileInfo.LASTKEY, Arrays.copyOfRange(lastKeyBuffer,
lastKeyOffset, lastKeyOffset + lastKeyLength), false);
}
// Average key length.
int avgKeyLen =
entryCount == 0 ? 0 : (int) (totalKeyLength / entryCount);
fileInfo.append(FileInfo.AVG_KEY_LEN, Bytes.toBytes(avgKeyLen), false);
// Average value length.
int avgValueLen =
entryCount == 0 ? 0 : (int) (totalValueLength / entryCount);
fileInfo.append(FileInfo.AVG_VALUE_LEN, Bytes.toBytes(avgValueLen), false);
}
/**
* Add to the file info. All added key/value pairs can be obtained using
* {@link HFile.Reader#loadFileInfo()}.
*
* @param k Key
* @param v Value
* @throws IOException in case the key or the value are invalid
*/
@Override
public void appendFileInfo(final byte[] k, final byte[] v)
throws IOException {
fileInfo.append(k, v, true);
}
/**
* Sets the file info offset in the trailer, finishes up populating fields in
* the file info, and writes the file info into the given data output. The
* reason the data output is not always {@link #outputStream} is that we store
* file info as a block in version 2.
*
* @param trailer fixed file trailer
* @param out the data output to write the file info to
* @throws IOException
*/
protected final void writeFileInfo(FixedFileTrailer trailer, DataOutput out)
throws IOException {
trailer.setFileInfoOffset(outputStream.getPos());
finishFileInfo();
fileInfo.write(out);
}
/**
* Checks that the given key does not violate the key order.
*
* @param key Key to check.
* @return true if the key is duplicate
* @throws IOException if the key or the key order is wrong
*/
protected boolean checkKey(final byte[] key, final int offset,
final int length) throws IOException {
boolean isDuplicateKey = false;
if (key == null || length <= 0) {
throw new IOException("Key cannot be null or empty");
}
if (lastKeyBuffer != null) {
int keyComp = comparator.compare(lastKeyBuffer, lastKeyOffset,
lastKeyLength, key, offset, length);
if (keyComp > 0) {
throw new IOException("Added a key not lexically larger than"
+ " previous key="
+ Bytes.toStringBinary(key, offset, length)
+ ", lastkey="
+ Bytes.toStringBinary(lastKeyBuffer, lastKeyOffset,
lastKeyLength));
} else if (keyComp == 0) {
isDuplicateKey = true;
}
}
return isDuplicateKey;
}
/** Checks the given value for validity. */
protected void checkValue(final byte[] value, final int offset,
final int length) throws IOException {
if (value == null) {
throw new IOException("Value cannot be null");
}
}
/**
* @return Path or null if we were passed a stream rather than a Path.
*/
@Override
public Path getPath() {
return path;
}
@Override
public String toString() {
return "writer=" + (path != null ? path.toString() : null) + ", name="
+ name + ", compression=" + compressAlgo.getName();
}
/**
* Sets remaining trailer fields, writes the trailer to disk, and optionally
* closes the output stream.
*/
protected void finishClose(FixedFileTrailer trailer) throws IOException {
trailer.setMetaIndexCount(metaNames.size());
trailer.setTotalUncompressedBytes(totalUncompressedBytes+ trailer.getTrailerSize());
trailer.setEntryCount(entryCount);
trailer.setCompressionCodec(compressAlgo);
trailer.serialize(outputStream);
if (closeOutputStream) {
outputStream.close();
outputStream = null;
}
}
public static Compression.Algorithm compressionByName(String algoName) {
if (algoName == null)
return HFile.DEFAULT_COMPRESSION_ALGORITHM;
return Compression.getCompressionAlgorithmByName(algoName);
}
/** A helper method to create HFile output streams in constructors */
protected static FSDataOutputStream createOutputStream(Configuration conf,
FileSystem fs, Path path) throws IOException {
FsPermission perms = FSUtils.getFilePermissions(fs, conf,
HConstants.DATA_FILE_UMASK_KEY);
return FSUtils.create(fs, path, perms);
}
}