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author | Davies Liu <davies@databricks.com> | 2015-12-21 14:21:43 -0800 |
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committer | Davies Liu <davies.liu@gmail.com> | 2015-12-21 14:21:43 -0800 |
commit | 29cecd4a42f6969613e5b2a40f2724f99e7eec01 (patch) | |
tree | 261b40272c991649ce584b7cec2056dcd2b6cf1c /core/src/main/scala/org/apache | |
parent | d655d37ddf59d7fb6db529324ac8044d53b2622a (diff) | |
download | spark-29cecd4a42f6969613e5b2a40f2724f99e7eec01.tar.gz spark-29cecd4a42f6969613e5b2a40f2724f99e7eec01.tar.bz2 spark-29cecd4a42f6969613e5b2a40f2724f99e7eec01.zip |
[SPARK-12388] change default compression to lz4
According the benchmark [1], LZ4-java could be 80% (or 30%) faster than Snappy.
After changing the compressor to LZ4, I saw 20% improvement on end-to-end time for a TPCDS query (Q4).
[1] https://github.com/ning/jvm-compressor-benchmark/wiki
cc rxin
Author: Davies Liu <davies@databricks.com>
Closes #10342 from davies/lz4.
Diffstat (limited to 'core/src/main/scala/org/apache')
-rw-r--r-- | core/src/main/scala/org/apache/spark/io/CompressionCodec.scala | 12 | ||||
-rw-r--r-- | core/src/main/scala/org/apache/spark/io/LZ4BlockInputStream.java | 263 |
2 files changed, 269 insertions, 6 deletions
diff --git a/core/src/main/scala/org/apache/spark/io/CompressionCodec.scala b/core/src/main/scala/org/apache/spark/io/CompressionCodec.scala index ca74eedf89..717804626f 100644 --- a/core/src/main/scala/org/apache/spark/io/CompressionCodec.scala +++ b/core/src/main/scala/org/apache/spark/io/CompressionCodec.scala @@ -17,10 +17,10 @@ package org.apache.spark.io -import java.io.{IOException, InputStream, OutputStream} +import java.io._ import com.ning.compress.lzf.{LZFInputStream, LZFOutputStream} -import net.jpountz.lz4.{LZ4BlockInputStream, LZ4BlockOutputStream} +import net.jpountz.lz4.LZ4BlockOutputStream import org.xerial.snappy.{Snappy, SnappyInputStream, SnappyOutputStream} import org.apache.spark.SparkConf @@ -49,7 +49,8 @@ private[spark] object CompressionCodec { private val configKey = "spark.io.compression.codec" private[spark] def supportsConcatenationOfSerializedStreams(codec: CompressionCodec): Boolean = { - codec.isInstanceOf[SnappyCompressionCodec] || codec.isInstanceOf[LZFCompressionCodec] + (codec.isInstanceOf[SnappyCompressionCodec] || codec.isInstanceOf[LZFCompressionCodec] + || codec.isInstanceOf[LZ4CompressionCodec]) } private val shortCompressionCodecNames = Map( @@ -92,12 +93,11 @@ private[spark] object CompressionCodec { } } - val FALLBACK_COMPRESSION_CODEC = "lzf" - val DEFAULT_COMPRESSION_CODEC = "snappy" + val FALLBACK_COMPRESSION_CODEC = "snappy" + val DEFAULT_COMPRESSION_CODEC = "lz4" val ALL_COMPRESSION_CODECS = shortCompressionCodecNames.values.toSeq } - /** * :: DeveloperApi :: * LZ4 implementation of [[org.apache.spark.io.CompressionCodec]]. diff --git a/core/src/main/scala/org/apache/spark/io/LZ4BlockInputStream.java b/core/src/main/scala/org/apache/spark/io/LZ4BlockInputStream.java new file mode 100644 index 0000000000..27b6f0d4a3 --- /dev/null +++ b/core/src/main/scala/org/apache/spark/io/LZ4BlockInputStream.java @@ -0,0 +1,263 @@ +package org.apache.spark.io; + +/* + * Licensed 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. + */ + +import java.io.EOFException; +import java.io.FilterInputStream; +import java.io.IOException; +import java.io.InputStream; +import java.util.zip.Checksum; + +import net.jpountz.lz4.LZ4BlockOutputStream; +import net.jpountz.lz4.LZ4Exception; +import net.jpountz.lz4.LZ4Factory; +import net.jpountz.lz4.LZ4FastDecompressor; +import net.jpountz.util.SafeUtils; +import net.jpountz.xxhash.StreamingXXHash32; +import net.jpountz.xxhash.XXHash32; +import net.jpountz.xxhash.XXHashFactory; + +/** + * {@link InputStream} implementation to decode data written with + * {@link LZ4BlockOutputStream}. This class is not thread-safe and does not + * support {@link #mark(int)}/{@link #reset()}. + * @see LZ4BlockOutputStream + * + * This is based on net.jpountz.lz4.LZ4BlockInputStream + * + * changes: https://github.com/davies/lz4-java/commit/cc1fa940ac57cc66a0b937300f805d37e2bf8411 + * + * TODO: merge this into upstream + */ +public final class LZ4BlockInputStream extends FilterInputStream { + + // Copied from net.jpountz.lz4.LZ4BlockOutputStream + static final byte[] MAGIC = new byte[] { 'L', 'Z', '4', 'B', 'l', 'o', 'c', 'k' }; + static final int MAGIC_LENGTH = MAGIC.length; + + static final int HEADER_LENGTH = + MAGIC_LENGTH // magic bytes + + 1 // token + + 4 // compressed length + + 4 // decompressed length + + 4; // checksum + + static final int COMPRESSION_LEVEL_BASE = 10; + + static final int COMPRESSION_METHOD_RAW = 0x10; + static final int COMPRESSION_METHOD_LZ4 = 0x20; + + static final int DEFAULT_SEED = 0x9747b28c; + + private final LZ4FastDecompressor decompressor; + private final Checksum checksum; + private byte[] buffer; + private byte[] compressedBuffer; + private int originalLen; + private int o; + private boolean finished; + + /** + * Create a new {@link InputStream}. + * + * @param in the {@link InputStream} to poll + * @param decompressor the {@link LZ4FastDecompressor decompressor} instance to + * use + * @param checksum the {@link Checksum} instance to use, must be + * equivalent to the instance which has been used to + * write the stream + */ + public LZ4BlockInputStream(InputStream in, LZ4FastDecompressor decompressor, Checksum checksum) { + super(in); + this.decompressor = decompressor; + this.checksum = checksum; + this.buffer = new byte[0]; + this.compressedBuffer = new byte[HEADER_LENGTH]; + o = originalLen = 0; + finished = false; + } + + /** + * Create a new instance using {@link XXHash32} for checksuming. + * @see #LZ4BlockInputStream(InputStream, LZ4FastDecompressor, Checksum) + * @see StreamingXXHash32#asChecksum() + */ + public LZ4BlockInputStream(InputStream in, LZ4FastDecompressor decompressor) { + this(in, decompressor, XXHashFactory.fastestInstance().newStreamingHash32(DEFAULT_SEED).asChecksum()); + } + + /** + * Create a new instance which uses the fastest {@link LZ4FastDecompressor} available. + * @see LZ4Factory#fastestInstance() + * @see #LZ4BlockInputStream(InputStream, LZ4FastDecompressor) + */ + public LZ4BlockInputStream(InputStream in) { + this(in, LZ4Factory.fastestInstance().fastDecompressor()); + } + + @Override + public int available() throws IOException { + refill(); + return originalLen - o; + } + + @Override + public int read() throws IOException { + refill(); + if (finished) { + return -1; + } + return buffer[o++] & 0xFF; + } + + @Override + public int read(byte[] b, int off, int len) throws IOException { + SafeUtils.checkRange(b, off, len); + refill(); + if (finished) { + return -1; + } + len = Math.min(len, originalLen - o); + System.arraycopy(buffer, o, b, off, len); + o += len; + return len; + } + + @Override + public int read(byte[] b) throws IOException { + return read(b, 0, b.length); + } + + @Override + public long skip(long n) throws IOException { + refill(); + if (finished) { + return -1; + } + final int skipped = (int) Math.min(n, originalLen - o); + o += skipped; + return skipped; + } + + private void refill() throws IOException { + if (finished || o < originalLen) { + return; + } + try { + readFully(compressedBuffer, HEADER_LENGTH); + } catch (EOFException e) { + finished = true; + return; + } + for (int i = 0; i < MAGIC_LENGTH; ++i) { + if (compressedBuffer[i] != MAGIC[i]) { + throw new IOException("Stream is corrupted"); + } + } + final int token = compressedBuffer[MAGIC_LENGTH] & 0xFF; + final int compressionMethod = token & 0xF0; + final int compressionLevel = COMPRESSION_LEVEL_BASE + (token & 0x0F); + if (compressionMethod != COMPRESSION_METHOD_RAW && compressionMethod != COMPRESSION_METHOD_LZ4) + { + throw new IOException("Stream is corrupted"); + } + final int compressedLen = SafeUtils.readIntLE(compressedBuffer, MAGIC_LENGTH + 1); + originalLen = SafeUtils.readIntLE(compressedBuffer, MAGIC_LENGTH + 5); + final int check = SafeUtils.readIntLE(compressedBuffer, MAGIC_LENGTH + 9); + assert HEADER_LENGTH == MAGIC_LENGTH + 13; + if (originalLen > 1 << compressionLevel + || originalLen < 0 + || compressedLen < 0 + || (originalLen == 0 && compressedLen != 0) + || (originalLen != 0 && compressedLen == 0) + || (compressionMethod == COMPRESSION_METHOD_RAW && originalLen != compressedLen)) { + throw new IOException("Stream is corrupted"); + } + if (originalLen == 0 && compressedLen == 0) { + if (check != 0) { + throw new IOException("Stream is corrupted"); + } + refill(); + return; + } + if (buffer.length < originalLen) { + buffer = new byte[Math.max(originalLen, buffer.length * 3 / 2)]; + } + switch (compressionMethod) { + case COMPRESSION_METHOD_RAW: + readFully(buffer, originalLen); + break; + case COMPRESSION_METHOD_LZ4: + if (compressedBuffer.length < originalLen) { + compressedBuffer = new byte[Math.max(compressedLen, compressedBuffer.length * 3 / 2)]; + } + readFully(compressedBuffer, compressedLen); + try { + final int compressedLen2 = + decompressor.decompress(compressedBuffer, 0, buffer, 0, originalLen); + if (compressedLen != compressedLen2) { + throw new IOException("Stream is corrupted"); + } + } catch (LZ4Exception e) { + throw new IOException("Stream is corrupted", e); + } + break; + default: + throw new AssertionError(); + } + checksum.reset(); + checksum.update(buffer, 0, originalLen); + if ((int) checksum.getValue() != check) { + throw new IOException("Stream is corrupted"); + } + o = 0; + } + + private void readFully(byte[] b, int len) throws IOException { + int read = 0; + while (read < len) { + final int r = in.read(b, read, len - read); + if (r < 0) { + throw new EOFException("Stream ended prematurely"); + } + read += r; + } + assert len == read; + } + + @Override + public boolean markSupported() { + return false; + } + + @SuppressWarnings("sync-override") + @Override + public void mark(int readlimit) { + // unsupported + } + + @SuppressWarnings("sync-override") + @Override + public void reset() throws IOException { + throw new IOException("mark/reset not supported"); + } + + @Override + public String toString() { + return getClass().getSimpleName() + "(in=" + in + + ", decompressor=" + decompressor + ", checksum=" + checksum + ")"; + } + +} |