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ZstdCodec.java
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283 lines (245 loc) · 8.66 KB
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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.orc.impl;
import com.github.luben.zstd.Zstd;
import com.github.luben.zstd.ZstdCompressCtx;
import org.apache.orc.CompressionCodec;
import org.apache.orc.CompressionKind;
import java.io.IOException;
import java.nio.ByteBuffer;
/**
* @since 2.1.0
*/
public class ZstdCodec implements CompressionCodec, DirectDecompressionCodec {
private ZstdOptions zstdOptions = null;
private ZstdCompressCtx zstdCompressCtx = null;
public ZstdCodec(int level, int windowLog, int strategy) {
this.zstdOptions = new ZstdOptions(level, windowLog, strategy);
}
public ZstdCodec() {
this(3, 0, 0);
}
public ZstdOptions getZstdOptions() {
return zstdOptions;
}
// Thread local buffer
private static final ThreadLocal<byte[]> threadBuffer =
ThreadLocal.withInitial(() -> null);
protected static byte[] getBuffer(int size) {
byte[] result = threadBuffer.get();
if (result == null || result.length < size || result.length > size * 2) {
result = new byte[size];
threadBuffer.set(result);
}
return result;
}
static class ZstdOptions implements Options {
private int level;
private int windowLog;
private int strategy;
ZstdOptions(int level, int windowLog, int strategy) {
this.level = level;
this.windowLog = windowLog;
this.strategy = strategy;
}
@Override
public ZstdOptions copy() {
return new ZstdOptions(level, windowLog, strategy);
}
@Override
public Options setSpeed(SpeedModifier newValue) {
return this;
}
/**
* Sets the Zstandard long mode maximum back-reference distance, expressed
* as a power of 2.
* <p>
* The value must be between ZSTD_WINDOWLOG_MIN (10) and ZSTD_WINDOWLOG_MAX
* (30 and 31 on 32/64-bit architectures, respectively).
* <p>
* A value of 0 is a special value indicating to use the default
* ZSTD_WINDOWLOG_LIMIT_DEFAULT of 27, which corresponds to back-reference
* window size of 128MiB.
*
* @param newValue The desired power-of-2 value back-reference distance.
* @return ZstdOptions
*/
public ZstdOptions setWindowLog(int newValue) {
if ((newValue < Zstd.windowLogMin() || newValue > Zstd.windowLogMax()) && newValue != 0) {
throw new IllegalArgumentException(
String.format(
"Zstd compression window size should be in the range %d to %d,"
+ " or set to the default value of 0.",
Zstd.windowLogMin(),
Zstd.windowLogMax()));
}
windowLog = newValue;
return this;
}
/**
* Sets the Zstandard compression codec compression level directly using
* the integer setting. This value is typically between 0 and 22, with
* larger numbers indicating more aggressive compression and lower speed.
* <p>
* This method provides additional granularity beyond the setSpeed method
* so that users can select a specific level.
*
* @param newValue The level value of compression to set.
* @return ZstdOptions
*/
public ZstdOptions setLevel(int newValue) {
if (newValue < Zstd.minCompressionLevel() || newValue > Zstd.maxCompressionLevel()) {
throw new IllegalArgumentException(
String.format(
"Zstd compression level should be in the range %d to %d",
Zstd.minCompressionLevel(),
Zstd.maxCompressionLevel()));
}
level = newValue;
return this;
}
public ZstdOptions setStrategy(int newValue) {
// https://facebook.github.io/zstd/zstd_manual.html#Chapter5
// Although the value is between 1 and 9 and 0 means `use default`, ZStd can change it.
strategy = newValue;
return this;
}
@Override
public ZstdOptions setData(DataKind newValue) {
return this; // We don't support setting DataKind in ZstdCodec.
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ZstdOptions that = (ZstdOptions) o;
if (level != that.level) return false;
if (strategy != that.strategy) return false;
return windowLog == that.windowLog;
}
@Override
public int hashCode() {
int result = level;
result = 31 * result + windowLog;
result = 31 * result + strategy;
return result;
}
}
private static final ZstdOptions DEFAULT_OPTIONS =
new ZstdOptions(3, 0, 0);
@Override
public Options getDefaultOptions() {
return DEFAULT_OPTIONS.copy();
}
/**
* Compresses an input ByteBuffer into an output ByteBuffer using Zstandard
* compression. If the maximum bound of the number of output bytes exceeds
* the output ByteBuffer size, the remaining bytes are written to the overflow
* ByteBuffer.
*
* @param in the bytes to compress
* @param out the compressed bytes
* @param overflow put any additional bytes here
* @param options the options to control compression
* @return true if input data is compressed. Otherwise, false.
*/
@Override
public boolean compress(ByteBuffer in, ByteBuffer out,
ByteBuffer overflow,
Options options) throws IOException {
int inBytes = in.remaining();
// Skip with minimum ZStandard format size:
// https://datatracker.ietf.org/doc/html/rfc8878#name-zstandard-frames
// Magic Number (4 bytes) + Frame Header (2 bytes) + Data Block Header (3 bytes)
if (inBytes < 10) return false;
ZstdOptions zso = (ZstdOptions) options;
zstdCompressCtx = new ZstdCompressCtx();
zstdCompressCtx.setLevel(zso.level);
zstdCompressCtx.setLong(zso.windowLog);
zstdCompressCtx.setChecksum(false);
zstdCompressCtx.setStrategy(zso.strategy);
try {
byte[] compressed = getBuffer((int) Zstd.compressBound(inBytes));
int outBytes = zstdCompressCtx.compressByteArray(compressed, 0, compressed.length,
in.array(), in.arrayOffset() + in.position(), inBytes);
if (outBytes < inBytes) {
int remaining = out.remaining();
if (remaining >= outBytes) {
System.arraycopy(compressed, 0, out.array(), out.arrayOffset() +
out.position(), outBytes);
out.position(out.position() + outBytes);
} else {
System.arraycopy(compressed, 0, out.array(), out.arrayOffset() +
out.position(), remaining);
out.position(out.limit());
System.arraycopy(compressed, remaining, overflow.array(),
overflow.arrayOffset(), outBytes - remaining);
overflow.position(outBytes - remaining);
}
return true;
} else {
return false;
}
} finally {
zstdCompressCtx.close();
}
}
@Override
public void decompress(ByteBuffer in, ByteBuffer out) throws IOException {
if (in.isDirect() && out.isDirect()) {
directDecompress(in, out);
return;
}
int srcOffset = in.arrayOffset() + in.position();
int srcSize = in.remaining();
int dstOffset = out.arrayOffset() + out.position();
int dstSize = out.remaining() - dstOffset;
long decompressOut =
Zstd.decompressByteArray(out.array(), dstOffset, dstSize, in.array(),
srcOffset, srcSize);
in.position(in.limit());
out.position(dstOffset + (int) decompressOut);
out.flip();
}
@Override
public boolean isAvailable() {
return true;
}
@Override
public void directDecompress(ByteBuffer in, ByteBuffer out) throws IOException {
Zstd.decompress(out, in);
out.flip();
}
@Override
public void reset() {
}
@Override
public void destroy() {
if (zstdCompressCtx != null) {
zstdCompressCtx.close();
}
}
@Override
public CompressionKind getKind() {
return CompressionKind.ZSTD;
}
@Override
public void close() {
OrcCodecPool.returnCodec(CompressionKind.ZSTD, this);
}
}