com.arangodb.shaded.netty.handler.codec.compression.ByteBufChecksum Maven / Gradle / Ivy
/*
* Copyright 2016 The Netty Project
*
* The Netty Project 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:
*
* https://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 com.arangodb.shaded.netty.handler.codec.compression;
import com.arangodb.shaded.netty.buffer.ByteBuf;
import com.arangodb.shaded.netty.util.ByteProcessor;
import com.arangodb.shaded.netty.util.internal.ObjectUtil;
import com.arangodb.shaded.netty.util.internal.PlatformDependent;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.util.zip.Adler32;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
/**
* {@link Checksum} implementation which can directly act on a {@link ByteBuf}.
*
* Implementations may optimize access patterns depending on if the {@link ByteBuf} is backed by a
* byte array ({@link ByteBuf#hasArray()} is {@code true}) or not.
*/
abstract class ByteBufChecksum implements Checksum {
private static final Method ADLER32_UPDATE_METHOD;
private static final Method CRC32_UPDATE_METHOD;
static {
// See if we can use fast-path when using ByteBuf that is not heap based as Adler32 and CRC32 added support
// for update(ByteBuffer) in JDK8.
ADLER32_UPDATE_METHOD = updateByteBuffer(new Adler32());
CRC32_UPDATE_METHOD = updateByteBuffer(new CRC32());
}
private final ByteProcessor updateProcessor = new ByteProcessor() {
@Override
public boolean process(byte value) throws Exception {
update(value);
return true;
}
};
private static Method updateByteBuffer(Checksum checksum) {
if (PlatformDependent.javaVersion() >= 8) {
try {
Method method = checksum.getClass().getDeclaredMethod("update", ByteBuffer.class);
method.invoke(checksum, ByteBuffer.allocate(1));
return method;
} catch (Throwable ignore) {
return null;
}
}
return null;
}
static ByteBufChecksum wrapChecksum(Checksum checksum) {
ObjectUtil.checkNotNull(checksum, "checksum");
if (checksum instanceof ByteBufChecksum) {
return (ByteBufChecksum) checksum;
}
if (checksum instanceof Adler32 && ADLER32_UPDATE_METHOD != null) {
return new ReflectiveByteBufChecksum(checksum, ADLER32_UPDATE_METHOD);
}
if (checksum instanceof CRC32 && CRC32_UPDATE_METHOD != null) {
return new ReflectiveByteBufChecksum(checksum, CRC32_UPDATE_METHOD);
}
return new SlowByteBufChecksum(checksum);
}
/**
* @see #update(byte[], int, int)
*/
public void update(ByteBuf b, int off, int len) {
if (b.hasArray()) {
update(b.array(), b.arrayOffset() + off, len);
} else {
b.forEachByte(off, len, updateProcessor);
}
}
private static final class ReflectiveByteBufChecksum extends SlowByteBufChecksum {
private final Method method;
ReflectiveByteBufChecksum(Checksum checksum, Method method) {
super(checksum);
this.method = method;
}
@Override
public void update(ByteBuf b, int off, int len) {
if (b.hasArray()) {
update(b.array(), b.arrayOffset() + off, len);
} else {
try {
method.invoke(checksum, CompressionUtil.safeNioBuffer(b, off, len));
} catch (Throwable cause) {
throw new Error();
}
}
}
}
private static class SlowByteBufChecksum extends ByteBufChecksum {
protected final Checksum checksum;
SlowByteBufChecksum(Checksum checksum) {
this.checksum = checksum;
}
@Override
public void update(int b) {
checksum.update(b);
}
@Override
public void update(byte[] b, int off, int len) {
checksum.update(b, off, len);
}
@Override
public long getValue() {
return checksum.getValue();
}
@Override
public void reset() {
checksum.reset();
}
}
}