io.netty.handler.codec.compression.ZlibDecoder Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of redisson-all Show documentation
Show all versions of redisson-all Show documentation
Easy Redis Java client and Real-Time Data Platform. Valkey compatible. Sync/Async/RxJava3/Reactive API. Client side caching. Over 50 Redis based Java objects and services: JCache API, Apache Tomcat, Hibernate, Spring, Set, Multimap, SortedSet, Map, List, Queue, Deque, Semaphore, Lock, AtomicLong, Map Reduce, Bloom filter, Scheduler, RPC
/*
* Copyright 2012 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 io.netty.handler.codec.compression;
import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
/**
* Decompresses a {@link ByteBuf} using the deflate algorithm.
*/
public abstract class ZlibDecoder extends ByteToMessageDecoder {
/**
* Maximum allowed size of the decompression buffer.
*/
protected final int maxAllocation;
/**
* Same as {@link #ZlibDecoder(int)} with maxAllocation = 0.
*/
public ZlibDecoder() {
this(0);
}
/**
* Construct a new ZlibDecoder.
* @param maxAllocation
* Maximum size of the decompression buffer. Must be >= 0.
* If zero, maximum size is decided by the {@link ByteBufAllocator}.
*/
public ZlibDecoder(int maxAllocation) {
this.maxAllocation = checkPositiveOrZero(maxAllocation, "maxAllocation");
}
/**
* Returns {@code true} if and only if the end of the compressed stream
* has been reached.
*/
public abstract boolean isClosed();
/**
* Allocate or expand the decompression buffer, without exceeding the maximum allocation.
* Calls {@link #decompressionBufferExhausted(ByteBuf)} if the buffer is full and cannot be expanded further.
*/
protected ByteBuf prepareDecompressBuffer(ChannelHandlerContext ctx, ByteBuf buffer, int preferredSize) {
if (buffer == null) {
if (maxAllocation == 0) {
return ctx.alloc().heapBuffer(preferredSize);
}
return ctx.alloc().heapBuffer(Math.min(preferredSize, maxAllocation), maxAllocation);
}
// this always expands the buffer if possible, even if the expansion is less than preferredSize
// we throw the exception only if the buffer could not be expanded at all
// this means that one final attempt to deserialize will always be made with the buffer at maxAllocation
if (buffer.ensureWritable(preferredSize, true) == 1) {
// buffer must be consumed so subclasses don't add it to output
// we therefore duplicate it when calling decompressionBufferExhausted() to guarantee non-interference
// but wait until after to consume it so the subclass can tell how much output is really in the buffer
decompressionBufferExhausted(buffer.duplicate());
buffer.skipBytes(buffer.readableBytes());
throw new DecompressionException("Decompression buffer has reached maximum size: " + buffer.maxCapacity());
}
return buffer;
}
/**
* Called when the decompression buffer cannot be expanded further.
* Default implementation is a no-op, but subclasses can override in case they want to
* do something before the {@link DecompressionException} is thrown, such as log the
* data that was decompressed so far.
*/
protected void decompressionBufferExhausted(ByteBuf buffer) {
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy