netty5/codec-http/src/main/java/io/netty/handler/codec/http/LastHttpContent.java
Trustin Lee 3a9f472161 Make retained derived buffers recyclable
Related: #4333 #4421 #5128

Motivation:

slice(), duplicate() and readSlice() currently create a non-recyclable
derived buffer instance. Under heavy load, an application that creates a
lot of derived buffers can put the garbage collector under pressure.

Modifications:

- Add the following methods which creates a non-recyclable derived buffer
  - retainedSlice()
  - retainedDuplicate()
  - readRetainedSlice()
- Add the new recyclable derived buffer implementations, which has its
  own reference count value
- Add ByteBufHolder.retainedDuplicate()
- Add ByteBufHolder.replace(ByteBuf) so that..
  - a user can replace the content of the holder in a consistent way
  - copy/duplicate/retainedDuplicate() can delegate the holder
    construction to replace(ByteBuf)
- Use retainedDuplicate() and retainedSlice() wherever possible
- Miscellaneous:
  - Rename DuplicateByteBufTest to DuplicatedByteBufTest (missing 'D')
  - Make ReplayingDecoderByteBuf.reject() return an exception instead of
    throwing it so that its callers don't need to add dummy return
    statement

Result:

Derived buffers are now recycled when created via retainedSlice() and
retainedDuplicate() and derived from a pooled buffer
2016-05-17 11:16:13 +02:00

145 lines
3.3 KiB
Java

/*
* 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:
*
* 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 io.netty.handler.codec.http;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.handler.codec.DecoderResult;
/**
* The last {@link HttpContent} which has trailing headers.
*/
public interface LastHttpContent extends HttpContent {
/**
* The 'end of content' marker in chunked encoding.
*/
LastHttpContent EMPTY_LAST_CONTENT = new LastHttpContent() {
@Override
public ByteBuf content() {
return Unpooled.EMPTY_BUFFER;
}
@Override
public LastHttpContent copy() {
return EMPTY_LAST_CONTENT;
}
@Override
public LastHttpContent duplicate() {
return this;
}
@Override
public LastHttpContent replace(ByteBuf content) {
return new DefaultLastHttpContent(content);
}
@Override
public LastHttpContent retainedDuplicate() {
return this;
}
@Override
public HttpHeaders trailingHeaders() {
return EmptyHttpHeaders.INSTANCE;
}
@Override
public DecoderResult decoderResult() {
return DecoderResult.SUCCESS;
}
@Override
@Deprecated
public DecoderResult getDecoderResult() {
return decoderResult();
}
@Override
public void setDecoderResult(DecoderResult result) {
throw new UnsupportedOperationException("read only");
}
@Override
public int refCnt() {
return 1;
}
@Override
public LastHttpContent retain() {
return this;
}
@Override
public LastHttpContent retain(int increment) {
return this;
}
@Override
public LastHttpContent touch() {
return this;
}
@Override
public LastHttpContent touch(Object hint) {
return this;
}
@Override
public boolean release() {
return false;
}
@Override
public boolean release(int decrement) {
return false;
}
@Override
public String toString() {
return "EmptyLastHttpContent";
}
};
HttpHeaders trailingHeaders();
@Override
LastHttpContent copy();
@Override
LastHttpContent duplicate();
@Override
LastHttpContent retainedDuplicate();
@Override
LastHttpContent replace(ByteBuf content);
@Override
LastHttpContent retain(int increment);
@Override
LastHttpContent retain();
@Override
LastHttpContent touch();
@Override
LastHttpContent touch(Object hint);
}