netty5/buffer/src/main/java/io/netty/buffer/WrappedByteBuf.java
Nick Hill 128403b492 Introduce ByteBuf.maxFastWritableBytes() method (#9086)
Motivation

ByteBuf capacity is automatically increased as needed up to maxCapacity
when writing beyond the buffer's current capacity. However there's no
way to tell in general whether such an increase will result in a
relatively costly internal buffer re-allocation.

For unpooled buffers it always does, in pooled cases it depends on the
size of the associated chunk of allocated memory, which I don't think is
currently exposed in any way.

It would sometimes be useful to know where this limit is when making
external decisions about whether to reuse or preemptively reallocate.

It would also be advantageous to take this limit into account when
auto-increasing the capacity during writes, to defer such reallocation
until really necessary.

Modifications

Introduce new AbstractByteBuf.maxFastWritableBytes() method which will
return a value >= writableBytes() and <= maxWritableBytes().

Make use of the new method in the sizing decision made by the
AbstractByteBuf.ensureWritable(...) methods.

Result

Less reallocation/copying.
2019-05-22 20:11:24 +02:00

1047 lines
23 KiB
Java

/*
* Copyright 2013 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.buffer;
import io.netty.util.ByteProcessor;
import io.netty.util.internal.StringUtil;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.ScatteringByteChannel;
import java.nio.charset.Charset;
/**
* Wraps another {@link ByteBuf}.
*
* It's important that the {@link #readerIndex()} and {@link #writerIndex()} will not do any adjustments on the
* indices on the fly because of internal optimizations made by {@link ByteBufUtil#writeAscii(ByteBuf, CharSequence)}
* and {@link ByteBufUtil#writeUtf8(ByteBuf, CharSequence)}.
*/
class WrappedByteBuf extends ByteBuf {
protected final ByteBuf buf;
protected WrappedByteBuf(ByteBuf buf) {
if (buf == null) {
throw new NullPointerException("buf");
}
this.buf = buf;
}
@Override
public final boolean hasMemoryAddress() {
return buf.hasMemoryAddress();
}
@Override
public final long memoryAddress() {
return buf.memoryAddress();
}
@Override
public final int capacity() {
return buf.capacity();
}
@Override
public ByteBuf capacity(int newCapacity) {
buf.capacity(newCapacity);
return this;
}
@Override
public final int maxCapacity() {
return buf.maxCapacity();
}
@Override
public final ByteBufAllocator alloc() {
return buf.alloc();
}
@Override
public final ByteOrder order() {
return buf.order();
}
@Override
public ByteBuf order(ByteOrder endianness) {
return buf.order(endianness);
}
@Override
public final ByteBuf unwrap() {
return buf;
}
@Override
public ByteBuf asReadOnly() {
return buf.asReadOnly();
}
@Override
public boolean isReadOnly() {
return buf.isReadOnly();
}
@Override
public final boolean isDirect() {
return buf.isDirect();
}
@Override
public final int readerIndex() {
return buf.readerIndex();
}
@Override
public final ByteBuf readerIndex(int readerIndex) {
buf.readerIndex(readerIndex);
return this;
}
@Override
public final int writerIndex() {
return buf.writerIndex();
}
@Override
public final ByteBuf writerIndex(int writerIndex) {
buf.writerIndex(writerIndex);
return this;
}
@Override
public ByteBuf setIndex(int readerIndex, int writerIndex) {
buf.setIndex(readerIndex, writerIndex);
return this;
}
@Override
public final int readableBytes() {
return buf.readableBytes();
}
@Override
public final int writableBytes() {
return buf.writableBytes();
}
@Override
public final int maxWritableBytes() {
return buf.maxWritableBytes();
}
@Override
public int maxFastWritableBytes() {
return buf.maxFastWritableBytes();
}
@Override
public final boolean isReadable() {
return buf.isReadable();
}
@Override
public final boolean isWritable() {
return buf.isWritable();
}
@Override
public final ByteBuf clear() {
buf.clear();
return this;
}
@Override
public final ByteBuf markReaderIndex() {
buf.markReaderIndex();
return this;
}
@Override
public final ByteBuf resetReaderIndex() {
buf.resetReaderIndex();
return this;
}
@Override
public final ByteBuf markWriterIndex() {
buf.markWriterIndex();
return this;
}
@Override
public final ByteBuf resetWriterIndex() {
buf.resetWriterIndex();
return this;
}
@Override
public ByteBuf discardReadBytes() {
buf.discardReadBytes();
return this;
}
@Override
public ByteBuf discardSomeReadBytes() {
buf.discardSomeReadBytes();
return this;
}
@Override
public ByteBuf ensureWritable(int minWritableBytes) {
buf.ensureWritable(minWritableBytes);
return this;
}
@Override
public int ensureWritable(int minWritableBytes, boolean force) {
return buf.ensureWritable(minWritableBytes, force);
}
@Override
public boolean getBoolean(int index) {
return buf.getBoolean(index);
}
@Override
public byte getByte(int index) {
return buf.getByte(index);
}
@Override
public short getUnsignedByte(int index) {
return buf.getUnsignedByte(index);
}
@Override
public short getShort(int index) {
return buf.getShort(index);
}
@Override
public short getShortLE(int index) {
return buf.getShortLE(index);
}
@Override
public int getUnsignedShort(int index) {
return buf.getUnsignedShort(index);
}
@Override
public int getUnsignedShortLE(int index) {
return buf.getUnsignedShortLE(index);
}
@Override
public int getMedium(int index) {
return buf.getMedium(index);
}
@Override
public int getMediumLE(int index) {
return buf.getMediumLE(index);
}
@Override
public int getUnsignedMedium(int index) {
return buf.getUnsignedMedium(index);
}
@Override
public int getUnsignedMediumLE(int index) {
return buf.getUnsignedMediumLE(index);
}
@Override
public int getInt(int index) {
return buf.getInt(index);
}
@Override
public int getIntLE(int index) {
return buf.getIntLE(index);
}
@Override
public long getUnsignedInt(int index) {
return buf.getUnsignedInt(index);
}
@Override
public long getUnsignedIntLE(int index) {
return buf.getUnsignedIntLE(index);
}
@Override
public long getLong(int index) {
return buf.getLong(index);
}
@Override
public long getLongLE(int index) {
return buf.getLongLE(index);
}
@Override
public char getChar(int index) {
return buf.getChar(index);
}
@Override
public float getFloat(int index) {
return buf.getFloat(index);
}
@Override
public double getDouble(int index) {
return buf.getDouble(index);
}
@Override
public ByteBuf getBytes(int index, ByteBuf dst) {
buf.getBytes(index, dst);
return this;
}
@Override
public ByteBuf getBytes(int index, ByteBuf dst, int length) {
buf.getBytes(index, dst, length);
return this;
}
@Override
public ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
buf.getBytes(index, dst, dstIndex, length);
return this;
}
@Override
public ByteBuf getBytes(int index, byte[] dst) {
buf.getBytes(index, dst);
return this;
}
@Override
public ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
buf.getBytes(index, dst, dstIndex, length);
return this;
}
@Override
public ByteBuf getBytes(int index, ByteBuffer dst) {
buf.getBytes(index, dst);
return this;
}
@Override
public ByteBuf getBytes(int index, OutputStream out, int length) throws IOException {
buf.getBytes(index, out, length);
return this;
}
@Override
public int getBytes(int index, GatheringByteChannel out, int length) throws IOException {
return buf.getBytes(index, out, length);
}
@Override
public int getBytes(int index, FileChannel out, long position, int length) throws IOException {
return buf.getBytes(index, out, position, length);
}
@Override
public CharSequence getCharSequence(int index, int length, Charset charset) {
return buf.getCharSequence(index, length, charset);
}
@Override
public ByteBuf setBoolean(int index, boolean value) {
buf.setBoolean(index, value);
return this;
}
@Override
public ByteBuf setByte(int index, int value) {
buf.setByte(index, value);
return this;
}
@Override
public ByteBuf setShort(int index, int value) {
buf.setShort(index, value);
return this;
}
@Override
public ByteBuf setShortLE(int index, int value) {
buf.setShortLE(index, value);
return this;
}
@Override
public ByteBuf setMedium(int index, int value) {
buf.setMedium(index, value);
return this;
}
@Override
public ByteBuf setMediumLE(int index, int value) {
buf.setMediumLE(index, value);
return this;
}
@Override
public ByteBuf setInt(int index, int value) {
buf.setInt(index, value);
return this;
}
@Override
public ByteBuf setIntLE(int index, int value) {
buf.setIntLE(index, value);
return this;
}
@Override
public ByteBuf setLong(int index, long value) {
buf.setLong(index, value);
return this;
}
@Override
public ByteBuf setLongLE(int index, long value) {
buf.setLongLE(index, value);
return this;
}
@Override
public ByteBuf setChar(int index, int value) {
buf.setChar(index, value);
return this;
}
@Override
public ByteBuf setFloat(int index, float value) {
buf.setFloat(index, value);
return this;
}
@Override
public ByteBuf setDouble(int index, double value) {
buf.setDouble(index, value);
return this;
}
@Override
public ByteBuf setBytes(int index, ByteBuf src) {
buf.setBytes(index, src);
return this;
}
@Override
public ByteBuf setBytes(int index, ByteBuf src, int length) {
buf.setBytes(index, src, length);
return this;
}
@Override
public ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
buf.setBytes(index, src, srcIndex, length);
return this;
}
@Override
public ByteBuf setBytes(int index, byte[] src) {
buf.setBytes(index, src);
return this;
}
@Override
public ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
buf.setBytes(index, src, srcIndex, length);
return this;
}
@Override
public ByteBuf setBytes(int index, ByteBuffer src) {
buf.setBytes(index, src);
return this;
}
@Override
public int setBytes(int index, InputStream in, int length) throws IOException {
return buf.setBytes(index, in, length);
}
@Override
public int setBytes(int index, ScatteringByteChannel in, int length) throws IOException {
return buf.setBytes(index, in, length);
}
@Override
public int setBytes(int index, FileChannel in, long position, int length) throws IOException {
return buf.setBytes(index, in, position, length);
}
@Override
public ByteBuf setZero(int index, int length) {
buf.setZero(index, length);
return this;
}
@Override
public int setCharSequence(int index, CharSequence sequence, Charset charset) {
return buf.setCharSequence(index, sequence, charset);
}
@Override
public boolean readBoolean() {
return buf.readBoolean();
}
@Override
public byte readByte() {
return buf.readByte();
}
@Override
public short readUnsignedByte() {
return buf.readUnsignedByte();
}
@Override
public short readShort() {
return buf.readShort();
}
@Override
public short readShortLE() {
return buf.readShortLE();
}
@Override
public int readUnsignedShort() {
return buf.readUnsignedShort();
}
@Override
public int readUnsignedShortLE() {
return buf.readUnsignedShortLE();
}
@Override
public int readMedium() {
return buf.readMedium();
}
@Override
public int readMediumLE() {
return buf.readMediumLE();
}
@Override
public int readUnsignedMedium() {
return buf.readUnsignedMedium();
}
@Override
public int readUnsignedMediumLE() {
return buf.readUnsignedMediumLE();
}
@Override
public int readInt() {
return buf.readInt();
}
@Override
public int readIntLE() {
return buf.readIntLE();
}
@Override
public long readUnsignedInt() {
return buf.readUnsignedInt();
}
@Override
public long readUnsignedIntLE() {
return buf.readUnsignedIntLE();
}
@Override
public long readLong() {
return buf.readLong();
}
@Override
public long readLongLE() {
return buf.readLongLE();
}
@Override
public char readChar() {
return buf.readChar();
}
@Override
public float readFloat() {
return buf.readFloat();
}
@Override
public double readDouble() {
return buf.readDouble();
}
@Override
public ByteBuf readBytes(int length) {
return buf.readBytes(length);
}
@Override
public ByteBuf readSlice(int length) {
return buf.readSlice(length);
}
@Override
public ByteBuf readRetainedSlice(int length) {
return buf.readRetainedSlice(length);
}
@Override
public ByteBuf readBytes(ByteBuf dst) {
buf.readBytes(dst);
return this;
}
@Override
public ByteBuf readBytes(ByteBuf dst, int length) {
buf.readBytes(dst, length);
return this;
}
@Override
public ByteBuf readBytes(ByteBuf dst, int dstIndex, int length) {
buf.readBytes(dst, dstIndex, length);
return this;
}
@Override
public ByteBuf readBytes(byte[] dst) {
buf.readBytes(dst);
return this;
}
@Override
public ByteBuf readBytes(byte[] dst, int dstIndex, int length) {
buf.readBytes(dst, dstIndex, length);
return this;
}
@Override
public ByteBuf readBytes(ByteBuffer dst) {
buf.readBytes(dst);
return this;
}
@Override
public ByteBuf readBytes(OutputStream out, int length) throws IOException {
buf.readBytes(out, length);
return this;
}
@Override
public int readBytes(GatheringByteChannel out, int length) throws IOException {
return buf.readBytes(out, length);
}
@Override
public int readBytes(FileChannel out, long position, int length) throws IOException {
return buf.readBytes(out, position, length);
}
@Override
public CharSequence readCharSequence(int length, Charset charset) {
return buf.readCharSequence(length, charset);
}
@Override
public ByteBuf skipBytes(int length) {
buf.skipBytes(length);
return this;
}
@Override
public ByteBuf writeBoolean(boolean value) {
buf.writeBoolean(value);
return this;
}
@Override
public ByteBuf writeByte(int value) {
buf.writeByte(value);
return this;
}
@Override
public ByteBuf writeShort(int value) {
buf.writeShort(value);
return this;
}
@Override
public ByteBuf writeShortLE(int value) {
buf.writeShortLE(value);
return this;
}
@Override
public ByteBuf writeMedium(int value) {
buf.writeMedium(value);
return this;
}
@Override
public ByteBuf writeMediumLE(int value) {
buf.writeMediumLE(value);
return this;
}
@Override
public ByteBuf writeInt(int value) {
buf.writeInt(value);
return this;
}
@Override
public ByteBuf writeIntLE(int value) {
buf.writeIntLE(value);
return this;
}
@Override
public ByteBuf writeLong(long value) {
buf.writeLong(value);
return this;
}
@Override
public ByteBuf writeLongLE(long value) {
buf.writeLongLE(value);
return this;
}
@Override
public ByteBuf writeChar(int value) {
buf.writeChar(value);
return this;
}
@Override
public ByteBuf writeFloat(float value) {
buf.writeFloat(value);
return this;
}
@Override
public ByteBuf writeDouble(double value) {
buf.writeDouble(value);
return this;
}
@Override
public ByteBuf writeBytes(ByteBuf src) {
buf.writeBytes(src);
return this;
}
@Override
public ByteBuf writeBytes(ByteBuf src, int length) {
buf.writeBytes(src, length);
return this;
}
@Override
public ByteBuf writeBytes(ByteBuf src, int srcIndex, int length) {
buf.writeBytes(src, srcIndex, length);
return this;
}
@Override
public ByteBuf writeBytes(byte[] src) {
buf.writeBytes(src);
return this;
}
@Override
public ByteBuf writeBytes(byte[] src, int srcIndex, int length) {
buf.writeBytes(src, srcIndex, length);
return this;
}
@Override
public ByteBuf writeBytes(ByteBuffer src) {
buf.writeBytes(src);
return this;
}
@Override
public int writeBytes(InputStream in, int length) throws IOException {
return buf.writeBytes(in, length);
}
@Override
public int writeBytes(ScatteringByteChannel in, int length) throws IOException {
return buf.writeBytes(in, length);
}
@Override
public int writeBytes(FileChannel in, long position, int length) throws IOException {
return buf.writeBytes(in, position, length);
}
@Override
public ByteBuf writeZero(int length) {
buf.writeZero(length);
return this;
}
@Override
public int writeCharSequence(CharSequence sequence, Charset charset) {
return buf.writeCharSequence(sequence, charset);
}
@Override
public int indexOf(int fromIndex, int toIndex, byte value) {
return buf.indexOf(fromIndex, toIndex, value);
}
@Override
public int bytesBefore(byte value) {
return buf.bytesBefore(value);
}
@Override
public int bytesBefore(int length, byte value) {
return buf.bytesBefore(length, value);
}
@Override
public int bytesBefore(int index, int length, byte value) {
return buf.bytesBefore(index, length, value);
}
@Override
public int forEachByte(ByteProcessor processor) {
return buf.forEachByte(processor);
}
@Override
public int forEachByte(int index, int length, ByteProcessor processor) {
return buf.forEachByte(index, length, processor);
}
@Override
public int forEachByteDesc(ByteProcessor processor) {
return buf.forEachByteDesc(processor);
}
@Override
public int forEachByteDesc(int index, int length, ByteProcessor processor) {
return buf.forEachByteDesc(index, length, processor);
}
@Override
public ByteBuf copy() {
return buf.copy();
}
@Override
public ByteBuf copy(int index, int length) {
return buf.copy(index, length);
}
@Override
public ByteBuf slice() {
return buf.slice();
}
@Override
public ByteBuf retainedSlice() {
return buf.retainedSlice();
}
@Override
public ByteBuf slice(int index, int length) {
return buf.slice(index, length);
}
@Override
public ByteBuf retainedSlice(int index, int length) {
return buf.retainedSlice(index, length);
}
@Override
public ByteBuf duplicate() {
return buf.duplicate();
}
@Override
public ByteBuf retainedDuplicate() {
return buf.retainedDuplicate();
}
@Override
public int nioBufferCount() {
return buf.nioBufferCount();
}
@Override
public ByteBuffer nioBuffer() {
return buf.nioBuffer();
}
@Override
public ByteBuffer nioBuffer(int index, int length) {
return buf.nioBuffer(index, length);
}
@Override
public ByteBuffer[] nioBuffers() {
return buf.nioBuffers();
}
@Override
public ByteBuffer[] nioBuffers(int index, int length) {
return buf.nioBuffers(index, length);
}
@Override
public ByteBuffer internalNioBuffer(int index, int length) {
return buf.internalNioBuffer(index, length);
}
@Override
public boolean hasArray() {
return buf.hasArray();
}
@Override
public byte[] array() {
return buf.array();
}
@Override
public int arrayOffset() {
return buf.arrayOffset();
}
@Override
public String toString(Charset charset) {
return buf.toString(charset);
}
@Override
public String toString(int index, int length, Charset charset) {
return buf.toString(index, length, charset);
}
@Override
public int hashCode() {
return buf.hashCode();
}
@Override
@SuppressWarnings("EqualsWhichDoesntCheckParameterClass")
public boolean equals(Object obj) {
return buf.equals(obj);
}
@Override
public int compareTo(ByteBuf buffer) {
return buf.compareTo(buffer);
}
@Override
public String toString() {
return StringUtil.simpleClassName(this) + '(' + buf.toString() + ')';
}
@Override
public ByteBuf retain(int increment) {
buf.retain(increment);
return this;
}
@Override
public ByteBuf retain() {
buf.retain();
return this;
}
@Override
public ByteBuf touch() {
buf.touch();
return this;
}
@Override
public ByteBuf touch(Object hint) {
buf.touch(hint);
return this;
}
@Override
public final boolean isReadable(int size) {
return buf.isReadable(size);
}
@Override
public final boolean isWritable(int size) {
return buf.isWritable(size);
}
@Override
public final int refCnt() {
return buf.refCnt();
}
@Override
public boolean release() {
return buf.release();
}
@Override
public boolean release(int decrement) {
return buf.release(decrement);
}
@Override
final boolean isAccessible() {
return buf.isAccessible();
}
}