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/* This file is part of VoltDB.
* Copyright (C) 2008-2020 VoltDB Inc.
*
* This file contains original code and/or modifications of original code.
* Any modifications made by VoltDB Inc. are licensed under the following
* terms and conditions:
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see .
*/
/* Copyright (C) 2008
* Evan Jones
* Massachusetts Institute of Technology
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
package org.voltcore.network;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.util.ArrayDeque;
import java.util.BitSet;
import java.util.Deque;
import java.util.Iterator;
import java.util.List;
import org.voltcore.utils.DBBPool.BBContainer;
import com.google_voltpatches.common.collect.ImmutableList;
/**
Provides a non-blocking stream-like interface on top of the Java NIO ReadableByteChannel. It calls
the underlying read() method only when needed.
*/
public class NIOReadStream {
public int dataAvailable() {
return m_totalAvailable;
}
int getInt() {
// TODO: Optimize?
byte[] intbytes = new byte[4];
getBytes(intbytes);
int output = 0;
for (int i = 0; i < intbytes.length; ++i) {
output <<= 8;
output |= (intbytes[i]) & 0xff;
}
return output;
}
/**
* Move all bytes in current read buffers to output array, free read buffers
* back to thread local memory pool.
* @param output
*/
void getBytes(byte[] output) {
if (m_totalAvailable < output.length) {
throw new IllegalStateException("Requested " + output.length + " bytes; only have "
+ m_totalAvailable + " bytes; call tryRead() first");
}
int bytesCopied = 0;
while (bytesCopied < output.length) {
BBContainer firstC = m_readBBContainers.peekFirst();
if (firstC == null) {
// Steal the write buffer
m_poolBBContainer.b().flip();
m_readBBContainers.add(m_poolBBContainer);
firstC = m_poolBBContainer;
m_poolBBContainer = null;
}
ByteBuffer first = firstC.b();
assert first.remaining() > 0;
// Copy bytes from first into output
int bytesRemaining = first.remaining();
int bytesToCopy = output.length - bytesCopied;
if (bytesToCopy > bytesRemaining) bytesToCopy = bytesRemaining;
first.get(output, bytesCopied, bytesToCopy);
bytesCopied += bytesToCopy;
m_totalAvailable -= bytesToCopy;
if (first.remaining() == 0) {
// read an entire block: move it to the empty buffers list
m_readBBContainers.poll();
firstC.discard();
}
}
}
Slice getSlice(final int size) {
if (size < 0) {
throw new IllegalArgumentException("negative slice size: " + size);
}
if (m_totalAvailable < size) {
throw new IllegalStateException("Requested " + size + " bytes; only have "
+ m_totalAvailable + " bytes; call tryRead() first");
}
ImmutableList.Builder slices = ImmutableList.builder();
int bytesSliced = 0;
while (bytesSliced < size) {
BBContainer firstC = m_readBBContainers.peekFirst();
if (firstC == null) {
// Steal the write buffer
m_poolBBContainer.b().flip();
m_readBBContainers.add(m_poolBBContainer);
firstC = m_poolBBContainer;
m_poolBBContainer = null;
}
ByteBuffer first = firstC.b();
assert first.remaining() > 0 : "no remaining bytes to read";
int bytesRemaining = first.remaining();
int bytesToCopy = size - bytesSliced;
if (bytesToCopy > bytesRemaining) {
bytesToCopy = bytesRemaining;
}
slices.add(new ContainerSlice(firstC, bytesToCopy));
first.position(first.position() + bytesToCopy);
bytesSliced += bytesToCopy;
m_totalAvailable -= bytesToCopy;
if (first.remaining() == 0) {
m_readBBContainers.poll();
}
}
return new Slice(slices.build());
}
void peekBytes(byte [] output) {
if (m_totalAvailable < output.length) {
throw new IllegalStateException("Requested " + output.length + " bytes; only have "
+ m_totalAvailable + " bytes; call tryRead() first");
}
int bytesPeeked = 0;
Iterator cntnritr = m_readBBContainers.iterator();
while (bytesPeeked < output.length) {
final ByteBuffer slice;
if (!cntnritr.hasNext()) {
slice = m_poolBBContainer.b().duplicate();
slice.flip();
} else {
slice = cntnritr.next().b().slice();
}
// Copy bytes from first into output
int bytesRemaining = slice.remaining();
int bytesToCopy = output.length - bytesPeeked;
if (bytesToCopy > bytesRemaining) bytesToCopy = bytesRemaining;
slice.get(output, bytesPeeked, bytesToCopy);
bytesPeeked += bytesToCopy;
}
}
int read(ReadableByteChannel channel, int maxBytes, NetworkDBBPool pool) throws IOException {
int bytesRead = 0;
int lastRead = 1;
try {
while (bytesRead < maxBytes && lastRead > 0) {
ByteBuffer poolBuffer = null;
if (m_poolBBContainer == null) {
m_poolBBContainer = pool.acquire();
poolBuffer = m_poolBBContainer.b();
poolBuffer.clear();
} else {
poolBuffer = m_poolBBContainer.b();
}
lastRead = channel.read(poolBuffer);
// EOF, no data read
if (lastRead < 0 && bytesRead == 0) {
if (poolBuffer.position() == 0) {
m_poolBBContainer.discard();
m_poolBBContainer = null;
}
return -1;
}
//Data read
if (lastRead > 0) {
bytesRead += lastRead;
if (!poolBuffer.hasRemaining()) {
poolBuffer.flip();
m_readBBContainers.add(m_poolBBContainer);
m_poolBBContainer = null;
} else {
break;
}
} else if (poolBuffer.position() == 0) {
m_poolBBContainer.discard();
m_poolBBContainer = null;
}
}
} finally {
if (bytesRead > 0) {
m_bytesRead += bytesRead;
m_totalAvailable += bytesRead;
}
}
return bytesRead;
}
void shutdown() {
for (BBContainer c : m_readBBContainers) {
c.discard();
}
if (m_poolBBContainer != null) {
m_poolBBContainer.discard();
}
m_readBBContainers.clear();
m_poolBBContainer = null;
}
private final Deque m_readBBContainers = new ArrayDeque();
private BBContainer m_poolBBContainer = null;
protected int m_totalAvailable = 0;
private long m_bytesRead = 0;
private long m_lastBytesRead = 0;
long getBytesRead(boolean interval) {
if (interval) {
final long bytesRead = m_bytesRead;
final long bytesReadThisTime = bytesRead - m_lastBytesRead;
m_lastBytesRead = bytesRead;
return bytesReadThisTime;
} else {
return m_bytesRead;
}
}
/**
* Component class to {@link Slice} that encompasses a
* {@link BBContainer}
*/
private static final class ContainerSlice {
private final BBContainer bbc;
private final ByteBuffer bb;
private final boolean discard;
private final int size;
private ContainerSlice(BBContainer bbc, final int size) {
discard = size == bbc.b().remaining();
ByteBuffer slice = bbc.b().slice();
slice.limit(size);
bb = slice;
this.bbc = bbc;
this.size = size;
}
}
/**
* A means to defer {@link BBContainer#discard()}. When
* the data is read from {@link NIOReadStream#m_readBBContainers} it may
* span one or more {@link BBContainer}. This class collects them, and
* uses a {@link io.netty.buffer.CompositeByteBuf} to map
* them for easy read access
*/
public static final class Slice {
private final List m_slices;
public final io.netty.buffer.ByteBuf bb;
private final BitSet m_discarded;
private Slice(List slices) {
ByteBuffer [] bbs = new ByteBuffer[slices.size()];
m_discarded = new BitSet(slices.size());
for (int i = 0; i < slices.size(); ++i) {
bbs[i] = slices.get(i).bb;
}
bb = io.netty.buffer.Unpooled.wrappedBuffer(bbs);
m_slices = slices;
}
public Slice markConsumed() {
if (bb.isReadable()) {
bb.readerIndex(bb.writerIndex());
}
return this;
}
public int discard() {
int discarded = 0;
int size = 0;
for (int i = 0; i < m_slices.size(); ++i) {
ContainerSlice slc = m_slices.get(i);
size += slc.size;
if (m_discarded.get(i)) continue;
if (slc.discard && bb.readerIndex() >= size) {
slc.bbc.discard();
m_discarded.set(i);
discarded += 1;
}
}
return discarded;
}
}
}
