io.questdb.network.Kqueue Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of core Show documentation
QuestDB is High Performance Time Series Database
There is a newer version: 5.0.1
/*******************************************************************************
 *     ___                  _   ____  ____
 *    / _ \ _   _  ___  ___| |_|  _ \| __ )
 *   | | | | | | |/ _ \/ __| __| | | |  _ \
 *   | |_| | |_| |  __/\__ \ |_| |_| | |_) |
 *    \__\_\\__,_|\___||___/\__|____/|____/
 *
 *  Copyright (c) 2014-2019 Appsicle
 *  Copyright (c) 2019-2020 QuestDB
 *
 *  Licensed 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.questdb.network;

import io.questdb.log.Log;
import io.questdb.log.LogFactory;
import io.questdb.std.Files;
import io.questdb.std.Unsafe;

import java.io.Closeable;

public final class Kqueue implements Closeable {
    private static final Log LOG = LogFactory.getLog(Kqueue.class);
    private final long changeList;
    private final long eventList;
    private final int kq;
    private final int capacity;
    private final KqueueFacade kqf;
    private final int bufferSize;
    private long writeAddress;
    private long readAddress;

    public Kqueue(int capacity) {
        this(KqueueFacadeImpl.INSTANCE, capacity);
    }

    public Kqueue(KqueueFacade kqf, int capacity) {
        this.kqf = kqf;
        this.capacity = capacity;
        this.bufferSize = KqueueAccessor.SIZEOF_KEVENT * capacity;
        this.changeList = this.writeAddress = Unsafe.calloc(bufferSize);
        this.eventList = this.readAddress = Unsafe.calloc(bufferSize);
        this.kq = kqf.kqueue();
        if (this.kq != -1) {
            Files.bumpFileCount();
        }
    }

    @Override
    public void close() {
        kqf.getNetworkFacade().close(kq, LOG);
        Unsafe.free(this.changeList, bufferSize);
        Unsafe.free(this.eventList, bufferSize);
    }

    public long getData() {
        return Unsafe.getUnsafe().getLong(readAddress + KqueueAccessor.DATA_OFFSET);
    }

    public int getFd() {
        return (int) Unsafe.getUnsafe().getLong(readAddress + KqueueAccessor.FD_OFFSET);
    }

    public int getFilter() {
        return Unsafe.getUnsafe().getShort(readAddress + KqueueAccessor.FILTER_OFFSET);
    }

    public int getFlags() {
        return Unsafe.getUnsafe().getShort(readAddress + KqueueAccessor.FLAGS_OFFSET);
    }

    public int listen(long sfd) {
        writeAddress = changeList;
        commonFd(sfd, 0);
        Unsafe.getUnsafe().putShort(writeAddress + KqueueAccessor.FILTER_OFFSET, KqueueAccessor.EVFILT_READ);
        Unsafe.getUnsafe().putShort(writeAddress + KqueueAccessor.FLAGS_OFFSET, KqueueAccessor.EV_ADD);
        return register(1);
    }

    public int poll() {
        return kqf.kevent(kq, 0, 0, eventList, capacity);
    }

    public void readFD(int fd, long data) {
        commonFd(fd, data);
        Unsafe.getUnsafe().putShort(writeAddress + KqueueAccessor.FILTER_OFFSET, KqueueAccessor.EVFILT_READ);
        Unsafe.getUnsafe().putShort(writeAddress + KqueueAccessor.FLAGS_OFFSET, (short) (KqueueAccessor.EV_ADD | KqueueAccessor.EV_ONESHOT));
    }

    public int register(int n) {
        return kqf.kevent(kq, changeList, n, 0, 0);
    }

    public void setReadOffset(int offset) {
        this.readAddress = eventList + offset;
    }

    public void setWriteOffset(int offset) {
        this.writeAddress = changeList + offset;
    }

    public void writeFD(int fd, long data) {
        commonFd(fd, data);
        Unsafe.getUnsafe().putShort(writeAddress + KqueueAccessor.FILTER_OFFSET, KqueueAccessor.EVFILT_WRITE);
        Unsafe.getUnsafe().putShort(writeAddress + KqueueAccessor.FLAGS_OFFSET, (short) (KqueueAccessor.EV_ADD | KqueueAccessor.EV_ONESHOT));
    }

    private void commonFd(long fd, long data) {
        Unsafe.getUnsafe().putLong(writeAddress + KqueueAccessor.FD_OFFSET, fd);
        Unsafe.getUnsafe().putLong(writeAddress + KqueueAccessor.DATA_OFFSET, data);
    }
}