com.datastax.oss.driver.internal.core.os.JnrLibc Maven / Gradle / Ivy
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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 com.datastax.oss.driver.internal.core.os;
import java.util.Optional;
import java.util.function.Consumer;
import jnr.posix.POSIX;
import jnr.posix.POSIXFactory;
import jnr.posix.Timeval;
import jnr.posix.util.DefaultPOSIXHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class JnrLibc implements Libc {
private static final Logger LOG = LoggerFactory.getLogger(JnrLibc.class);
private final Optional posix;
public JnrLibc() {
this.posix = loadPosix();
}
@Override
public Optional gettimeofday() {
return this.posix.flatMap(this::gettimeofdayImpl);
}
@Override
public Optional getpid() {
return this.posix.map(POSIX::getpid);
}
@Override
public boolean available() {
return this.posix.isPresent();
}
private Optional loadPosix() {
try {
return Optional.of(POSIXFactory.getPOSIX(new DefaultPOSIXHandler(), true))
.flatMap(p -> catchAll(p, posix -> posix.getpid(), "Error calling getpid()"))
.flatMap(p -> catchAll(p, this::gettimeofdayImpl, "Error calling gettimeofday()"));
} catch (Throwable t) {
LOG.debug("Error loading POSIX", t);
return Optional.empty();
}
}
private Optional catchAll(POSIX posix, Consumer fn, String debugStr) {
try {
fn.accept(posix);
return Optional.of(posix);
} catch (Throwable t) {
LOG.debug(debugStr, t);
return Optional.empty();
}
}
private Optional gettimeofdayImpl(POSIX posix) {
Timeval tv = posix.allocateTimeval();
int rv = posix.gettimeofday(tv);
if (rv != 0) {
LOG.debug("Expected 0 return value from gettimeofday(), observed " + rv);
return Optional.empty();
}
return Optional.of(tv.sec() * 1_000_000 + tv.usec());
}
}