netty5/resolver-dns/src/main/java/io/netty/resolver/dns/TraceDnsQueryLifecycleObserver.java
Scott Mitchell 1767814a46 Replace DnsNameResolverContext#trace special code with an implementation of DnsQueryLifecycleObserver
Motivation:
DnsQueryLifecycleObserver is designed to capture the life cycle of every query. DnsNameResolverContext has a custom trace mechanism which consists of a StringBuilder and manual calls throughout the class. We can remove some special case code in DnsNameResolverContext and instead use a special implementation of DnsQueryLifecycleObserver when trace is enabled.

Modifications:
- Remove all references to the boolean trace variables in DnsNameResolverContext and DnsNameResolver
- Introduce TraceDnsQueryLifecycleObserver which will be used when trace is enabled and will log similar data as what trace currently provides

Result:
Less special case code in DnsNameResolverContext and instead delegate to TraceDnsQueryLifecycleObserver to capture trace information.
2017-06-23 09:04:59 -07:00

88 lines
3.1 KiB
Java

/*
* Copyright 2017 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.resolver.dns;
import io.netty.channel.ChannelFuture;
import io.netty.handler.codec.dns.DnsQuestion;
import io.netty.handler.codec.dns.DnsResponseCode;
import io.netty.util.internal.logging.InternalLogLevel;
import io.netty.util.internal.logging.InternalLogger;
import java.net.InetSocketAddress;
import java.util.List;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
final class TraceDnsQueryLifecycleObserver implements DnsQueryLifecycleObserver {
private final InternalLogger logger;
private final InternalLogLevel level;
private final DnsQuestion question;
private InetSocketAddress dnsServerAddress;
TraceDnsQueryLifecycleObserver(DnsQuestion question, InternalLogger logger, InternalLogLevel level) {
this.question = checkNotNull(question, "question");
this.logger = checkNotNull(logger, "logger");
this.level = checkNotNull(level, "level");
}
@Override
public void queryWritten(InetSocketAddress dnsServerAddress, ChannelFuture future) {
this.dnsServerAddress = dnsServerAddress;
}
@Override
public void queryCancelled(int queriesRemaining) {
if (dnsServerAddress != null) {
logger.log(level, "from {} : {} cancelled with {} queries remaining", dnsServerAddress, question,
queriesRemaining);
} else {
logger.log(level, "{} query never written and cancelled with {} queries remaining", question,
queriesRemaining);
}
}
@Override
public DnsQueryLifecycleObserver queryRedirected(List<InetSocketAddress> nameServers) {
logger.log(level, "from {} : {} redirected", dnsServerAddress, question);
return this;
}
@Override
public DnsQueryLifecycleObserver queryCNAMEd(DnsQuestion cnameQuestion) {
logger.log(level, "from {} : {} CNAME question {}", dnsServerAddress, question, cnameQuestion);
return this;
}
@Override
public DnsQueryLifecycleObserver queryNoAnswer(DnsResponseCode code) {
logger.log(level, "from {} : {} no answer {}", dnsServerAddress, question, code);
return this;
}
@Override
public void queryFailed(Throwable cause) {
if (dnsServerAddress != null) {
logger.log(level, "from {} : {} failure", dnsServerAddress, question, cause);
} else {
logger.log(level, "{} query never written and failed", question, cause);
}
}
@Override
public void querySucceed() {
}
}