io.grpc.internal.BaseDnsNameResolverProvider Maven / Gradle / Ivy
/*
* Copyright 2019 The gRPC Authors
*
* 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.grpc.internal;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.base.Stopwatch;
import io.grpc.InternalServiceProviders;
import io.grpc.NameResolver;
import io.grpc.NameResolverProvider;
import java.net.URI;
/**
* Base provider of name resolvers for name agnostic consumption.
*/
public abstract class BaseDnsNameResolverProvider extends NameResolverProvider {
private static final String SCHEME = "dns";
@VisibleForTesting
public static final String ENABLE_GRPCLB_PROPERTY_NAME =
"io.grpc.internal.DnsNameResolverProvider.enable_grpclb";
/** Returns boolean value of system property {@link #ENABLE_GRPCLB_PROPERTY_NAME}. */
protected abstract boolean isSrvEnabled();
@Override
public DnsNameResolver newNameResolver(URI targetUri, NameResolver.Args args) {
if (SCHEME.equals(targetUri.getScheme())) {
String targetPath = Preconditions.checkNotNull(targetUri.getPath(), "targetPath");
Preconditions.checkArgument(targetPath.startsWith("/"),
"the path component (%s) of the target (%s) must start with '/'", targetPath, targetUri);
String name = targetPath.substring(1);
return new DnsNameResolver(
targetUri.getAuthority(),
name,
args,
GrpcUtil.SHARED_CHANNEL_EXECUTOR,
Stopwatch.createUnstarted(),
InternalServiceProviders.isAndroid(getClass().getClassLoader()),
isSrvEnabled());
} else {
return null;
}
}
@Override
public String getDefaultScheme() {
return SCHEME;
}
@Override
protected boolean isAvailable() {
return true;
}
}