1 /* 2 * Copyright 2016 The gRPC Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.grpc.internal; 18 19 import com.google.common.annotations.VisibleForTesting; 20 import io.grpc.InternalChannelz.ChannelStats; 21 import io.grpc.InternalInstrumented; 22 import io.grpc.LoadBalancer; 23 import javax.annotation.Nullable; 24 25 /** 26 * The base interface of the Subchannels returned by {@link 27 * io.grpc.LoadBalancer.Helper#createSubchannel}. 28 */ 29 abstract class AbstractSubchannel extends LoadBalancer.Subchannel { 30 31 /** 32 * Same as {@link InternalSubchannel#obtainActiveTransport}. 33 */ 34 @Nullable obtainActiveTransport()35 abstract ClientTransport obtainActiveTransport(); 36 37 /** 38 * Returns the InternalSubchannel as an {@code Instrumented<T>} for the sole purpose of channelz 39 * unit tests. 40 */ 41 @VisibleForTesting getInternalSubchannel()42 abstract InternalInstrumented<ChannelStats> getInternalSubchannel(); 43 } 44