-
Notifications
You must be signed in to change notification settings - Fork 180
/
LoadBalancer.java
51 lines (46 loc) · 2.17 KB
/
LoadBalancer.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
/*
* Copyright © 2018 Apple Inc. and the ServiceTalk project 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.servicetalk.client.api;
import io.servicetalk.concurrent.api.ListenableAsyncCloseable;
import io.servicetalk.concurrent.api.Publisher;
import io.servicetalk.concurrent.api.Single;
import java.net.SocketAddress;
import java.util.function.Function;
import java.util.function.Predicate;
/**
* Given multiple {@link SocketAddress}es select the most desired {@link SocketAddress} to use. This is typically used
* to determine which connection to issue a request to.
*
* @param <C> The type of connection.
*/
public interface LoadBalancer<C extends LoadBalancedConnection> extends ListenableAsyncCloseable {
/**
* Select the most appropriate connection for a request. Returned connection may be used concurrently for other
* requests.
*
* @param selector A {@link Function} that evaluates a connection for selection.
* This selector should return {@code null} if the connection <strong>MUST</strong> not be selected.
* This selector is guaranteed to be called for any connection that is returned from this method.
* @return a {@link Single} that completes with the most appropriate connection to use.
*/
Single<C> selectConnection(Predicate<C> selector);
/**
* A {@link Publisher} of events provided by this {@link LoadBalancer}. This maybe used to broadcast internal state
* of this {@link LoadBalancer} to provide hints/visibility for external usage.
* @return A {@link Publisher} of events provided by this {@link LoadBalancer}.
*/
Publisher<Object> eventStream();
}