File size: 5,495 Bytes
77731d1 |
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 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 |
/*
* Copyright 2020 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.
*
*/
import {
LoadBalancer,
ChannelControlHelper,
LoadBalancingConfig,
createLoadBalancer,
} from './load-balancer';
import { SubchannelAddress } from './subchannel-address';
import { ChannelOptions } from './channel-options';
import { ConnectivityState } from './connectivity-state';
import { Picker } from './picker';
import { ChannelRef, SubchannelRef } from './channelz';
import { SubchannelInterface } from './subchannel-interface';
const TYPE_NAME = 'child_load_balancer_helper';
export class ChildLoadBalancerHandler implements LoadBalancer {
private currentChild: LoadBalancer | null = null;
private pendingChild: LoadBalancer | null = null;
private latestConfig: LoadBalancingConfig | null = null;
private ChildPolicyHelper = class {
private child: LoadBalancer | null = null;
constructor(private parent: ChildLoadBalancerHandler) {}
createSubchannel(
subchannelAddress: SubchannelAddress,
subchannelArgs: ChannelOptions
): SubchannelInterface {
return this.parent.channelControlHelper.createSubchannel(
subchannelAddress,
subchannelArgs
);
}
updateState(connectivityState: ConnectivityState, picker: Picker): void {
if (this.calledByPendingChild()) {
if (connectivityState === ConnectivityState.CONNECTING) {
return;
}
this.parent.currentChild?.destroy();
this.parent.currentChild = this.parent.pendingChild;
this.parent.pendingChild = null;
} else if (!this.calledByCurrentChild()) {
return;
}
this.parent.channelControlHelper.updateState(connectivityState, picker);
}
requestReresolution(): void {
const latestChild = this.parent.pendingChild ?? this.parent.currentChild;
if (this.child === latestChild) {
this.parent.channelControlHelper.requestReresolution();
}
}
setChild(newChild: LoadBalancer) {
this.child = newChild;
}
addChannelzChild(child: ChannelRef | SubchannelRef) {
this.parent.channelControlHelper.addChannelzChild(child);
}
removeChannelzChild(child: ChannelRef | SubchannelRef) {
this.parent.channelControlHelper.removeChannelzChild(child);
}
private calledByPendingChild(): boolean {
return this.child === this.parent.pendingChild;
}
private calledByCurrentChild(): boolean {
return this.child === this.parent.currentChild;
}
};
constructor(private readonly channelControlHelper: ChannelControlHelper) {}
protected configUpdateRequiresNewPolicyInstance(
oldConfig: LoadBalancingConfig,
newConfig: LoadBalancingConfig
): boolean {
return oldConfig.getLoadBalancerName() !== newConfig.getLoadBalancerName();
}
/**
* Prerequisites: lbConfig !== null and lbConfig.name is registered
* @param addressList
* @param lbConfig
* @param attributes
*/
updateAddressList(
addressList: SubchannelAddress[],
lbConfig: LoadBalancingConfig,
attributes: { [key: string]: unknown }
): void {
let childToUpdate: LoadBalancer;
if (
this.currentChild === null ||
this.latestConfig === null ||
this.configUpdateRequiresNewPolicyInstance(this.latestConfig, lbConfig)
) {
const newHelper = new this.ChildPolicyHelper(this);
const newChild = createLoadBalancer(lbConfig, newHelper)!;
newHelper.setChild(newChild);
if (this.currentChild === null) {
this.currentChild = newChild;
childToUpdate = this.currentChild;
} else {
if (this.pendingChild) {
this.pendingChild.destroy();
}
this.pendingChild = newChild;
childToUpdate = this.pendingChild;
}
} else {
if (this.pendingChild === null) {
childToUpdate = this.currentChild;
} else {
childToUpdate = this.pendingChild;
}
}
this.latestConfig = lbConfig;
childToUpdate.updateAddressList(addressList, lbConfig, attributes);
}
exitIdle(): void {
if (this.currentChild) {
this.currentChild.exitIdle();
if (this.pendingChild) {
this.pendingChild.exitIdle();
}
}
}
resetBackoff(): void {
if (this.currentChild) {
this.currentChild.resetBackoff();
if (this.pendingChild) {
this.pendingChild.resetBackoff();
}
}
}
destroy(): void {
/* Note: state updates are only propagated from the child balancer if that
* object is equal to this.currentChild or this.pendingChild. Since this
* function sets both of those to null, no further state updates will
* occur after this function returns. */
if (this.currentChild) {
this.currentChild.destroy();
this.currentChild = null;
}
if (this.pendingChild) {
this.pendingChild.destroy();
this.pendingChild = null;
}
}
getTypeName(): string {
return TYPE_NAME;
}
}
|