/var/www/qr4y.com/server/delivery/node_modules/@grpc/grpc-js/src
Edit: /var/www/qr4y.com/server/delivery/node_modules/@grpc/grpc-js/src/load-balancer.ts (7483B)
/*
* Copyright 2019 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 { ChannelOptions } from './channel-options';
import { Subchannel } from './subchannel';
import { SubchannelAddress } from './subchannel-address';
import { ConnectivityState } from './connectivity-state';
import { Picker } from './picker';
import { ChannelRef, SubchannelRef } from './channelz';
import { SubchannelInterface } from './subchannel-interface';
/**
* A collection of functions associated with a channel that a load balancer
* can call as necessary.
*/
export interface ChannelControlHelper {
/**
* Returns a subchannel connected to the specified address.
* @param subchannelAddress The address to connect to
* @param subchannelArgs Extra channel arguments specified by the load balancer
*/
createSubchannel(
subchannelAddress: SubchannelAddress,
subchannelArgs: ChannelOptions
): SubchannelInterface;
/**
* Passes a new subchannel picker up to the channel. This is called if either
* the connectivity state changes or if a different picker is needed for any
* other reason.
* @param connectivityState New connectivity state
* @param picker New picker
*/
updateState(connectivityState: ConnectivityState, picker: Picker): void;
/**
* Request new data from the resolver.
*/
requestReresolution(): void;
addChannelzChild(child: ChannelRef | SubchannelRef): void;
removeChannelzChild(child: ChannelRef | SubchannelRef): void;
}
/**
* Create a child ChannelControlHelper that overrides some methods of the
* parent while letting others pass through to the parent unmodified. This
* allows other code to create these children without needing to know about
* all of the methods to be passed through.
* @param parent
* @param overrides
*/
export function createChildChannelControlHelper(parent: ChannelControlHelper, overrides: Partial
): ChannelControlHelper {
return {
createSubchannel: overrides.createSubchannel?.bind(overrides) ?? parent.createSubchannel.bind(parent),
updateState: overrides.updateState?.bind(overrides) ?? parent.updateState.bind(parent),
requestReresolution: overrides.requestReresolution?.bind(overrides) ?? parent.requestReresolution.bind(parent),
addChannelzChild: overrides.addChannelzChild?.bind(overrides) ?? parent.addChannelzChild.bind(parent),
removeChannelzChild: overrides.removeChannelzChild?.bind(overrides) ?? parent.removeChannelzChild.bind(parent)
};
}
/**
* Tracks one or more connected subchannels and determines which subchannel
* each request should use.
*/
export interface LoadBalancer {
/**
* Gives the load balancer a new list of addresses to start connecting to.
* The load balancer will start establishing connections with the new list,
* but will continue using any existing connections until the new connections
* are established
* @param addressList The new list of addresses to connect to
* @param lbConfig The load balancing config object from the service config,
* if one was provided
*/
updateAddressList(
addressList: SubchannelAddress[],
lbConfig: LoadBalancingConfig,
attributes: { [key: string]: unknown }
): void;
/**
* If the load balancer is currently in the IDLE state, start connecting.
*/
exitIdle(): void;
/**
* If the load balancer is currently in the CONNECTING or TRANSIENT_FAILURE
* state, reset the current connection backoff timeout to its base value and
* transition to CONNECTING if in TRANSIENT_FAILURE.
*/
resetBackoff(): void;
/**
* The load balancer unrefs all of its subchannels and stops calling methods
* of its channel control helper.
*/
destroy(): void;
/**
* Get the type name for this load balancer type. Must be constant across an
* entire load balancer implementation class and must match the name that the
* balancer implementation class was registered with.
*/
getTypeName(): string;
}
export interface LoadBalancerConstructor {
new (channelControlHelper: ChannelControlHelper): LoadBalancer;
}
export interface LoadBalancingConfig {
getLoadBalancerName(): string;
toJsonObject(): object;
}
export interface LoadBalancingConfigConstructor {
// eslint-disable-next-line @typescript-eslint/no-explicit-any
new (...args: any): LoadBalancingConfig;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
createFromJson(obj: any): LoadBalancingConfig;
}
const registeredLoadBalancerTypes: {
[name: string]: {
LoadBalancer: LoadBalancerConstructor;
LoadBalancingConfig: LoadBalancingConfigConstructor;
};
} = {};
let defaultLoadBalancerType: string | null = null;
export function registerLoadBalancerType(
typeName: string,
loadBalancerType: LoadBalancerConstructor,
loadBalancingConfigType: LoadBalancingConfigConstructor
) {
registeredLoadBalancerTypes[typeName] = {
LoadBalancer: loadBalancerType,
LoadBalancingConfig: loadBalancingConfigType,
};
}
export function registerDefaultLoadBalancerType(typeName: string) {
defaultLoadBalancerType = typeName;
}
export function createLoadBalancer(
config: LoadBalancingConfig,
channelControlHelper: ChannelControlHelper
): LoadBalancer | null {
const typeName = config.getLoadBalancerName();
if (typeName in registeredLoadBalancerTypes) {
return new registeredLoadBalancerTypes[typeName].LoadBalancer(
channelControlHelper
);
} else {
return null;
}
}
export function isLoadBalancerNameRegistered(typeName: string): boolean {
return typeName in registeredLoadBalancerTypes;
}
export function getFirstUsableConfig(
configs: LoadBalancingConfig[],
fallbackTodefault?: true
): LoadBalancingConfig;
export function getFirstUsableConfig(
configs: LoadBalancingConfig[],
fallbackTodefault = false
): LoadBalancingConfig | null {
for (const config of configs) {
if (config.getLoadBalancerName() in registeredLoadBalancerTypes) {
return config;
}
}
if (fallbackTodefault) {
if (defaultLoadBalancerType) {
return new registeredLoadBalancerTypes[
defaultLoadBalancerType
]!.LoadBalancingConfig();
} else {
return null;
}
} else {
return null;
}
}
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export function validateLoadBalancingConfig(obj: any): LoadBalancingConfig {
if (!(obj !== null && typeof obj === 'object')) {
throw new Error('Load balancing config must be an object');
}
const keys = Object.keys(obj);
if (keys.length !== 1) {
throw new Error(
'Provided load balancing config has multiple conflicting entries'
);
}
const typeName = keys[0];
if (typeName in registeredLoadBalancerTypes) {
return registeredLoadBalancerTypes[
typeName
].LoadBalancingConfig.createFromJson(obj[typeName]);
} else {
throw new Error(`Unrecognized load balancing config name ${typeName}`);
}
}