/var/www/greso.tech/server/nsm/node_modules/@grpc/grpc-js/src
Edit: /var/www/greso.tech/server/nsm/node_modules/@grpc/grpc-js/src/picker.ts (4328B)
/*
* 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 { StatusObject } from './call-interface';
import { Metadata } from './metadata';
import { Status } from './constants';
import { LoadBalancer } from './load-balancer';
import { SubchannelInterface } from './subchannel-interface';
export enum PickResultType {
COMPLETE,
QUEUE,
TRANSIENT_FAILURE,
DROP,
}
export interface PickResult {
pickResultType: PickResultType;
/**
* The subchannel to use as the transport for the call. Only meaningful if
* `pickResultType` is COMPLETE. If null, indicates that the call should be
* dropped.
*/
subchannel: SubchannelInterface | null;
/**
* The status object to end the call with. Populated if and only if
* `pickResultType` is TRANSIENT_FAILURE.
*/
status: StatusObject | null;
onCallStarted: (() => void) | null;
onCallEnded: ((statusCode: Status) => void) | null;
}
export interface CompletePickResult extends PickResult {
pickResultType: PickResultType.COMPLETE;
subchannel: SubchannelInterface | null;
status: null;
onCallStarted: (() => void) | null;
onCallEnded: ((statusCode: Status) => void) | null;
}
export interface QueuePickResult extends PickResult {
pickResultType: PickResultType.QUEUE;
subchannel: null;
status: null;
onCallStarted: null;
onCallEnded: null;
}
export interface TransientFailurePickResult extends PickResult {
pickResultType: PickResultType.TRANSIENT_FAILURE;
subchannel: null;
status: StatusObject;
onCallStarted: null;
onCallEnded: null;
}
export interface DropCallPickResult extends PickResult {
pickResultType: PickResultType.DROP;
subchannel: null;
status: StatusObject;
onCallStarted: null;
onCallEnded: null;
}
export interface PickArgs {
metadata: Metadata;
extraPickInfo: { [key: string]: string };
}
/**
* A proxy object representing the momentary state of a load balancer. Picks
* subchannels or returns other information based on that state. Should be
* replaced every time the load balancer changes state.
*/
export interface Picker {
pick(pickArgs: PickArgs): PickResult;
}
/**
* A standard picker representing a load balancer in the TRANSIENT_FAILURE
* state. Always responds to every pick request with an UNAVAILABLE status.
*/
export class UnavailablePicker implements Picker {
private status: StatusObject;
constructor(status?: StatusObject) {
if (status !== undefined) {
this.status = status;
} else {
this.status = {
code: Status.UNAVAILABLE,
details: 'No connection established',
metadata: new Metadata(),
};
}
}
pick(pickArgs: PickArgs): TransientFailurePickResult {
return {
pickResultType: PickResultType.TRANSIENT_FAILURE,
subchannel: null,
status: this.status,
onCallStarted: null,
onCallEnded: null
};
}
}
/**
* A standard picker representing a load balancer in the IDLE or CONNECTING
* state. Always responds to every pick request with a QUEUE pick result
* indicating that the pick should be tried again with the next `Picker`. Also
* reports back to the load balancer that a connection should be established
* once any pick is attempted.
*/
export class QueuePicker {
private calledExitIdle = false;
// Constructed with a load balancer. Calls exitIdle on it the first time pick is called
constructor(private loadBalancer: LoadBalancer) {}
pick(pickArgs: PickArgs): QueuePickResult {
if (!this.calledExitIdle) {
process.nextTick(() => {
this.loadBalancer.exitIdle();
});
this.calledExitIdle = true;
}
return {
pickResultType: PickResultType.QUEUE,
subchannel: null,
status: null,
onCallStarted: null,
onCallEnded: null
};
}
}