@grpc/grpc-js
Version:
gRPC Library for Node - pure JS implementation
119 lines (118 loc) • 4.65 kB
TypeScript
import { ChannelCredentials } from './channel-credentials';
import { Metadata } from './metadata';
import { ChannelOptions } from './channel-options';
import { ConnectivityState } from './connectivity-state';
import { GrpcUri } from './uri-parser';
import { SubchannelAddress } from './subchannel-address';
import { SubchannelRef } from './channelz';
import { ConnectivityStateListener } from './subchannel-interface';
import { SubchannelCallInterceptingListener } from './subchannel-call';
import { SubchannelCall } from './subchannel-call';
import { SubchannelConnector } from './transport';
export declare class Subchannel {
private channelTarget;
private subchannelAddress;
private options;
private credentials;
private connector;
/**
* The subchannel's current connectivity state. Invariant: `session` === `null`
* if and only if `connectivityState` is IDLE or TRANSIENT_FAILURE.
*/
private connectivityState;
/**
* The underlying http2 session used to make requests.
*/
private transport;
/**
* Indicates that the subchannel should transition from TRANSIENT_FAILURE to
* CONNECTING instead of IDLE when the backoff timeout ends.
*/
private continueConnecting;
/**
* A list of listener functions that will be called whenever the connectivity
* state changes. Will be modified by `addConnectivityStateListener` and
* `removeConnectivityStateListener`
*/
private stateListeners;
private backoffTimeout;
private keepaliveTime;
/**
* Tracks channels and subchannel pools with references to this subchannel
*/
private refcount;
/**
* A string representation of the subchannel address, for logging/tracing
*/
private subchannelAddressString;
private readonly channelzEnabled;
private channelzRef;
private channelzTrace;
private callTracker;
private childrenTracker;
private streamTracker;
/**
* A class representing a connection to a single backend.
* @param channelTarget The target string for the channel as a whole
* @param subchannelAddress The address for the backend that this subchannel
* will connect to
* @param options The channel options, plus any specific subchannel options
* for this subchannel
* @param credentials The channel credentials used to establish this
* connection
*/
constructor(channelTarget: GrpcUri, subchannelAddress: SubchannelAddress, options: ChannelOptions, credentials: ChannelCredentials, connector: SubchannelConnector);
private getChannelzInfo;
private trace;
private refTrace;
private handleBackoffTimer;
/**
* Start a backoff timer with the current nextBackoff timeout
*/
private startBackoff;
private stopBackoff;
private startConnectingInternal;
/**
* Initiate a state transition from any element of oldStates to the new
* state. If the current connectivityState is not in oldStates, do nothing.
* @param oldStates The set of states to transition from
* @param newState The state to transition to
* @returns True if the state changed, false otherwise
*/
private transitionToState;
ref(): void;
unref(): void;
unrefIfOneRef(): boolean;
createCall(metadata: Metadata, host: string, method: string, listener: SubchannelCallInterceptingListener): SubchannelCall;
/**
* If the subchannel is currently IDLE, start connecting and switch to the
* CONNECTING state. If the subchannel is current in TRANSIENT_FAILURE,
* the next time it would transition to IDLE, start connecting again instead.
* Otherwise, do nothing.
*/
startConnecting(): void;
/**
* Get the subchannel's current connectivity state.
*/
getConnectivityState(): ConnectivityState;
/**
* Add a listener function to be called whenever the subchannel's
* connectivity state changes.
* @param listener
*/
addConnectivityStateListener(listener: ConnectivityStateListener): void;
/**
* Remove a listener previously added with `addConnectivityStateListener`
* @param listener A reference to a function previously passed to
* `addConnectivityStateListener`
*/
removeConnectivityStateListener(listener: ConnectivityStateListener): void;
/**
* Reset the backoff timeout, and immediately start connecting if in backoff.
*/
resetBackoff(): void;
getAddress(): string;
getChannelzRef(): SubchannelRef;
getRealSubchannel(): this;
throttleKeepalive(newKeepaliveTime: number): void;
}