pip-services3-rpc-node
Version:
Remote procedure calls for Pip.Services in Node.js
177 lines • 6.66 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.DirectClient = void 0;
const pip_services3_commons_node_1 = require("pip-services3-commons-node");
const pip_services3_components_node_1 = require("pip-services3-components-node");
const pip_services3_components_node_2 = require("pip-services3-components-node");
const pip_services3_commons_node_2 = require("pip-services3-commons-node");
/**
* Abstract client that calls controller directly in the same memory space.
*
* It is used when multiple microservices are deployed in a single container (monolyth)
* and communication between them can be done by direct calls rather then through
* the network.
*
* ### Configuration parameters ###
*
* - dependencies:
* - controller: override controller descriptor
*
* ### References ###
*
* - <code>\*:logger:\*:\*:1.0</code> (optional) [[https://pip-services3-node.github.io/pip-services3-components-node/interfaces/log.ilogger.html ILogger]] components to pass log messages
* - <code>\*:counters:\*:\*:1.0</code> (optional) [[https://pip-services3-node.github.io/pip-services3-components-node/interfaces/count.icounters.html ICounters]] components to pass collected measurements
* - <code>\*:controller:\*:\*:1.0</code> controller to call business methods
*
* ### Example ###
*
* class MyDirectClient extends DirectClient<IMyController> implements IMyClient {
*
* public constructor() {
* super();
* this._dependencyResolver.put('controller', new Descriptor(
* "mygroup", "controller", "*", "*", "*"));
* }
* ...
*
* public getData(correlationId: string, id: string,
* callback: (err: any, result: MyData) => void): void {
*
* let timing = this.instrument(correlationId, 'myclient.get_data');
* this._controller.getData(correlationId, id, (err, result) => {
* timing.endTiming();
* this.instrumentError(correlationId, 'myclient.get_data', err, result, callback);
* });
* }
* ...
* }
*
* let client = new MyDirectClient();
* client.setReferences(References.fromTuples(
* new Descriptor("mygroup","controller","default","default","1.0"), controller
* ));
*
* client.getData("123", "1", (err, result) => {
* ...
* });
*/
class DirectClient {
/**
* Creates a new instance of the client.
*/
constructor() {
/**
* The open flag.
*/
this._opened = true;
/**
* The logger.
*/
this._logger = new pip_services3_components_node_1.CompositeLogger();
/**
* The performance counters
*/
this._counters = new pip_services3_components_node_2.CompositeCounters();
/**
* The dependency resolver to get controller reference.
*/
this._dependencyResolver = new pip_services3_commons_node_1.DependencyResolver();
this._dependencyResolver.put('controller', 'none');
}
/**
* Configures component by passing configuration parameters.
*
* @param config configuration parameters to be set.
*/
configure(config) {
this._dependencyResolver.configure(config);
}
/**
* Sets references to dependent components.
*
* @param references references to locate the component dependencies.
*/
setReferences(references) {
this._logger.setReferences(references);
this._counters.setReferences(references);
this._dependencyResolver.setReferences(references);
this._controller = this._dependencyResolver.getOneRequired('controller');
}
/**
* Adds instrumentation to log calls and measure call time.
* It returns a CounterTiming object that is used to end the time measurement.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param name a method name.
* @returns CounterTiming object to end the time measurement.
*/
instrument(correlationId, name) {
this._logger.trace(correlationId, "Calling %s method", name);
this._counters.incrementOne(name + '.call_count');
return this._counters.beginTiming(name + ".call_time");
}
/**
* Adds instrumentation to error handling.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param name a method name.
* @param err an occured error
* @param result (optional) an execution result
* @param callback (optional) an execution callback
*/
instrumentError(correlationId, name, err, result = null, callback = null) {
if (err != null) {
this._logger.error(correlationId, err, "Failed to call %s method", name);
this._counters.incrementOne(name + '.call_errors');
}
if (callback)
callback(err, result);
}
/**
* Checks if the component is opened.
*
* @returns true if the component has been opened and false otherwise.
*/
isOpen() {
return this._opened;
}
/**
* Opens the component.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param callback callback function that receives error or null no errors occured.
*/
open(correlationId, callback) {
if (this._opened) {
callback(null);
return;
}
if (this._controller == null) {
let err = new pip_services3_commons_node_2.ConnectionException(correlationId, 'NO_CONTROLLER', 'Controller reference is missing');
if (callback) {
callback(err);
return;
}
else {
throw err;
}
}
this._opened = true;
this._logger.info(correlationId, "Opened direct client");
callback(null);
}
/**
* Closes component and frees used resources.
*
* @param correlationId (optional) transaction id to trace execution through call chain.
* @param callback callback function that receives error or null no errors occured.
*/
close(correlationId, callback) {
if (this._opened)
this._logger.info(correlationId, "Closed direct client");
this._opened = false;
callback(null);
}
}
exports.DirectClient = DirectClient;
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