gcf-helper/dist/lib/MetricsHandler.js

Google Cloud Functions Helper

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
class MetricsHandler {
    constructor(gcfHelper) {
        this.gcfHelper = gcfHelper;
        this.buffer = [];
        this.timeout = null;
    }
    increment(metricName, value = 1, labels = {}) {
        const metric = {
            type: "counter",
            metric: metricName,
            value,
            labels,
        };
        this.buffer.push(metric);
        this.flushOrSpawn();
    }
    set(metricName, value = 0, labels = {}) {
        const metric = {
            type: "gauge",
            metric: metricName,
            value,
            labels,
        };
        this.buffer.push(metric);
        this.flushOrSpawn();
    }
    kill() {
        if (this.timeout) {
            clearTimeout(this.timeout);
        }
    }
    flushOrSpawn() {
        const ftms = this.gcfHelper.functionOptions.metricsFlushTimeoutMs;
        if (!ftms || ftms < 0) {
            this.flush(); // promise ignored
            return;
        }
        // timeout already running
        if (this.timeout !== null) {
            return;
        }
        this.timeout = setTimeout(() => {
            this.flush(); // promise ignored
            this.timeout = null;
        }, ftms);
    }
    async flush() {
        // expects await this.gcfHelper.ensureMetricsReady() to be called first
        try {
            if (!this.buffer.length) {
                return;
            }
            const readBuffer = Buffer.from(JSON.stringify(this.buffer));
            this.buffer = [];
            await this.gcfHelper.functionOptions
                .pubSubClient.topic(this.gcfHelper.functionOptions.metricsTopic)
                .publish(readBuffer);
        }
        catch (error) {
            console.log(`Failed to publish metrics to pubsub topic: ${error.message}.`);
        }
    }
}
exports.default = MetricsHandler;