@opencensus/core/build/src/metrics/gauges/gauge.js

"use strict";
/**
 * Copyright 2018, OpenCensus 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.
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.PointEntry = exports.Gauge = void 0;
const time_util_1 = require("../../common/time-util");
const validations_1 = require("../../common/validations");
const utils_1 = require("../utils");
/**
 * Gauge metric
 */
class Gauge {
    /**
     * Constructs a new Gauge instance.
     *
     * @param name The name of the metric.
     * @param description The description of the metric.
     * @param unit The unit of the metric.
     * @param type The type of metric.
     * @param labelKeys The list of the label keys.
     * @param constantLabels The map of constant labels for the Metric.
     */
    constructor(name, description, unit, type, labelKeys, constantLabels) {
        this.labelKeys = labelKeys;
        this.constantLabels = constantLabels;
        this.registeredPoints = new Map();
        this.labelKeysLength = labelKeys.length;
        const keysAndConstantKeys = [...labelKeys, ...constantLabels.keys()];
        this.constantLabelValues = [...constantLabels.values()];
        this.metricDescriptor = {
            name,
            description,
            unit,
            type,
            labelKeys: keysAndConstantKeys,
        };
        this.defaultLabelValues = utils_1.initializeDefaultLabels(this.labelKeysLength);
    }
    /**
     * Creates a TimeSeries and returns a Point if the specified
     * labelValues is not already associated with this gauge, else returns an
     * existing Point.
     *
     * It is recommended to keep a reference to the Point instead of always
     * calling this method for manual operations.
     *
     * @param labelValues The list of the label values.
     * @returns The value of single gauge.
     */
    getOrCreateTimeSeries(labelValues) {
        validations_1.validateArrayElementsNotNull(validations_1.validateNotNull(labelValues, Gauge.LABEL_VALUES), Gauge.LABEL_VALUE);
        return this.registerTimeSeries(labelValues);
    }
    /**
     * Returns a Point for a gauge with all labels not set, or default
     * labels.
     *
     * @returns The value of single gauge.
     */
    getDefaultTimeSeries() {
        return this.registerTimeSeries(this.defaultLabelValues);
    }
    /**
     * Removes the TimeSeries from the gauge metric, if it is present. i.e.
     * references to previous Point objects are invalid (not part of the
     * metric).
     *
     * @param labelValues The list of label values.
     */
    removeTimeSeries(labelValues) {
        validations_1.validateNotNull(labelValues, Gauge.LABEL_VALUES);
        this.registeredPoints.delete(utils_1.hashLabelValues(labelValues));
    }
    /**
     * Removes all TimeSeries from the gauge metric. i.e. references to all
     * previous Point objects are invalid (not part of the metric).
     */
    clear() {
        this.registeredPoints.clear();
    }
    /**
     * Registers a TimeSeries and returns a Point if the specified
     * labelValues is not already associated with this gauge, else returns an
     * existing Point.
     *
     * @param labelValues The list of the label values.
     * @returns The value of single gauge.
     */
    registerTimeSeries(labelValues) {
        const hash = utils_1.hashLabelValues(labelValues);
        // return if the specified labelValues is already associated with the point.
        if (this.registeredPoints.has(hash)) {
            return this.registeredPoints.get(hash);
        }
        if (this.labelKeysLength !== labelValues.length) {
            throw new Error(Gauge.ERROR_MESSAGE_INVALID_SIZE);
        }
        const point = new PointEntry([...labelValues, ...this.constantLabelValues]);
        this.registeredPoints.set(hash, point);
        return point;
    }
    /**
     * Provides a Metric with one or more TimeSeries.
     *
     * @returns The Metric, or null if TimeSeries is not present in Metric.
     */
    getMetric() {
        if (this.registeredPoints.size === 0) {
            return null;
        }
        const timestamp = time_util_1.getTimestampWithProcessHRTime();
        return {
            descriptor: this.metricDescriptor,
            timeseries: Array.from(this.registeredPoints, ([_, point]) => point.getTimeSeries(timestamp)),
        };
    }
}
exports.Gauge = Gauge;
Gauge.LABEL_VALUE = 'labelValue';
Gauge.LABEL_VALUES = 'labelValues';
Gauge.ERROR_MESSAGE_INVALID_SIZE = "Label Keys and Label Values don't have same size";
/**
 * The value of a single point in the Gauge.TimeSeries.
 */
class PointEntry {
    constructor(labelValues) {
        this.value = 0;
        this.labelValues = labelValues;
    }
    /**
     * Adds the given value to the current value. The values can be negative.
     *
     * @param amt The value to add.
     */
    add(amt) {
        this.value = this.value + amt;
    }
    /**
     * Sets the given value.
     *
     * @param val The new value.
     */
    set(val) {
        this.value = val;
    }
    /**
     * Returns the TimeSeries with one or more Point.
     *
     * @param timestamp The time at which the gauge is recorded.
     * @returns The TimeSeries.
     */
    getTimeSeries(timestamp) {
        return {
            labelValues: this.labelValues,
            points: [{ value: this.value, timestamp }],
        };
    }
}
exports.PointEntry = PointEntry;
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