hot-shots/lib/statsFunctions.js

const helpers = require('./helpers');

/**
 * Separated out of statsd.js for clarity, these are the timing and other stats functions that are what are called the most
 * when using hot-shots
 */
function applyStatsFns (Client) {

  /**
   * Represents the timing stat
   * @param stat {String|Array} The stat(s) to send
   * @param time {Number|Date} The time in milliseconds to send or Date object of which the difference is calculated
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.timing = function (stat, time, sampleRate, tags, callback) {
    const t = time instanceof Date ? new Date() - time : time;
    this.sendAll(stat, t, 'ms', sampleRate, tags, callback);
  };

  /**
   * Represents the timing stat by recording the duration a function takes to run (in milliseconds)
   * @param func {Function} The function to run
   * @param stat {String|Array} The stat(s) to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.timer = function (func, stat, sampleRate, tags, callback) {
    const _this = this;

    return (...args) => {
      const start = process.hrtime();
      try {
        return func(...args);
      } finally {
        // get duration in milliseconds
        const durationComponents = process.hrtime(start);
        const seconds = durationComponents[0];
        const nanoseconds = durationComponents[1];
        const duration = (seconds * 1000) + (nanoseconds / 1E6);

        _this.timing(
          stat,
          duration,
          sampleRate,
          tags,
          callback
        );
      }
    };
  };

  /**
   * Decorates an async function with timing recording behaviour.
   *
   * This version of `timer` will record the time take for the asyncronus action returned by `func`
   * not just the execution time of `func` itself.
   *
   * @param func {<T,A>(...A):Promise<T>} The function to run
   * @param stat {String|Array} The stat(s) to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.asyncTimer = function (func, stat, sampleRate, tags, callback) {
    const self = this;
    return (...args) => {
      const end = hrtimer();
      const p = func(...args);
      const recordStat = () => { self.timing(stat, end(), sampleRate, tags, callback); };
      p.then(recordStat, recordStat);
      return p;
    };
  };

  /**
   * High-resolution timer
   */
  function hrtimer() {
    const start = process.hrtime();

    return () => {
      const durationComponents = process.hrtime(start);
      const seconds = durationComponents[0];
      const nanoseconds = durationComponents[1];
      const duration = (seconds * 1000) + (nanoseconds / 1E6);
      return duration;
    };
  }


  /**
   * Increments a stat by a specified amount
   * @param stat {String|Array} The stat(s) to send
   * @param value The value to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.increment = function (stat, value, sampleRate, tags, callback) {
    // allow use of tags without explicit value or sampleRate
    if (arguments.length < 3) {
      if (typeof value !== 'number') {
        tags = value;
        value = undefined;
      }
    }
    // we explicitly check for undefined and null (and don't do a "! value" check)
    // so that 0 values are allowed and sent through as-is
    if (value === undefined || value === null) {
      value = 1;
    }
    this.sendAll(stat, value, 'c', sampleRate, tags, callback);
  };

  /**
   * Decrements a stat by a specified amount
   * @param stat {String|Array} The stat(s) to send
   * @param value The value to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.decrement = function (stat, value, sampleRate, tags, callback) {
    // allow use of tags without explicit value or sampleRate
    if (arguments.length < 3) {
      if (typeof value !== 'number') {
        tags = value;
        value = undefined;
      }
    }
    // we explicitly check for undefined and null (and don't do a "! value" check)
    // so that 0 values are allowed and sent through as-is
    if (value === undefined || value === null) {
      value = 1;
    }

    this.sendAll(stat, -value, 'c', sampleRate, tags, callback);
  };

  /**
   * Represents the histogram stat
   * @param stat {String|Array} The stat(s) to send
   * @param value The value to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.histogram = function (stat, value, sampleRate, tags, callback) {
    this.sendAll(stat, value, 'h', sampleRate, tags, callback);
  };

  /**
   * Represents the distribution stat
   * @param stat {String|Array} The stat(s) to send
   * @param value The value to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.distribution = function (stat, value, sampleRate, tags, callback) {
    this.sendAll(stat, value, 'd', sampleRate, tags, callback);
  };


  /**
   * Gauges a stat by a specified amount
   * @param stat {String|Array} The stat(s) to send
   * @param value The value to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.gauge = function (stat, value, sampleRate, tags, callback) {
    this.sendAll(stat, value, 'g', sampleRate, tags, callback);
  };

  /**
   * Counts unique values by a specified amount
   * @param stat {String|Array} The stat(s) to send
   * @param value The value to send
   * @param sampleRate {Number=} The Number of times to sample (0 to 1). Optional.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.unique = Client.prototype.set = function (stat, value, sampleRate, tags, callback) {
    this.sendAll(stat, value, 's', sampleRate, tags, callback);
  };

  /**
   * Send a service check
   * @param name {String} The name of the service check
   * @param status {Number=} The status of the service check (0 to 3).
   * @param options
   *   @option date_happened {Date} Assign a timestamp to the event. Default is now.
   *   @option hostname {String} Assign a hostname to the check.
   *   @option message {String} Assign a message to the check.
   * @param tags {Array=} The Array of tags to add to the check. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.check = function (name, status, options, tags, callback) {
    if (this.telegraf) {
      const err = new Error('Not supported by Telegraf / InfluxDB');
      if (callback) {
        return callback(err);
      }
      else if (this.errorHandler) {
        return this.errorHandler(err);
      }

      throw err;
    }

    const check = ['_sc', this.prefix + name + this.suffix, status], metadata = options || {};

    if (metadata.date_happened) {
      const timestamp = helpers.formatDate(metadata.date_happened);
      if (timestamp) {
        check.push(`d:${timestamp}`);
      }
    }
    if (metadata.hostname) {
      check.push(`h:${metadata.hostname}`);
    }

    let mergedTags = this.globalTags;
    if (tags && typeof(tags) === 'object') {
      mergedTags = helpers.overrideTags(mergedTags, tags, this.telegraf);
    }
    if (mergedTags.length > 0) {
      check.push(`#${mergedTags.join(',')}`);
    }

    // message has to be the last part of a service check
    if (metadata.message) {
      check.push(`m:${metadata.message}`);
    }

    // allow for tags to be omitted and callback to be used in its place
    if (typeof tags === 'function' && callback === undefined) {
      callback = tags;
    }

    const message = check.join('|');
    // Service checks are unique in that message has to be the last element in
    // the stat if provided, so we can't append tags like other checks. This
    // directly calls the `_send` method to avoid appending tags, since we've
    // already added them.
    this._send(message, callback);
  };

  /**
   * Send on an event
   * @param title {String} The title of the event
   * @param text {String} The description of the event.  Optional- title is used if not given.
   * @param options
   *   @option date_happened {Date} Assign a timestamp to the event. Default is now.
   *   @option hostname {String} Assign a hostname to the event.
   *   @option aggregation_key {String} Assign an aggregation key to the event, to group it with some others.
   *   @option priority {String} Can be ‘normal’ or ‘low’. Default is 'normal'.
   *   @option source_type_name {String} Assign a source type to the event.
   *   @option alert_type {String} Can be ‘error’, ‘warning’, ‘info’ or ‘success’. Default is 'info'.
   * @param tags {Array=} The Array of tags to add to metrics. Optional.
   * @param callback {Function=} Callback when message is done being delivered. Optional.
   */
  Client.prototype.event = function (title, text, options, tags, callback) {
    if (this.telegraf) {
      const err = new Error('Not supported by Telegraf / InfluxDB');
      if (callback) {
        return callback(err);
      }
      else if (this.errorHandler) {
        return this.errorHandler(err);
      }

      throw err;
    }

    // Convert to strings
    let message;

    const msgTitle = String(title ? title : '');
    let msgText = String(text ? text : msgTitle);
    // Escape new lines (unescaping is supported by DataDog)
    msgText = msgText.replace(/\n/g, '\\n');

    // start out the message with the event-specific title and text info
    message = `_e{${msgTitle.length},${msgText.length}}:${msgTitle}|${msgText}`;

    // add in the event-specific options
    if (options) {
      if (options.date_happened) {
        const timestamp = helpers.formatDate(options.date_happened);
        if (timestamp) {
          message += `|d:${timestamp}`;
        }
      }
      if (options.hostname) {
        message += `|h:${options.hostname}`;
      }
      if (options.aggregation_key) {
        message += `|k:${options.aggregation_key}`;
      }
      if (options.priority) {
        message += `|p:${options.priority}`;
      }
      if (options.source_type_name) {
        message += `|s:${options.source_type_name}`;
      }
      if (options.alert_type) {
        message += `|t:${options.alert_type}`;
      }
    }

    // allow for tags to be omitted and callback to be used in its place
    if (typeof tags === 'function' && callback === undefined) {
      callback = tags;
    }

    this.send(message, tags, callback);
  };
}

module.exports = applyStatsFns;