decaffeinate

libraries/metrics/Gruntfile.coffee

@@ -1,29 +0,0 @@
-module.exports = (grunt) ->
-	grunt.initConfig
-		coffee:
-			unit_tests:
-				expand: true
-				cwd:  "test/unit/coffee"
-				src: ["**/*.coffee"]
-				dest: "test/unit/js/"
-				ext:  ".js"
-
-		clean:
-			unit_tests: ["test/unit/js"]
-
-		mochaTest:
-			unit:
-				options:
-					reporter: grunt.option('reporter') or 'spec'
-					grep: grunt.option("grep")
-
-				src: ["test/unit/js/**/*.js"]
-
-	grunt.loadNpmTasks 'grunt-contrib-coffee'
-	grunt.loadNpmTasks 'grunt-contrib-clean'
-	grunt.loadNpmTasks 'grunt-mocha-test'
-	grunt.loadNpmTasks 'grunt-execute'
-	grunt.loadNpmTasks 'grunt-bunyan'
-
-	grunt.registerTask 'compile:unit_tests', ['clean:unit_tests', 'coffee:unit_tests']
-	grunt.registerTask 'test:unit',          ['compile:unit_tests', 'mochaTest:unit']

libraries/metrics/Gruntfile.js

@@ -0,0 +1,41 @@
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+module.exports = function(grunt) {
+	grunt.initConfig({
+		coffee: {
+			unit_tests: {
+				expand: true,
+				cwd:  "test/unit/coffee",
+				src: ["**/*.coffee"],
+				dest: "test/unit/js/",
+				ext:  ".js"
+			}
+		},
+
+		clean: {
+			unit_tests: ["test/unit/js"]
+		},
+
+		mochaTest: {
+			unit: {
+				options: {
+					reporter: grunt.option('reporter') || 'spec',
+					grep: grunt.option("grep")
+				},
+
+				src: ["test/unit/js/**/*.js"]
+			}
+		}});
+
+	grunt.loadNpmTasks('grunt-contrib-coffee');
+	grunt.loadNpmTasks('grunt-contrib-clean');
+	grunt.loadNpmTasks('grunt-mocha-test');
+	grunt.loadNpmTasks('grunt-execute');
+	grunt.loadNpmTasks('grunt-bunyan');
+
+	grunt.registerTask('compile:unit_tests', ['clean:unit_tests', 'coffee:unit_tests']);
+	return grunt.registerTask('test:unit',          ['compile:unit_tests', 'mochaTest:unit']);
+};

libraries/metrics/event_loop.coffee

@@ -1,18 +0,0 @@
-module.exports = EventLoopMonitor =
-	monitor: (logger, interval = 1000, log_threshold = 100) ->
-		Metrics = require "./metrics"
-		# check for logger on startup to avoid exceptions later if undefined
-		throw new Error("logger is undefined") if !logger?
-		# monitor delay in setInterval to detect event loop blocking
-		previous = Date.now()
-		intervalId = setInterval () ->
-			now = Date.now()
-			offset = now - previous - interval
-			if offset > log_threshold
-				logger.warn {offset: offset}, "slow event loop"
-			previous = now
-			Metrics.timing("event-loop-millsec", offset)
-		, interval
-		
-		Metrics.registerDestructor () ->
-			clearInterval(intervalId)

libraries/metrics/event_loop.js

@@ -0,0 +1,30 @@
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+let EventLoopMonitor;
+module.exports = (EventLoopMonitor = {
+	monitor(logger, interval, log_threshold) {
+		if (interval == null) { interval = 1000; }
+		if (log_threshold == null) { log_threshold = 100; }
+		const Metrics = require("./metrics");
+		// check for logger on startup to avoid exceptions later if undefined
+		if ((logger == null)) { throw new Error("logger is undefined"); }
+		// monitor delay in setInterval to detect event loop blocking
+		let previous = Date.now();
+		const intervalId = setInterval(function() {
+			const now = Date.now();
+			const offset = now - previous - interval;
+			if (offset > log_threshold) {
+				logger.warn({offset}, "slow event loop");
+			}
+			previous = now;
+			return Metrics.timing("event-loop-millsec", offset);
+		}
+		, interval);
+		
+		return Metrics.registerDestructor(() => clearInterval(intervalId));
+	}
+});

libraries/metrics/http.coffee

@@ -1,53 +0,0 @@
-os = require("os")
-yn = require("yn")
-
-STACKDRIVER_LOGGING = yn(process.env['STACKDRIVER_LOGGING'])
-
-module.exports.monitor = (logger) ->
-	return (req, res, next) ->
-		Metrics = require("./metrics")
-		startTime = process.hrtime()
-		end = res.end
-		res.end = () ->
-			end.apply(this, arguments)
-			responseTime = process.hrtime(startTime)
-			responseTimeMs = Math.round(responseTime[0] * 1000 + responseTime[1] / 1000000)
-			requestSize = parseInt(req.headers["content-length"], 10)
-			if req.route?.path?
-				routePath = req.route.path.toString().replace(/\//g, '_').replace(/\:/g, '').slice(1)
-				Metrics.timing("http_request", responseTimeMs, null, {method:req.method, status_code: res.statusCode, path:routePath})
-				if requestSize
-					Metrics.summary("http_request_size_bytes", requestSize, {method:req.method, status_code: res.statusCode, path:routePath})
-			remoteIp = req.ip || req.socket?.socket?.remoteAddress || req.socket?.remoteAddress
-			reqUrl = req.originalUrl || req.url
-			referrer = req.headers['referer'] || req.headers['referrer']
-			if STACKDRIVER_LOGGING
-				info =
-					httpRequest:
-						requestMethod: req.method
-						requestUrl: reqUrl
-						requestSize: requestSize
-						status: res.statusCode
-						responseSize: res._headers?["content-length"]
-						userAgent: req.headers["user-agent"]
-						remoteIp: remoteIp
-						referer: referrer
-						latency:
-							seconds: responseTime[0]
-							nanos: responseTime[1]
-						protocol: req.protocol
-			else
-				info =
-					req:
-						url: reqUrl
-						method: req.method
-						referrer: referrer
-						"remote-addr": remoteIp
-						"user-agent": req.headers["user-agent"]
-						"content-length": req.headers["content-length"]
-					res:
-						"content-length": res._headers?["content-length"]
-						statusCode: res.statusCode
-					"response-time": responseTimeMs
-			logger.info(info, "%s %s", req.method, reqUrl)
-		next()

libraries/metrics/http.js

@@ -0,0 +1,77 @@
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS103: Rewrite code to no longer use __guard__
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+const os = require("os");
+const yn = require("yn");
+
+const STACKDRIVER_LOGGING = yn(process.env['STACKDRIVER_LOGGING']);
+
+module.exports.monitor = logger => (function(req, res, next) {
+    const Metrics = require("./metrics");
+    const startTime = process.hrtime();
+    const {
+        end
+    } = res;
+    res.end = function() {
+        let info;
+        end.apply(this, arguments);
+        const responseTime = process.hrtime(startTime);
+        const responseTimeMs = Math.round((responseTime[0] * 1000) + (responseTime[1] / 1000000));
+        const requestSize = parseInt(req.headers["content-length"], 10);
+        if ((req.route != null ? req.route.path : undefined) != null) {
+            const routePath = req.route.path.toString().replace(/\//g, '_').replace(/\:/g, '').slice(1);
+            Metrics.timing("http_request", responseTimeMs, null, {method:req.method, status_code: res.statusCode, path:routePath});
+            if (requestSize) {
+                Metrics.summary("http_request_size_bytes", requestSize, {method:req.method, status_code: res.statusCode, path:routePath});
+            }
+        }
+        const remoteIp = req.ip || __guard__(req.socket != null ? req.socket.socket : undefined, x => x.remoteAddress) || (req.socket != null ? req.socket.remoteAddress : undefined);
+        const reqUrl = req.originalUrl || req.url;
+        const referrer = req.headers['referer'] || req.headers['referrer'];
+        if (STACKDRIVER_LOGGING) {
+            info = {
+                httpRequest: {
+                    requestMethod: req.method,
+                    requestUrl: reqUrl,
+                    requestSize,
+                    status: res.statusCode,
+                    responseSize: (res._headers != null ? res._headers["content-length"] : undefined),
+                    userAgent: req.headers["user-agent"],
+                    remoteIp,
+                    referer: referrer,
+                    latency: {
+                        seconds: responseTime[0],
+                        nanos: responseTime[1]
+                    },
+                    protocol: req.protocol
+                }
+            };
+        } else {
+            info = {
+                req: {
+                    url: reqUrl,
+                    method: req.method,
+                    referrer,
+                    "remote-addr": remoteIp,
+                    "user-agent": req.headers["user-agent"],
+                    "content-length": req.headers["content-length"]
+                },
+                res: {
+                    "content-length": (res._headers != null ? res._headers["content-length"] : undefined),
+                    statusCode: res.statusCode
+                },
+                "response-time": responseTimeMs
+            };
+        }
+        return logger.info(info, "%s %s", req.method, reqUrl);
+    };
+    return next();
+});
+
+function __guard__(value, transform) {
+  return (typeof value !== 'undefined' && value !== null) ? transform(value) : undefined;
+}

libraries/metrics/index.js

@@ -1,2 +0,0 @@
-require("coffee-script")
-module.exports = require('./metrics');

libraries/metrics/memory.coffee

@@ -1,85 +0,0 @@
-# record memory usage each minute and run a periodic gc(), keeping cpu
-# usage within allowable range of 1ms per minute. Also, dynamically
-# adjust the period between gc()'s to reach a target of the gc saving
-# 4 megabytes each time.
-
-oneMinute = 60 * 1000
-oneMegaByte = 1024 * 1024
-
-CpuTimeBucket = 100 # current cpu time allowance in milliseconds
-CpuTimeBucketMax = 100 # maximum amount of cpu time allowed in bucket
-CpuTimeBucketRate = 10 # add this many milliseconds per minute
-
-gcInterval = 1 # how many minutes between gc (parameter is dynamically adjusted)
-countSinceLastGc = 0 # how many minutes since last gc
-MemoryChunkSize = 4 # how many megabytes we need to free to consider gc worth doing
-
-readyToGc = () ->
-	# update allowed cpu time
-	CpuTimeBucket = CpuTimeBucket + CpuTimeBucketRate
-	CpuTimeBucket = if CpuTimeBucket < CpuTimeBucketMax then CpuTimeBucket else CpuTimeBucketMax
-	# update counts since last gc
-	countSinceLastGc = countSinceLastGc + 1
-	# check there is enough time since last gc and we have enough cpu
-	return (countSinceLastGc > gcInterval) && (CpuTimeBucket > 0)
-
-executeAndTime = (fn) ->
-	# time the execution of fn() and subtract from cpu allowance
-	t0 = process.hrtime()
-	fn()
-	dt = process.hrtime(t0)
-	timeTaken = (dt[0] + dt[1]*1e-9) * 1e3 # in milliseconds
-	CpuTimeBucket -= Math.ceil timeTaken
-	return timeTaken
-
-inMegaBytes = (obj) ->
-	# convert process.memoryUsage hash {rss,heapTotal,heapFreed} into megabytes
-	result = {}
-	for k, v of obj
-		result[k] = (v / oneMegaByte).toFixed(2)
-	return result
-
-updateMemoryStats = (oldMem, newMem) ->
-	countSinceLastGc = 0
-	delta = {}
-	for k of newMem
-		delta[k] = (newMem[k] - oldMem[k]).toFixed(2)
-	# take the max of all memory measures
-	savedMemory = Math.max -delta.rss, -delta.heapTotal, -delta.heapUsed
-	delta.megabytesFreed = savedMemory
-	# did it do any good?
-	if savedMemory < MemoryChunkSize
-		gcInterval = gcInterval + 1 # no, so wait longer next time
-	else
-		gcInterval = Math.max gcInterval - 1, 1 # yes, wait less time
-	return delta
-
-module.exports = MemoryMonitor =
-	monitor: (logger) ->
-		interval = setInterval () ->
-			MemoryMonitor.Check(logger)
-		, oneMinute
-		Metrics = require "./metrics"
-		Metrics.registerDestructor () ->
-			clearInterval(interval)
-
-	Check: (logger) ->
-		Metrics = require "./metrics"
-		memBeforeGc = mem = inMegaBytes process.memoryUsage()
-		Metrics.gauge("memory.rss", mem.rss)
-		Metrics.gauge("memory.heaptotal", mem.heapTotal)
-		Metrics.gauge("memory.heapused", mem.heapUsed)
-		Metrics.gauge("memory.gc-interval", gcInterval)
-		#Metrics.gauge("memory.cpu-time-bucket", CpuTimeBucket)
-
-		logger.log mem, "process.memoryUsage()"
-
-		if global.gc? && readyToGc()
-			gcTime = (executeAndTime global.gc).toFixed(2)
-			memAfterGc = inMegaBytes process.memoryUsage()
-			deltaMem = updateMemoryStats(memBeforeGc, memAfterGc)
-			logger.log {gcTime, memBeforeGc, memAfterGc, deltaMem, gcInterval, CpuTimeBucket}, "global.gc() forced"
-			#Metrics.timing("memory.gc-time", gcTime)
-			Metrics.gauge("memory.gc-rss-freed", -deltaMem.rss)
-			Metrics.gauge("memory.gc-heaptotal-freed", -deltaMem.heapTotal)
-			Metrics.gauge("memory.gc-heapused-freed",  -deltaMem.heapUsed)

libraries/metrics/memory.js

@@ -0,0 +1,103 @@
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+// record memory usage each minute and run a periodic gc(), keeping cpu
+// usage within allowable range of 1ms per minute. Also, dynamically
+// adjust the period between gc()'s to reach a target of the gc saving
+// 4 megabytes each time.
+
+let MemoryMonitor;
+const oneMinute = 60 * 1000;
+const oneMegaByte = 1024 * 1024;
+
+let CpuTimeBucket = 100; // current cpu time allowance in milliseconds
+const CpuTimeBucketMax = 100; // maximum amount of cpu time allowed in bucket
+const CpuTimeBucketRate = 10; // add this many milliseconds per minute
+
+let gcInterval = 1; // how many minutes between gc (parameter is dynamically adjusted)
+let countSinceLastGc = 0; // how many minutes since last gc
+const MemoryChunkSize = 4; // how many megabytes we need to free to consider gc worth doing
+
+const readyToGc = function() {
+	// update allowed cpu time
+	CpuTimeBucket = CpuTimeBucket + CpuTimeBucketRate;
+	CpuTimeBucket = CpuTimeBucket < CpuTimeBucketMax ? CpuTimeBucket : CpuTimeBucketMax;
+	// update counts since last gc
+	countSinceLastGc = countSinceLastGc + 1;
+	// check there is enough time since last gc and we have enough cpu
+	return (countSinceLastGc > gcInterval) && (CpuTimeBucket > 0);
+};
+
+const executeAndTime = function(fn) {
+	// time the execution of fn() and subtract from cpu allowance
+	const t0 = process.hrtime();
+	fn();
+	const dt = process.hrtime(t0);
+	const timeTaken = (dt[0] + (dt[1]*1e-9)) * 1e3; // in milliseconds
+	CpuTimeBucket -= Math.ceil(timeTaken);
+	return timeTaken;
+};
+
+const inMegaBytes = function(obj) {
+	// convert process.memoryUsage hash {rss,heapTotal,heapFreed} into megabytes
+	const result = {};
+	for (let k in obj) {
+		const v = obj[k];
+		result[k] = (v / oneMegaByte).toFixed(2);
+	}
+	return result;
+};
+
+const updateMemoryStats = function(oldMem, newMem) {
+	countSinceLastGc = 0;
+	const delta = {};
+	for (let k in newMem) {
+		delta[k] = (newMem[k] - oldMem[k]).toFixed(2);
+	}
+	// take the max of all memory measures
+	const savedMemory = Math.max(-delta.rss, -delta.heapTotal, -delta.heapUsed);
+	delta.megabytesFreed = savedMemory;
+	// did it do any good?
+	if (savedMemory < MemoryChunkSize) {
+		gcInterval = gcInterval + 1; // no, so wait longer next time
+	} else {
+		gcInterval = Math.max(gcInterval - 1, 1); // yes, wait less time
+	}
+	return delta;
+};
+
+module.exports = (MemoryMonitor = {
+	monitor(logger) {
+		const interval = setInterval(() => MemoryMonitor.Check(logger)
+		, oneMinute);
+		const Metrics = require("./metrics");
+		return Metrics.registerDestructor(() => clearInterval(interval));
+	},
+
+	Check(logger) {
+		let mem;
+		const Metrics = require("./metrics");
+		const memBeforeGc = (mem = inMegaBytes(process.memoryUsage()));
+		Metrics.gauge("memory.rss", mem.rss);
+		Metrics.gauge("memory.heaptotal", mem.heapTotal);
+		Metrics.gauge("memory.heapused", mem.heapUsed);
+		Metrics.gauge("memory.gc-interval", gcInterval);
+		//Metrics.gauge("memory.cpu-time-bucket", CpuTimeBucket)
+
+		logger.log(mem, "process.memoryUsage()");
+
+		if ((global.gc != null) && readyToGc()) {
+			const gcTime = (executeAndTime(global.gc)).toFixed(2);
+			const memAfterGc = inMegaBytes(process.memoryUsage());
+			const deltaMem = updateMemoryStats(memBeforeGc, memAfterGc);
+			logger.log({gcTime, memBeforeGc, memAfterGc, deltaMem, gcInterval, CpuTimeBucket}, "global.gc() forced");
+			//Metrics.timing("memory.gc-time", gcTime)
+			Metrics.gauge("memory.gc-rss-freed", -deltaMem.rss);
+			Metrics.gauge("memory.gc-heaptotal-freed", -deltaMem.heapTotal);
+			return Metrics.gauge("memory.gc-heapused-freed",  -deltaMem.heapUsed);
+		}
+	}
+});

libraries/metrics/metrics.coffee

@@ -1,140 +0,0 @@
-console.log("using prometheus")
-
-prom = require('./prom_wrapper')
-
-collectDefaultMetrics = prom.collectDefaultMetrics
-
-appname = "unknown"
-hostname = require('os').hostname()
-
-destructors = []
-
-require "./uv_threadpool_size"
-
-module.exports = Metrics =
-	register: prom.registry
-
-	initialize: (_name, opts = {}) ->
-		appname = _name
-		collectDefaultMetrics({ timeout: 5000, prefix: Metrics.buildPromKey()})
-		if opts.ttlInMinutes
-			prom.ttlInMinutes = opts.ttlInMinutes
-
-		console.log("ENABLE_TRACE_AGENT set to #{process.env['ENABLE_TRACE_AGENT']}")
-		if process.env['ENABLE_TRACE_AGENT'] == "true"
-			console.log("starting google trace agent")
-			traceAgent = require('@google-cloud/trace-agent')
-
-			traceOpts =
-				ignoreUrls: [/^\/status/, /^\/health_check/]
-			traceAgent.start(traceOpts)
-
-		console.log("ENABLE_DEBUG_AGENT set to #{process.env['ENABLE_DEBUG_AGENT']}")
-		if process.env['ENABLE_DEBUG_AGENT'] == "true"
-			console.log("starting google debug agent")
-			debugAgent = require('@google-cloud/debug-agent')
-			debugAgent.start({
-				allowExpressions: true,
-				serviceContext: {
-					service: appname,
-					version: process.env['BUILD_VERSION']
-				}
-			})
-
-		console.log("ENABLE_PROFILE_AGENT set to #{process.env['ENABLE_PROFILE_AGENT']}")
-		if process.env['ENABLE_PROFILE_AGENT'] == "true"
-			console.log("starting google profile agent")
-			profiler = require('@google-cloud/profiler')
-			profiler.start({
-				serviceContext: {
-					service: appname,
-					version: process.env['BUILD_VERSION']
-				}
-			})
-
-		Metrics.inc("process_startup")
-
-	registerDestructor: (func) ->
-		destructors.push func
-
-	injectMetricsRoute: (app) ->
-		app.get('/metrics', (req, res) ->
-			res.set('Content-Type', prom.registry.contentType)
-			res.end(prom.registry.metrics())
-		)
-
-	buildPromKey: (key = "")->
-		key.replace /[^a-zA-Z0-9]/g, "_"
-
-	sanitizeValue: (value) ->
-		parseFloat(value)
-
-	set : (key, value, sampleRate = 1)->
-		console.log("counts are not currently supported")
-
-	inc : (key, sampleRate = 1, opts = {})->
-		key = Metrics.buildPromKey(key)
-		opts.app = appname
-		opts.host = hostname
-		prom.metric('counter', key).inc(opts)
-		if process.env['DEBUG_METRICS']
-			console.log("doing inc", key, opts)
-
-	count : (key, count, sampleRate = 1, opts = {})->
-		key = Metrics.buildPromKey(key)
-		opts.app = appname
-		opts.host = hostname
-		prom.metric('counter', key).inc(opts, count)
-		if process.env['DEBUG_METRICS']
-			console.log("doing count/inc", key, opts)
-
-	summary : (key, value, opts = {})->
-		key = Metrics.buildPromKey(key)
-		opts.app = appname
-		opts.host = hostname
-		prom.metric('summary', key).observe(opts, value)
-		if process.env['DEBUG_METRICS']
-			console.log("doing summary", key, value, opts)
-
-	timing: (key, timeSpan, sampleRate, opts = {})->
-		key = Metrics.buildPromKey("timer_" + key)
-		opts.app = appname
-		opts.host = hostname
-		prom.metric('summary', key).observe(opts, timeSpan)
-		if process.env['DEBUG_METRICS']
-			console.log("doing timing", key, opts)
-
-	Timer : class
-		constructor :(key, sampleRate = 1, opts)->
-			this.start = new Date()
-			key = Metrics.buildPromKey(key)
-			this.key = key
-			this.sampleRate = sampleRate
-			this.opts = opts
-
-		done:->
-			timeSpan = new Date - this.start
-			Metrics.timing(this.key, timeSpan, this.sampleRate, this.opts)
-			return timeSpan
-
-	gauge : (key, value, sampleRate = 1, opts)->
-		key = Metrics.buildPromKey(key)
-		prom.metric('gauge', key).set({app: appname, host: hostname, status: opts?.status}, this.sanitizeValue(value))
-		if process.env['DEBUG_METRICS']
-			console.log("doing gauge", key, opts)
-
-	globalGauge: (key, value, sampleRate = 1, opts)->
-		key = Metrics.buildPromKey(key)
-		prom.metric('gauge', key).set({app: appname, status: opts?.status},this.sanitizeValue(value))
-
-	mongodb: require "./mongodb"
-	http: require "./http"
-	open_sockets: require "./open_sockets"
-	event_loop: require "./event_loop"
-	memory: require "./memory"
-
-	timeAsyncMethod: require('./timeAsyncMethod')
-
-	close: () ->
-		for func in destructors
-			func()

libraries/metrics/metrics.js

@@ -0,0 +1,188 @@
+/*
+ * decaffeinate suggestions:
+ * DS101: Remove unnecessary use of Array.from
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+let Metrics;
+console.log("using prometheus");
+
+const prom = require('./prom_wrapper');
+
+const {
+    collectDefaultMetrics
+} = prom;
+
+let appname = "unknown";
+const hostname = require('os').hostname();
+
+const destructors = [];
+
+require("./uv_threadpool_size");
+
+module.exports = (Metrics = {
+	register: prom.registry,
+
+	initialize(_name, opts) {
+		if (opts == null) { opts = {}; }
+		appname = _name;
+		collectDefaultMetrics({ timeout: 5000, prefix: Metrics.buildPromKey()});
+		if (opts.ttlInMinutes) {
+			prom.ttlInMinutes = opts.ttlInMinutes;
+		}
+
+		console.log(`ENABLE_TRACE_AGENT set to ${process.env['ENABLE_TRACE_AGENT']}`);
+		if (process.env['ENABLE_TRACE_AGENT'] === "true") {
+			console.log("starting google trace agent");
+			const traceAgent = require('@google-cloud/trace-agent');
+
+			const traceOpts =
+				{ignoreUrls: [/^\/status/, /^\/health_check/]};
+			traceAgent.start(traceOpts);
+		}
+
+		console.log(`ENABLE_DEBUG_AGENT set to ${process.env['ENABLE_DEBUG_AGENT']}`);
+		if (process.env['ENABLE_DEBUG_AGENT'] === "true") {
+			console.log("starting google debug agent");
+			const debugAgent = require('@google-cloud/debug-agent');
+			debugAgent.start({
+				allowExpressions: true,
+				serviceContext: {
+					service: appname,
+					version: process.env['BUILD_VERSION']
+				}
+			});
+		}
+
+		console.log(`ENABLE_PROFILE_AGENT set to ${process.env['ENABLE_PROFILE_AGENT']}`);
+		if (process.env['ENABLE_PROFILE_AGENT'] === "true") {
+			console.log("starting google profile agent");
+			const profiler = require('@google-cloud/profiler');
+			profiler.start({
+				serviceContext: {
+					service: appname,
+					version: process.env['BUILD_VERSION']
+				}
+			});
+		}
+
+		return Metrics.inc("process_startup");
+	},
+
+	registerDestructor(func) {
+		return destructors.push(func);
+	},
+
+	injectMetricsRoute(app) {
+		return app.get('/metrics', function(req, res) {
+			res.set('Content-Type', prom.registry.contentType);
+			return res.end(prom.registry.metrics());
+		});
+	},
+
+	buildPromKey(key){
+		if (key == null) { key = ""; }
+		return key.replace(/[^a-zA-Z0-9]/g, "_");
+	},
+
+	sanitizeValue(value) {
+		return parseFloat(value);
+	},
+
+	set(key, value, sampleRate){
+		if (sampleRate == null) { sampleRate = 1; }
+		return console.log("counts are not currently supported");
+	},
+
+	inc(key, sampleRate, opts){
+		if (sampleRate == null) { sampleRate = 1; }
+		if (opts == null) { opts = {}; }
+		key = Metrics.buildPromKey(key);
+		opts.app = appname;
+		opts.host = hostname;
+		prom.metric('counter', key).inc(opts);
+		if (process.env['DEBUG_METRICS']) {
+			return console.log("doing inc", key, opts);
+		}
+	},
+
+	count(key, count, sampleRate, opts){
+		if (sampleRate == null) { sampleRate = 1; }
+		if (opts == null) { opts = {}; }
+		key = Metrics.buildPromKey(key);
+		opts.app = appname;
+		opts.host = hostname;
+		prom.metric('counter', key).inc(opts, count);
+		if (process.env['DEBUG_METRICS']) {
+			return console.log("doing count/inc", key, opts);
+		}
+	},
+
+	summary(key, value, opts){
+		if (opts == null) { opts = {}; }
+		key = Metrics.buildPromKey(key);
+		opts.app = appname;
+		opts.host = hostname;
+		prom.metric('summary', key).observe(opts, value);
+		if (process.env['DEBUG_METRICS']) {
+			return console.log("doing summary", key, value, opts);
+		}
+	},
+
+	timing(key, timeSpan, sampleRate, opts){
+		if (opts == null) { opts = {}; }
+		key = Metrics.buildPromKey("timer_" + key);
+		opts.app = appname;
+		opts.host = hostname;
+		prom.metric('summary', key).observe(opts, timeSpan);
+		if (process.env['DEBUG_METRICS']) {
+			return console.log("doing timing", key, opts);
+		}
+	},
+
+	Timer : class {
+		constructor(key, sampleRate, opts){
+			if (sampleRate == null) { sampleRate = 1; }
+			this.start = new Date();
+			key = Metrics.buildPromKey(key);
+			this.key = key;
+			this.sampleRate = sampleRate;
+			this.opts = opts;
+		}
+
+		done() {
+			const timeSpan = new Date - this.start;
+			Metrics.timing(this.key, timeSpan, this.sampleRate, this.opts);
+			return timeSpan;
+		}
+	},
+
+	gauge(key, value, sampleRate, opts){
+		if (sampleRate == null) { sampleRate = 1; }
+		key = Metrics.buildPromKey(key);
+		prom.metric('gauge', key).set({app: appname, host: hostname, status: (opts != null ? opts.status : undefined)}, this.sanitizeValue(value));
+		if (process.env['DEBUG_METRICS']) {
+			return console.log("doing gauge", key, opts);
+		}
+	},
+
+	globalGauge(key, value, sampleRate, opts){
+		if (sampleRate == null) { sampleRate = 1; }
+		key = Metrics.buildPromKey(key);
+		return prom.metric('gauge', key).set({app: appname, status: (opts != null ? opts.status : undefined)},this.sanitizeValue(value));
+	},
+
+	mongodb: require("./mongodb"),
+	http: require("./http"),
+	open_sockets: require("./open_sockets"),
+	event_loop: require("./event_loop"),
+	memory: require("./memory"),
+
+	timeAsyncMethod: require('./timeAsyncMethod'),
+
+	close() {
+		return Array.from(destructors).map((func) =>
+			func());
+	}
+});

libraries/metrics/mongodb.coffee

@@ -1,100 +0,0 @@
-module.exports =
-	monitor: (mongodb_require_path, logger) ->
-
-		try
-			# for the v1 driver the methods to wrap are in the mongodb
-			# module in lib/mongodb/db.js
-			mongodb = require("#{mongodb_require_path}")
-
-		try
-			# for the v2 driver the relevant methods are in the mongodb-core
-			# module in lib/topologies/{server,replset,mongos}.js
-			v2_path = mongodb_require_path.replace(/\/mongodb$/, '/mongodb-core')
-			mongodbCore = require(v2_path)
-
-		Metrics = require("./metrics")
-
-		monitorMethod = (base, method, type) ->
-			return unless base?
-			return unless (_method = base[method])?
-			arglen = _method.length
-
-			mongo_driver_v1_wrapper = (db_command, options, callback) ->
-				if (typeof callback == 'undefined')
-					callback = options
-					options = {}
-
-				collection = db_command.collectionName
-				if collection.match(/\$cmd$/)
-					# Ignore noisy command methods like authenticating, ismaster and ping
-					return _method.call this, db_command, options, callback
-
-				key = "mongo-requests.#{collection}.#{type}"
-				if db_command.query?
-					query = Object.keys(db_command.query).sort().join("_")
-					key += "." + query
-
-				timer = new Metrics.Timer("mongo", {collection: collection, query:query})
-				start = new Date()
-				_method.call this, db_command, options, () ->
-					timer.done()
-					time = new Date() - start
-					logger.log
-						query: db_command.query
-						query_type: type
-						collection: collection
-						"response-time": new Date() - start
-						"mongo request"
-					callback.apply this, arguments
-
-			mongo_driver_v2_wrapper = (ns, ops, options, callback) ->
-				if (typeof callback == 'undefined')
-					callback = options
-					options = {}
-
-				if ns.match(/\$cmd$/)
-					# Ignore noisy command methods like authenticating, ismaster and ping
-					return _method.call this, ns, ops, options, callback
-
-				key = "mongo-requests.#{ns}.#{type}"
-				if ops[0].q?  # ops[0].q
-					query = Object.keys(ops[0].q).sort().join("_")
-					key += "." + query
-
-				timer = new Metrics.Timer(key)
-				start = new Date()
-				_method.call this, ns, ops, options, () ->
-					timer.done()
-					time = new Date() - start
-					logger.log
-						query: ops[0].q
-						query_type: type
-						collection: ns
-						"response-time": new Date() - start
-						"mongo request"
-					callback.apply this, arguments
-
-			if arglen == 3
-				base[method] = mongo_driver_v1_wrapper
-			else if arglen == 4
-				base[method] = mongo_driver_v2_wrapper
-
-		monitorMethod(mongodb?.Db.prototype, "_executeQueryCommand",  "query")
-		monitorMethod(mongodb?.Db.prototype, "_executeRemoveCommand", "remove")
-		monitorMethod(mongodb?.Db.prototype, "_executeInsertCommand", "insert")
-		monitorMethod(mongodb?.Db.prototype, "_executeUpdateCommand", "update")
-
-		monitorMethod(mongodbCore?.Server.prototype, "command", "command")
-		monitorMethod(mongodbCore?.Server.prototype, "remove", "remove")
-		monitorMethod(mongodbCore?.Server.prototype, "insert", "insert")
-		monitorMethod(mongodbCore?.Server.prototype, "update", "update")
-
-		monitorMethod(mongodbCore?.ReplSet.prototype, "command", "command")
-		monitorMethod(mongodbCore?.ReplSet.prototype, "remove", "remove")
-		monitorMethod(mongodbCore?.ReplSet.prototype, "insert", "insert")
-		monitorMethod(mongodbCore?.ReplSet.prototype, "update", "update")
-
-		monitorMethod(mongodbCore?.Mongos.prototype, "command", "command")
-		monitorMethod(mongodbCore?.Mongos.prototype, "remove", "remove")
-		monitorMethod(mongodbCore?.Mongos.prototype, "insert", "insert")
-		monitorMethod(mongodbCore?.Mongos.prototype, "update", "update")

libraries/metrics/mongodb.js

@@ -0,0 +1,128 @@
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+module.exports = {
+	monitor(mongodb_require_path, logger) {
+
+		let mongodb, mongodbCore;
+		try {
+			// for the v1 driver the methods to wrap are in the mongodb
+			// module in lib/mongodb/db.js
+			mongodb = require(`${mongodb_require_path}`);
+		} catch (error) {}
+
+		try {
+			// for the v2 driver the relevant methods are in the mongodb-core
+			// module in lib/topologies/{server,replset,mongos}.js
+			const v2_path = mongodb_require_path.replace(/\/mongodb$/, '/mongodb-core');
+			mongodbCore = require(v2_path);
+		} catch (error1) {}
+
+		const Metrics = require("./metrics");
+
+		const monitorMethod = function(base, method, type) {
+			let _method;
+			if (base == null) { return; }
+			if ((_method = base[method]) == null) { return; }
+			const arglen = _method.length;
+
+			const mongo_driver_v1_wrapper = function(db_command, options, callback) {
+				let query;
+				if (typeof callback === 'undefined') {
+					callback = options;
+					options = {};
+				}
+
+				const collection = db_command.collectionName;
+				if (collection.match(/\$cmd$/)) {
+					// Ignore noisy command methods like authenticating, ismaster and ping
+					return _method.call(this, db_command, options, callback);
+				}
+
+				let key = `mongo-requests.${collection}.${type}`;
+				if (db_command.query != null) {
+					query = Object.keys(db_command.query).sort().join("_");
+					key += "." + query;
+				}
+
+				const timer = new Metrics.Timer("mongo", {collection, query});
+				const start = new Date();
+				return _method.call(this, db_command, options, function() {
+					timer.done();
+					const time = new Date() - start;
+					logger.log({
+						query: db_command.query,
+						query_type: type,
+						collection,
+						"response-time": new Date() - start
+					},
+						"mongo request");
+					return callback.apply(this, arguments);
+				});
+			};
+
+			const mongo_driver_v2_wrapper = function(ns, ops, options, callback) {
+				let query;
+				if (typeof callback === 'undefined') {
+					callback = options;
+					options = {};
+				}
+
+				if (ns.match(/\$cmd$/)) {
+					// Ignore noisy command methods like authenticating, ismaster and ping
+					return _method.call(this, ns, ops, options, callback);
+				}
+
+				let key = `mongo-requests.${ns}.${type}`;
+				if (ops[0].q != null) {  // ops[0].q
+					query = Object.keys(ops[0].q).sort().join("_");
+					key += "." + query;
+				}
+
+				const timer = new Metrics.Timer(key);
+				const start = new Date();
+				return _method.call(this, ns, ops, options, function() {
+					timer.done();
+					const time = new Date() - start;
+					logger.log({
+						query: ops[0].q,
+						query_type: type,
+						collection: ns,
+						"response-time": new Date() - start
+					},
+						"mongo request");
+					return callback.apply(this, arguments);
+				});
+			};
+
+			if (arglen === 3) {
+				return base[method] = mongo_driver_v1_wrapper;
+			} else if (arglen === 4) {
+				return base[method] = mongo_driver_v2_wrapper;
+			}
+		};
+
+		monitorMethod(mongodb != null ? mongodb.Db.prototype : undefined, "_executeQueryCommand",  "query");
+		monitorMethod(mongodb != null ? mongodb.Db.prototype : undefined, "_executeRemoveCommand", "remove");
+		monitorMethod(mongodb != null ? mongodb.Db.prototype : undefined, "_executeInsertCommand", "insert");
+		monitorMethod(mongodb != null ? mongodb.Db.prototype : undefined, "_executeUpdateCommand", "update");
+
+		monitorMethod(mongodbCore != null ? mongodbCore.Server.prototype : undefined, "command", "command");
+		monitorMethod(mongodbCore != null ? mongodbCore.Server.prototype : undefined, "remove", "remove");
+		monitorMethod(mongodbCore != null ? mongodbCore.Server.prototype : undefined, "insert", "insert");
+		monitorMethod(mongodbCore != null ? mongodbCore.Server.prototype : undefined, "update", "update");
+
+		monitorMethod(mongodbCore != null ? mongodbCore.ReplSet.prototype : undefined, "command", "command");
+		monitorMethod(mongodbCore != null ? mongodbCore.ReplSet.prototype : undefined, "remove", "remove");
+		monitorMethod(mongodbCore != null ? mongodbCore.ReplSet.prototype : undefined, "insert", "insert");
+		monitorMethod(mongodbCore != null ? mongodbCore.ReplSet.prototype : undefined, "update", "update");
+
+		monitorMethod(mongodbCore != null ? mongodbCore.Mongos.prototype : undefined, "command", "command");
+		monitorMethod(mongodbCore != null ? mongodbCore.Mongos.prototype : undefined, "remove", "remove");
+		monitorMethod(mongodbCore != null ? mongodbCore.Mongos.prototype : undefined, "insert", "insert");
+		return monitorMethod(mongodbCore != null ? mongodbCore.Mongos.prototype : undefined, "update", "update");
+	}
+};

libraries/metrics/open_sockets.coffee

@@ -1,28 +0,0 @@
-URL = require "url"
-seconds = 1000
-
-# In Node 0.10 the default is 5, which means only 5 open connections at one.
-# Node 0.12 has a default of Infinity. Make sure we have no limit set,
-# regardless of Node version.
-require("http").globalAgent.maxSockets = Infinity
-require("https").globalAgent.maxSockets = Infinity
-
-module.exports = OpenSocketsMonitor =
-	monitor: (logger) ->
-		interval = setInterval () ->
-			OpenSocketsMonitor.gaugeOpenSockets()
-		, 5 * seconds
-		Metrics = require "./metrics"
-		Metrics.registerDestructor () ->
-			clearInterval(interval)
-
-	gaugeOpenSockets: () ->
-		Metrics = require "./metrics"
-		for url, agents of require('http').globalAgent.sockets
-			url = URL.parse("http://#{url}")
-			hostname = url.hostname?.replace(/\./g, "_")
-			Metrics.gauge "open_connections.http.#{hostname}", agents.length
-		for url, agents of require('https').globalAgent.sockets
-			url = URL.parse("https://#{url}")
-			hostname = url.hostname?.replace(/\./g, "_")
-			Metrics.gauge "open_connections.https.#{hostname}", agents.length

libraries/metrics/open_sockets.js

@@ -0,0 +1,48 @@
+/*
+ * decaffeinate suggestions:
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS205: Consider reworking code to avoid use of IIFEs
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+let OpenSocketsMonitor;
+const URL = require("url");
+const seconds = 1000;
+
+// In Node 0.10 the default is 5, which means only 5 open connections at one.
+// Node 0.12 has a default of Infinity. Make sure we have no limit set,
+// regardless of Node version.
+require("http").globalAgent.maxSockets = Infinity;
+require("https").globalAgent.maxSockets = Infinity;
+
+module.exports = (OpenSocketsMonitor = {
+	monitor(logger) {
+		const interval = setInterval(() => OpenSocketsMonitor.gaugeOpenSockets()
+		, 5 * seconds);
+		const Metrics = require("./metrics");
+		return Metrics.registerDestructor(() => clearInterval(interval));
+	},
+
+	gaugeOpenSockets() {
+		let agents, hostname, url;
+		const Metrics = require("./metrics");
+		const object = require('http').globalAgent.sockets;
+		for (url in object) {
+			agents = object[url];
+			url = URL.parse(`http://${url}`);
+			hostname = url.hostname != null ? url.hostname.replace(/\./g, "_") : undefined;
+			Metrics.gauge(`open_connections.http.${hostname}`, agents.length);
+		}
+		return (() => {
+			const result = [];
+			const object1 = require('https').globalAgent.sockets;
+			for (url in object1) {
+				agents = object1[url];
+				url = URL.parse(`https://${url}`);
+				hostname = url.hostname != null ? url.hostname.replace(/\./g, "_") : undefined;
+				result.push(Metrics.gauge(`open_connections.https.${hostname}`, agents.length));
+			}
+			return result;
+		})();
+	}
+});

libraries/metrics/prom_wrapper.coffee

@@ -1,114 +0,0 @@
-prom = require('prom-client')
-registry = require('prom-client').register
-metrics = new Map()
-
-
-optsKey = (opts) ->
-	keys = Object.keys(opts)
-	return '' if keys.length == 0
-
-	keys = keys.sort()
-
-	hash = '';
-	for key in keys
-		hash += "," if hash.length
-		hash += "#{key}:#{opts[key]}"
-
-	return hash
-
-extendOpts = (opts, labelNames) ->
-	for label in labelNames
-		opts[label] ||= ''
-	return opts
-
-optsAsArgs = (opts, labelNames) ->
-	args = []
-	for label in labelNames
-		args.push(opts[label] || '')
-	return args
-
-
-PromWrapper =
-	ttlInMinutes: 0
-	registry: registry
-
-	metric: (type, name) ->
-		metrics.get(name) || new MetricWrapper(type, name)
-
-	collectDefaultMetrics: prom.collectDefaultMetrics
-
-
-class MetricWrapper
-	constructor: (type, name) ->
-		metrics.set(name, this)
-		@name = name
-		@instances = new Map()
-		@lastAccess = new Date()
-		@metric = switch type
-			when "counter"
-				new prom.Counter({
-					name: name,
-					help: name,
-					labelNames: ['app','host','status','method', 'path']
-				})
-			when "summary"
-				new prom.Summary({
-					name: name,
-					help: name,
-					maxAgeSeconds: 60,
-					ageBuckets: 10,
-					labelNames: ['app', 'host', 'path', 'status_code', 'method', 'collection', 'query']
-				})
-			when "gauge"
-				new prom.Gauge({
-					name: name,
-					help: name,
-					labelNames: ['app','host', 'status']
-				})
-
-	inc: (opts, value) ->
-		@_execMethod 'inc', opts, value
-
-	observe: (opts, value) ->
-		@_execMethod 'observe', opts, value
-
-	set: (opts, value) ->
-		@_execMethod 'set', opts, value
-
-	sweep: () ->
-		thresh = new Date(Date.now() - 1000 * 60 * PromWrapper.ttlInMinutes)
-		@instances.forEach (instance, key) =>
-			if thresh > instance.time
-				if process.env['DEBUG_METRICS']
-					console.log("Sweeping stale metric instance", @name, opts: instance.opts, key)
-				@metric.remove(optsAsArgs(instance.opts, @metric.labelNames)...)
-
-		if thresh > @lastAccess
-			if process.env['DEBUG_METRICS']
-				console.log("Sweeping stale metric", @name, thresh, @lastAccess)
-			metrics.delete(@name)
-			registry.removeSingleMetric(@name)
-
-	_execMethod: (method, opts, value) ->
-		opts = extendOpts(opts, @metric.labelNames)
-		key = optsKey(opts)
-		@instances.set(key, { time: new Date(), opts }) unless key == ''
-		@lastAccess = new Date()
-		@metric[method](opts, value)
-
-
-unless PromWrapper.sweepRegistered
-	if process.env['DEBUG_METRICS']
-		console.log("Registering sweep method")
-	PromWrapper.sweepRegistered = true
-	setInterval(
-		() ->
-			if PromWrapper.ttlInMinutes
-				if process.env['DEBUG_METRICS']
-					console.log("Sweeping metrics")
-				metrics.forEach (metric, key) =>
-					metric.sweep()
-	60000)
-
-
-module.exports = PromWrapper

libraries/metrics/prom_wrapper.js

@@ -0,0 +1,148 @@
+/*
+ * decaffeinate suggestions:
+ * DS101: Remove unnecessary use of Array.from
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS205: Consider reworking code to avoid use of IIFEs
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+const prom = require('prom-client');
+const registry = require('prom-client').register;
+const metrics = new Map();
+
+
+const optsKey = function(opts) {
+	let keys = Object.keys(opts);
+	if (keys.length === 0) { return ''; }
+
+	keys = keys.sort();
+
+	let hash = '';
+	for (let key of Array.from(keys)) {
+		if (hash.length) { hash += ","; }
+		hash += `${key}:${opts[key]}`;
+	}
+
+	return hash;
+};
+
+const extendOpts = function(opts, labelNames) {
+	for (let label of Array.from(labelNames)) {
+		if (!opts[label]) { opts[label] = ''; }
+	}
+	return opts;
+};
+
+const optsAsArgs = function(opts, labelNames) {
+	const args = [];
+	for (let label of Array.from(labelNames)) {
+		args.push(opts[label] || '');
+	}
+	return args;
+};
+
+
+const PromWrapper = {
+	ttlInMinutes: 0,
+	registry,
+
+	metric(type, name) {
+		return metrics.get(name) || new MetricWrapper(type, name);
+	},
+
+	collectDefaultMetrics: prom.collectDefaultMetrics
+};
+
+
+class MetricWrapper {
+	constructor(type, name) {
+		metrics.set(name, this);
+		this.name = name;
+		this.instances = new Map();
+		this.lastAccess = new Date();
+		this.metric = (() => { switch (type) {
+			case "counter":
+				return new prom.Counter({
+					name,
+					help: name,
+					labelNames: ['app','host','status','method', 'path']
+				});
+			case "summary":
+				return new prom.Summary({
+					name,
+					help: name,
+					maxAgeSeconds: 60,
+					ageBuckets: 10,
+					labelNames: ['app', 'host', 'path', 'status_code', 'method', 'collection', 'query']
+				});
+			case "gauge":
+				return new prom.Gauge({
+					name,
+					help: name,
+					labelNames: ['app','host', 'status']
+				});
+		} })();
+	}
+
+	inc(opts, value) {
+		return this._execMethod('inc', opts, value);
+	}
+
+	observe(opts, value) {
+		return this._execMethod('observe', opts, value);
+	}
+
+	set(opts, value) {
+		return this._execMethod('set', opts, value);
+	}
+
+	sweep() {
+		const thresh = new Date(Date.now() - (1000 * 60 * PromWrapper.ttlInMinutes));
+		this.instances.forEach((instance, key) => {
+			if (thresh > instance.time) {
+				if (process.env['DEBUG_METRICS']) {
+					console.log("Sweeping stale metric instance", this.name, {opts: instance.opts}, key);
+				}
+				return this.metric.remove(...Array.from(optsAsArgs(instance.opts, this.metric.labelNames) || []));
+			}
+		});
+
+		if (thresh > this.lastAccess) {
+			if (process.env['DEBUG_METRICS']) {
+				console.log("Sweeping stale metric", this.name, thresh, this.lastAccess);
+			}
+			metrics.delete(this.name);
+			return registry.removeSingleMetric(this.name);
+		}
+	}
+
+	_execMethod(method, opts, value) {
+		opts = extendOpts(opts, this.metric.labelNames);
+		const key = optsKey(opts);
+		if (key !== '') { this.instances.set(key, { time: new Date(), opts }); }
+		this.lastAccess = new Date();
+		return this.metric[method](opts, value);
+	}
+}
+
+
+if (!PromWrapper.sweepRegistered) {
+	if (process.env['DEBUG_METRICS']) {
+		console.log("Registering sweep method");
+	}
+	PromWrapper.sweepRegistered = true;
+	setInterval(
+		function() {
+			if (PromWrapper.ttlInMinutes) {
+				if (process.env['DEBUG_METRICS']) {
+					console.log("Sweeping metrics");
+				}
+				return metrics.forEach((metric, key) => {
+					return metric.sweep();
+				});
+			}
+		},
+	60000);
+}
+
+
+module.exports = PromWrapper;

libraries/metrics/test/unit/coffee/event_loop.coffee

@@ -1,34 +0,0 @@
-require('coffee-script')
-chai = require('chai')
-should = chai.should()
-expect = chai.expect
-path = require('path')
-modulePath = path.join __dirname, '../../../event_loop.coffee'
-SandboxedModule = require('sandboxed-module')
-sinon = require("sinon")
-
-describe 'event_loop', ->
-
-	before ->
-		@metrics = {
-			timing: sinon.stub()
-			registerDestructor: sinon.stub()
-		}
-		@logger = {
-			warn: sinon.stub()
-		}
-		@event_loop = SandboxedModule.require modulePath, requires:
-			'./metrics': @metrics
-
-	describe 'with a logger provided', ->
-		before  ->
-			@event_loop.monitor(@logger)
-
-		it 'should register a destructor with metrics', ->
-			@metrics.registerDestructor.called.should.equal true
-
-	describe 'without a logger provided', ->
-		
-		it 'should throw an exception', ->
-			expect(@event_loop.monitor).to.throw('logger is undefined')
-

libraries/metrics/test/unit/coffee/timeAsyncMethodTests.coffee

@@ -1,126 +0,0 @@
-require('coffee-script')
-chai = require('chai')
-should = chai.should()
-expect = chai.expect
-path = require('path')
-modulePath = path.join __dirname, '../../../timeAsyncMethod.coffee'
-SandboxedModule = require('sandboxed-module')
-sinon = require("sinon")
-
-
-describe 'timeAsyncMethod', ->
-
-	beforeEach ->
-		@Timer = {done: sinon.stub()}
-		@TimerConstructor = sinon.stub().returns(@Timer)
-		@metrics = {
-			Timer: @TimerConstructor
-			inc: sinon.stub()
-		}
-		@timeAsyncMethod = SandboxedModule.require modulePath, requires:
-			'./metrics': @metrics
-
-		@testObject = {
-			nextNumber: (n, callback=(err, result)->) ->
-				setTimeout(
-					() ->
-						callback(null, n+1)
-					, 100
-				)
-		}
-
-	it 'should have the testObject behave correctly before wrapping', (done) ->
-		@testObject.nextNumber 2, (err, result) ->
-			expect(err).to.not.exist
-			expect(result).to.equal 3
-			done()
-
-	it 'should wrap method without error', (done) ->
-		@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-		done()
-
-	it 'should transparently wrap method invocation in timer', (done) ->
-		@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-		@testObject.nextNumber 2, (err, result) =>
-			expect(err).to.not.exist
-			expect(result).to.equal 3
-			expect(@TimerConstructor.callCount).to.equal 1
-			expect(@Timer.done.callCount).to.equal 1
-			done()
-
-	it 'should increment success count', (done) ->
-		@metrics.inc = sinon.stub()
-		@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-		@testObject.nextNumber 2, (err, result) =>
-			expect(@metrics.inc.callCount).to.equal 1
-			expect(@metrics.inc.calledWith('someContext_result', 1, { method: 'TestObject_nextNumber', status: 'success'})).to.equal true
-			done()
-
-	describe 'when base method produces an error', ->
-		beforeEach ->
-			@metrics.inc = sinon.stub()
-			@testObject.nextNumber = (n, callback=(err, result)->) ->
-				setTimeout(
-					() ->
-						callback(new Error('woops'))
-					, 100
-				)
-
-		it 'should propagate the error transparently', (done) ->
-			@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-			@testObject.nextNumber 2, (err, result) =>
-				expect(err).to.exist
-				expect(err).to.be.instanceof Error
-				expect(result).to.not.exist
-				done()
-
-		it 'should increment failure count', (done) ->
-			@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-			@testObject.nextNumber 2, (err, result) =>
-				expect(@metrics.inc.callCount).to.equal 1
-				expect(@metrics.inc.calledWith('someContext_result', 1, { method: 'TestObject_nextNumber', status: 'failed'})).to.equal true
-				done()
-
-	describe 'when a logger is supplied', ->
-		beforeEach ->
-			@logger = {log: sinon.stub()}
-
-		it 'should also call logger.log', (done) ->
-			@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject', @logger
-			@testObject.nextNumber 2, (err, result) =>
-				expect(err).to.not.exist
-				expect(result).to.equal 3
-				expect(@TimerConstructor.callCount).to.equal 1
-				expect(@Timer.done.callCount).to.equal 1
-				expect(@logger.log.callCount).to.equal 1
-				done()
-
-	describe 'when the wrapper cannot be applied', ->
-		beforeEach ->
-
-		it 'should raise an error', ->
-			badWrap = () =>
-				@timeAsyncMethod @testObject, 'DEFINITELY_NOT_A_REAL_METHOD', 'someContext.TestObject'
-			expect(badWrap).to.throw(
-				/^.*expected object property 'DEFINITELY_NOT_A_REAL_METHOD' to be a function.*$/
-			)
-
-	describe 'when the wrapped function is not using a callback', ->
-		beforeEach ->
-			@realMethod =  sinon.stub().returns(42)
-			@testObject.nextNumber = @realMethod
-
-		it 'should not throw an error', ->
-			@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-			badCall = () =>
-				@testObject.nextNumber 2
-			expect(badCall).to.not.throw(Error)
-
-		it 'should call the underlying method', ->
-			@timeAsyncMethod @testObject, 'nextNumber', 'someContext.TestObject'
-			result = @testObject.nextNumber(12)
-			expect(@realMethod.callCount).to.equal 1
-			expect(@realMethod.calledWith(12)).to.equal true
-			expect(result).to.equal 42
-
-

libraries/metrics/timeAsyncMethod.coffee

@@ -1,44 +0,0 @@
-
-module.exports = (obj, methodName, prefix, logger) ->
-	metrics = require('./metrics')
-
-	if typeof obj[methodName] != 'function'
-		throw new Error("[Metrics] expected object property '#{methodName}' to be a function")
-
-	key = "#{prefix}.#{methodName}"
-
-	realMethod = obj[methodName]
-
-	splitPrefix = prefix.split(".")
-	startPrefix = splitPrefix[0]
-
-	if splitPrefix[1]?
-		modifedMethodName = "#{splitPrefix[1]}_#{methodName}"
-	else
-		modifedMethodName = methodName
-	obj[methodName] = (originalArgs...) ->
-
-		[firstArgs..., callback] = originalArgs
-
-		if !callback? || typeof callback != 'function'
-			if logger?
-				logger.log "[Metrics] expected wrapped method '#{methodName}' to be invoked with a callback"
-			return realMethod.apply this, originalArgs
-
-		timer = new metrics.Timer(startPrefix, 1, {method: modifedMethodName})
-
-		realMethod.call this, firstArgs..., (callbackArgs...) ->
-			elapsedTime = timer.done()
-			possibleError = callbackArgs[0]
-			if possibleError? 
-				metrics.inc "#{startPrefix}_result", 1, {status:"failed", method: modifedMethodName}
-			else
-				metrics.inc "#{startPrefix}_result", 1, {status:"success", method: modifedMethodName}
-			if logger?
-				loggableArgs = {}
-				try
-					for arg, idx in firstArgs
-						if arg.toString().match(/^[0-9a-f]{24}$/)
-							loggableArgs["#{idx}"] = arg
-				logger.log {key, args: loggableArgs, elapsedTime}, "[Metrics] timed async method call"
-			callback.apply this, callbackArgs

libraries/metrics/timeAsyncMethod.js

@@ -0,0 +1,66 @@
+/*
+ * decaffeinate suggestions:
+ * DS101: Remove unnecessary use of Array.from
+ * DS102: Remove unnecessary code created because of implicit returns
+ * DS201: Simplify complex destructure assignments
+ * DS207: Consider shorter variations of null checks
+ * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
+ */
+
+module.exports = function(obj, methodName, prefix, logger) {
+	let modifedMethodName;
+	const metrics = require('./metrics');
+
+	if (typeof obj[methodName] !== 'function') {
+		throw new Error(`[Metrics] expected object property '${methodName}' to be a function`);
+	}
+
+	const key = `${prefix}.${methodName}`;
+
+	const realMethod = obj[methodName];
+
+	const splitPrefix = prefix.split(".");
+	const startPrefix = splitPrefix[0];
+
+	if (splitPrefix[1] != null) {
+		modifedMethodName = `${splitPrefix[1]}_${methodName}`;
+	} else {
+		modifedMethodName = methodName;
+	}
+	return obj[methodName] = function(...originalArgs) {
+
+		const adjustedLength = Math.max(originalArgs.length, 1), firstArgs = originalArgs.slice(0, adjustedLength - 1), callback = originalArgs[adjustedLength - 1];
+
+		if ((callback == null) || (typeof callback !== 'function')) {
+			if (logger != null) {
+				logger.log(`[Metrics] expected wrapped method '${methodName}' to be invoked with a callback`);
+			}
+			return realMethod.apply(this, originalArgs);
+		}
+
+		const timer = new metrics.Timer(startPrefix, 1, {method: modifedMethodName});
+
+		return realMethod.call(this, ...Array.from(firstArgs), function(...callbackArgs) {
+			const elapsedTime = timer.done();
+			const possibleError = callbackArgs[0];
+			if (possibleError != null) { 
+				metrics.inc(`${startPrefix}_result`, 1, {status:"failed", method: modifedMethodName});
+			} else {
+				metrics.inc(`${startPrefix}_result`, 1, {status:"success", method: modifedMethodName});
+			}
+			if (logger != null) {
+				const loggableArgs = {};
+				try {
+					for (let idx = 0; idx < firstArgs.length; idx++) {
+						const arg = firstArgs[idx];
+						if (arg.toString().match(/^[0-9a-f]{24}$/)) {
+							loggableArgs[`${idx}`] = arg;
+						}
+					}
+				} catch (error) {}
+				logger.log({key, args: loggableArgs, elapsedTime}, "[Metrics] timed async method call");
+			}
+			return callback.apply(this, callbackArgs);
+		});
+	};
+};

libraries/metrics/uv_threadpool_size.coffee

@@ -1,3 +0,0 @@
-unless process.env.UV_THREADPOOL_SIZE
-	process.env.UV_THREADPOOL_SIZE=16
-	console.log "Set UV_THREADPOOL_SIZE=#{process.env.UV_THREADPOOL_SIZE}"

libraries/metrics/uv_threadpool_size.js

@@ -0,0 +1,4 @@
+if (!process.env.UV_THREADPOOL_SIZE) {
+	process.env.UV_THREADPOOL_SIZE=16;
+	console.log(`Set UV_THREADPOOL_SIZE=${process.env.UV_THREADPOOL_SIZE}`);
+}