statman-gauge   

statman-gauge is one of the metrics from the statman library. Loosely based upon codehale metric package, a gauge is an instantaneous measurement metric. This can be use to capture things like the size of a queue, number of messages processed, or some other interesting thing within your system.

WARNING!! if you look at the word gauge long enough, it looks misspelled

Install it!

$3

Install using npm:
`` bash
npm install statman-gauge
`

Reference in your app:
` javascript
var Gauge = require('statman-gauge');
var gauge = Gauge('gauge-name');
`

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Install using npm:
` bash
npm install statman
`

Reference in your app:
` javascript
var statman = require('statman');
var gauge = statman.Gauge('gauge-name');
`

Use it!

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+ Gauge() => create instance of a gauge
+ Gauge(name) => create instance of a gauge with name
+ Gauge(name, f()) => create instance of a gauge with name, where f is a function that returns the value for the gauge

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+ increment() => increment value by 1
+ increment(value) => increment by value
` javascript
gauge.increment(); //increment by 1
gauge.increment(10); //increment by 10
`

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+ decrement() => decrement value by 1
+ decrement(value) => decrement by value
` javascript
gauge.decrement(); //decrement by 1
gauge.decrement(10); //decrement by 10
`

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+ set(value) => set value of gauge
` javascript
gauge.set(5);
`

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+ value() => get the value of the gauge
` javascript
gauge.value();
`

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Suppose that we want to create a gauage that measures that size of a queue. The below indicates how to register this.

#### Method 1 (use gauge directly)
` javascript
var Gauge = require('statman-gauge');
var gauge = Gauge('queueSize');

function enqueue(message) {
data.push(message);
gauge.increment();
}

function dequeue() {
data.pop(message);
gauge.decrement();
}
`

#### Method 2 (use gauge via statman)
`
TODO
`

#### Method 3 (use custom value function)
` javascript
var Gauge = require('statman-gauge');
var gauge = Gauge('queueSize', function() {
return data.size();
});

function enqueue(message) {
data.push(message);
}

function dequeue() {
data.pop(message);
}
`

Build it!


- Make sure that you have node and npm installed
- Clone source code to you local machine
- Setup dependencies: npm install
- run tests: npm test`