call-limit

Limit the number of simultaneous executions of a async function.

const fs = require('fs')
const limit = require('call-limit')
const limitedStat = limit(fs.stat, 5)

Or with promise returning functions:

const fs = Bluebird.promisifyAll(require('fs'))
const limit = require('call-limit')
const limitedStat = limit.promise(fs.statAsync, 5)

USAGE:

Given that:

const limit = require('call-limit')

limit(func, maxRunning) → limitedFunc

The returned function will execute up to maxRunning calls of func at once. Beyond that they get queued and called when the previous call completes.

func must accept a callback as the final argument and must call it when it completes, or call-limit won't know to dequeue the next thing to run.

By contrast, callers to limitedFunc do NOT have to pass in a callback, but if they do they'll be called when func calls its callback.

limit.promise(func, maxRunning) → limitedFunc

The returned function will execute up to maxRunning calls of func at once. Beyond that they get queued and called when the previous call completes.

func must return a promise.

limitedFunc will return a promise that resolves with the promise returned from the call to func.

limit.method(class, methodName, maxRunning)

This is sugar for:

class.prototype.methodName = limit(class.prototype.methodName, maxRunning)

limit.method(object, methodName, maxRunning)

This is sugar for:

object.methodName = limit(object.methodName, maxRunning)

For example limit.promise.method(fs, 'stat', 5) is the same as fs.stat = limit.promise(fs.stat, 5).

limit.promise.method(class, methodName, maxRunning)

This is sugar for:

class.prototype.methodName = limit.promise(class.prototype.methodName, maxRunning)

limit.promise.method(object, methodName, maxRunning)

This is sugar for:

object.methodName = limit.promise(object.methodName, maxRunning)

For example limit.promise.method(fs, 'statAsync', 5) is the same as fs.statAsync = limit.promise(fs.statAsync, 5).