device_home/node_modules/p-limit/readme.md

   1 # p-limit [![Build Status](https://travis-ci.org/sindresorhus/p-limit.svg?branch=master)](https://travis-ci.org/sindresorhus/p-limit)
   2
   3 > Run multiple promise-returning & async functions with limited concurrency
   4
   5 ## Install
   6
   7 ```
   8 $ npm install p-limit
   9 ```
  10
  11 ## Usage
  12
  13 ```js
  14 const pLimit = require('p-limit');
  15
  16 const limit = pLimit(1);
  17
  18 const input = [
  19         limit(() => fetchSomething('foo')),
  20         limit(() => fetchSomething('bar')),
  21         limit(() => doSomething())
  22 ];
  23
  24 (async () => {
  25         // Only one promise is run at once
  26         const result = await Promise.all(input);
  27         console.log(result);
  28 })();
  29 ```
  30
  31 ## API
  32
  33 ### pLimit(concurrency)
  34
  35 Returns a `limit` function.
  36
  37 #### concurrency
  38
  39 Type: `number`\
  40 Minimum: `1`\
  41 Default: `Infinity`
  42
  43 Concurrency limit.
  44
  45 ### limit(fn, ...args)
  46
  47 Returns the promise returned by calling `fn(...args)`.
  48
  49 #### fn
  50
  51 Type: `Function`
  52
  53 Promise-returning/async function.
  54
  55 #### args
  56
  57 Any arguments to pass through to `fn`.
  58
  59 Support for passing arguments on to the `fn` is provided in order to be able to avoid creating unnecessary closures. You probably don't need this optimization unless you're pushing a *lot* of functions.
  60
  61 ### limit.activeCount
  62
  63 The number of promises that are currently running.
  64
  65 ### limit.pendingCount
  66
  67 The number of promises that are waiting to run (i.e. their internal `fn` was not called yet).
  68
  69 ### limit.clearQueue()
  70
  71 Discard pending promises that are waiting to run.
  72
  73 This might be useful if you want to teardown the queue at the end of your program's lifecycle or discard any function calls referencing an intermediary state of your app.
  74
  75 Note: This does not cancel promises that are already running.
  76
  77 ## FAQ
  78
  79 ### How is this different from the [`p-queue`](https://github.com/sindresorhus/p-queue) package?
  80
  81 This package is only about limiting the number of concurrent executions, while `p-queue` is a fully featured queue implementation with lots of different options, introspection, and ability to pause the queue.
  82
  83 ## Related
  84
  85 - [p-queue](https://github.com/sindresorhus/p-queue) - Promise queue with concurrency control
  86 - [p-throttle](https://github.com/sindresorhus/p-throttle) - Throttle promise-returning & async functions
  87 - [p-debounce](https://github.com/sindresorhus/p-debounce) - Debounce promise-returning & async functions
  88 - [p-all](https://github.com/sindresorhus/p-all) - Run promise-returning & async functions concurrently with optional limited concurrency
  89 - [More…](https://github.com/sindresorhus/promise-fun)
  90
  91 ---
  92
  93 <div align="center">
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