https://github.com/dash-os/set-queue
Simple FIFO Queue built on top of ES6 Set
https://github.com/dash-os/set-queue
Last synced: 3 months ago
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Simple FIFO Queue built on top of ES6 Set
- Host: GitHub
- URL: https://github.com/dash-os/set-queue
- Owner: Dash-OS
- License: mit
- Created: 2017-05-28T04:25:11.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2017-05-31T22:50:20.000Z (about 9 years ago)
- Last Synced: 2024-12-31T17:38:58.976Z (over 1 year ago)
- Language: JavaScript
- Size: 9.77 KB
- Stars: 0
- Watchers: 4
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# SetQueue
Extremely simple FIFO Queue using ES6 Set. Note that Set's require every value to
be unique so this is generally better suited for dealing with situations other than
simple values.
> Package Developer uses this to handle queues of Promises where we want to process
> the resolved promises in a FIFO-fashion on-demand.
At this time the package only implements the `Set` api partially and it is meant to
just be a simple queue mechanism. `Set` was used here over array as it will allow
us to easily manipulate the queue in the future (for example directly removing values).
### Example
```js
import SetQueue from 'set-queue'
const Queue = new SetQueue()
Queue.add(1).add(2).add(3)
Queue.size ; // 3
const value = Queue.next() ; // 1
Queue.size ; // 2
for ( let item of Queue ) {
console.log(item) ; // 2, 3
}
Queue.size ; // 0
```
### SagaObservable Example
Below is the source for [saga-observable](https://github.com/Dash-OS/saga-observable) which
is what the micro-package was developed for.
```js
import { cancelled } from 'redux-saga/effects'
import { CANCEL } from 'redux-saga'
import SetQueue from 'set-queue'
const CreateSagaPromise = (promise, handler, oncancel) => {
const SagaPromise = new promise(handler)
SagaPromise[CANCEL] = oncancel
return SagaPromise
}
const build_config = config => ({
name: 'saga-observable',
promise: Promise,
throttle: undefined,
...config
})
export default class SagaObservable {
constructor(config) {
this.config = build_config(config)
this.promise = this.config.promise
this.name = Symbol(this.config.name)
this.queues = {
actions: new SetQueue(),
dispatch: new SetQueue(),
}
}
publish = (...args) => {
if (this.queues.dispatch.size) {
this.queues.dispatch.next()(args)
} else {
this.queues.actions.add(args)
}
}
next = () => {
if (this.queues.actions.length) {
return this.promise.resolve(this.queues.actions.next())
} else {
return CreateSagaPromise(
this.promise,
resolve => this.queues.dispatch.add(resolve),
this.cancelled
)
}
}
cancelled = () => {
this.isCancelled = true
delete this.queues
delete this.promise
this.next = () => { throw new Error(`[SagaObservable] : ${this.name} next called after Cancellation`) }
this.publish = (...args) => { console.warn('[SagaObservable] : Publish Received after Cancellation ', this.name, args) }
return cancelled()
}
}
```