# pewl > Generic Pooling Library Latest version **0.1.0** (published 2017-11-06) · ISC license · 0 weekly downloads ## Install ```sh npm install pewl pnpm add pewl yarn add pewl bun add pewl ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support; pre 1.0. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 0.1.0 | | Published | 2017-11-06 | | First published | 2017-11-06 | | Weekly downloads | 0 | | License | ISC | | TypeScript types | none | | Module format | CommonJS | | Dependencies | 3 | | Known vulnerabilities | 0 | | Install scripts | no | | Author | Dave Gramlich | | Maintainers | callmehiphop | ## Links - npm: https://www.npmjs.com/package/pewl - npm.io page: https://npm.io/package/pewl ## Dependencies (3) - [delay](https://npm.io/package/delay.md) ^2.0.0 - [arrify](https://npm.io/package/arrify.md) ^1.0.1 - [p-queue](https://npm.io/package/p-queue.md) ^2.2.0 ## Recent versions - 0.1.0 (latest) — 2017-11-06 ## README # Pewl > Generic pooling library Useful for managing resources like database connections. ## Install ```sh $ npm install pewl ``` ## Usage Here's a simple example of how to get up and running with `pewl`. ```js const Pool = require('pewl'); // create a Pool instance. const pool = new Pool({ create: () => asyncFuncThatCreatesResource(), destroy: resource => asyncFuncThatDestroysResource(resource) }); // open the pool await pool.open(); // get a resource from the pool const resource = await pool.acquire(); // return the resource to the pool pool.release(resource); // close the pool when finished await pool.close(); ``` ## API ### Pool([options]) Returns a new `pool` instance. #### options Type: `Object` ##### acquireTimeout Type: `number` Default: `Infinity` Duration to wait before rejecting acquire request. ##### attributes Type: `string[]` Attributes used to describe the Pool when using a Cluster. ##### concurrency Type: `number` Default: `Infinity` Concurrency limit for making resource requests. ##### create Type: `Function` Function that returns a Promise that resolves with a resource. ##### destroy Type: `Function` Accepts a resource value and attempts to destroy it, returning a promise upon completion. ##### diesAfter Type: `number` Default: `Infinity` Marks a resource as *dead* after this duration. ##### fifo Type: `boolean` Default: `true` Treats the Pool like a stack (as opposed to a queue). ##### idlesAfter Type: `number` Default: `600000` Marks a resource as *idle* after this duration. ##### isDead Type: `Function` Accepts a Resource object and returns a boolean stating whether or not the resource is dead. ##### isIdle Type: `Function` Accepts a Resource object and returns a boolean stating whether or not the resource is idle. ##### max Type: `number` Default: `Infinity` Maximum number of resources the pool can create. ##### maxIdle Type: `number` Default: `Infinity` Maximum number of idle resources the pool can contain with respect to the `min` and `max` options. ##### min Type: `number` Default: `0` Minimum number of resources that must be in the pool at all times. ##### ping Type: `Function` Accepts a resource value and attempts to ping it, returning a promise upon completion. ##### pingInterval Type: `number` Default: `600000` Frequency to ping idle resources. ##### skimInterval Type: `number` Frequency to check for and dispose of dead and idle resources with respect to the `min` and `max` options. ### Pool#acquire([options]) Returns a promise that settles when a resource is acquired. #### options Type: `Object` ##### priority Type: `Number` Default: `0` Priority of operation. Operations with greater priority will be schedule first. ### Pool#close() Returns a promise that settles once all resources have been destroyed. ### Pool#destroy(resource) Returns a promise that settles once the suppled resource is destroyed. ### Pool#open() Returns a promise that settles once the pool is opened and filled to the `min` value. ### Pool#release(resource) Releases a resource back into the pool. ### Pool#available Number of available resources. ### Pool#borrowed Number of borrowed resources. ### Pool#idle Number of idle resources. ### Pool#size Total number of resources in pool. ### Cluster([options]) Returns a new `cluster` instance. #### options Type: `Object` Options to be applied to all `pool` instances within the cluster. ##### acquireTimeout Type: `number` Default: `Infinity` Duration to wait before rejecting acquire request. ##### concurrency Type: `number` Default: `Infinity` Concurrency limit for making resource requests. ##### diesAfter Type: `number` Default: `Infinity` Marks a resource as *dead* after this duration. ##### fifo Type: `boolean` Default: `true` Treats the Pool like a stack (as opposed to a queue). ##### idlesAfter Type: `number` Default: `600000` Marks a resource as *idle* after this duration. ##### ping Type: `Function` Accepts a resource value and attempts to ping it, returning a promise upon completion. ##### pingInterval Type: `number` Default: `600000` Frequency to ping idle resources. ##### pools Type: `Pool[]` List of `pool` instances. ##### skimInterval Type: `number` Frequency to check for and dispose of dead and idle resources with respect to the `min` and `max` options. ### Cluster#acquire([options]) Returns a promise that settles when a resource is acquired. #### options Type: `Object` ##### attributes Type: `string[]` List of attributes that the resource must have. ##### priority Type: `number` Default: `0` Priority of operation. Operations with greater priority will be schedule first. ### Cluster#add(pool) Adds a `pool` instance to the cluster. ### Cluster#close() Returns a promise that settles once the cluster and all the `pool` instances have been closed. ### Cluster#destroy(resource) Destroys the provided resource. ### Cluster#open() Returns a promise that settles once all the `pool` instances have been opened and filled. ### Cluster#release(resource) Releases the resource back into the cluster. ### Cluster#stats([attributes]) Gets a `ClusterStats` object for the cluster resources. #### attributes Type: `String[]` Attributes to apply to the stats. ## Managing multiple Pools ```js const Pool = require('pewl'); // create a pool of read-only resources const readPool = new Pool({ attributes: ['r'], ... }); // create a pool of read-write resources const readWritePool = new Pool({ attributes: ['r', 'w'], ... }); // create a cluster to manage both pools const cluster = new Pool.Cluster({ pools: [readPool, readWritePool] }); // start all the things! await cluster.open(); // acquire the first available resource const readOnlyResource = await cluster.acquire(); // release the resource back into the cluster cluster.release(readOnlyResource); // acquire a write capable resource const readWriteResource = await cluster.acquire({ attributes: ['w'] }); // destroy the write capable resource cluster.destroy(readWriteResource); // close all the things! await cluster.close(); ``` --- _Source: https://npm.io/package/pewl · Machine-readable twin of the npm.io package page. 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