About

Generic resource pool. Can be used to reuse or throttle expensive resources such as database connections.

Installation

$ npm install generic-pool

Example

// Create a MySQL connection pool with
// a max of 10 connections and a 30 second max idle time
var poolModule = require('generic-pool');
var pool = poolModule.Pool({
    name     : 'mysql',
    create   : function(callback) {
        var Client = require('mysql').Client;
        var c = new Client();
        c.user     = 'scott';
        c.password = 'tiger';
        c.database = 'mydb';
        c.connect();
        callback(c);
    },
    destroy  : function(client) { client.end(); },
    max      : 10,
    idleTimeoutMillis : 30000
});

// borrow connection - callback function is called
// once a resource becomes available
pool.borrow(function(client) {
    client.query("select * from foo", [], function() {
        // return object back to pool
        pool.returnToPool(client);
    });
});

Documentation

Pool() accepts an object with these slots:

              name : name of pool (string, optional)
            create : function that returns a new resource
                       should call callback() with the created resource
           destroy : function that accepts a resource and destroys it
               max : maximum number of resources to create at any given time
 idleTimeoutMillis : max milliseconds a resource can go unused before it should be destroyed
                     (default 30000)
reapIntervalMillis : frequency to check for idle resources (default 1000)

Run Tests

$ npm install expresso
$ expresso -I lib test/*.js