phantom-pool

Resource pool based on generic-pool for PhantomJS.

Creating new phantom instances with phantom.create() can be slow. If you are frequently creating new instances and destroying them, as a result of HTTP requests for example, this module can help by keeping a pool of phantom instances alive and making it easy to re-use them across requests.

Here's an artificial benchmark to illustrate:

Starting benchmark without pool
noPool-0: 786.829ms
noPool-1: 790.822ms
noPool-2: 795.150ms
noPool-3: 788.928ms
noPool-4: 793.788ms
noPool-5: 798.075ms
noPool-6: 813.130ms
noPool-7: 803.801ms
noPool-8: 782.936ms
noPool-9: 805.630ms
Starting benchmark with pool
pool-0: 48.160ms
pool-1: 98.966ms
pool-2: 89.573ms
pool-3: 99.057ms
pool-4: 101.970ms
pool-5: 102.967ms
pool-6: 102.938ms
pool-7: 99.359ms
pool-8: 101.972ms
pool-9: 103.309ms
Done

Using pool in this benchmark results in an average >8x speed increase.

Install

npm install --save phantom-pool

Requires Node v6+

Usage

See ./test directory for usage examples.

constcreatePhantomPool=require('phantom-pool')// Returns a generic-pool instanceconstpool=createPhantomPool({max: 10,// defaultmin: 2,// default// how long a resource can stay idle in pool before being removedidleTimeoutMillis: 30000,// default.// maximum number of times an individual resource can be reused before being destroyed; set to 0 to disablemaxUses: 50,// default// function to validate an instance prior to use; see https://github.com/coopernurse/node-pool#createpoolvalidator: ()=>Promise.resolve(true),// defaults to always resolving true// validate resource before borrowing; required for `maxUses and `validator`testOnBorrow: true,// default// For all opts, see opts at https://github.com/coopernurse/node-pool#createpoolphantomArgs: [['--ignore-ssl-errors=true','--disk-cache=true'],{logLevel: 'debug',}],// arguments passed to phantomjs-node directly, default is `[]`. For all opts, see https://github.com/amir20/phantomjs-node#phantom-object-api})// Automatically acquires a phantom instance and releases it back to the// pool when the function resolves or throwspool.use(async(instance)=>{constpage=awaitinstance.createPage()conststatus=awaitpage.open('http://google.com',{operation: 'GET'})if(status!=='success'){thrownewError('cannot open google.com')}constcontent=awaitpage.property('content')returncontent}).then((content)=>{console.log(content)})// Destroying the pool:pool.drain().then(()=>pool.clear())// For more API doc, see https://github.com/coopernurse/node-pool#generic-pool

Security

When using phantom-pool, you should be aware that the phantom instance you are getting might not be in a completely clean state. It could have browser history, cookies or other persistent data from a previous use.

If that is an issue for you, make sure you clean up any sensitive data on the phantom instance before returning it to the pool.