mapnik-pool

If you want to use node-mapnik in an app with concurrency, you'll want to use a map pool. By design Mapnik Maps are not meant to be shared between threads because datasources hold state. This may change in the future but for now using a single map instance with async node-mapnik rendering functions may your app. Also using several map instances will give you a significant speedup. mapnik-pool manages a generic-pool of mapnik.Map instances so you don't have to.

install

npm install --save mapnik-pool

dependency structure

mapnik-pool is a peerDependency of node-mapnik: you bring your own Mapnik version, as long as its ~1.0.0.

example

var mapnik = require('mapnik'),
    mapnikPool = require('mapnik-pool')(mapnik),
    fs = require('fs');
 
var pool = mapnikPool.fromString(fs.readFileSync('mymap.xml', 'utf8'));
 
pool.acquire(function(err, map) {
    // pooled map
});

api

fromString(str, initOptions, mapOptions)

• str: a Mapnik XML string
• initOptions: options for initialization. Currently, size for map, bufferSize. Default { size: 256 }
• mapOptions: options for the fromString method.