AllanHao / geobuf-example

Example consuming geobuf protocol buffer in Open Layers map

Example GeoBuf

This example uses mapbox/geobuf, a compact binary encoding for geographic data to serve and consume GeoJSON data in protocol buffers.

The purpose of this example is to illustrate how large datasets can be efficiently compacted and served over HTTP.

The original dataset I am using is a 15 MB shapefile representing Oregon census tracts (ftp://ftp2.census.gov/geo/pvs/tiger2010st/41_Oregon/41/tl_2010_41_tract10.zip). When converted to GeoJSON, the file is 26.7 MB in size. Converting to a protocol buffer brings the size down to 3.3 MB. When compressed through gzip, the resulting file size is 3.1 MB.

Running this example

There are two components, a simple express server to serve out the file (in the server folder) and a simple client app built with OpenLayers.

To start the server (running on port 3000):

$ cd server
$ npm install
$ node server.js

To bundle and run the client app (new tab in terminal):

$ cd client
$ npm install
$ npm start

Then navigate to http://localhost:1234/