slosh - mini realtime web

slosh is the server component for a realtime data visualization project. The name is to show that I've actually heard of bosh, but I needed something sloppier.

What it Does

slosh allows http clients to respond to events as they occur using long-polling techniques.

Integration with existing services is quite easy. Services simply POST into a topic URL and a GET on the same URL will return that data in XML form.

For example point your browser to http://localhost:8000/topics/test -- The browser will hang indefinitely waiting for a results. Now run the following:

curl -d 'x=hello!' http://localhost:8000/topics/test

You should instantly see results in your browser:

<res saw="1">
  <p>
    <x>hello!</x>
  </p>
</res>

If you repeat the above query three times and reload with the browser, you should see queued results immediately:

<res saw="3">
  <p>
    <x>hello!</x>
  </p>
  <p>
    <x>hello!</x>
  </p>
  <p>
    <x>hello!</x>
  </p>
</res>

The saw value describes how many incoming messages were received by the server. It may be larger than the number of requests you receive if the rate of incoming requests is higher than the rate at which you're processing the results.

Formats

The default output format is XML. However, JSON is also optionally supported and may be requested at access time by adding .json to the topic path.

For exaple, the following paths pull data from the same topic in XML format:

/topics/test
/topics/test.xml

If you wanted the same data, but in JSON format, you'd ask for the following:

/topics/test.json

Running

Copy slosh.tac.sample to slosh.tac and optionally edit for your document root then use twistd to launch it.

To see the example app interactively on console, you can do the following:

cp slosh.tac.sample slosh.tac
twistd -ny slosh.tac

Requirements

twisted is required to do anything at all.

If you want JSON formatted results, the python-cjson egg is required.