Collection of functions to use bitcoin.de API in python, using twisted as asynchronous framework.

• Tested in python2.7
• Implements all API-calls

• BitcoinDeAPI: Encapsulates the basic encryption handling nesseccary to communicate with the bitcoin.de API. Hooks for different error and success handlers are build in, following the async model of twisted.
• BitcoinDeAPINonce: Adds an Error Handler in case the nonce is wrong. Tries to reset it to a sensible value
• QueuedBitcoinDeAPI: Adds queueing support for requests to reflect bitcoin.de's credit system
• PriorityBitcoinDeAPI: Adds priority awareness for requests

As the bitcoin.de API restricts spamming using a credit-system, with requests costing between 2 and 3 credits each, a queueing system is added that tracks available credits and throttles requests accordingly. In case a retryperiode is returned, no requests are send out until the system has recovered. Requests are not send out back-to-back, but with a .2s gap. Otherwise bitcoin.de's nonce system might get confused, as proper order of delivery doesn't seem to be guaranteed. Connection pooling helps with this issue, otherwise a .4s gap has to be applied.

If the same request is already enqueued, waiting for execution, it doesn't get enqueued, but the callback is added to the first request's callback chain.

In addition the JSON dict containing the response-body, the following fields are added: {code': 200, u'credits': 18, u'errors': [], 'phrase': 'OK'}

bitoin.de supplies a 'websocket' interface to inform in realtime about changes to the marketplace. It's based on socket.io (version 09.16 for ws. and ws1.bitcoin.de) and doesn't provide simple websocket connectivity. ws2. and ws3.bitcoin.de use version 2.0.11 of socket.io

Tested in both python2.7 and python3.7 with latest twisted library

• https Get request to base address returns connection-options (websocket,longpolling,...)
• Switch to desired Protocol using the same https connection
• Receive websocket packages, send heartbeat to keep connection open

Implementations for 09.16 and 2.0.11 differ slightly.

bitcoinDEws implementation uses twisted basic.LineReceiver to make the GET request to the base-address, some crude line-magic to process the response and initiate the protocol-switching. No real websocket implementation is used, but a line-oriented bare minimum.

• ClientIo0916Protocol/ClientIo2011Protocol encapsulates the basic connection handling
• WSjsonBitcoinDEProtocol and -2 add JSON data handling
• BitcoinWSSourceV09 and BitcoinWSSourceV20 implement Factories to handle each source
• BitcoinWSmulti processes input from multiple sources (ws., ws1., ...)
• Each event-type (add/rm/skn/po/spr) is implemented in it's own class
• Each event-type is handled through a bitcoinWSeventstream, only forwarding first reception of an event from the sources
• BitcoinDESubscribe offers a subscription service to add 'callbacks' for each event type, delivered through BitcoinWSmulti.Deliver, for use in async apps