pymeds/debug.py

#!/usr/bin/env python
# Copyright 2006 John-Mark Gurney <jmg@funkthat.com>

__version__ = '$Change$'
# $Id$

from twisted.internet import reactor
import twisted.internet.error

# Make sure to update the global line when adding a new function
__all__ = [ 'appendnamespace', 'insertnamespace', 'insertringbuf' ]

DEFAULTRINGSIZE = 50

appendnamespace = lambda k, v: []
insertnamespace = lambda k, v: None
insertringbuf = lambda k, l = DEFAULTRINGSIZE: None

# This code from: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/68429
class RingBuffer:
	def __init__(self,size_max):
		self.max = size_max
		self.data = []
	def append(self,x):
		"""append an element at the end of the buffer"""
		self.data.append(x)
		if len(self.data) == self.max:
			self.cur=0
			self.__class__ = RingBufferFull
	def get(self):
  		""" return a list of elements from the oldest to the newest"""
		return self.data

class RingBufferFull:
	def __init__(self,n):
		raise "you should use RingBuffer"
	def append(self,x):		
		self.data[self.cur]=x
		self.cur=(self.cur+1) % self.max
	def get(self):
		return self.data[self.cur:]+self.data[:self.cur]

def doDebugging(opt):
	if not opt:
		return

	global insertnamespace, appendnamespace, insertringbuf

	def insertnamespace(k, v):
		assert isinstance(k, basestring)
		sf.namespace[k] = v

	def appendnamespace(k, v):
		try:
			sf.namespace[k].append(v)
		except KeyError:
			sf.namespace[k] = [ v ]

	def insertringbuf(k, l = DEFAULTRINGSIZE):
		insertnamespace(k, RingBuffer(l))

	from twisted.manhole import telnet

	class Debug(telnet.Shell):
		def welcomeMessage(self):
			data = [ '', 'PyMedS Debugging Console', '', '' ]
			return '\r\n'.join(data)
		
	sf = telnet.ShellFactory()
	sf.protocol = Debug
	try:
		reactor.listenTCP(56283, sf)
	except twisted.internet.error.CannotListenError:
		print 'WARNING: cannot bind to debugger port.'