Added experimental module with a base session

src/sessions/__init__.py

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+# -*- coding: utf-8 -*-

src/sessions/base.py

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+# -*- coding: utf-8 -*-
+""" A base class to be derived in possible new sessions for TWBlue and services."""
+import paths
+import output
+import time
+import sound
+import logging
+import config_utils
+import shelve
+import application
+import os
+import session_exceptions as Exceptions
+log = logging.getLogger("sessionmanager.session")
+
+class baseSession(object):
+	""" toDo: Decorators does not seem to be working when using them in an inherited class."""
+
+	# Decorators.
+
+	def _require_login(fn):
+		""" Decorator for checking if the user is logged in.
+		Some functions may need this to avoid making unneeded calls."""
+		def f(self, *args, **kwargs):
+			if self.logged == True:
+				fn(self, *args, **kwargs)
+			else:
+				raise Exceptions.NotLoggedSessionError("You are not logged in yet.")
+		return f
+
+	def _require_configuration(fn):
+		""" Check if the user has a configured session."""
+		def f(self, *args, **kwargs):
+			if self.settings != None:
+				fn(self, *args, **kwargs)
+			else:
+				raise Exceptions.NotConfiguredSessionError("Not configured.")
+		return f
+
+	def __init__(self, session_id):
+		""" session_id (str): The name of the folder inside the config directory where the session is located."""
+		super(baseSession, self).__init__()
+		self.session_id = session_id
+		self.logged = False
+		self.settings = None
+		self.db={}
+  
+	@property
+	def is_logged(self):
+		return self.logged
+
+	def get_configuration(self):
+		""" Get settings for a session."""
+		file_ = "%s/session.conf" % (self.session_id,)
+		log.debug("Creating config file %s" % (file_,))
+		self.settings = config_utils.load_config(paths.config_path(file_), paths.app_path("Conf.defaults"))
+		self.init_sound()
+		self.deshelve()
+
+	def init_sound(self):
+		try: self.sound = sound.soundSystem(self.settings["sound"])
+		except: pass
+
+	@_require_configuration
+	def login(self, verify_credentials=True):
+		pass
+
+	@_require_configuration
+	def authorise(self):
+		pass
+
+	def shelve(self):
+		"""Shelve the database to allow for persistance."""
+		shelfname=paths.config_path(str(self.session_id)+"/cache.db")
+		if self.settings["general"]["persist_size"] == 0:
+			if os.path.exists(shelfname):
+				os.remove(shelfname)
+			return
+		try:
+			if not os.path.exists(shelfname):
+				output.speak("Generating database, this might take a while.",True)
+			shelf=shelve.open(paths.config_path(shelfname),'c')
+			for key,value in self.db.items():
+				if type(key) != str and type(key) != unicode:
+					output.speak("Uh oh, while shelving the database, a key of type " + str(type(key)) + " has been found. It will be converted to type str, but this will cause all sorts of problems on deshelve. Please bring this to the attention of the " + application.name + " developers immediately. More information about the error will be written to the error log.",True)
+					log.error("Uh oh, " + str(key) + " is of type " + str(type(key)) + "!")
+				# Convert unicode objects to UTF-8 strings before shelve these objects.
+				if type(value) == list and self.settings["general"]["persist_size"] != -1 and len(value) > self.settings["general"]["persist_size"]:
+					shelf[str(key.encode("utf-8"))]=value[self.settings["general"]["persist_size"]:]
+				else:
+					shelf[str(key.encode("utf-8"))]=value
+			shelf.close()
+		except:
+			output.speak("An exception occurred while shelving the " + application.name + " database. It will be deleted and rebuilt automatically. If this error persists, send the error log to the " + application.name + " developers.",True)
+			log.exception("Exception while shelving" + shelfname)
+			os.remove(shelfname)
+
+	def deshelve(self):
+		"""Import a shelved database."""
+		shelfname=paths.config_path(str(self.session_id)+"/cache.db")
+		if self.settings["general"]["persist_size"] == 0:
+			if os.path.exists(shelfname):
+				os.remove(shelfname)
+			return
+		try:
+			shelf=shelve.open(paths.config_path(shelfname),'c')
+			for key,value in shelf.items():
+				self.db[key]=value
+			shelf.close()
+		except:
+			output.speak("An exception occurred while deshelving the " + application.name + " database. It will be deleted and rebuilt automatically. If this error persists, send the error log to the " + application.name + " developers.",True)
+			log.exception("Exception while deshelving" + shelfname)
+			try: 
+				os.remove(shelfname)
+			except:
+				pass
+

src/sessions/session_exceptions.py

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+# -*- coding: cp1252 -*-
+import exceptions
+
+class InvalidSessionError(exceptions.Exception): pass
+class NonExistentSessionError(exceptions.Exception): pass
+class NotLoggedSessionError(exceptions.BaseException): pass
+class NotConfiguredSessionError(exceptions.BaseException): pass
+class RequireCredentialsSessionError(exceptions.BaseException): pass
+class AlreadyAuthorisedError(exceptions.BaseException): pass