New plugin system - first hack

1 files changed, 153 insertions, 420 deletions

diff --git a/portato/plugin.py b/portato/plugin.py
index 5926922..6160d5e 100644
--- a/portato/plugin.py
+++ b/portato/plugin.py
@@ -3,349 +3,145 @@
 # File: portato/plugin.py
 # This file is part of the Portato-Project, a graphical portage-frontend.
 #
-# Copyright (C) 2007 René 'Necoro' Neumann
+# Copyright (C) 2008 René 'Necoro' Neumann
 # This is free software.  You may redistribute copies of it under the terms of
 # the GNU General Public License version 2.
 # There is NO WARRANTY, to the extent permitted by law.
 #
 # Written by René 'Necoro' Neumann <necoro@necoro.net>
 
-"""A module containing the management of the plugin system."""
-
 from __future__ import absolute_import
 
-import os, os.path
-from xml.dom.minidom import parse
-from lxml import etree
-
-from .constants import PLUGIN_DIR, XSD_LOCATION
-from .helper import debug, info, warning, error, flatten
-
-class PluginImportException (ImportError):
-	pass
-
-class Options (object):
-	"""The <options>-element."""
-
-	__options = ("disabled", "blocking")
-
-	def __init__ (self, options = None):
-
-		self.disabled = False
-		self.blocking = False
-
-		if options:
-			self.parse(options)
-
-	def parse (self, options):
-		for opt in options:
-			nodes = opt.childNodes
-			type = str(nodes[0].nodeValue.strip())
-			if type in self.__options:
-				self.set(type, True)
-
-	def get (self, name):
-		return self.__getattribute__(name)
+from collections import defaultdict
+from functools import wraps
 
-	def set (self, name, value):
-		return self.__setattr__(name, value)
+from .helper import debug, warning, info
 
-class Menu:
-	"""A single <menu>-element."""
-	def __init__ (self, plugin, label, call):
-		"""Constructor.
-
-		@param plugin: the plugin this menu belongs to
-		@type plugin: Plugin
-		@param label: the label to show
-		@type label: string
-		@param call: the function to call relative to the import statement
-		@type call: string
-
-		@raises PluginImportException: if the plugin's import could not be imported"""
+class Menu (object):
+	__slots__ = ("label", "call")
 
+	def __init__ (self, label, call):
 		self.label = label
-		self.plugin = plugin
-
-		if self.plugin.needs_import(): # get import
-			imp = self.plugin.get_import()
-			try:
-				mod = __import__(imp, globals(), locals(), [call])
-			except ImportError:
-				raise PluginImportException, imp
-
-			try:
-				self.call = eval("mod."+call) # build function
-			except AttributeError:
-				raise PluginImportException, imp
-		else:
-			try:
-				self.call = eval(call)
-			except AttributeError:
-				raise PluginImportException, imp
-
-class Connect:
-	"""A single <connect>-element."""
-
-	def __init__ (self, hook, type, depend_plugin):
-		"""Constructor.
-
-		@param hook: the parent Hook
-		@type hook: Hook
-		@param type: the type of the connect ("before", "after", "override")
-		@type type: string
-		@param depend_plugin: a plugin we are dependant on
-		@type depend_plugin: string or None"""
-
-		self.type = type
-		self.hook = hook
-		self.depend_plugin = depend_plugin
-
-	def is_before_type (self):
-		return self.type == "before"
-
-	def is_after_type (self):
-		return self.type == "after"
-
-	def is_override_type (self):
-		return self.type == "override"
-
-class Hook:
-	"""A single <hook>-element."""
-
-	def __init__ (self, plugin, hook, call):
-		"""Constructor.
+		self.call = call
 
-		@param plugin: the parent Plugin
-		@type plugin: Plugin
-		@param hook: the hook to add to
-		@type hook: string
-		@param call: the call to make
-		@type call: string"""
+class Call (object):
+	__slots__ = ("plugin", "hook", "call", "type", "dep")
 
+	def __init__ (self, plugin, hook, call, type = "before", dep = None):
 		self.plugin = plugin
 		self.hook = hook
 		self.call = call
-		self.connects = []
-
-	def parse_connects (self, connects):
-		"""This gets a list of <connect>-elements and parses them.
-		
-		@param connects: the list of <connect>'s
-		@type connects: NodeList"""
-		
-		if not connects: # no connects - assume "before" connect
-			self.connects.append(Connect(self, "before", None))
-		
-		for c in connects:
-			type = c.getAttribute("type")
-			if type == '': 
-				type = "before"
-
-			# get dep_plugin if available
-			dep_plugin = None
-			if c.hasChildNodes():
-				nodes = c.childNodes
-				dep_plugin = nodes[0].nodeValue.strip()
-
-			connect = Connect(self, type, dep_plugin)
-			self.connects.append(connect)
-		
-class Plugin:
-	"""A complete plugin."""
-
-	(STAT_DISABLED, STAT_TEMP_ENABLED, STAT_ENABLED, STAT_TEMP_DISABLED) = range(4)
-
-	def __init__ (self, file, name, author):
-		"""Constructor.
-
-		@param file: the file name of the plugin.xml
-		@type file: string
-		@param name: the name of the plugin
-		@type name: Node
-		@param author: the author of the plugin
-		@type author: Node"""
-
-		self.file = file
-		self.name = name.firstChild.nodeValue.strip()
-		self.author = author.firstChild.nodeValue.strip()
-		self._import = None
-		self.hooks = []
-		self.menus = []
-		self.options = Options()
-
-		self.status = self.STAT_ENABLED
-
-	def parse_hooks (self, hooks):
-		"""Gets an <hooks>-elements and parses it.
-
-		@param hooks: the hooks node
-		@type hooks: NodeList"""
+		self.type = type
+		self.dep = dep
 
-		if hooks:
-			for h in hooks[0].getElementsByTagName("hook"):
-				hook = Hook(self, str(h.getAttribute("type")), str(h.getAttribute("call")))
-				hook.parse_connects(h.getElementsByTagName("connect"))
-				self.hooks.append(hook)
+class Hook (object):
+	__slots__ = ("before", "override", "after")
 
-	def parse_menus (self, menus):
-		"""Get a list of <menu>-elements and parses them.
+	def __init__ (self):
+		self.before = []
+		self.override = None
+		self.after = []
 
-		@param menus: the menu nodelist
-		@type menus: NodeList"""
+class Plugin (object):
 
-		if menus:
-			for item in menus[0].getElementsByTagName("item"):
-				menu = Menu(self, item.firstChild.nodeValue.strip(), str(item.getAttribute("call")))
-				self.menus.append(menu)
+	(STAT_DISABLED, STAT_TEMP_ENABLED, STAT_ENABLED, STAT_TEMP_DISABLED) = range(4)
 
-	def parse_options (self, options):
-		if options:
-			for o in options:
-				self.options.parse(o.getElementsByTagName("option"))
+	def __init__ (self):
+		self.__menus = []
+		self.__calls = []
+		self.state = STAT_ENABLED
 
-		self.status = self.STAT_DISABLED if self.options.get("disabled") else self.STAT_ENABLED
-	
-	def set_import (self, imports):
-		"""This gets a list of imports and parses them - setting the import needed to call the plugin.
-
-		@param imports: list of imports
-		@type imports: NodeList
-		
-		@raises PluginImportException: if the plugin's import could not be imported"""
+	@property
+	def author (self):
+		return getattr(self, "__author__", "")
 
-		if imports:
-			self._import = str(imports[0].firstChild.nodeValue.strip())
+	@property
+	def description (self):
+		if hasattr(self, "__description__"):
+			return self.__description__
+		else:
+			return getattr(self, "__doc__", "")
 
-			try: # try loading
-				mod = __import__(self._import)
-				del mod
-			except ImportError:
-				raise PluginImportException, self._import
+	@property
+	def name (self):
+		return getattr(self, "__name__", self.__class__.__name__)
 
-	def needs_import (self):
-		"""Returns True if an import is required prior to calling the plugin.
-		@rtype: bool"""
-		return self._import is not None
+	@property
+	def menus (self):
+		return iter(self.__menus)
 
-	def get_import (self):
-		"""Returns the module to import.
-		@rtype: string"""
-		return self._import
+	@property
+	def calls (self):
+		return iter(self.__calls)
 
-	def get_option(self, name):
-		return self.options.get(name)
+	def add_menu (self, label, callable):
+		self.__menus.append(Menu(label, callable))
 
-	def set_option (self, name, value):
-		return self.options.set(name, value)
+	def add_call (self, hook, callable, type = "before", dep = None):
+		self.__calls.append(Call(self, hook, callable, type, dep))
 
 	def is_enabled (self):
 		return (self.status in (self.STAT_ENABLED, self.STAT_TEMP_ENABLED))
 
-class PluginQueue:
+class PluginQueue (object):
 	"""Class managing and loading the plugins."""
 
-	def __init__ (self, frontend, load = True):
-		"""Constructor.
-		
-		@param frontend: the frontend used
-		@type frontend: string
-		@param load: if False nothing is loaded
-		@type load: bool"""
+	def __init__ (self):
+		"""
+		Constructor.
+		"""
 
-		self.frontend = frontend
-		self.list = []
-		self.hooks = {}
-		if load:
-			self._load()
+		self.plugins = []
+		self.hooks = defaultdict(Hook)
+		self._load()
 
 	def get_plugins (self, list_disabled = True):
-		return [x for x in self.list if (x.is_enabled() or list_disabled)]
+		return (x for x in self.plugins if (x.is_enabled() or list_disabled))
 
-	def get_plugin_data (self, list_disabled = False):
-		return [(x.name, x.author) for x in self.list if (x.is_enabled() or list_disabled)]
+	def _load (self):
+		"""Load the plugins."""
+		self._organize()
 
-	def get_plugin_menus (self, list_disabled = False):
-		return flatten([x.menus for x in self.list if (x.is_enabled() or list_disabled)])
+	def add (self, plugin):
+		self.plugins.append(plugin)
 
 	def hook (self, hook, *hargs, **hkwargs):
-		"""This is a method taking care of calling the plugins.
-		
-		B{Example}::
-			
-			@pluginQueue.hook("some_hook", data)
-			def function (a, b, c):
-				orig_call(b,c,data)
-			
-			def function (a, b, c):
-				hook = pluginQueue.hook("some_hook", data)
-				hook(orig_call)(b,c,data)
-
-		@param hook: the name of the hook
-		@type hook: string"""
-			
-		def call (cmd):
-			"""Convienience function for calling a connect.
-			@param cmd: the actual Connect
-			@type cmd: Connect"""
-
-			imp = ""
-			if cmd.hook.plugin.needs_import(): # get import
-				imp = cmd.hook.plugin.get_import()
-				try:
-					mod = __import__(imp, globals(), locals(), [cmd.hook.call])
-				except ImportError:
-					error(_("%s cannot be imported."), imp)
-					return
-
-				try:
-					f = eval("mod."+cmd.hook.call) # build function
-				except AttributeError:
-					error(_("%s cannot be imported."), cmd.hook.call)
-			else:
-				try:
-					f = eval(cmd.hook.call)
-				except AttributeError:
-					error(_("%s cannot be imported."), cmd.hook.call)
-
-			return f(*hargs, **hkwargs) # call function
 
 		def hook_decorator (func):
-			"""This is the real decorator."""
-			
-			if hook in self.hooks:
-				list = self.hooks[hook]
-			else:
-				list = ([],[],[])
+			h = self.hooks.hook
+
+			active = Hook()
 
 			# remove disabled
-			_list = ([],[],[])
-			for i in range(len(list)):
-				for cmd in list[i]:
-					if cmd.hook.plugin.is_enabled():
-						_list[i].append(cmd)
-			
-			list = _list
+			for type in ("before", "after"):
+				calls = getattr(h, type)
+				aCalls = getattr(active, type)
+				for call in calls:
+					if call.plugin.is_enabled():
+						aCalls.append(call)
 
+			if h.override and h.override.plugin.is_enabled():
+				active.override = h.override
+
+			@wraps(func)
 			def wrapper (*args, **kwargs):
-				
 				ret = None
 
 				# before
-				for cmd in list[0]:
-					debug(_("Accessing hook '%(hook)s' of plugin '%(plugin)s' (before)."), {"hook" : hook, "plugin": cmd.hook.plugin.name})
-					call(cmd)
+				for call in active.before:
+					debug("Accessing hook '%(hook)s' of plugin '%(plugin)s' (before).", {"hook" : hook, "plugin": call.plugin.name})
+					call.call(*hargs, **hkwargs)
 				
-				if list[1]: # override
-					info(_("Overriding hook '%(hook)s' with plugin '%(plugin)s'."), {"hook": hook, "plugin": list[1][0].hook.plugin.name})
-					ret = call(list[1][0])
+				if active.override: # override
+					info(_("Overriding hook '%(hook)s' with plugin '%(plugin)s'."), {"hook": hook, "plugin": active.override.plugin.name})
+					ret = active.override.call(*hargs, **hkwargs)
 				else: # normal
 					ret = func(*args, **kwargs)
 
 				# after
-				for cmd in list[2]:
-					debug(_("Accessing hook '%(hook)s' of plugin '%(plugin)s' (after)."), {"hook":hook, "plugin": cmd.hook.plugin.name})
-					call(cmd)
+				for call in active.after:
+					debug("Accessing hook '%(hook)s' of plugin '%(plugin)s' (after).", {"hook": hook, "plugin": call.plugin.name})
+					call.call(*hargs, **hkwargs)
 
 				return ret
 
@@ -353,166 +149,99 @@ class PluginQueue:
 
 		return hook_decorator
 
-	def _load (self):
-		"""Load the plugins."""
-		plugins = filter(lambda x: x.endswith(".xml"), os.listdir(PLUGIN_DIR))
-		plugins = map(lambda x: os.path.join(PLUGIN_DIR, x), plugins)
-		schema = etree.XMLSchema(file = XSD_LOCATION)
-
-		for p in plugins:
-			
-			try:
-				schema.assertValid(etree.parse(p))
-			except etree.XMLSyntaxError:
-				error(_("Loading plugin '%s' failed. Invalid XML syntax."), p)
-				continue
-			except etree.DocumentInvalid:
-				error(_("Loading plugin '%s' failed. Plugin does not comply with schema."), p)
-				continue
-
-			doc = parse(p)
-			
-			try:
-				list = doc.getElementsByTagName("plugin")
-				elem = list[0]
-
-				frontendOK = None
-				frontends = elem.getElementsByTagName("frontends")
-				if frontends:
-					nodes = frontends[0].childNodes
-					for f in nodes[0].nodeValue.strip().split():
-						if f == self.frontend:
-							frontendOK = True # one positive is enough
-							break
-						elif frontendOK is None: # do not make negative if we already have a positive
-							frontendOK = False
-
-				if frontendOK is None or frontendOK == True:
-					plugin = Plugin(p, elem.getElementsByTagName("name")[0], elem.getElementsByTagName("author")[0])
-					plugin.parse_hooks(elem.getElementsByTagName("hooks"))
-					plugin.set_import(elem.getElementsByTagName("import"))
-					plugin.parse_menus(elem.getElementsByTagName("menu"))
-					plugin.parse_options(elem.getElementsByTagName("options"))
-				
-					self.list.append(plugin)
-					info(_("Plugin '%s' loaded."), p)
-			
-			except PluginImportException, e:
-				error(_("Loading plugin '%(plugin)s' failed: Could not import %(import)s"), {"plugin": p, "import": e[0]})
-			finally:
-				doc.unlink()
-
-		self._organize()
-
 	def _organize (self):
 		"""Creates the lists of connects in a way, that all dependencies are fullfilled."""
-		unresolved_before = {} 
-		unresolved_after = {}
-		star_before = {} # should be _before_ all other
-		star_after = {} # should be _after_ all other
-
-		for plugin in self.list: # plugins
-			for hook in plugin.hooks: # hooks in plugin
-				if not hook.hook in self.hooks:
-					self.hooks[hook.hook] = ([], [], [])
-
-				for connect in hook.connects: # connects in hook
-					
-					# type="before"
-					if connect.is_before_type():
-						if connect.depend_plugin is None: # no dependency -> straight add
-							self.hooks[hook.hook][0].append(connect)
-						elif connect.depend_plugin == "*":
-							self.hooks[hook.hook][0][0:0] = [connect]
-						elif connect.depend_plugin == "-*":
-							if not hook.hook in star_before:
-								star_before[hook.hook] = []
-
-							star_before[hook.hook].append(connect)
+		unresolved_before = defaultdict(list)
+		unresolved_after = defaultdict(list)
+		star_before = defaultdict(Hook) # should be _before_ all other
+		star_after = defaultdict(Hook) # should be _after_ all other
+
+		for plugin in self.plugins: # plugins
+			for call in plugin.calls: # hooks in plugin
+				if call.type == "before":
+					if call.dep is None: # no dependency -> straight add
+						self.hooks[call.hook].before.append(call)
+					elif call.dep == "*":
+						self.hooks[call.hook].before.insert(0, call)
+					elif call.dep == "-*":
+						star_before[call.hook].append(call)
+					else:
+						named = [x.plugin.name for x in self.hooks[call.hook].before]
+						if call.dep in named:
+							self.hooks[call.hook].before.insert(named.index(call.dep), call)
 						else:
-							named = [x.plugin.name for x in self.hooks[hook.hook][0]]
-							if connect.depend_plugin in named:
-								self.hooks[hook.hook][0].insert(named.index(connect.depend_plugin), connect)
-							else:
-								if not hook.hook in unresolved_before:
-									unresolved_before[hook.hook] = []
-								
-								unresolved_before[hook.hook].append(connect)
-
-					# type = "after"
-					elif connect.is_after_type():
-						if connect.depend_plugin is None: # no dependency -> straight add
-							self.hooks[hook.hook][2].append(connect)
-						elif connect.depend_plugin == "*":
-							if not hook.hook in star_after:
-								star_after[hook.hook] = []
-
-							star_after[hook.hook].append(connect)
-						elif connect.depend_plugin == "-*":
-							self.hooks[hook.hook][2][0:0] = [connect]
+							unresolved_before[call.hook].append(call)
+
+				elif call.type == "after":
+					if call.dep is None: # no dependency -> straight add
+						self.hooks[call.hook].after.append(call)
+					elif call.dep == "*":
+						star_after[call.hook].append(call)
+					elif call.dep == "-*":
+						self.hooks[call.hook].after.insert(0, call)
+					else:
+						named = [x.plugin.name for x in self.hooks[call.hook].after]
+						if call.dep in named:
+							self.hooks[call.hook].after.insert(named.index(call.dep)+1, call)
 						else:
-							named = [x.hook.plugin.name for x in self.hooks[hook.hook][2]]
-							if connect.depend_plugin in named:
-								self.hooks[hook.hook][2].insert(named.index(connect.depend_plugin)+1, connect)
-							else:
-								if not hook.hook in unresolved_after:
-									unresolved_after[hook.hook] = []
-								
-								unresolved_after[hook.hook].append(connect)
+							unresolved_after[call.hook].append(call)
+				
+				# type = "override"
+				elif call.type == "override":
+					if self.hooks[call.hook].override:
+						warning(_("For hook '%(hook)s' an override is already defined by plugin '%(plugin)s'!"), {"hook": call.hook, "plugin": self.hooks[call.hook].override.plugin.name})
+						warning(_("It is now replaced by the one from plugin '%s'!"), call.plugin.name)
 					
-					# type = "override"
-					elif connect.is_override_type():
-						if self.hooks[hook.hook][1]:
-							warning(_("For hook '%(hook)s' an override is already defined by plugin '%(plugin)s'!"), {"hook": hook.hook, "plugin": self.hooks[hook.hook][1][0]})
-						
-						self.hooks[hook.hook][1][:1] = [connect]
-						continue
+					self.hooks[call.hook].override = call
+					continue
 		
 		self._resolve_unresolved(unresolved_before, unresolved_after)
 
-		for hook in star_before:
-			self.hooks[hook][0].extend(star_before[hook]) # append the list
+		for hook, calls in star_before.iteritems():
+			self.hooks[hook].before.extend(calls) # append the list
 
-		for hook in star_after:
-			self.hooks[hook][2].extend(star_after[hook]) # append the list
+		for hook, calls in star_after.iteritems():
+			self.hooks[hook].after.extend(calls) # append the list
 
 
 	def _resolve_unresolved (self, before, after):
-		def resolve(hook, list, idx, add):
+		def resolve(hook, list, type, add):
 			if not list: 
 				return
 			
-			changed = False
-			for connect in list[:]:
-				named = [x.plugin.name for x in self.hooks[hook][idx]]
-				if connect.depend_plugin in named:
-					changed = True
-					self.hooks[hook][idx].insert(named.index(connect.depend_plugin)+add, connect)
-					list.remove(connect)
+			callList = getattr(self.hooks[hook], type)
+			named = [x.plugin.name for x in callList]
+
+			while list and named:
+				newNamed = [] # use newNamed, so in each iteration only the plugins inserted last are searched
+				for call in list[:]:
+					if call.dep in named:
+						callList.insert(named.index(call.dep)+add, call)
+						list.remove(call)
+						newNamed.append(call.plugin.name)
 
-			if changed:
-				resolve(hook, list, idx, add)
+				named = newNamed
 
 			for l in list:
-				warning("Command for hook '%(hook)s' in plugin '%(plugin)s' could not be added due to missing dependant: '%(dep)s'!", {"hook": hook, "plugin": l.hook.plugin.name, "dep": l.depend_plugin})
+				warning(_("Command for hook '%(hook)s' in plugin '%(plugin)s' could not be added due to missing dependant: '%(dep)s'!"), {"hook": hook, "plugin": l.plugin.name, "dep": l.dep})
 
 		for hook in before:
-			resolve(hook, before[hook], 0, 0)
+			resolve(hook, before[hook], "before", 0)
 		
 		for hook in after:
-			resolve(hook, after[hook], 2, 1)
+			resolve(hook, after[hook], "after", 1)
 
 
 __plugins = None
 
-def load_plugins(frontend):
-	"""Loads the plugins for a given frontend.
-	@param frontend: The frontend. See L{constants.FRONTENDS} for the correct list of values.
-	@type frontend: string"""
-
+def load_plugins():
+	"""
+	Loads the plugins.
+	"""
+	
 	global __plugins
-	if __plugins is None or __plugins.frontend != frontend:
-		__plugins = PluginQueue(frontend)
+	if __plugins is None:
+		__plugins = PluginQueue()
 
 def get_plugin_queue():
 	"""Returns the actual L{PluginQueue}. If it is C{None}, they are not being loaded yet.
@@ -528,3 +257,7 @@ def hook(hook, *args, **kwargs):
 		return pseudo_decorator
 	else:
 		return __plugins.hook(hook, *args, **kwargs)
+
+def register (plugin):
+	if __plugins is not None:
+		__plugins.add(plugin)