Merge branch 'taskdep' into async

Author: Byron

lib/git/async/channel.py

@@ -21,61 +21,57 @@ class Channel(object):
 	If the channel is closed, any read operation will result in an exception
 	
 	This base class is not instantiated directly, but instead serves as constructor
-	for RWChannel pairs.
+	for Rwriter pairs.
 	
 	Create a new channel """
-	__slots__ = tuple()
-
-
-class WChannel(Channel):
-	"""The write end of a channel - it is thread-safe"""
-	__slots__ = ('_queue')
+	__slots__ = 'queue'
 
 	# The queue to use to store the actual data
 	QueueCls = AsyncQueue
 
 	def __init__(self):
-		"""initialize this instance, able to hold max_items at once
-		Write calls will block if the channel is full, until someone reads from it"""
-		self._queue = self.QueueCls()
-	
-	#{ Interface 
-	def write(self, item, block=True, timeout=None):
-		"""Send an item into the channel, it can be read from the read end of the 
-		channel accordingly
-		:param item: Item to send
-		:param block: If True, the call will block until there is free space in the 
-			channel
-		:param timeout: timeout in seconds for blocking calls.
-		:raise ReadOnly: when writing into closed channel"""
-		# let the queue handle the 'closed' attribute, we write much more often 
-		# to an open channel than to a closed one, saving a few cycles
-		self._queue.put(item, block, timeout)
-		
+		"""initialize this instance with a queue holding the channel contents""" 
+		self.queue = self.QueueCls()
+
+
+class SerialChannel(Channel):
+	"""A slightly faster version of a Channel, which sacrificed thead-safety for performance"""
+	QueueCls = SyncQueue
+
+
+class Writer(object):
+	"""The write end of a channel, a file-like interface for a channel"""
+	__slots__ = ('write', 'channel')
+	
+	def __init__(self, channel):
+		"""Initialize the writer to use the given channel"""
+		self.channel = channel
+		self.write = channel.queue.put
+	
+	#{ Interface
 	def size(self):
-		""":return: approximate number of items that could be read from the read-ends
-			of this channel"""
-		return self._queue.qsize()
+		return self.channel.queue.qsize()
 
 	def close(self):
 		"""Close the channel. Multiple close calls on a closed channel are no 
 		an error"""
-		self._queue.set_writable(False)
+		self.channel.queue.set_writable(False)
 
 	def closed(self):
 		""":return: True if the channel was closed"""
-		return not self._queue.writable()
+		return not self.channel.queue.writable()
 	#} END interface 
 
 
-class CallbackWChannel(WChannel):
+class CallbackWriter(Writer):
 	"""The write end of a channel which allows you to setup a callback to be 
 	called after an item was written to the channel"""
 	__slots__ = ('_pre_cb')
 
-	def __init__(self):
-		WChannel.__init__(self)
+	def __init__(self, channel):
+		Writer.__init__(self, channel)
 		self._pre_cb = None
+		self.write = self._write
 
 	def set_pre_cb(self, fun = lambda item: item):
 		"""Install a callback to be called before the given item is written.
@@ -88,25 +84,19 @@ def set_pre_cb(self, fun = lambda item: item):
 		self._pre_cb = fun
 		return prev
 
-	def write(self, item, block=True, timeout=None):
+	def _write(self, item, block=True, timeout=None):
 		if self._pre_cb:
 			item = self._pre_cb(item)
-		WChannel.write(self, item, block, timeout)
+		self.channel.queue.put(item, block, timeout)
 
-	
-class SerialWChannel(WChannel):
-	"""A slightly faster version of a WChannel, which sacrificed thead-safety for
-	performance"""
-	QueueCls = SyncQueue
-
 
-class RChannel(Channel):
-	"""The read-end of a corresponding write channel"""
-	__slots__ = '_wc'
+class Reader(object):
+	"""Allows reading from a channel"""
+	__slots__ = 'channel'
 
-	def __init__(self, wchannel):
+	def __init__(self, channel):
 		"""Initialize this instance from its parent write channel"""
-		self._wc = wchannel
+		self.channel = channel
 
 
 	#{ Interface
@@ -135,7 +125,7 @@ def read(self, count=0, block=True, timeout=None):
 
 		# in non-blocking mode, its all not a problem
 		out = list()
-		queue = self._wc._queue
+		queue = self.channel.queue
 		if not block:
 			# be as fast as possible in non-blocking mode, hence
 			# its a bit 'unrolled'
@@ -198,12 +188,12 @@ def read(self, count=0, block=True, timeout=None):
 
 	#} END interface 
 
-class CallbackRChannel(RChannel):
+class CallbackReader(Reader):
 	"""A channel which sends a callback before items are read from the channel"""
 	__slots__ = "_pre_cb"
 
-	def __init__(self, wc):
-		RChannel.__init__(self, wc)
+	def __init__(self, channel):
+		Reader.__init__(self, channel)
 		self._pre_cb = None
 
 	def set_pre_cb(self, fun = lambda count: None):
@@ -220,18 +210,20 @@ def set_pre_cb(self, fun = lambda count: None):
 	def read(self, count=0, block=True, timeout=None):
 		if self._pre_cb:
 			self._pre_cb(count)
-		return RChannel.read(self, count, block, timeout)
+		return Reader.read(self, count, block, timeout)
 
 
 #} END classes
 
 #{ Constructors
-def mkchannel(wctype = WChannel, rctype = RChannel):
-	"""Create a channel, which consists of one write end and one read end
-	:return: tuple(write_channel, read_channel)
+def mkchannel(ctype = Channel, wtype = Writer, rtype = Reader):
+	"""Create a channel, with a reader and a writer
+	:return: tuple(reader, writer)
+	:param ctype: Channel to instantiate
 	:param wctype: The type of the write channel to instantiate
 	:param rctype: The type of the read channel to instantiate"""
-	wc = wctype()
-	rc = rctype(wc)
+	c = ctype()
+	wc = wtype(c)
+	rc = rtype(c)
 	return wc, rc
 #} END constructors

lib/git/async/graph.py

@@ -25,14 +25,24 @@ class Graph(object):
 
 	def __init__(self):
 		self.nodes = list()
+
+	def __del__(self):
+		"""Deletes bidericational dependencies"""
+		for node in self.nodes:
+			node.in_nodes = None
+			node.out_nodes = None
+		# END cleanup nodes
+		
+		# otherwise the nodes would keep floating around
 
+
 	def add_node(self, node):
 		"""Add a new node to the graph
 		:return: the newly added node"""
 		self.nodes.append(node)
 		return node
 
-	def del_node(self, node):
+	def remove_node(self, node):
 		"""Delete a node from the graph
 		:return: self"""
 		try:
@@ -46,6 +56,8 @@ def del_node(self, node):
 			del(outn.in_nodes[outn.in_nodes.index(node)])
 		for inn in node.in_nodes:
 			del(inn.out_nodes[inn.out_nodes.index(node)])
+		node.out_nodes = list()
+		node.in_nodes = list()
 		return self
 
 	def add_edge(self, u, v):
@@ -87,25 +99,26 @@ def add_edge(self, u, v):
 
 		return self
 
-	def visit_input_inclusive_depth_first(self, node, visitor=lambda n: True ):
-		"""Visit all input nodes of the given node, depth first, calling visitor
-		for each node on our way. If the function returns False, the traversal 
-		will not go any deeper, but continue at the next branch
-		It will return the actual input node in the end !"""
-		nodes = node.in_nodes[:]
+	def input_inclusive_dfirst_reversed(self, node):
+		"""Return all input nodes of the given node, depth first,
+		It will return the actual input node last, as it is required
+		like that by the pool"""
+		stack = [node]
 		seen = set()
 
 		# depth first
-		while nodes:
-			n = nodes.pop()
+		out = list()
+		while stack:
+			n = stack.pop()
 			if n in seen:
 				continue
 			seen.add(n)
+			out.append(n)
 
 			# only proceed in that direction if visitor is fine with it
-			if visitor(n):
-				nodes.extend(n.in_nodes)
+			stack.extend(n.in_nodes)
 			# END call visitor
 		# END while walking
-		visitor(node)
+		out.reverse()
+		return out