thread: adjusted worker thread not to provide an output queue anymore - this is handled by the task system

graph: implemented it including test according to the pools requirements
pool: implemented set_pool_size

1 files changed, 74 insertions, 10 deletions

diff --git a/lib/git/async/graph.py b/lib/git/async/graph.py
index 0c0a2137..b4d6aa00 100644
--- a/lib/git/async/graph.py
+++ b/lib/git/async/graph.py
@@ -6,31 +6,95 @@ class Node(object):
 	we need"""
 	__slots__ = ('in_nodes', 'out_nodes')
 	
+	def __init__(self):
+		self.in_nodes = list()
+		self.out_nodes = list()
+	
 	
 class Graph(object):
 	"""A simple graph implementation, keeping nodes and providing basic access and 
-	editing functions"""
+	editing functions. The performance is only suitable for small graphs of not 
+	more than 10 nodes !"""
 	__slots__ = "nodes"
 	
 	def __init__(self):
 		self.nodes = list()
 	
 	def add_node(self, node):
-		"""Add a new node to the graph"""
-		raise NotImplementedError()
+		"""Add a new node to the graph
+		:return: the newly added node"""
+		self.nodes.append(node)
+		return node
 	
 	def del_node(self, node):
-		"""Delete a node from the graph"""
-		raise NotImplementedError()
+		"""Delete a node from the graph
+		:return: self"""
+		# clear connections
+		for outn in node.out_nodes:
+			del(outn.in_nodes[outn.in_nodes.index(node)])
+		for inn in node.in_nodes:
+			del(inn.out_nodes[inn.out_nodes.index(node)])
+		del(self.nodes[self.nodes.index(node)]) 
+		return self
 	
 	def add_edge(self, u, v):
 		"""Add an undirected edge between the given nodes u and v.
+		
+		return: self
 		:raise ValueError: If the new edge would create a cycle"""
-		raise NotImplementedError()
+		if u is v:
+			raise ValueError("Cannot connect a node with itself")
+		
+		# are they already connected ?
+		if 	u in v.in_nodes and v in u.out_nodes or \
+			v in u.in_nodes and u in v.out_nodes:
+			return self
+		# END handle connection exists
+		
+		# cycle check - if we can reach any of the two by following either ones 
+		# history, its a cycle
+		for start, end in ((u, v), (v,u)):
+			if not start.in_nodes: 
+				continue
+			nodes = start.in_nodes[:]
+			seen = set()
+			# depth first search - its faster
+			while nodes:
+				n = nodes.pop()
+				if n in seen:
+					continue
+				seen.add(n)
+				if n is end:
+					raise ValueError("Connecting u with v would create a cycle")
+				nodes.extend(n.in_nodes)
+			# END while we are searching
+		# END for each direction to look
+		
+		# connection is valid, set it up
+		u.out_nodes.append(v)
+		v.in_nodes.append(u)
+		
+		return self
 	
-	def visit_input_depth_first(self, node, visitor=lambda n: True ):
+	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"""
-		raise NotImplementedError()
-
+		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[:]
+		seen = set()
+		
+		# depth first
+		while nodes:
+			n = nodes.pop()
+			if n in seen:
+				continue
+			seen.add(n)
+			
+			# only proceed in that direction if visitor is fine with it
+			if visitor(n):
+				nodes.extend(n.in_nodes)
+			# END call visitor
+		# END while walking
+		visitor(node)
+