Bug #275047 - Split _emerge/__init__.py into smaller pieces (part 3).

Thanks to Sebastian Mingramm (few) <s.mingramm@gmx.de> for this patch.

svn path=/main/trunk/; revision=13668

1 files changed, 77 insertions, 0 deletions

diff --git a/pym/_emerge/QueueScheduler.py b/pym/_emerge/QueueScheduler.py
new file mode 100644
index 000000000..f88c13caa
--- /dev/null
+++ b/pym/_emerge/QueueScheduler.py
@@ -0,0 +1,77 @@
+from _emerge.PollScheduler import PollScheduler
+
+class QueueScheduler(PollScheduler):
+
+	"""
+	Add instances of SequentialTaskQueue and then call run(). The
+	run() method returns when no tasks remain.
+	"""
+
+	def __init__(self, max_jobs=None, max_load=None):
+		PollScheduler.__init__(self)
+
+		if max_jobs is None:
+			max_jobs = 1
+
+		self._max_jobs = max_jobs
+		self._max_load = max_load
+		self.sched_iface = self._sched_iface_class(
+			register=self._register,
+			schedule=self._schedule_wait,
+			unregister=self._unregister)
+
+		self._queues = []
+		self._schedule_listeners = []
+
+	def add(self, q):
+		self._queues.append(q)
+
+	def remove(self, q):
+		self._queues.remove(q)
+
+	def run(self):
+
+		while self._schedule():
+			self._poll_loop()
+
+		while self._running_job_count():
+			self._poll_loop()
+
+	def _schedule_tasks(self):
+		"""
+		@rtype: bool
+		@returns: True if there may be remaining tasks to schedule,
+			False otherwise.
+		"""
+		while self._can_add_job():
+			n = self._max_jobs - self._running_job_count()
+			if n < 1:
+				break
+
+			if not self._start_next_job(n):
+				return False
+
+		for q in self._queues:
+			if q:
+				return True
+		return False
+
+	def _running_job_count(self):
+		job_count = 0
+		for q in self._queues:
+			job_count += len(q.running_tasks)
+		self._jobs = job_count
+		return job_count
+
+	def _start_next_job(self, n=1):
+		started_count = 0
+		for q in self._queues:
+			initial_job_count = len(q.running_tasks)
+			q.schedule()
+			final_job_count = len(q.running_tasks)
+			if final_job_count > initial_job_count:
+				started_count += (final_job_count - initial_job_count)
+			if started_count >= n:
+				break
+		return started_count
+