More messing around with backfill_node to allow finer grained control of order segments are fetched

backfiller/backfiller/main.py

@@ -132,7 +132,8 @@ def is_iterable(x):
 
 
 def backfill_node(base_dir, node, stream, variants, hours=None, start=None,
-		stop=None, order=None, recent_cutoff=60):
+		stop=None, hour_order=None, segment_order='random', get_full_hour=True,
+		recent_cutoff=60):
 	"""Backfill from remote node.
 
 	Backfill from node/stream/variants to base_dir/stream/variants.
@@ -142,14 +143,22 @@ def backfill_node(base_dir, node, stream, variants, hours=None, start=None,
 		backfill only hours in iterable. Otherwise backfill the last N hours,
 		starting with the lastest.
 	start -- Only backfill hours starting after or equal to this datetime
-		object. If None (default), backfill all hours.
+		object. If None (default), backfill all hours. If get_full_hour is
+		False, only segments starting after start will be backfilled.
 	stop -- Only backfill hours starting before or equal to this datetime
-		object. If None (default), backfill all hours.
-	order -- If 'random', randomise the order of hours. If 'forward', sort the
-		hours in ascending order. If 'reverse', sort the hours in descending
-		order. Otherwise, do not change the order of hours (default).
+		object. If None (default), backfill all hours. If get_full_hour is
+		False, only segments finishing before stop will be backfilled.
+	hour_order -- If 'random', randomise the order of hours. If 'forward', sort
+		the hours in ascending order. If 'reverse', sort the hours in descending		order. Otherwise, do not change the order of hours (default).
+	segment_order -- If 'random', randomise the order of segments (default).
+		If 'forward', sort the segment in ascending order. If 'reverse', sort
+		the segments in descending order. Otherwise, do not change the order of
+		segments.
+	get_full_hour -- If True (default), get all segments in an hour. If False,
+		use start and stop to limit which segments are backfilled.
 	recent_cutoff -- Skip backfilling segments younger than this number of
 		seconds to prioritise letting the downloader grab these segments."""
+
 	logging.info('Starting backfilling from {}'.format(node))
 
 	if hours is None:
@@ -172,14 +181,12 @@ def backfill_node(base_dir, node, stream, variants, hours=None, start=None,
 	if stop is not None:
 		hours = [hour for hour in hours if hour <= stop]
 
-	# useful if running in parallel and expecting to fetch a segments from
-	# multiple hours (say on start up) so that you don't try to backfill the
-	# same hour at the same time 
-	if order == 'random':
+	# useful if running in parallel so multiple nodes don't request the same hour at the same time
+	if hour_order == 'random':
 		random.shuffle(hours)
-	elif order == 'forward':
+	elif hour_order == 'forward':
 		hours.sort()
-	elif order == 'reverse':
+	elif hour_order == 'reverse':
 		hours.sort(reverse=True)
 
 	for variant in variants:
@@ -188,7 +195,15 @@ def backfill_node(base_dir, node, stream, variants, hours=None, start=None,
 
 			local_segments = set(list_local_segments(base_dir, stream, variant, hour))
 			remote_segments = set(list_remote_segments(node, stream, variant, hour))
-			missing_segments = remote_segments - local_segments
+			missing_segments = list(remote_segments - local_segments)
+
+			# useful if running in parallel so multiple nodes don't request the same segment at the same time
+			if segment_order == 'random':
+				random.shuffle(missing_segments)
+			elif segment_order == 'forward':
+				missing_segments.sort()
+			elif segment_order == 'reverse':
+				missing_segments.sort(reverse=True)
 
 			for missing_segment in missing_segments:
 
@@ -201,6 +216,11 @@ def backfill_node(base_dir, node, stream, variants, hours=None, start=None,
 					logging.warning('File {} invaid: {}'.format(path, e.value))
 					continue
 				
+				if not get_full_hour and start is not None and segment['start'] < start:
+					continue
+				if not get_full_hour and start is not None and segment['end'] > stop:
+					continue
+
 				#to avoid getting in the downloader's way ignore segments less than recent_cutoff old
 				if datetime.datetime.utcnow() - segment['start'] < datetime.timedelta(seconds=recent_cutoff):
 					continue