chat-archiver: Merge all files every minute

chat_archiver/chat_archiver/main.py

@@ -19,6 +19,7 @@ import gevent.queue
 from common import ensure_directory
 
 from girc import Client
+from monotonic import monotonic
 
 # How long each batch is
 BATCH_INTERVAL = 60
@@ -239,25 +240,44 @@ def get_batch_files(path, batch_time):
 	]
 
 
-def merge_all(path):
+def merge_all(path, interval=None, stopping=None):
 	"""Repeatedly scans the batch directory for batch files with the same batch time, and merges them.
-	Returns once it finds no duplicate files."""
-	while True:
-		by_time = {}
-		for hour in os.listdir(path):
-			for name in os.listdir(os.path.join(path, hour)):
-				if not name.endswith(".json"):
-					continue
-			time = "-".join(name.split("-")[:3])
-			timestamp = "{}:{}".format(hour, time)
-			by_time[timestamp] = by_time.get(timestamp, 0) + 1
-		if not any(count > 1 for timestamp, count in by_time.items()):
+	By default, returns once it finds no duplicate files.
+	If interval is given, re-scans after that number of seconds.
+	If a gevent.event.Event() is passed in as stopping arg, returns when that event is set.
+	"""
+	if stopping is None:
+		# nothing will ever set this, but it's easier to not special-case it everywhere
+		stopping = gevent.event.Event()
+	while not stopping.is_set():
+		start = monotonic()
+		# loop until no changes
+		while True:
+			logging.debug("Scanning for merges")
+			by_time = {}
+			for hour in os.listdir(path):
+				for name in os.listdir(os.path.join(path, hour)):
+					if not name.endswith(".json"):
+						continue
+				time = "-".join(name.split("-")[:3])
+				timestamp = "{}:{}".format(hour, time)
+				by_time[timestamp] = by_time.get(timestamp, 0) + 1
+			if not any(count > 1 for timestamp, count in by_time.items()):
+				logging.info("All batches are merged")
+				break
+			for timestamp, count in by_time.items():
+				if count > 1:
+					logging.info("Merging {} batches at time {}".format(count, timestamp))
+					batch_time = timegm(time.strptime(timestamp, "%Y-%m-%dT%H:%M:%S"))
+					merge_batch_files(path, batch_time)
+		if interval is None:
+			# one-shot
 			break
-		for timestamp, count in by_time.items():
-			if count > 1:
-				logging.info("Merging {} batches at time {}".format(count, timestamp))
-				batch_time = timegm(time.strptime(timestamp, "%Y-%m-%dT%H:%M:%S"))
-				merge_batch_files(path, batch_time)
+		next_run = start + interval
+		remaining = next_run - monotonic()
+		if remaining > 0:
+			logging.debug("Waiting {}s for next merge scan".format(remaining))
+			stopping.wait(remaining)
 
 
 def merge_batch_files(path, batch_time):
@@ -399,7 +419,7 @@ def merge_messages(left, right):
 	return result
 
 
-def main(channel, nick, oauth_token_path, base_dir='/mnt', name=None):
+def main(channel, nick, oauth_token_path, base_dir='/mnt', name=None, merge_interval=60):
 	with open(oauth_token_path) as f:
 		oauth_token = f.read()
 	# To ensure uniqueness even if multiple instances are running on the same host,
@@ -411,13 +431,19 @@ def main(channel, nick, oauth_token_path, base_dir='/mnt', name=None):
 	stopping = gevent.event.Event()
 	gevent.signal_handler(signal.SIGTERM, stopping.set)
 
+	merger = gevent.spawn(merge_all,
+		os.path.join(base_dir, channel, "chat"),
+		interval=merge_interval,
+		stopping=stopping
+	)
+
 	logging.info("Starting")
 	for index in count():
 		# To ensure uniqueness between clients, include a client number
 		archiver = Archiver("{}.{}".format(name, index), base_dir, channel, nick, oauth_token)
 		worker = gevent.spawn(archiver.run)
 		# wait for either graceful exit, error, or for a signal from the archiver that a reconnect was requested
-		gevent.wait([stopping, worker, archiver.got_reconnect], count=1)
+		gevent.wait([stopping, worker, merger, archiver.got_reconnect], count=1)
 		if stopping.is_set():
 			archiver.stop()
 			worker.get()
@@ -427,7 +453,13 @@ def main(channel, nick, oauth_token_path, base_dir='/mnt', name=None):
 		if archiver.got_reconnect.is_set():
 			logging.info("Got RECONNECT, creating new client while waiting for old one to finish")
 			continue
-		# the only remaining case is that the worker failed, re-raise
+		# the only remaining case is that something failed. stop everything and re-raise.
+		logging.warning("Stopping due to worker dying")
+		stopping.set()
+		worker.join()
+		merger.join()
+		# at least one of these two should raise
 		worker.get()
-		assert False, "Not stopping, but worker exited successfully"
+		merger.get()
+		assert False, "Worker unexpectedly exited successfully"
 	logging.info("Gracefully stopped")

chat_archiver/setup.py

@@ -10,5 +10,6 @@ setup(
 	install_requires=[
 		'argh',
 		'gevent',
+		'monotonic',
 	],
 )