From 4be39bf9859bab05a6cb61bf7d6145dc267367de Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 4 Aug 2012 17:13:20 +0000
Subject: [PATCH] Replace those complicated wait construct by a efficient Timer
 class.

Timer is a low-resolution timeout system that lets us have
long timeouts very energy-efficient and interuptable.
---
 collecty/__init__.py         | 12 ++++----
 collecty/plugins/__init__.py |  2 ++
 collecty/plugins/base.py     | 54 +++++++++++++++++++++++++++---------
 3 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/collecty/__init__.py b/collecty/__init__.py
index 5e684f4..b7e1f22 100644
--- a/collecty/__init__.py
+++ b/collecty/__init__.py
@@ -47,14 +47,13 @@ class Collecty(object):
 	# The default interval, when all data is written to disk.
 	SUBMIT_INTERVAL = 300
 
-	HEARTBEAT = 2
-
 	def __init__(self):
 		self.config = configparser.ConfigParser()
 		self.instances = []
 
 		# Indicates whether this process should be running or not.
 		self.running = True
+		self.timer = plugins.Timer(self.SUBMIT_INTERVAL, heartbeat=2)
 
 		# Add all automatic plugins.
 		self.add_autocreate_plugins()
@@ -110,14 +109,11 @@ class Collecty(object):
 			i.start()
 
 		# Regularly submit all data to disk.
-		counter = self.SUBMIT_INTERVAL / self.HEARTBEAT
 		while self.running:
-			time.sleep(self.HEARTBEAT)
-			counter -= 1
+			self.timer.reset()
 
-			if counter == 0:
+			if self.timer.wait():
 				self.submit_all()
-				counter = self.SUBMIT_INTERVAL / self.HEARTBEAT
 
 		# Wait until all instances are finished.
 		while self.instances:
@@ -142,6 +138,8 @@ class Collecty(object):
 		log.debug(_("Received shutdown signal"))
 
 		self.running = False
+		if self.timer:
+			self.timer.cancel()
 
 		# Propagating shutdown to all threads.
 		for i in self.instances:
diff --git a/collecty/plugins/__init__.py b/collecty/plugins/__init__.py
index a8af815..71cf971 100644
--- a/collecty/plugins/__init__.py
+++ b/collecty/plugins/__init__.py
@@ -19,6 +19,8 @@
 #                                                                             #
 ###############################################################################
 
+from base import Timer
+
 import cpu
 import loadavg
 import memory
diff --git a/collecty/plugins/base.py b/collecty/plugins/base.py
index 472a3a0..e85653e 100644
--- a/collecty/plugins/base.py
+++ b/collecty/plugins/base.py
@@ -28,6 +28,34 @@ import time
 from ..constants import *
 from ..i18n import _
 
+class Timer(object):
+	def __init__(self, timeout, heartbeat=1):
+		self.timeout = timeout
+		self.heartbeat = heartbeat
+
+		self.reset()
+
+	def reset(self):
+		# Save start time.
+		self.start = time.time()
+
+		# Has this timer been killed?
+		self.killed = False
+
+	@property
+	def elapsed(self):
+		return time.time() - self.start
+
+	def cancel(self):
+		self.killed = True
+
+	def wait(self):
+		while self.elapsed < self.timeout and not self.killed:
+			time.sleep(self.heartbeat)
+
+		return self.elapsed > self.timeout
+
+
 class Plugin(threading.Thread):
 	# The name of this plugin.
 	name = None
@@ -56,10 +84,6 @@ class Plugin(threading.Thread):
 		self.log = logging.getLogger("collecty.plugins.%s" % self.name)
 		self.log.propagate = 1
 
-		# Keepalive options
-		self.heartbeat = 2
-		self.running = True
-
 		self.data = []
 
 		# Create the database file.
@@ -68,6 +92,10 @@ class Plugin(threading.Thread):
 		# Run some custom initialization.
 		self.init()
 
+		# Keepalive options
+		self.running = True
+		self.timer = Timer(self.interval)
+
 		self.log.info(_("Successfully initialized."))
 	
 	def __repr__(self):
@@ -164,19 +192,15 @@ class Plugin(threading.Thread):
 	def run(self):
 		self.log.debug(_("Started."))
 
-		counter = 0
 		while self.running:
-			if counter == 0:
+			# Reset the timer.
+			self.timer.reset()
+
+			# Wait until the timer has successfully elapsed.
+			if self.timer.wait():
 				self.log.debug(_("Collecting..."))
 				self._read()
 
-				self.log.debug(_("Sleeping for %.4fs.") % self.interval)
-
-				counter = self.interval / self.heartbeat
-
-			time.sleep(self.heartbeat)
-			counter -= 1
-
 		self._submit()
 		self.log.debug(_("Stopped."))
 
@@ -184,6 +208,10 @@ class Plugin(threading.Thread):
 		self.log.debug(_("Received shutdown signal."))
 		self.running = False
 
+		# Kill any running timers.
+		if self.timer:
+			self.timer.cancel()
+
 	@property
 	def now(self):
 		"""
-- 
2.39.2