From b951907912df463bf727de826dc87365c96cfe6d Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 21 Mar 2013 17:24:09 +0100
Subject: [PATCH] Autodetect network interfaces to monitor

---
 powerline/lib/threaded.py    |  7 ++++--
 powerline/segments/common.py | 45 ++++++++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/powerline/lib/threaded.py b/powerline/lib/threaded.py
index b9841cec..8d8ff5d4 100644
--- a/powerline/lib/threaded.py
+++ b/powerline/lib/threaded.py
@@ -67,11 +67,14 @@ class ThreadedSegment(Thread):
 			self.update()
 
 	def startup(self, **kwargs):
+		# Normally .update() succeeds to run before value is requested, meaning
+		# that user is getting values he needs directly at vim startup. Without
+		# .startup() we will not have to wait long until receiving bug “I opened
+		# vim, but branch information is only shown after I move cursor”.
 		self.run_once = False
 
-		self.set_state(**kwargs)
-
 		if not self.is_alive():
+			self.set_state(**kwargs)
 			self.start()
 
 
diff --git a/powerline/segments/common.py b/powerline/segments/common.py
index dfa1a3ae..551a1dd4 100644
--- a/powerline/segments/common.py
+++ b/powerline/segments/common.py
@@ -452,6 +452,12 @@ try:
 			return None
 		return if_io.bytes_recv, if_io.bytes_sent
 
+	def _get_interfaces():
+		io_counters = psutil.network_io_counters(pernic=True)
+		for interface, data in io_counters.items():
+			if data:
+				yield interface, data.bytes_recv, data.bytes_sent
+
 	def _get_user():
 		return psutil.Process(os.getpid()).username
 
@@ -476,6 +482,12 @@ except ImportError:
 		except IOError:
 			return None
 
+	def _get_interfaces():
+		for interface in os.listdir('/sys/class/net'):
+			x = _get_bytes(interface)
+			if x is not None:
+				yield interface, x[0], x[1]
+
 	def _get_user():  # NOQA
 		return os.environ.get('USER', None)
 
@@ -552,13 +564,42 @@ def uptime(format='{days}d {hours:02d}h {minutes:02d}m'):
 
 
 class NetworkLoadSegment(KwThreadedSegment):
+	import re
 	interfaces = {}
+	replace_num_pat = re.compile(r'[a-zA-Z]+')
 
 	@staticmethod
-	def key(interface='eth0', **kwargs):
+	def key(interface='detect', **kwargs):
 		return interface
 
 	def compute_state(self, interface):
+		if interface == 'detect':
+			proc_exists = getattr(self, 'proc_exists', None)
+			if proc_exists is None:
+				proc_exists = self.proc_exists = os.path.exists('/proc/net/route')
+			if proc_exists:
+				# Look for default interface in routing table
+				with open('/proc/net/route', 'rb') as f:
+					for line in f.readlines():
+						parts = line.split()
+						if len(parts) > 1:
+							iface, destination = parts[:2]
+							if not destination.replace(b'0', b''):
+								interface = iface.decode('utf-8')
+								break
+			if interface == 'detect':
+				# Choose interface with most total activity, excluding some
+				# well known interface names
+				interface, total = 'eth0', -1
+				for name, rx, tx in _get_interfaces():
+					base = self.replace_num_pat.match(name)
+					if None in (base, rx, tx) or base.group() in ('lo', 'vmnet', 'sit'):
+						continue
+					activity = rx + tx
+					if activity > total:
+						total = activity
+						interface = name
+
 		if interface in self.interfaces:
 			idata = self.interfaces[interface]
 			try:
@@ -603,7 +644,7 @@ falls back to reading
 :file:`/sys/class/net/{interface}/statistics/{rx,tx}_bytes`.
 
 :param str interface:
-	network interface to measure
+	network interface to measure (use the special value "detect" to have powerline try to auto-detect the network interface)
 :param str suffix:
 	string appended to each load string
 :param bool si_prefix: