statistics: Add system stats

Report os load, process cpu time, and system available memory to each
statistics report.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/statistics.py

@@ -1,9 +1,24 @@
 # Support for logging periodic statistics
 #
-# Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2018-2020  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
-import logging
+import os, time, logging
+
+def get_os_stats(eventtime):
+    # Get core usage stats
+    msg = "sysload=%.2f cputime=%.3f" % (os.getloadavg()[0], time.clock())
+    # Get available system memory
+    try:
+        f = open("/proc/meminfo", "rb")
+        data = f.read()
+        f.close()
+        for line in data.split('\n'):
+            if line.startswith("MemAvailable:"):
+                msg = "%s memavail=%s" % (msg, line.split()[1])
+    except:
+        pass
+    return (False, msg)
 
 class PrinterStats:
     def __init__(self, config):
@@ -21,6 +36,7 @@ class PrinterStats:
     def generate_stats(self, eventtime):
         stats = [cb(eventtime) for cb in self.stats_cb]
         if max([s[0] for s in stats]):
+            stats.append(get_os_stats(eventtime))
             logging.info("Stats %.1f: %s", eventtime,
                          ' '.join([s[1] for s in stats]))
         return eventtime + 1.