statistics: Export the OS and process load in a get_status() method

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

docs/Command_Templates.md

@@ -307,6 +307,9 @@ The following are common printer attributes:
   between micro-controller architectures and with each code revision.
 - `printer.mcu.last_stats.<statistics_name>`: Statistics information
   on the micro-controller connection.
+- `printer.system_stats.sysload`, `printer.system_stats.cputime`,
+  `printer.system_stats.memavail`: Information on the host operating
+  system and process load.
 
 The above list is subject to change - if using an attribute be sure to
 review the [Config Changes document](Config_Changes.md) when upgrading

klippy/extras/statistics.py

@@ -1,25 +1,53 @@
 # Support for logging periodic statistics
 #
-# Copyright (C) 2018-2020  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2018-2021  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import os, time, logging
 
-def get_os_stats(eventtime):
+class PrinterSysStats:
-    # Get core usage stats
+    def __init__(self, config):
-    msg = "sysload=%.2f cputime=%.3f" % (os.getloadavg()[0], time.clock())
+        printer = config.get_printer()
-    # Get available system memory
+        self.last_process_time = self.total_process_time = 0.
+        self.last_load_avg = 0.
+        self.last_mem_avail = 0
+        self.mem_file = None
         try:
-        f = open("/proc/meminfo", "rb")
+            self.mem_file = open("/proc/meminfo", "rb")
-        data = f.read()
+        except:
-        f.close()
+            pass
+        printer.register_event_handler("klippy:disconnect", self._disconnect)
+    def _disconnect(self):
+        if self.mem_file is not None:
+            self.mem_file.close()
+            self.mem_file = None
+    def stats(self, eventtime):
+        # Get core usage stats
+        ptime = time.clock()
+        pdiff = ptime - self.last_process_time
+        self.last_process_time = ptime
+        if pdiff > 0.:
+            self.total_process_time += pdiff
+        self.last_load_avg = os.getloadavg()[0]
+        msg = "sysload=%.2f cputime=%.3f" % (self.last_load_avg,
+                                             self.total_process_time)
+        # Get available system memory
+        if self.mem_file is not None:
+            try:
+                self.mem_file.seek(0)
+                data = self.mem_file.read()
                 for line in data.split('\n'):
                     if line.startswith("MemAvailable:"):
-                msg = "%s memavail=%s" % (msg, line.split()[1])
+                        self.last_mem_avail = int(line.split()[1])
+                        msg = "%s memavail=%d" % (msg, self.last_mem_avail)
                         break
             except:
                 pass
         return (False, msg)
+    def get_status(self, eventtime):
+        return {'sysload': self.last_load_avg,
+                'cputime': self.total_process_time,
+                'memavail': self.last_mem_avail}
 
 class PrinterStats:
     def __init__(self, config):
@@ -37,10 +65,10 @@ 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.
 
 def load_config(config):
+    config.get_printer().add_object('system_stats', PrinterSysStats(config))
     return PrinterStats(config)