using pytailer to improve log reading efficiency

openvpn.py

@@ -14,6 +14,7 @@ import humanize
 from tornado.template import Template
 import stat
 import shutil
+import tailer
 
 
 def generate_config(in_fp, cfg):
@@ -141,12 +142,15 @@ class Openvpn:
                 self.run_cmd(proxy_cmd, group=f"vpn{self.idx}")))
             self.run_task.append(self.loop.create_task(self.monitor_task()))
 
-    def get_log(self):
+    def get_log(self, lines=10):
         # regenerate log_fp
         _ = self.get_cfg()
         try:
+            if not lines:
                 with open(self.log_fp, "r") as log_f:
-                return log_f.read()
+                    return log_f.readlines()
+            else:
+                return tailer.tail(open(self.log_fp, "r"), lines)
         except:
             return ""
 
@@ -179,22 +183,28 @@ class Openvpn:
         self.stop()
         self.start()
 
-    def get_io_stat(self):
+    def get_io_stat(self, lines=5):
         try:
-            return open(self.io_stat_fp, "r").read()
+            if not lines:
+                return open(self.io_stat_fp, "r").readlines()
+            else:
+                return tailer.tail(open(self.io_stat_fp, "r"), lines)
         except:
             return ""
 
-    def get_ping_stat(self):
+    def get_ping_stat(self, lines=5):
         try:
-            return open(self.ping_stat_fp, "r").read()
+            if not lines:
+                return open(self.ping_stat_fp, "r").readlines()
+            else:
+                return tailer.tail(open(self.ping_stat_fp, "r"), lines)
         except:
             return ""
 
     def get_latest_speed(self):
         try:
-            buf = open(self.io_stat_fp, "r").readlines()
-            buf = [[float(i) for i in l.split(",")] for l in buf[-2:]]
+            buf = self.get_io_stat(2)
+            buf = [[float(i) for i in l.split(",")] for l in buf]
             assert len(buf) >= 2, "not enough points, need >=2"
             delta_t = buf[1][0] - buf[0][0]
             down_speed = (buf[1][1] - buf[0][1])/delta_t

test.py

@@ -28,12 +28,12 @@ class MainHandler(tornado.web.RequestHandler):
                 buf += f"pid: {op.pids} <br/>\n"
                 buf += "log: <br/>\n"
                 buf += "<pre>\n"
-                buf += op.get_log()
+                buf += "\n".join(op.get_log(lines=10))
                 buf += f"\nSpeed: {op.get_latest_speed()}\n"
                 buf += "\nio_stat\n"
-                buf += "\n".join(op.get_io_stat().splitlines()[-5:])
+                buf += "\n".join(op.get_io_stat(lines=5))
                 buf += "\nping_stat\n"
-                buf += "\n".join(op.get_ping_stat().splitlines()[-5:])
+                buf += "\n".join(op.get_ping_stat(lines=5))
                 buf += "\n</pre>\n"
         buf += "</body>\n</html>"
         self.write(buf)