Update the pipe_cmd plugin to use asyncio and be awesome

plugins/pipe_cmd.py

@@ -6,10 +6,10 @@ This plugins allows commands to be sent to poezio via a named pipe.
 
 
 from plugin import BasePlugin
-import threading
 import os
 import stat
 import logging
+import asyncio
 
 log = logging.getLogger(__name__)
 
@@ -25,19 +25,30 @@ class Plugin(BasePlugin):
             os.mkfifo(self.pipename)
 
         if not stat.S_ISFIFO(os.stat(self.pipename).st_mode):
-            log.error("File %s is not a fifo file" % self.pipename)
-            raise TypeError
+            raise TypeError("File %s is not a fifo file" % self.pipename)
 
-        thread = threading.Thread(target=self.main_loop)
-        thread.setDaemon(True)
-        thread.start()
+        self.fd = os.open(self.pipename, os.O_RDONLY|os.O_NONBLOCK)
 
-    def main_loop(self):
-        while not self.stop:
-            fd = open(self.pipename, 'r')
-            line = fd.read().strip()
-            self.api.run_command(line)
-            fd.close()
+        self.data = b""
+        asyncio.get_event_loop().add_reader(self.fd, self.read_from_fifo)
+
+    def read_from_fifo(self):
+        data = os.read(self.fd, 512)
+        if not data:
+            # EOF, close the fifo. And reopen it
+            asyncio.get_event_loop().remove_reader(self.fd)
+            os.close(self.fd)
+            self.fd = os.open(self.pipename, os.O_RDONLY|os.O_NONBLOCK)
+            asyncio.get_event_loop().add_reader(self.fd, self.read_from_fifo)
+            self.data = b''
+        else:
+            self.data += data
+        l = self.data.split(b'\n', 1)
+        if len(l) == 2:
+            line, self.data = l
+            log.debug("run: %s" % (line.decode().strip()))
+            self.api.run_command(line.decode().strip())
 
     def cleanup(self):
-        self.stop = True
+        asyncio.get_event_loop().remove_reader(self.fd)
+        os.close(self.fd)