osc-lib: Fix SLIP client CPU usage

By not reading byte by byte, we reduce the CPU usage by half.

Co-authored-by: Martijn Braam <martijn@brixit.nl>

Author: aastefanov

osc-lib/fosdemosc/slip_client.py

@@ -28,26 +28,33 @@ def send(self, content: Union[OscMessage, OscBundle]) -> None:
 
     def receive(self) -> bytes:
         buffer = b''
+        buf = b''
+        n = 0
         while True:
-            c = self.ser.read(1)
-            if c is None or not len(c):
-                raise serial.SerialTimeoutException('Cannot read from serial port')
-
+            if n == len(buf):
+                buf = self.ser.read(self.ser.in_waiting or 1)
+                n = 0
+                if buf is None or not len(buf):
+                    raise serial.SerialTimeoutException('Cannot read from serial port')
+                buf = bytes(buf)
+            c = bytes(buf[n:n+1])
+            n+=1
             if c == self.END:
                 if len(buffer):
                     break
                 continue
 
             if c == self.ESC:
-                c = self.ser.read(1)
+                c = bytes(buf[n])
+                n+=1
                 if c is None or not len(c):
                     raise serial.SerialTimeoutException('Packet ended too early')
                 if c == self.ESC_END:
                     buffer += self.END
                 elif c == self.ESC_ESC:
                     buffer += self.ESC
             else:
-                buffer += c
+                buffer += bytes(c)
         return buffer
 
     def receive_obj(self) -> OscBundle | OscMessage: