Reduce os.read/os.write cutpaste.

econtext/core.py

@@ -385,6 +385,18 @@ class Side(object):
             os.close(self.fd)
             self.fd = None
 
+    def read(self, n=CHUNK_SIZE):
+        s, disconnected = io_op(os.read, self.fd, n)
+        if disconnected:
+            return ''
+        return s
+
+    def write(self, s):
+        written, disconnected = io_op(os.write, self.fd, s[:CHUNK_SIZE])
+        if disconnected:
+            return None
+        return written
+
 
 class BasicStream(object):
     """
@@ -467,8 +479,8 @@ class Stream(BasicStream):
         :py:class:`StreamError` on failure."""
         IOLOG.debug('%r.on_receive()', self)
 
-        buf, disconnected = io_op(os.read, self.receive_side.fd, CHUNK_SIZE)
-        if disconnected:
+        buf = self.receive_side.read()
+        if buf is None:
             buf = ''
 
         self._input_buf += buf
@@ -516,10 +528,8 @@ class Stream(BasicStream):
     def on_transmit(self, broker):
         """Transmit buffered messages."""
         IOLOG.debug('%r.on_transmit()', self)
-        written, disconnected = io_op(os.write, self.transmit_side.fd,
-                                      self._output_buf[:CHUNK_SIZE])
-
-        if disconnected:
+        written = self.transmit_side.write(self._output_buf)
+        if written is None:
             LOG.debug('%r.on_transmit(): disconnection detected', self)
             self.on_disconnect()
             return