fix #113, make Reader.peek() work on Python 3

netlib/tcp.py

@@ -25,6 +25,10 @@
 
 version_check.check_pyopenssl_version()
 
+if six.PY2:
+    socket_fileobject = socket._fileobject
+else:
+    socket_fileobject = socket.SocketIO
 
 EINTR = 4
 
@@ -270,7 +274,7 @@ def peek(self, length):
             TlsException if there was an error with pyOpenSSL.
             NotImplementedError if the underlying file object is not a (pyOpenSSL) socket
         """
-        if isinstance(self.o, socket._fileobject):
+        if isinstance(self.o, socket_fileobject):
             try:
                 return self.o._sock.recv(length, socket.MSG_PEEK)
             except socket.error as e:
@@ -423,8 +427,17 @@ class _Connection(object):
     def __init__(self, connection):
         if connection:
             self.connection = connection
-            self.rfile = Reader(self.connection.makefile('rb', self.rbufsize))
-            self.wfile = Writer(self.connection.makefile('wb', self.wbufsize))
+            # Ideally, we would use the Buffered IO in Python 3 by default.
+            # Unfortunately, the implementation of .peek() is broken for n>1 bytes,
+            # as it may just return what's left in the buffer and not all the bytes we want.
+            # As a workaround, we just use unbuffered sockets directly.
+            # https://mail.python.org/pipermail/python-dev/2009-June/089986.html
+            if six.PY2:
+                self.rfile = Reader(self.connection.makefile('rb', self.rbufsize))
+                self.wfile = Writer(self.connection.makefile('wb', self.wbufsize))
+            else:
+                self.rfile = Reader(socket.SocketIO(self.connection, "rb"))
+                self.wfile = Writer(socket.SocketIO(self.connection, "wb"))
         else:
             self.connection = None
             self.rfile = None
@@ -663,8 +676,15 @@ def connect(self):
             connection.connect(self.address())
             if not self.source_address:
                 self.source_address = Address(connection.getsockname())
-            self.rfile = Reader(connection.makefile('rb', self.rbufsize))
-            self.wfile = Writer(connection.makefile('wb', self.wbufsize))
+
+            # See _Connection.__init__ why we do this dance.
+            if six.PY2:
+                self.rfile = Reader(connection.makefile('rb', self.rbufsize))
+                self.wfile = Writer(connection.makefile('wb', self.wbufsize))
+            else:
+                self.rfile = Reader(socket.SocketIO(connection, "rb"))
+                self.wfile = Writer(socket.SocketIO(connection, "wb"))
+
         except (socket.error, IOError) as err:
             raise TcpException(
                 'Error connecting to "%s": %s' %

test/test_tcp.py

@@ -723,7 +723,7 @@ def test_peek(self):
         c.wfile.write(testval)
         c.wfile.flush()
 
-        assert c.rfile.peek(4) == "peek"[:4]
+        assert c.rfile.peek(4) == b"peek"[:4]
         assert c.rfile.peek(6) == testval