Support more objects that implement the buffer protocal by asking for the...

Support more objects that implement the buffer protocal by asking for the len() of their memoryview, not the len() of themselves.

Also potentially reduces the number of calls to memoryview so may be slightly more efficient.

Fixes #466.

changelog.rst

@@ -25,6 +25,9 @@ Unreleased
 - In non-monkey-patched environments under Python 2.7.9 or above or
   Python 3, using a gevent SSL socket could cause the greenlet to
   block. See :issue:`597` by David Ford.
+- ``gevent.socket.socket.sendall`` supports arbitrary objects that
+  implement the buffer protocol (such as ctypes structurs), just like
+  native sockets. Reported in :issue:`466` by tzickel.
 
 1.1a1 (Jun 29, 2015)
 ====================

gevent/_fileobject2.py

@@ -95,11 +95,12 @@ class SocketAdapter(object):
 
     def sendall(self, data):
         fileno = self.fileno()
-        bytes_total = len(data)
+        data_memory = _get_memory(data)
+        bytes_total = len(data_memory)
         bytes_written = 0
         while True:
             try:
-                bytes_written += _write(fileno, _get_memory(data, bytes_written))
+                bytes_written += _write(fileno, data_memory[bytes_written:])
             except (IOError, OSError) as ex:
                 code = ex.args[0]
                 if code not in ignored_errors:

gevent/_socket2.py

@@ -20,14 +20,19 @@ _fileobject = __socket__._fileobject
 if sys.version_info[:2] < (2, 7):
     _get_memory = buffer
 else:
-    def _get_memory(string, offset):
+    def _get_memory(data):
         try:
-            return memoryview(string)[offset:]
+            mv = memoryview(data)
+            if mv.shape:
+                return mv
+            # No shape, probably working with a ctypes object,
+            # or something else exotic that supports the buffer interface
+            return mv.tobytes()
         except TypeError:
             # fixes "python2.7 array.array doesn't support memoryview used in
             # gevent.socket.send" issue
             # (http://code.google.com/p/gevent/issues/detail?id=94)
-            return buffer(string, offset)
+            return buffer(data)
 
 
 class _closedsocket(object):
@@ -287,17 +292,18 @@ class socket(object):
             data = data.encode()
         # this sendall is also reused by gevent.ssl.SSLSocket subclass,
         # so it should not call self._sock methods directly
+        data_memory = _get_memory(data)
         if self.timeout is None:
             data_sent = 0
-            while data_sent < len(data):
-                data_sent += self.send(_get_memory(data, data_sent), flags)
+            while data_sent < len(data_memory):
+                data_sent += self.send(data_memory[data_sent:], flags)
         else:
             timeleft = self.timeout
             end = time.time() + timeleft
             data_sent = 0
             while True:
-                data_sent += self.send(_get_memory(data, data_sent), flags, timeout=timeleft)
-                if data_sent >= len(data):
+                data_sent += self.send(data_memory[data_sent:], flags, timeout=timeleft)
+                if data_sent >= len(data_memory):
                     return
                 timeleft = end - time.time()
                 if timeleft <= 0:

gevent/_socket3.py

@@ -23,8 +23,13 @@ __dns__ = _socketcommon.__dns__
 SocketIO = __socket__.SocketIO
 
 
-def _get_memory(string, offset):
-    return memoryview(string)[offset:]
+def _get_memory(data):
+    mv = memoryview(data)
+    if mv.shape:
+        return mv
+    # No shape, probably working with a ctypes object,
+    # or something else exotic that supports the buffer interface
+    return mv.tobytes()
 
 timeout_default = object()
 
@@ -320,17 +325,18 @@ class socket(object):
                 raise
 
     def sendall(self, data, flags=0):
+        data_memory = _get_memory(data)
         if self.timeout is None:
             data_sent = 0
-            while data_sent < len(data):
-                data_sent += self.send(_get_memory(data, data_sent), flags)
+            while data_sent < len(data_memory):
+                data_sent += self.send(data_memory[data_sent:], flags)
         else:
             timeleft = self.timeout
             end = time.time() + timeleft
             data_sent = 0
             while True:
-                data_sent += self.send(_get_memory(data, data_sent), flags, timeout=timeleft)
-                if data_sent >= len(data):
+                data_sent += self.send(data_memory[data_sent:], flags, timeout=timeleft)
+                if data_sent >= len(data_memory):
                     break
                 timeleft = end - time.time()
                 if timeleft <= 0:

greentest/test__socket_send_memoryview.py

+# See issue #466
+import ctypes
+
+
+class AnStructure(ctypes.Structure):
+    _fields_ = [("x", ctypes.c_int)]
+
+
+def _send(socket):
+    for meth in ('sendall', 'send'):
+        anStructure = AnStructure()
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.connect(('127.0.0.1', 12345))
+        getattr(sock, meth)(anStructure)
+
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.connect(('127.0.0.1', 12345))
+        sock.settimeout(1.0)
+        getattr(sock, meth)(anStructure)
+
+
+def TestSendBuiltinSocket():
+    import socket
+    _send(socket)
+
+
+def TestSendGeventSocket():
+    import gevent.socket
+    _send(gevent.socket)
+
+if __name__ == '__main__':
+    TestSendBuiltinSocket()
+    TestSendGeventSocket()