trinamic driver and bytesio module

Change-Id: Id634e7514fecab6fd6bc3edf81e25ad41c2bb12f

secop/bytesio.py

@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+#  -*- coding: utf-8 -*-
+# *****************************************************************************
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Markus Zolliker <markus.zolliker@psi.ch>
+# *****************************************************************************
+"""byte oriented stream communication"""
+
+import time
+import re
+
+from secop.lib.asynconn import AsynConn, ConnectionClosed
+from secop.modules import Property, Command
+from secop.stringio import BaseIO
+from secop.datatypes import BLOBType, IntRange, ArrayOf, TupleOf, StringType
+from secop.errors import CommunicationFailedError, CommunicationSilentError
+
+
+HEX_CODE = re.compile(r'[0-9a-fA-F][0-9a-fA-F]$')
+
+
+class BytesIO(BaseIO):
+    identification = Property(
+        """identification
+
+        a list of tuples with commands and expected responses, to be sent on connect.
+        commands and responses are whitespace separated items
+        an item is either:
+        - a two digit hexadecimal number (byte value)
+        - a character
+        - ?? indicating ignored bytes in responses
+        """, datatype=ArrayOf(TupleOf(StringType(), StringType())), default=[], export=False)
+
+    def connectStart(self):
+        if not self.is_connected:
+            uri = self.uri
+            self._conn = AsynConn(uri, b'')
+            self.is_connected = True
+            for command, match in self.identification:
+                cmdbytes = bytes([int(c, 16) if HEX_CODE.match(c) else ord(c) for c in command.split()])
+                replypat = [int(c, 16) if HEX_CODE.match(c.replace('??', '-1')) else ord(c) for c in command.split()]
+                reply = self.communicate(cmdbytes, len(replypat))
+                if any(b != c and c != -1 for b, c in zip(reply, replypat)):
+                    self.closeConnection()
+                    raise CommunicationFailedError('bad response: %r does not match %r' % (command, match))
+
+    @Command((BLOBType(), IntRange(0)), result=BLOBType())
+    def communicate(self, command, nbytes):
+        """send a command and receive nbytes as reply"""
+        if not self.is_connected:
+            self.read_is_connected()  # try to reconnect
+            if not self._conn:
+                raise CommunicationSilentError('can not connect to %r' % self.uri)
+        try:
+            with self._lock:
+                # read garbage and wait before send
+                try:
+                    if self.wait_before:
+                        time.sleep(self.wait_before)
+                    garbage = self._conn.flush_recv()
+                    if garbage:
+                        self.log.debug('garbage: %r', garbage)
+                    self._conn.send(command)
+                    self.log.debug('send: %r', command)
+                    reply = self._conn.readbytes(nbytes, self.timeout)
+                except ConnectionClosed:
+                    self.closeConnection()
+                    raise CommunicationFailedError('disconnected')
+                self.log.debug('recv: %r', reply)
+                return reply
+        except Exception as e:
+            if str(e) == self._last_error:
+                raise CommunicationSilentError(str(e))
+            self._last_error = str(e)
+            self.log.error(self._last_error)
+            raise