serialization.py

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#!/usr/bin/env python
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# Author: Jorge Santos

import genpy
import rospy
import roslib
import cStringIO as StringIO


class SerializationError(Exception):
    pass

def serialize_msg(msg):
    try:
        buffer = StringIO.StringIO()
        rospy.msg.serialize_message(buffer, 0, msg)
        ser_msg = buffer.getvalue()
    except rospy.exceptions.ROSSerializationException as e:
        raise SerializationError('Serialization failed: %s' % str(e))
    else:
        return ser_msg
    finally:
        buffer.close()

def deserialize_msg(ser_msg, msg_class):
    try:
        msg_queue = list()
        buffer = StringIO.StringIO()
        buffer.write(ser_msg)
        rospy.msg.deserialize_messages(buffer, msg_queue, msg_class)
    except genpy.DeserializationError as e:
        raise SerializationError('Deserialization failed: %s' % str(e))
    else:
        if len(msg_queue) == 0:
            # Probably deserialize_messages would had raised an exception instead
            raise SerializationError('Deserialization returned 0 messages')
        if len(msg_queue) > 1:
            # This should be impossible
            rospy.logwarn("More than one object deserialized (%d)!" % len(msg_queue))
        return msg_queue.pop()
    finally:
        buffer.close()