API: Add support for type aliases
[vpp.git] / src / vpp-api / python / vpp_papi / vpp_papi.py
index 0c40f17..bd2682f 100644 (file)
 #
 
 from __future__ import print_function
 #
 
 from __future__ import print_function
-import sys, os, logging, collections, struct, json, threading, glob
-import atexit, Queue
-
-logging.basicConfig(level=logging.DEBUG)
-import vpp_api
+from __future__ import absolute_import
+import sys
+import os
+import logging
+import collections
+import struct
+import json
+import threading
+import fnmatch
+import weakref
+import atexit
+from . vpp_serializer import VPPType, VPPEnumType, VPPUnionType, BaseTypes
+from . vpp_serializer import VPPMessage, vpp_get_type, VPPTypeAlias
+from . vpp_format import VPPFormat
+
+if sys.version[0] == '2':
+    import Queue as queue
+else:
+    import queue as queue
+
+
+class VppEnumType(type):
+    def __getattr__(cls, name):
+        t = vpp_get_type(name)
+        return t.enum
+
+
+# Python3
+# class VppEnum(metaclass=VppEnumType):
+#    pass
+class VppEnum(object):
+    __metaclass__ = VppEnumType
+
+
+def vpp_atexit(vpp_weakref):
+    """Clean up VPP connection on shutdown."""
+    vpp_instance = vpp_weakref()
+    if vpp_instance and vpp_instance.transport.connected:
+        vpp_instance.logger.debug('Cleaning up VPP on exit')
+        vpp_instance.disconnect()
 
 
-def eprint(*args, **kwargs):
-    """Print critical diagnostics to stderr."""
-    print(*args, file=sys.stderr, **kwargs)
 
 
-def vpp_atexit(self):
-    """Clean up VPP connection on shutdown."""
-    if self.connected:
-        eprint ('Cleaning up VPP on exit')
-        self.disconnect()
+def vpp_iterator(d):
+    if sys.version[0] == '2':
+        return d.iteritems()
+    else:
+        return d.items()
 
 
 
 
-class Empty(object):
+class VppApiDynamicMethodHolder(object):
     pass
 
 
     pass
 
 
@@ -45,7 +77,7 @@ class FuncWrapper(object):
         return self._func(**kwargs)
 
 
         return self._func(**kwargs)
 
 
-class VPP():
+class VPP(object):
     """VPP interface.
 
     This class provides the APIs to VPP.  The APIs are loaded
     """VPP interface.
 
     This class provides the APIs to VPP.  The APIs are loaded
@@ -57,7 +89,66 @@ class VPP():
     provides a means to register a callback function to receive
     these messages in a background thread.
     """
     provides a means to register a callback function to receive
     these messages in a background thread.
     """
-    def __init__(self, apifiles = None, testmode = False, async_thread = True):
+
+    def process_json_file(self, apidef_file):
+        api = json.load(apidef_file)
+        types = {}
+        for t in api['enums']:
+            t[0] = 'vl_api_' + t[0] + '_t'
+            types[t[0]] = {'type': 'enum', 'data': t}
+        for t in api['unions']:
+            t[0] = 'vl_api_' + t[0] + '_t'
+            types[t[0]] = {'type': 'union', 'data': t}
+        for t in api['types']:
+            t[0] = 'vl_api_' + t[0] + '_t'
+            types[t[0]] = {'type': 'type', 'data': t}
+        for t, v in api['aliases'].items():
+            types['vl_api_' + t + '_t'] = {'type': 'alias', 'data': v}
+
+        i = 0
+        while True:
+            unresolved = {}
+            for k, v in types.items():
+                t = v['data']
+                if not vpp_get_type(k):
+                    if v['type'] == 'enum':
+                        try:
+                            VPPEnumType(t[0], t[1:])
+                        except ValueError:
+                            unresolved[k] = v
+                    elif v['type'] == 'union':
+                        try:
+                            VPPUnionType(t[0], t[1:])
+                        except ValueError:
+                            unresolved[k] = v
+                    elif v['type'] == 'type':
+                        try:
+                            VPPType(t[0], t[1:])
+                        except ValueError:
+                            unresolved[k] = v
+                    elif v['type'] == 'alias':
+                        try:
+                            VPPTypeAlias(k, t)
+                        except ValueError:
+                            unresolved[k] = v
+            if len(unresolved) == 0:
+                break
+            if i > 3:
+                raise ValueError('Unresolved type definitions {}'
+                                 .format(unresolved))
+            types = unresolved
+            i += 1
+
+        for m in api['messages']:
+            try:
+                self.messages[m[0]] = VPPMessage(m[0], m[1:])
+            except NotImplementedError:
+                self.logger.error('Not implemented error for {}'.format(m[0]))
+
+    def __init__(self, apifiles=None, testmode=False, async_thread=True,
+                 logger=None, loglevel=None,
+                 read_timeout=5, use_socket=False,
+                 server_address='/run/vpp-api.sock'):
         """Create a VPP API object.
 
         apifiles is a list of files containing API
         """Create a VPP API object.
 
         apifiles is a list of files containing API
@@ -65,267 +156,198 @@ class VPP():
         dynamically created reflecting these APIs.  If not
         provided this will load the API files from VPP's
         default install location.
         dynamically created reflecting these APIs.  If not
         provided this will load the API files from VPP's
         default install location.
+
+        logger, if supplied, is the logging logger object to log to.
+        loglevel, if supplied, is the log level this logger is set
+        to report at (from the loglevels in the logging module).
         """
         """
+        if logger is None:
+            logger = logging.getLogger(__name__)
+            if loglevel is not None:
+                logger.setLevel(loglevel)
+        self.logger = logger
+
         self.messages = {}
         self.id_names = []
         self.id_msgdef = []
         self.messages = {}
         self.id_names = []
         self.id_msgdef = []
-        self.buffersize = 10000
-        self.connected = False
-        self.header = struct.Struct('>HI')
+        self.header = VPPType('header', [['u16', 'msgid'],
+                                         ['u32', 'client_index']])
         self.apifiles = []
         self.event_callback = None
         self.apifiles = []
         self.event_callback = None
-        self.message_queue = Queue.Queue()
-        self.read_timeout = 0
-        self.vpp_api = vpp_api
-        if async_thread:
-            self.event_thread = threading.Thread(target=self.thread_msg_handler)
-            self.event_thread.daemon = True
-            self.event_thread.start()
+        self.message_queue = queue.Queue()
+        self.read_timeout = read_timeout
+        self.async_thread = async_thread
+
+        if use_socket:
+            from . vpp_transport_socket import VppTransport
+        else:
+            from . vpp_transport_shmem import VppTransport
 
         if not apifiles:
             # Pick up API definitions from default directory
 
         if not apifiles:
             # Pick up API definitions from default directory
-            apifiles = glob.glob('/usr/share/vpp/api/*.api.json')
+            try:
+                apifiles = self.find_api_files()
+            except RuntimeError:
+                # In test mode we don't care that we can't find the API files
+                if testmode:
+                    apifiles = []
+                else:
+                    raise
 
         for file in apifiles:
             with open(file) as apidef_file:
 
         for file in apifiles:
             with open(file) as apidef_file:
-                api = json.load(apidef_file)
-                for t in api['types']:
-                    self.add_type(t[0], t[1:])
+                self.process_json_file(apidef_file)
 
 
-                for m in api['messages']:
-                    self.add_message(m[0], m[1:])
-       self.apifiles = apifiles
+        self.apifiles = apifiles
 
         # Basic sanity check
         if len(self.messages) == 0 and not testmode:
             raise ValueError(1, 'Missing JSON message definitions')
 
 
         # Basic sanity check
         if len(self.messages) == 0 and not testmode:
             raise ValueError(1, 'Missing JSON message definitions')
 
+        self.transport = VppTransport(self, read_timeout=read_timeout,
+                                      server_address=server_address)
         # Make sure we allow VPP to clean up the message rings.
         # Make sure we allow VPP to clean up the message rings.
-        atexit.register(vpp_atexit, self)
+        atexit.register(vpp_atexit, weakref.ref(self))
 
     class ContextId(object):
         """Thread-safe provider of unique context IDs."""
         def __init__(self):
             self.context = 0
 
     class ContextId(object):
         """Thread-safe provider of unique context IDs."""
         def __init__(self):
             self.context = 0
-           self.lock = threading.Lock()
+            self.lock = threading.Lock()
+
         def __call__(self):
             """Get a new unique (or, at least, not recently used) context."""
         def __call__(self):
             """Get a new unique (or, at least, not recently used) context."""
-           with self.lock:
-               self.context += 1
-               return self.context
+            with self.lock:
+                self.context += 1
+                return self.context
     get_context = ContextId()
 
     get_context = ContextId()
 
-    def status(self):
-        """Debug function: report current VPP API status to stdout."""
-        print('Connected') if self.connected else print('Not Connected')
-        print('Read API definitions from', ', '.join(self.apifiles))
-
-    def __struct (self, t, n = None, e = -1, vl = None):
-        """Create a packing structure for a message."""
-        base_types = { 'u8' : 'B',
-                       'u16' : 'H',
-                       'u32' : 'I',
-                       'i32' : 'i',
-                       'u64' : 'Q',
-                       'f64' : 'd',
-                       }
-        pack = None
-        if t in base_types:
-            pack = base_types[t]
-            if not vl:
-                if e > 0 and t == 'u8':
-                    # Fixed byte array
-                    return struct.Struct('>' + str(e) + 's')
-                if e > 0:
-                    # Fixed array of base type
-                    return [e, struct.Struct('>' + base_types[t])]
-                elif e == 0:
-                    # Old style variable array
-                    return [-1, struct.Struct('>' + base_types[t])]
-            else:
-                # Variable length array
-                return [vl, struct.Struct('>s')] if t == 'u8' else \
-                    [vl, struct.Struct('>' + base_types[t])]
-
-            return struct.Struct('>' + base_types[t])
-
-        if t in self.messages:
-            ### Return a list in case of array ###
-            if e > 0 and not vl:
-                return [e, lambda self, encode, buf, offset, args: (
-                    self.__struct_type(encode, self.messages[t], buf, offset,
-                                       args))]
-            if vl:
-                return [vl, lambda self, encode, buf, offset, args: (
-                    self.__struct_type(encode, self.messages[t], buf, offset,
-                                       args))]
-            elif e == 0:
-                # Old style VLA
-                raise NotImplementedError(1, 'No support for compound types ' + t)
-            return lambda self, encode, buf, offset, args: (
-                self.__struct_type(encode, self.messages[t], buf, offset, args)
-            )
-
-        raise ValueError(1, 'Invalid message type: ' + t)
-
-    def __struct_type(self, encode, msgdef, buf, offset, kwargs):
-        """Get a message packer or unpacker."""
-        if encode:
-            return self.__struct_type_encode(msgdef, buf, offset, kwargs)
-        else:
-            return self.__struct_type_decode(msgdef, buf, offset)
-
-    def __struct_type_encode(self, msgdef, buf, offset, kwargs):
-        off = offset
-        size = 0
-
-        for k in kwargs:
-            if k not in msgdef['args']:
-                raise ValueError(1, 'Invalid field-name in message call ' + k)
-
-        for k,v in msgdef['args'].iteritems():
-            off += size
-            if k in kwargs:
-                if type(v) is list:
-                    if callable(v[1]):
-                        e = kwargs[v[0]] if v[0] in kwargs else v[0]
-                        size = 0
-                        for i in range(e):
-                            size += v[1](self, True, buf, off + size,
-                                         kwargs[k][i])
-                    else:
-                        if v[0] in kwargs:
-                            l = kwargs[v[0]]
-                        else:
-                            l = len(kwargs[k])
-                        if v[1].size == 1:
-                            buf[off:off + l] = bytearray(kwargs[k])
-                            size = l
-                        else:
-                            size = 0
-                            for i in kwargs[k]:
-                                v[1].pack_into(buf, off + size, i)
-                                size += v[1].size
-                else:
-                    if callable(v):
-                        size = v(self, True, buf, off, kwargs[k])
-                    else:
-                        v.pack_into(buf, off, kwargs[k])
-                        size = v.size
-            else:
-                size = v.size if not type(v) is list else 0
-
-        return off + size - offset
+    def get_type(self, name):
+        return vpp_get_type(name)
 
 
+    @classmethod
+    def find_api_dir(cls):
+        """Attempt to find the best directory in which API definition
+        files may reside. If the value VPP_API_DIR exists in the environment
+        then it is first on the search list. If we're inside a recognized
+        location in a VPP source tree (src/scripts and src/vpp-api/python)
+        then entries from there to the likely locations in build-root are
+        added. Finally the location used by system packages is added.
 
 
-    def __getitem__(self, name):
-        if name in self.messages:
-            return self.messages[name]
-        return None
+        :returns: A single directory name, or None if no such directory
+            could be found.
+        """
+        dirs = []
 
 
-    def encode(self, msgdef, kwargs):
-        # Make suitably large buffer
-        buf = bytearray(self.buffersize)
-        offset = 0
-        size = self.__struct_type(True, msgdef, buf, offset, kwargs)
-        return buf[:offset + size]
-
-    def decode(self, msgdef, buf):
-        return self.__struct_type(False, msgdef, buf, 0, None)[1]
-
-    def __struct_type_decode(self, msgdef, buf, offset):
-        res = []
-        off = offset
-        size = 0
-        for k,v in msgdef['args'].iteritems():
-            off += size
-            if type(v) is list:
-                lst = []
-                if callable(v[1]): # compound type
-                    size = 0
-                    if v[0] in msgdef['args']: # vla
-                        e = res[v[2]]
-                    else: # fixed array
-                        e = v[0]
-                    res.append(lst)
-                    for i in range(e):
-                        (s,l) = v[1](self, False, buf, off + size, None)
-                        lst.append(l)
-                        size += s
-                    continue
-                if v[1].size == 1:
-                    if type(v[0]) is int:
-                        size = len(buf) - off
-                    else:
-                        size = res[v[2]]
-                    res.append(buf[off:off + size])
-                else:
-                    e = v[0] if type(v[0]) is int else res[v[2]]
-                    if e == -1:
-                        e = (len(buf) - off) / v[1].size
-                    lst = []
-                    res.append(lst)
-                    size = 0
-                    for i in range(e):
-                        lst.append(v[1].unpack_from(buf, off + size)[0])
-                        size += v[1].size
-            else:
-                if callable(v):
-                    (s,l) = v(self, False, buf, off, None)
-                    res.append(l)
-                    size += s
-                else:
-                    res.append(v.unpack_from(buf, off)[0])
-                    size = v.size
+        if 'VPP_API_DIR' in os.environ:
+            dirs.append(os.environ['VPP_API_DIR'])
 
 
-        return off + size - offset, msgdef['return_tuple']._make(res)
+        # perhaps we're in the 'src/scripts' or 'src/vpp-api/python' dir;
+        # in which case, plot a course to likely places in the src tree
+        import __main__ as main
+        if hasattr(main, '__file__'):
+            # get the path of the calling script
+            localdir = os.path.dirname(os.path.realpath(main.__file__))
+        else:
+            # use cwd if there is no calling script
+            localdir = os.getcwd()
+        localdir_s = localdir.split(os.path.sep)
+
+        def dmatch(dir):
+            """Match dir against right-hand components of the script dir"""
+            d = dir.split('/')  # param 'dir' assumes a / separator
+            length = len(d)
+            return len(localdir_s) > length and localdir_s[-length:] == d
+
+        def sdir(srcdir, variant):
+            """Build a path from srcdir to the staged API files of
+            'variant'  (typically '' or '_debug')"""
+            # Since 'core' and 'plugin' files are staged
+            # in separate directories, we target the parent dir.
+            return os.path.sep.join((
+                srcdir,
+                'build-root',
+                'install-vpp%s-native' % variant,
+                'vpp',
+                'share',
+                'vpp',
+                'api',
+            ))
+
+        srcdir = None
+        if dmatch('src/scripts'):
+            srcdir = os.path.sep.join(localdir_s[:-2])
+        elif dmatch('src/vpp-api/python'):
+            srcdir = os.path.sep.join(localdir_s[:-3])
+        elif dmatch('test'):
+            # we're apparently running tests
+            srcdir = os.path.sep.join(localdir_s[:-1])
+
+        if srcdir:
+            # we're in the source tree, try both the debug and release
+            # variants.
+            dirs.append(sdir(srcdir, '_debug'))
+            dirs.append(sdir(srcdir, ''))
+
+        # Test for staged copies of the scripts
+        # For these, since we explicitly know if we're running a debug versus
+        # release variant, target only the relevant directory
+        if dmatch('build-root/install-vpp_debug-native/vpp/bin'):
+            srcdir = os.path.sep.join(localdir_s[:-4])
+            dirs.append(sdir(srcdir, '_debug'))
+        if dmatch('build-root/install-vpp-native/vpp/bin'):
+            srcdir = os.path.sep.join(localdir_s[:-4])
+            dirs.append(sdir(srcdir, ''))
+
+        # finally, try the location system packages typically install into
+        dirs.append(os.path.sep.join(('', 'usr', 'share', 'vpp', 'api')))
+
+        # check the directories for existance; first one wins
+        for dir in dirs:
+            if os.path.isdir(dir):
+                return dir
 
 
-    def ret_tup(self, name):
-        if name in self.messages and 'return_tuple' in self.messages[name]:
-            return self.messages[name]['return_tuple']
         return None
 
         return None
 
-    def add_message(self, name, msgdef):
-        if name in self.messages:
-            raise ValueError('Duplicate message name: ' + name)
-
-        args = collections.OrderedDict()
-        argtypes = collections.OrderedDict()
-        fields = []
-        msg = {}
-        for i, f in enumerate(msgdef):
-            if type(f) is dict and 'crc' in f:
-                msg['crc'] = f['crc']
-                continue
-            field_type = f[0]
-            field_name = f[1]
-            if len(f) == 3 and f[2] == 0 and i != len(msgdef) - 2:
-                raise ValueError('Variable Length Array must be last: ' + name)
-            args[field_name] = self.__struct(*f)
-            argtypes[field_name] = field_type
-            if len(f) == 4: # Find offset to # elements field
-                args[field_name].append(args.keys().index(f[3]) - i)
-            fields.append(field_name)
-        msg['return_tuple'] = collections.namedtuple(name, fields,
-                                                     rename = True)
-        self.messages[name] = msg
-        self.messages[name]['args'] = args
-        self.messages[name]['argtypes'] = argtypes
-        return self.messages[name]
-
-    def add_type(self, name, typedef):
-        return self.add_message('vl_api_' + name + '_t', typedef)
-
-    def make_function(self, name, i, msgdef, multipart, async):
-        if (async):
-            f = lambda **kwargs: (self._call_vpp_async(i, msgdef, **kwargs))
+    @classmethod
+    def find_api_files(cls, api_dir=None, patterns='*'):
+        """Find API definition files from the given directory tree with the
+        given pattern. If no directory is given then find_api_dir() is used
+        to locate one. If no pattern is given then all definition files found
+        in the directory tree are used.
+
+        :param api_dir: A directory tree in which to locate API definition
+            files; subdirectories are descended into.
+            If this is None then find_api_dir() is called to discover it.
+        :param patterns: A list of patterns to use in each visited directory
+            when looking for files.
+            This can be a list/tuple object or a comma-separated string of
+            patterns. Each value in the list will have leading/trialing
+            whitespace stripped.
+            The pattern specifies the first part of the filename, '.api.json'
+            is appended.
+            The results are de-duplicated, thus overlapping patterns are fine.
+            If this is None it defaults to '*' meaning "all API files".
+        :returns: A list of file paths for the API files found.
+        """
+        if api_dir is None:
+            api_dir = cls.find_api_dir()
+            if api_dir is None:
+                raise RuntimeError("api_dir cannot be located")
+
+        if isinstance(patterns, list) or isinstance(patterns, tuple):
+            patterns = [p.strip() + '.api.json' for p in patterns]
         else:
         else:
-            f = lambda **kwargs: (self._call_vpp(i, msgdef, multipart, **kwargs))
-        args = self.messages[name]['args']
-        argtypes = self.messages[name]['argtypes']
-        f.__name__ = str(name)
-        f.__doc__ = ", ".join(["%s %s" % (argtypes[k], k) for k in args.keys()])
-        return f
+            patterns = [p.strip() + '.api.json' for p in patterns.split(",")]
+
+        api_files = []
+        for root, dirnames, files in os.walk(api_dir):
+            # iterate all given patterns and de-dup the result
+            files = set(sum([fnmatch.filter(files, p) for p in patterns], []))
+            for filename in files:
+                api_files.append(os.path.join(root, filename))
+
+        return api_files
 
     @property
     def api(self):
 
     @property
     def api(self):
@@ -333,83 +355,74 @@ class VPP():
             raise Exception("Not connected, api definitions not available")
         return self._api
 
             raise Exception("Not connected, api definitions not available")
         return self._api
 
-    def _register_functions(self, async=False):
+    def make_function(self, msg, i, multipart, do_async):
+        if (do_async):
+            def f(**kwargs):
+                return self._call_vpp_async(i, msg, **kwargs)
+        else:
+            def f(**kwargs):
+                return self._call_vpp(i, msg, multipart, **kwargs)
+
+        f.__name__ = str(msg.name)
+        f.__doc__ = ", ".join(["%s %s" %
+                               (msg.fieldtypes[j], k)
+                               for j, k in enumerate(msg.fields)])
+        return f
+
+    def _register_functions(self, do_async=False):
         self.id_names = [None] * (self.vpp_dictionary_maxid + 1)
         self.id_msgdef = [None] * (self.vpp_dictionary_maxid + 1)
         self.id_names = [None] * (self.vpp_dictionary_maxid + 1)
         self.id_msgdef = [None] * (self.vpp_dictionary_maxid + 1)
-        self._api = Empty()
-        for name, msgdef in self.messages.iteritems():
-            if name in self.vpp_dictionary:
-                if self.messages[name]['crc'] != self.vpp_dictionary[name]['crc']:
-                    raise ValueError(3, 'Failed CRC checksum ' + name +
-                                     ' ' + self.messages[name]['crc'] +
-                                     ' ' + self.vpp_dictionary[name]['crc'])
-                i = self.vpp_dictionary[name]['id']
-                self.id_msgdef[i] = msgdef
+        self._api = VppApiDynamicMethodHolder()
+        for name, msg in vpp_iterator(self.messages):
+            n = name + '_' + msg.crc[2:]
+            i = self.transport.get_msg_index(n.encode())
+            if i > 0:
+                self.id_msgdef[i] = msg
                 self.id_names[i] = name
                 self.id_names[i] = name
+                # TODO: Fix multipart (use services)
                 multipart = True if name.find('_dump') > 0 else False
                 multipart = True if name.find('_dump') > 0 else False
-                f = self.make_function(name, i, msgdef, multipart, async)
+                f = self.make_function(msg, i, multipart, do_async)
                 setattr(self._api, name, FuncWrapper(f))
                 setattr(self._api, name, FuncWrapper(f))
+            else:
+                self.logger.debug(
+                    'No such message type or failed CRC checksum: %s', n)
 
 
-                # old API stuff starts here - will be removed in 17.07
-                if hasattr(self, name):
-                    raise NameError(
-                        3, "Conflicting name in JSON definition: `%s'" % name)
-                setattr(self, name, f)
-                # old API stuff ends here
-
-    def _write (self, buf):
-        """Send a binary-packed message to VPP."""
-        if not self.connected:
-            raise IOError(1, 'Not connected')
-        return vpp_api.write(str(buf))
-
-    def _read (self):
-        if not self.connected:
-            raise IOError(1, 'Not connected')
-
-        return vpp_api.read(self.read_timeout)
-
-    def _load_dictionary(self):
-        self.vpp_dictionary = {}
-        self.vpp_dictionary_maxid = 0
-        d = vpp_api.msg_table()
-
-        if not d:
-            raise IOError(3, 'Cannot get VPP API dictionary')
-        for i,n in d:
-            name, crc =  n.rsplit('_', 1)
-            crc = '0x' + crc
-            self.vpp_dictionary[name] = { 'id' : i, 'crc' : crc }
-            self.vpp_dictionary_maxid = max(self.vpp_dictionary_maxid, i)
-
-    def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen, async):
-       rv = vpp_api.connect(name, msg_handler, chroot_prefix, rx_qlen)
+    def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen,
+                         do_async):
+        pfx = chroot_prefix.encode() if chroot_prefix else None
+
+        rv = self.transport.connect(name.encode(), pfx, msg_handler, rx_qlen)
         if rv != 0:
             raise IOError(2, 'Connect failed')
         if rv != 0:
             raise IOError(2, 'Connect failed')
-        self.connected = True
-
-        self._load_dictionary()
-        self._register_functions(async=async)
+        self.vpp_dictionary_maxid = self.transport.msg_table_max_index()
+        self._register_functions(do_async=do_async)
 
         # Initialise control ping
 
         # Initialise control ping
-        self.control_ping_index = self.vpp_dictionary['control_ping']['id']
+        crc = self.messages['control_ping'].crc
+        self.control_ping_index = self.transport.get_msg_index(
+            ('control_ping' + '_' + crc[2:]).encode())
         self.control_ping_msgdef = self.messages['control_ping']
         self.control_ping_msgdef = self.messages['control_ping']
+        if self.async_thread:
+            self.event_thread = threading.Thread(
+                target=self.thread_msg_handler)
+            self.event_thread.daemon = True
+            self.event_thread.start()
+        return rv
 
 
-    def connect(self, name, chroot_prefix = None, async = False, rx_qlen = 32):
+    def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
         """Attach to VPP.
 
         name - the name of the client.
         chroot_prefix - if VPP is chroot'ed, the prefix of the jail
         """Attach to VPP.
 
         name - the name of the client.
         chroot_prefix - if VPP is chroot'ed, the prefix of the jail
-        async - if true, messages are sent without waiting for a reply
+        do_async - if true, messages are sent without waiting for a reply
         rx_qlen - the length of the VPP message receive queue between
         client and server.
         """
         rx_qlen - the length of the VPP message receive queue between
         client and server.
         """
-        msg_handler = self.msg_handler_sync if not async \
-                      else self.msg_handler_async
+        msg_handler = self.transport.get_callback(do_async)
         return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
         return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
-                                     async)
+                                     do_async)
 
 
-    def connect_sync (self, name, chroot_prefix = None, rx_qlen = 32):
+    def connect_sync(self, name, chroot_prefix=None, rx_qlen=32):
         """Attach to VPP in synchronous mode. Application must poll for events.
 
         name - the name of the client.
         """Attach to VPP in synchronous mode. Application must poll for events.
 
         name - the name of the client.
@@ -419,12 +432,12 @@ class VPP():
         """
 
         return self.connect_internal(name, None, chroot_prefix, rx_qlen,
         """
 
         return self.connect_internal(name, None, chroot_prefix, rx_qlen,
-                                     async=False)
+                                     do_async=False)
 
     def disconnect(self):
         """Detach from VPP."""
 
     def disconnect(self):
         """Detach from VPP."""
-        rv = vpp_api.disconnect()
-        self.connected = False
+        rv = self.transport.disconnect()
+        self.message_queue.put("terminate event thread")
         return rv
 
     def msg_handler_sync(self, msg):
         return rv
 
     def msg_handler_sync(self, msg):
@@ -442,8 +455,6 @@ class VPP():
         if hasattr(r, 'context') and r.context > 0:
             context = r.context
 
         if hasattr(r, 'context') and r.context > 0:
             context = r.context
 
-        msgname = type(r).__name__
-
         if context == 0:
             # No context -> async notification that we feed to the callback
             self.message_queue.put_nowait(r)
         if context == 0:
             # No context -> async notification that we feed to the callback
             self.message_queue.put_nowait(r)
@@ -452,22 +463,20 @@ class VPP():
 
     def decode_incoming_msg(self, msg):
         if not msg:
 
     def decode_incoming_msg(self, msg):
         if not msg:
-            eprint('vpp_api.read failed')
+            self.logger.warning('vpp_api.read failed')
             return
             return
-
-        i, ci = self.header.unpack_from(msg, 0)
+        (i, ci), size = self.header.unpack(msg, 0)
         if self.id_names[i] == 'rx_thread_exit':
             return
 
         #
         # Decode message and returns a tuple.
         #
         if self.id_names[i] == 'rx_thread_exit':
             return
 
         #
         # Decode message and returns a tuple.
         #
-        msgdef = self.id_msgdef[i]
-        if not msgdef:
+        msgobj = self.id_msgdef[i]
+        if not msgobj:
             raise IOError(2, 'Reply message undefined')
 
             raise IOError(2, 'Reply message undefined')
 
-        r = self.decode(msgdef, msg)
-
+        r, size = msgobj.unpack(msg)
         return r
 
     def msg_handler_async(self, msg):
         return r
 
     def msg_handler_async(self, msg):
@@ -481,16 +490,22 @@ class VPP():
 
         msgname = type(r).__name__
 
 
         msgname = type(r).__name__
 
-       if self.event_callback:
-           self.event_callback(msgname, r)
+        if self.event_callback:
+            self.event_callback(msgname, r)
 
     def _control_ping(self, context):
         """Send a ping command."""
         self._call_vpp_async(self.control_ping_index,
 
     def _control_ping(self, context):
         """Send a ping command."""
         self._call_vpp_async(self.control_ping_index,
-                            self.control_ping_msgdef,
+                             self.control_ping_msgdef,
                              context=context)
 
                              context=context)
 
-    def _call_vpp(self, i, msgdef, multipart, **kwargs):
+    def validate_args(self, msg, kwargs):
+        d = set(kwargs.keys()) - set(msg.field_by_name.keys())
+        if d:
+            raise ValueError('Invalid argument {} to {}'
+                             .format(list(d), msg.name))
+
+    def _call_vpp(self, i, msg, multipart, **kwargs):
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
@@ -506,16 +521,23 @@ class VPP():
         no response within the timeout window.
         """
 
         no response within the timeout window.
         """
 
-        if not 'context' in kwargs:
+        if 'context' not in kwargs:
             context = self.get_context()
             kwargs['context'] = context
         else:
             context = kwargs['context']
         kwargs['_vl_msg_id'] = i
             context = self.get_context()
             kwargs['context'] = context
         else:
             context = kwargs['context']
         kwargs['_vl_msg_id'] = i
-        b = self.encode(msgdef, kwargs)
 
 
-        vpp_api.suspend()
-        self._write(b)
+        try:
+            if self.transport.socket_index:
+                kwargs['client_index'] = self.transport.socket_index
+        except AttributeError:
+            pass
+        self.validate_args(msg, kwargs)
+        b = msg.pack(kwargs)
+        self.transport.suspend()
+
+        self.transport.write(b)
 
         if multipart:
             # Send a ping after the request - we use its response
 
         if multipart:
             # Send a ping after the request - we use its response
@@ -525,14 +547,13 @@ class VPP():
         # Block until we get a reply.
         rl = []
         while (True):
         # Block until we get a reply.
         rl = []
         while (True):
-            msg = self._read()
+            msg = self.transport.read()
             if not msg:
             if not msg:
-                print('PNEUM ERROR: OH MY GOD')
-                raise IOError(2, 'PNEUM read failed')
-
+                raise IOError(2, 'VPP API client: read failed')
             r = self.decode_incoming_msg(msg)
             msgname = type(r).__name__
             r = self.decode_incoming_msg(msg)
             msgname = type(r).__name__
-            if not context in r or r.context == 0 or context != r.context:
+            if context not in r or r.context == 0 or context != r.context:
+                # Message being queued
                 self.message_queue.put_nowait(r)
                 continue
 
                 self.message_queue.put_nowait(r)
                 continue
 
@@ -544,11 +565,11 @@ class VPP():
 
             rl.append(r)
 
 
             rl.append(r)
 
-        vpp_api.resume()
+        self.transport.resume()
 
         return rl
 
 
         return rl
 
-    def _call_vpp_async(self, i, msgdef, **kwargs):
+    def _call_vpp_async(self, i, msg, **kwargs):
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
@@ -557,15 +578,20 @@ class VPP():
         supplied.
         The remainder of the kwargs are the arguments to the API call.
         """
         supplied.
         The remainder of the kwargs are the arguments to the API call.
         """
-        if not 'context' in kwargs:
+        if 'context' not in kwargs:
             context = self.get_context()
             kwargs['context'] = context
         else:
             context = kwargs['context']
             context = self.get_context()
             kwargs['context'] = context
         else:
             context = kwargs['context']
+        try:
+            if self.transport.socket_index:
+                kwargs['client_index'] = self.transport.socket_index
+        except AttributeError:
+            kwargs['client_index'] = 0
         kwargs['_vl_msg_id'] = i
         kwargs['_vl_msg_id'] = i
-        b = self.encode(msgdef, kwargs)
+        b = msg.pack(kwargs)
 
 
-        self._write(b)
+        self.transport.write(b)
 
     def register_event_callback(self, callback):
         """Register a callback for async messages.
 
     def register_event_callback(self, callback):
         """Register a callback for async messages.
@@ -586,7 +612,7 @@ class VPP():
         self.event_callback = callback
 
     def thread_msg_handler(self):
         self.event_callback = callback
 
     def thread_msg_handler(self):
-        """Python thread calling the user registerd message handler.
+        """Python thread calling the user registered message handler.
 
         This is to emulate the old style event callback scheme. Modern
         clients should provide their own thread to poll the event
 
         This is to emulate the old style event callback scheme. Modern
         clients should provide their own thread to poll the event
@@ -594,6 +620,11 @@ class VPP():
         """
         while True:
             r = self.message_queue.get()
         """
         while True:
             r = self.message_queue.get()
+            if r == "terminate event thread":
+                break
             msgname = type(r).__name__
             msgname = type(r).__name__
-           if self.event_callback:
-               self.event_callback(msgname, r)
+            if self.event_callback:
+                self.event_callback(msgname, r)
+
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4