Python API: Add enum and union support.

As well as a rewrite of the encoders/decoders to make it more readable and extensible.

Change-Id: I253369ac76303922bf9c11377622c8974fa92f19
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 0 insertions, 891 deletions

diff --git a/src/vpp-api/python/vpp_papi.py b/src/vpp-api/python/vpp_papi.py
deleted file mode 100644
index ece0e4ee52d..00000000000
--- a/src/vpp-api/python/vpp_papi.py
+++ /dev/null
@@ -1,891 +0,0 @@
-#!/usr/bin/env python
-#
-# Copyright (c) 2016 Cisco and/or its affiliates.
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at:
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-from __future__ import print_function
-import sys
-import os
-import logging
-import collections
-import struct
-import json
-import threading
-import fnmatch
-import weakref
-import atexit
-from cffi import FFI
-import cffi
-
-if sys.version[0] == '2':
-    import Queue as queue
-else:
-    import queue as queue
-
-ffi = FFI()
-ffi.cdef("""
-typedef void (*vac_callback_t)(unsigned char * data, int len);
-typedef void (*vac_error_callback_t)(void *, unsigned char *, int);
-int vac_connect(char * name, char * chroot_prefix, vac_callback_t cb,
-    int rx_qlen);
-int vac_disconnect(void);
-int vac_read(char **data, int *l, unsigned short timeout);
-int vac_write(char *data, int len);
-void vac_free(void * msg);
-
-int vac_get_msg_index(unsigned char * name);
-int vac_msg_table_size(void);
-int vac_msg_table_max_index(void);
-
-void vac_rx_suspend (void);
-void vac_rx_resume (void);
-void vac_set_error_handler(vac_error_callback_t);
- """)
-
-# Barfs on failure, no need to check success.
-vpp_api = ffi.dlopen('libvppapiclient.so')
-
-
-def vpp_atexit(vpp_weakref):
-    """Clean up VPP connection on shutdown."""
-    vpp_instance = vpp_weakref()
-    if vpp_instance.connected:
-        vpp_instance.logger.debug('Cleaning up VPP on exit')
-        vpp_instance.disconnect()
-
-
-vpp_object = None
-
-
-def vpp_iterator(d):
-    if sys.version[0] == '2':
-        return d.iteritems()
-    else:
-        return d.items()
-
-
-@ffi.callback("void(unsigned char *, int)")
-def vac_callback_sync(data, len):
-    vpp_object.msg_handler_sync(ffi.buffer(data, len))
-
-
-@ffi.callback("void(unsigned char *, int)")
-def vac_callback_async(data, len):
-    vpp_object.msg_handler_async(ffi.buffer(data, len))
-
-
-@ffi.callback("void(void *, unsigned char *, int)")
-def vac_error_handler(arg, msg, msg_len):
-    vpp_object.logger.warning("VPP API client:: %s", ffi.string(msg, msg_len))
-
-
-class Empty(object):
-    pass
-
-
-class FuncWrapper(object):
-    def __init__(self, func):
-        self._func = func
-        self.__name__ = func.__name__
-
-    def __call__(self, **kwargs):
-        return self._func(**kwargs)
-
-
-class VPP():
-    """VPP interface.
-
-    This class provides the APIs to VPP.  The APIs are loaded
-    from provided .api.json files and makes functions accordingly.
-    These functions are documented in the VPP .api files, as they
-    are dynamically created.
-
-    Additionally, VPP can send callback messages; this class
-    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,
-                 logger=None, loglevel=None,
-                 read_timeout=0):
-        """Create a VPP API object.
-
-        apifiles is a list of files containing API
-        descriptions that will be loaded - methods will be
-        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).
-        """
-        global vpp_object
-        vpp_object = self
-
-        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.connected = False
-        self.header = struct.Struct('>HI')
-        self.apifiles = []
-        self.event_callback = None
-        self.message_queue = queue.Queue()
-        self.read_timeout = read_timeout
-        self.vpp_api = vpp_api
-        self.async_thread = async_thread
-
-        if not apifiles:
-            # Pick up API definitions from default directory
-            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:
-                api = json.load(apidef_file)
-                for t in api['types']:
-                    self.add_type(t[0], t[1:])
-
-                for m in api['messages']:
-                    self.add_message(m[0], m[1:])
-        self.apifiles = apifiles
-
-        # Basic sanity check
-        if len(self.messages) == 0 and not testmode:
-            raise ValueError(1, 'Missing JSON message definitions')
-
-        # Make sure we allow VPP to clean up the message rings.
-        atexit.register(vpp_atexit, weakref.ref(self))
-
-        # Register error handler
-        vpp_api.vac_set_error_handler(vac_error_handler)
-
-        # Support legacy CFFI
-        # from_buffer supported from 1.8.0
-        (major, minor, patch) = [int(s) for s in
-                                 cffi.__version__.split('.', 3)]
-        if major >= 1 and minor >= 8:
-            self._write = self._write_new_cffi
-        else:
-            self._write = self._write_legacy_cffi
-
-    class ContextId(object):
-        """Thread-safe provider of unique context IDs."""
-        def __init__(self):
-            self.context = 0
-            self.lock = threading.Lock()
-
-        def __call__(self):
-            """Get a new unique (or, at least, not recently used) context."""
-            with self.lock:
-                self.context += 1
-                return self.context
-    get_context = ContextId()
-
-    @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.
-
-        :returns: A single directory name, or None if no such directory
-            could be found.
-        """
-        dirs = []
-
-        if 'VPP_API_DIR' in os.environ:
-            dirs.append(os.environ['VPP_API_DIR'])
-
-        # 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
-
-        return None
-
-    @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:
-            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
-
-    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', }
-
-        if t in base_types:
-            if not vl:
-                if e > 0 and t == 'u8':
-                    # Fixed byte array
-                    s = struct.Struct('>' + str(e) + 's')
-                    return s.size, s
-                if e > 0:
-                    # Fixed array of base type
-                    s = struct.Struct('>' + base_types[t])
-                    return s.size, [e, s]
-                elif e == 0:
-                    # Old style variable array
-                    s = struct.Struct('>' + base_types[t])
-                    return s.size, [-1, s]
-            else:
-                # Variable length array
-                if t == 'u8':
-                    s = struct.Struct('>s')
-                    return s.size, [vl, s]
-                else:
-                    s = struct.Struct('>' + base_types[t])
-                return s.size, [vl, s]
-
-            s = struct.Struct('>' + base_types[t])
-            return s.size, s
-
-        if t in self.messages:
-            size = self.messages[t]['sizes'][0]
-
-            # Return a list in case of array
-            if e > 0 and not vl:
-                return size, [e, lambda self, encode, buf, offset, args: (
-                    self.__struct_type(encode, self.messages[t], buf, offset,
-                                       args))]
-            if vl:
-                return size, [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 size, 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, 'Non existing argument [' + k + ']' +
-                                    ' used in call to: ' +
-                                 self.id_names[kwargs['_vl_msg_id']] + '()')
-
-        for k, v in vpp_iterator(msgdef['args']):
-            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]
-                        if e != len(kwargs[k]):
-                            raise (ValueError(1,
-                                              'Input list length mismatch: '
-                                              '%s (%s != %s)' %
-                                              (k, e, len(kwargs[k]))))
-                        size = 0
-                        for i in range(e):
-                            size += v[1](self, True, buf, off + size,
-                                         kwargs[k][i])
-                    else:
-                        if v[0] in kwargs:
-                            kwargslen = kwargs[v[0]]
-                            if kwargslen != len(kwargs[k]):
-                                raise ValueError(1,
-                                                 'Input list length mismatch:'
-                                                 ' %s (%s != %s)' %
-                                                 (k, kwargslen,
-                                                  len(kwargs[k])))
-                        else:
-                            kwargslen = len(kwargs[k])
-                        if v[1].size == 1:
-                            buf[off:off + kwargslen] = bytearray(kwargs[k])
-                            size = kwargslen
-                        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:
-                        if type(kwargs[k]) is str and v.size < len(kwargs[k]):
-                            raise ValueError(1,
-                                             'Input list length mismatch: '
-                                             '%s (%s < %s)' %
-                                             (k, v.size, len(kwargs[k])))
-                        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 __getitem__(self, name):
-        if name in self.messages:
-            return self.messages[name]
-        return None
-
-    def get_size(self, sizes, kwargs):
-        total_size = sizes[0]
-        for e in sizes[1]:
-            if e in kwargs and type(kwargs[e]) is list:
-                total_size += len(kwargs[e]) * sizes[1][e]
-        return total_size
-
-    def encode(self, msgdef, kwargs):
-        # Make suitably large buffer
-        size = self.get_size(msgdef['sizes'], kwargs)
-        buf = bytearray(size)
-        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 vpp_iterator(msgdef['args']):
-            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):
-                    size = 0
-                    (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
-
-        return off + size - offset, msgdef['return_tuple']._make(res)
-
-    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
-
-    def duplicate_check_ok(self, name, msgdef):
-        crc = None
-        for c in msgdef:
-            if type(c) is dict and 'crc' in c:
-                crc = c['crc']
-                break
-        if crc:
-            # We can get duplicates because of imports
-            if crc == self.messages[name]['crc']:
-                return True
-        return False
-
-    def add_message(self, name, msgdef, typeonly=False):
-        if name in self.messages:
-            if typeonly:
-                if self.duplicate_check_ok(name, msgdef):
-                    return
-            raise ValueError('Duplicate message name: ' + name)
-
-        args = collections.OrderedDict()
-        argtypes = collections.OrderedDict()
-        fields = []
-        msg = {}
-        total_size = 0
-        sizes = {}
-        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)
-            size, s = self.__struct(*f)
-            args[field_name] = s
-            if type(s) == list and type(s[0]) == int and \
-               type(s[1]) == struct.Struct:
-                if s[0] < 0:
-                    sizes[field_name] = size
-                else:
-                    sizes[field_name] = size
-                    total_size += s[0] * size
-            else:
-                sizes[field_name] = size
-                total_size += size
-
-            argtypes[field_name] = field_type
-            if len(f) == 4:  # Find offset to # elements field
-                idx = list(args.keys()).index(f[3]) - i
-                args[field_name].append(idx)
-            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
-        self.messages[name]['typeonly'] = typeonly
-        self.messages[name]['sizes'] = [total_size, sizes]
-        return self.messages[name]
-
-    def add_type(self, name, typedef):
-        return self.add_message('vl_api_' + name + '_t', typedef,
-                                typeonly=True)
-
-    def make_function(self, name, i, msgdef, multipart, async):
-        if (async):
-            def f(**kwargs):
-                return self._call_vpp_async(i, msgdef, **kwargs)
-        else:
-            def f(**kwargs):
-                return 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
-
-    @property
-    def api(self):
-        if not hasattr(self, "_api"):
-            raise Exception("Not connected, api definitions not available")
-        return self._api
-
-    def _register_functions(self, async=False):
-        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 vpp_iterator(self.messages):
-            if self.messages[name]['typeonly']:
-                continue
-            crc = self.messages[name]['crc']
-            n = name + '_' + crc[2:]
-            i = vpp_api.vac_get_msg_index(n.encode())
-            if i > 0:
-                self.id_msgdef[i] = msgdef
-                self.id_names[i] = name
-                multipart = True if name.find('_dump') > 0 else False
-                f = self.make_function(name, i, msgdef, multipart, async)
-                setattr(self._api, name, FuncWrapper(f))
-            else:
-                self.logger.debug(
-                    'No such message type or failed CRC checksum: %s', n)
-
-    def _write_new_cffi(self, buf):
-        """Send a binary-packed message to VPP."""
-        if not self.connected:
-            raise IOError(1, 'Not connected')
-        return vpp_api.vac_write(ffi.from_buffer(buf), len(buf))
-
-    def _write_legacy_cffi(self, buf):
-        """Send a binary-packed message to VPP."""
-        if not self.connected:
-            raise IOError(1, 'Not connected')
-        return vpp_api.vac_write(bytes(buf), len(buf))
-
-    def _read(self):
-        if not self.connected:
-            raise IOError(1, 'Not connected')
-        mem = ffi.new("char **")
-        size = ffi.new("int *")
-        rv = vpp_api.vac_read(mem, size, self.read_timeout)
-        if rv:
-            raise IOError(rv, 'vac_read failed')
-        msg = bytes(ffi.buffer(mem[0], size[0]))
-        vpp_api.vac_free(mem[0])
-        return msg
-
-    def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen,
-                         async):
-        pfx = chroot_prefix.encode() if chroot_prefix else ffi.NULL
-        rv = vpp_api.vac_connect(name.encode(), pfx, msg_handler, rx_qlen)
-        if rv != 0:
-            raise IOError(2, 'Connect failed')
-        self.connected = True
-
-        self.vpp_dictionary_maxid = vpp_api.vac_msg_table_max_index()
-        self._register_functions(async=async)
-
-        # Initialise control ping
-        crc = self.messages['control_ping']['crc']
-        self.control_ping_index = vpp_api.vac_get_msg_index(
-            ('control_ping' + '_' + crc[2:]).encode())
-        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):
-        """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
-        rx_qlen - the length of the VPP message receive queue between
-        client and server.
-        """
-        msg_handler = vac_callback_sync if not async else vac_callback_async
-        return self.connect_internal(name, msg_handler, chroot_prefix, rx_qlen,
-                                     async)
-
-    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.
-        chroot_prefix - if VPP is chroot'ed, the prefix of the jail
-        rx_qlen - the length of the VPP message receive queue between
-        client and server.
-        """
-
-        return self.connect_internal(name, ffi.NULL, chroot_prefix, rx_qlen,
-                                     async=False)
-
-    def disconnect(self):
-        """Detach from VPP."""
-        rv = vpp_api.vac_disconnect()
-        self.connected = False
-        self.message_queue.put("terminate event thread")
-        return rv
-
-    def msg_handler_sync(self, msg):
-        """Process an incoming message from VPP in sync mode.
-
-        The message may be a reply or it may be an async notification.
-        """
-        r = self.decode_incoming_msg(msg)
-        if r is None:
-            return
-
-        # If we have a context, then use the context to find any
-        # request waiting for a reply
-        context = 0
-        if hasattr(r, 'context') and r.context > 0:
-            context = r.context
-
-        if context == 0:
-            # No context -> async notification that we feed to the callback
-            self.message_queue.put_nowait(r)
-        else:
-            raise IOError(2, 'RPC reply message received in event handler')
-
-    def decode_incoming_msg(self, msg):
-        if not msg:
-            self.logger.warning('vpp_api.read failed')
-            return
-
-        i, ci = self.header.unpack_from(msg, 0)
-        if self.id_names[i] == 'rx_thread_exit':
-            return
-
-        #
-        # Decode message and returns a tuple.
-        #
-        msgdef = self.id_msgdef[i]
-        if not msgdef:
-            raise IOError(2, 'Reply message undefined')
-
-        r = self.decode(msgdef, msg)
-
-        return r
-
-    def msg_handler_async(self, msg):
-        """Process a message from VPP in async mode.
-
-        In async mode, all messages are returned to the callback.
-        """
-        r = self.decode_incoming_msg(msg)
-        if r is None:
-            return
-
-        msgname = type(r).__name__
-
-        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,
-                             self.control_ping_msgdef,
-                             context=context)
-
-    def _call_vpp(self, i, msgdef, multipart, **kwargs):
-        """Given a message, send the message and await a reply.
-
-        msgdef - the message packing definition
-        i - the message type index
-        multipart - True if the message returns multiple
-        messages in return.
-        context - context number - chosen at random if not
-        supplied.
-        The remainder of the kwargs are the arguments to the API call.
-
-        The return value is the message or message array containing
-        the response.  It will raise an IOError exception if there was
-        no response within the timeout window.
-        """
-
-        if 'context' not in kwargs:
-            context = self.get_context()
-            kwargs['context'] = context
-        else:
-            context = kwargs['context']
-        kwargs['_vl_msg_id'] = i
-        b = self.encode(msgdef, kwargs)
-
-        vpp_api.vac_rx_suspend()
-        self._write(b)
-
-        if multipart:
-            # Send a ping after the request - we use its response
-            # to detect that we have seen all results.
-            self._control_ping(context)
-
-        # Block until we get a reply.
-        rl = []
-        while (True):
-            msg = self._read()
-            if not msg:
-                raise IOError(2, 'VPP API client: read failed')
-
-            r = self.decode_incoming_msg(msg)
-            msgname = type(r).__name__
-            if context not in r or r.context == 0 or context != r.context:
-                self.message_queue.put_nowait(r)
-                continue
-
-            if not multipart:
-                rl = r
-                break
-            if msgname == 'control_ping_reply':
-                break
-
-            rl.append(r)
-
-        vpp_api.vac_rx_resume()
-
-        return rl
-
-    def _call_vpp_async(self, i, msgdef, **kwargs):
-        """Given a message, send the message and await a reply.
-
-        msgdef - the message packing definition
-        i - the message type index
-        context - context number - chosen at random if not
-        supplied.
-        The remainder of the kwargs are the arguments to the API call.
-        """
-        if 'context' not in kwargs:
-            context = self.get_context()
-            kwargs['context'] = context
-        else:
-            context = kwargs['context']
-        kwargs['_vl_msg_id'] = i
-        b = self.encode(msgdef, kwargs)
-
-        self._write(b)
-
-    def register_event_callback(self, callback):
-        """Register a callback for async messages.
-
-        This will be called for async notifications in sync mode,
-        and all messages in async mode.  In sync mode, replies to
-        requests will not come here.
-
-        callback is a fn(msg_type_name, msg_type) that will be
-        called when a message comes in.  While this function is
-        executing, note that (a) you are in a background thread and
-        may wish to use threading.Lock to protect your datastructures,
-        and (b) message processing from VPP will stop (so if you take
-        a long while about it you may provoke reply timeouts or cause
-        VPP to fill the RX buffer).  Passing None will disable the
-        callback.
-        """
-        self.event_callback = callback
-
-    def thread_msg_handler(self):
-        """Python thread calling the user registerd message handler.
-
-        This is to emulate the old style event callback scheme. Modern
-        clients should provide their own thread to poll the event
-        queue.
-        """
-        while True:
-            r = self.message_queue.get()
-            if r == "terminate event thread":
-                break
-            msgname = type(r).__name__
-            if self.event_callback:
-                self.event_callback(msgname, r)
-
-
-# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4