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Diffstat (limited to 'src/vpp-api/python/vpp_papi.py')
| -rw-r--r-- | src/vpp-api/python/vpp_papi.py | 891 |
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 |