summaryrefslogtreecommitdiffstats
path: root/src/vpp-api/python/vpp_papi.py
diff options
context:
space:
mode:
authorOle Troan <ot@cisco.com>2018-06-12 21:06:44 +0200
committerDamjan Marion <dmarion@me.com>2018-06-17 15:21:00 +0000
commita5ee900fb75201bbfceaf13c8bc57a13ed094988 (patch)
treeac866f01fca454d05ade6a6be200a429ea786f99 /src/vpp-api/python/vpp_papi.py
parent76440d9033822da4123d1c5bca1d4df12aef6280 (diff)
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>
Diffstat (limited to 'src/vpp-api/python/vpp_papi.py')
-rw-r--r--src/vpp-api/python/vpp_papi.py891
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