papi: add support for enumflag part 1 of 2
[vpp.git] / src / vpp-api / python / vpp_papi / vpp_papi.py
index e1a7059..b4d4686 100644 (file)
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (c) 2016 Cisco and/or its affiliates.
 # Licensed under the Apache License, Version 2.0 (the "License");
 #
 # Copyright (c) 2016 Cisco and/or its affiliates.
 # Licensed under the Apache License, Version 2.0 (the "License");
 
 from __future__ import print_function
 from __future__ import absolute_import
 
 from __future__ import print_function
 from __future__ import absolute_import
+import ctypes
+import ipaddress
 import sys
 import sys
+import multiprocessing as mp
 import os
 import os
+import queue
 import logging
 import logging
-import collections
-import struct
+import functools
 import json
 import threading
 import fnmatch
 import weakref
 import atexit
 import json
 import threading
 import fnmatch
 import weakref
 import atexit
-from . vpp_serializer import VPPType, VPPEnumType, VPPUnionType, BaseTypes
-from . vpp_serializer import VPPMessage
+import time
+from . vpp_format import verify_enum_hint
+from . vpp_serializer import VPPType, VPPEnumType, VPPEnumFlagType, VPPUnionType
+from . vpp_serializer import VPPMessage, vpp_get_type, VPPTypeAlias
+
+try:
+    import VppTransport
+except ModuleNotFoundError:
+    class V:
+        """placeholder for VppTransport as the implementation is dependent on
+        VPPAPIClient's initialization values
+        """
+
+    VppTransport = V
+
+logger = logging.getLogger('vpp_papi')
+logger.addHandler(logging.NullHandler())
+
+__all__ = ('FuncWrapper', 'VPP', 'VppApiDynamicMethodHolder',
+           'VppEnum', 'VppEnumType', 'VppEnumFlag',
+           'VPPIOError', 'VPPRuntimeError', 'VPPValueError',
+           'VPPApiClient', )
+
+
+def metaclass(metaclass):
+    @functools.wraps(metaclass)
+    def wrapper(cls):
+        return metaclass(cls.__name__, cls.__bases__, cls.__dict__.copy())
+
+    return wrapper
+
 
 
-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
+
+
+@metaclass(VppEnumType)
+class VppEnum:
+    pass
+
+
+@metaclass(VppEnumType)
+class VppEnumFlag:
+    pass
 
 
 def vpp_atexit(vpp_weakref):
     """Clean up VPP connection on shutdown."""
     vpp_instance = vpp_weakref()
     if vpp_instance and vpp_instance.transport.connected:
 
 
 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')
+        logger.debug('Cleaning up VPP on exit')
         vpp_instance.disconnect()
 
 
         vpp_instance.disconnect()
 
 
-def vpp_iterator(d):
-    if sys.version[0] == '2':
-        return d.iteritems()
-    else:
-        return d.items()
+def add_convenience_methods():
+    # provide convenience methods to IP[46]Address.vapi_af
+    def _vapi_af(self):
+        if 6 == self._version:
+            return VppEnum.vl_api_address_family_t.ADDRESS_IP6.value
+        if 4 == self._version:
+            return VppEnum.vl_api_address_family_t.ADDRESS_IP4.value
+        raise ValueError("Invalid _version.")
+
+    def _vapi_af_name(self):
+        if 6 == self._version:
+            return 'ip6'
+        if 4 == self._version:
+            return 'ip4'
+        raise ValueError("Invalid _version.")
+
+    ipaddress._IPAddressBase.vapi_af = property(_vapi_af)
+    ipaddress._IPAddressBase.vapi_af_name = property(_vapi_af_name)
 
 
 
 
-class VppApiDynamicMethodHolder(object):
+class VppApiDynamicMethodHolder:
     pass
 
 
     pass
 
 
-class FuncWrapper(object):
+class FuncWrapper:
     def __init__(self, func):
         self._func = func
         self.__name__ = func.__name__
     def __init__(self, func):
         self._func = func
         self.__name__ = func.__name__
+        self.__doc__ = func.__doc__
 
     def __call__(self, **kwargs):
         return self._func(**kwargs)
 
 
     def __call__(self, **kwargs):
         return self._func(**kwargs)
 
+    def __repr__(self):
+        return '<FuncWrapper(func=<%s(%s)>)>' % (self.__name__, self.__doc__)
 
 
-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 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}
-
-        i = 0
-        while True:
-            unresolved = {}
-            for k, v in types.items():
-                t = v['data']
-                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
-            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=logging.getLogger('vpp_papi'), loglevel='debug',
-                 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
-        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).
-        """
-        if logger is None:
-            logger = logging.getLogger(__name__)
-            if loglevel is not None:
-                logger.setLevel(loglevel)
-        self.logger = logger
+class VPPApiError(Exception):
+    pass
 
 
-        self.messages = {}
-        self.id_names = []
-        self.id_msgdef = []
-        self.header = VPPType('header', [['u16', 'msgid'],
-                                         ['u32', 'client_index']])
-        self.apifiles = []
-        self.event_callback = None
-        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
+class VPPNotImplementedError(NotImplementedError):
+    pass
 
 
-        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:
-                self.process_json_file(apidef_file)
+class VPPIOError(IOError):
+    pass
 
 
-        self.apifiles = apifiles
 
 
-        # Basic sanity check
-        if len(self.messages) == 0 and not testmode:
-            raise ValueError(1, 'Missing JSON message definitions')
+class VPPRuntimeError(RuntimeError):
+    pass
 
 
-        self.transport = VppTransport(self, read_timeout=read_timeout,
-                                      server_address=server_address)
-        # Make sure we allow VPP to clean up the message rings.
-        atexit.register(vpp_atexit, weakref.ref(self))
 
 
-    class ContextId(object):
-        """Thread-safe provider of unique context IDs."""
-        def __init__(self):
-            self.context = 0
-            self.lock = threading.Lock()
+class VPPValueError(ValueError):
+    pass
 
 
-        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()
 
 
+class VPPApiJSONFiles:
     @classmethod
     @classmethod
-    def find_api_dir(cls):
+    def find_api_dir(cls, dirs):
         """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
         """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
@@ -212,10 +155,6 @@ class VPP():
         :returns: A single directory name, or None if no such directory
             could be found.
         """
         :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
 
         # 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
@@ -277,7 +216,7 @@ class VPP():
         # finally, try the location system packages typically install into
         dirs.append(os.path.sep.join(('', 'usr', 'share', 'vpp', 'api')))
 
         # 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
+        # check the directories for existence; first one wins
         for dir in dirs:
             if os.path.isdir(dir):
                 return dir
         for dir in dirs:
             if os.path.isdir(dir):
                 return dir
@@ -285,7 +224,7 @@ class VPP():
         return None
 
     @classmethod
         return None
 
     @classmethod
-    def find_api_files(cls, api_dir=None, patterns='*'):
+    def find_api_files(cls, api_dir=None, patterns='*'):  # -> list
         """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
         """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
@@ -306,9 +245,9 @@ class VPP():
         :returns: A list of file paths for the API files found.
         """
         if api_dir is None:
         :returns: A list of file paths for the API files found.
         """
         if api_dir is None:
-            api_dir = cls.find_api_dir()
+            api_dir = cls.find_api_dir([])
             if api_dir is None:
             if api_dir is None:
-                raise RuntimeError("api_dir cannot be located")
+                raise VPPApiError("api_dir cannot be located")
 
         if isinstance(patterns, list) or isinstance(patterns, tuple):
             patterns = [p.strip() + '.api.json' for p in patterns]
 
         if isinstance(patterns, list) or isinstance(patterns, tuple):
             patterns = [p.strip() + '.api.json' for p in patterns]
@@ -324,10 +263,231 @@ class VPP():
 
         return api_files
 
 
         return api_files
 
+    @classmethod
+    def process_json_file(self, apidef_file):
+        api = json.load(apidef_file)
+        return self._process_json(api)
+
+    @classmethod
+    def process_json_str(self, json_str):
+        api = json.loads(json_str)
+        return self._process_json(api)
+
+    @staticmethod
+    def _process_json(api):  # -> Tuple[Dict, Dict]
+        types = {}
+        services = {}
+        messages = {}
+        try:
+            for t in api['enums']:
+                t[0] = 'vl_api_' + t[0] + '_t'
+                types[t[0]] = {'type': 'enum', 'data': t}
+        except KeyError:
+            pass
+        try:
+            for t in api['enumflags']:
+                t[0] = 'vl_api_' + t[0] + '_t'
+                types[t[0]] = {'type': 'enum', 'data': t}
+        except KeyError:
+            pass
+        try:
+            for t in api['unions']:
+                t[0] = 'vl_api_' + t[0] + '_t'
+                types[t[0]] = {'type': 'union', 'data': t}
+        except KeyError:
+            pass
+
+        try:
+            for t in api['types']:
+                t[0] = 'vl_api_' + t[0] + '_t'
+                types[t[0]] = {'type': 'type', 'data': t}
+        except KeyError:
+            pass
+
+        try:
+            for t, v in api['aliases'].items():
+                types['vl_api_' + t + '_t'] = {'type': 'alias', 'data': v}
+        except KeyError:
+            pass
+
+        try:
+            services.update(api['services'])
+        except KeyError:
+            pass
+
+        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
+                if not vpp_get_type(k):
+                    if v['type'] == 'enumflag':
+                        try:
+                            VPPEnumFlagType(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 VPPValueError('Unresolved type definitions {}'
+                                    .format(unresolved))
+            types = unresolved
+            i += 1
+        try:
+            for m in api['messages']:
+                try:
+                    messages[m[0]] = VPPMessage(m[0], m[1:])
+                except VPPNotImplementedError:
+                    ### OLE FIXME
+                    logger.error('Not implemented error for {}'.format(m[0]))
+        except KeyError:
+            pass
+        return messages, services
+
+
+class VPPApiClient:
+    """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.
+    """
+    apidir = None
+    VPPApiError = VPPApiError
+    VPPRuntimeError = VPPRuntimeError
+    VPPValueError = VPPValueError
+    VPPNotImplementedError = VPPNotImplementedError
+    VPPIOError = VPPIOError
+
+
+    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
+        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).
+        """
+        if logger is None:
+            logger = logging.getLogger(
+                "{}.{}".format(__name__, self.__class__.__name__))
+            if loglevel is not None:
+                logger.setLevel(loglevel)
+        self.logger = logger
+
+        self.messages = {}
+        self.services = {}
+        self.id_names = []
+        self.id_msgdef = []
+        self.header = VPPType('header', [['u16', 'msgid'],
+                                         ['u32', 'client_index']])
+        self.apifiles = []
+        self.event_callback = None
+        self.message_queue = queue.Queue()
+        self.read_timeout = read_timeout
+        self.async_thread = async_thread
+        self.event_thread = None
+        self.testmode = testmode
+        self.use_socket = use_socket
+        self.server_address = server_address
+        self._apifiles = apifiles
+        self.stats = {}
+
+        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
+            try:
+                apifiles = VPPApiJSONFiles.find_api_files(self.apidir)
+            except (RuntimeError, VPPApiError):
+                # In test mode we don't care that we can't find the API files
+                if testmode:
+                    apifiles = []
+                else:
+                    raise VPPRuntimeError
+
+        for file in apifiles:
+            with open(file) as apidef_file:
+                m, s = VPPApiJSONFiles.process_json_file(apidef_file)
+                self.messages.update(m)
+                self.services.update(s)
+
+        self.apifiles = apifiles
+
+        # Basic sanity check
+        if len(self.messages) == 0 and not testmode:
+            raise VPPValueError(1, 'Missing JSON message definitions')
+        if not(verify_enum_hint(VppEnum.vl_api_address_family_t)):
+            raise VPPRuntimeError("Invalid address family hints. "
+                                  "Cannot continue.")
+
+        self.transport = VppTransport(self, read_timeout=read_timeout,
+                                      server_address=server_address)
+        # Make sure we allow VPP to clean up the message rings.
+        atexit.register(vpp_atexit, weakref.ref(self))
+
+        add_convenience_methods()
+
+    def get_function(self, name):
+        return getattr(self._api, name)
+
+    class ContextId:
+        """Multiprocessing-safe provider of unique context IDs."""
+        def __init__(self):
+            self.context = mp.Value(ctypes.c_uint, 0)
+            self.lock = mp.Lock()
+
+        def __call__(self):
+            """Get a new unique (or, at least, not recently used) context."""
+            with self.lock:
+                self.context.value += 1
+                return self.context.value
+    get_context = ContextId()
+
+    def get_type(self, name):
+        return vpp_get_type(name)
+
     @property
     def api(self):
         if not hasattr(self, "_api"):
     @property
     def api(self):
         if not hasattr(self, "_api"):
-            raise Exception("Not connected, api definitions not available")
+            raise VPPApiError("Not connected, api definitions not available")
         return self._api
 
     def make_function(self, msg, i, multipart, do_async):
         return self._api
 
     def make_function(self, msg, i, multipart, do_async):
@@ -342,46 +502,52 @@ class VPP():
         f.__doc__ = ", ".join(["%s %s" %
                                (msg.fieldtypes[j], k)
                                for j, k in enumerate(msg.fields)])
         f.__doc__ = ", ".join(["%s %s" %
                                (msg.fieldtypes[j], k)
                                for j, k in enumerate(msg.fields)])
+        f.msg = msg
+
         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._api = VppApiDynamicMethodHolder()
         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._api = VppApiDynamicMethodHolder()
-        for name, msg in vpp_iterator(self.messages):
+        for name, msg in self.messages.items():
             n = name + '_' + msg.crc[2:]
             n = name + '_' + msg.crc[2:]
-            i = self.transport.get_msg_index(n.encode())
+            i = self.transport.get_msg_index(n)
             if i > 0:
                 self.id_msgdef[i] = msg
                 self.id_names[i] = name
             if i > 0:
                 self.id_msgdef[i] = msg
                 self.id_names[i] = name
-                # TODO: Fix multipart (use services)
-                multipart = True if name.find('_dump') > 0 else False
-                f = self.make_function(msg, i, multipart, do_async)
-                setattr(self._api, name, FuncWrapper(f))
+
+                # Create function for client side messages.
+                if name in self.services:
+                    f = self.make_function(msg, i, self.services[name], do_async)
+                    setattr(self._api, name, FuncWrapper(f))
             else:
                 self.logger.debug(
                     'No such message type or failed CRC checksum: %s', n)
 
     def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen,
                          do_async):
             else:
                 self.logger.debug(
                     'No such message type or failed CRC checksum: %s', n)
 
     def connect_internal(self, name, msg_handler, chroot_prefix, rx_qlen,
                          do_async):
-        pfx = chroot_prefix.encode() if chroot_prefix else None
+        pfx = chroot_prefix.encode('utf-8') if chroot_prefix else None
 
 
-        rv = self.transport.connect(name.encode(), pfx, msg_handler, rx_qlen)
+        rv = self.transport.connect(name, pfx,
+                                    msg_handler, rx_qlen)
         if rv != 0:
         if rv != 0:
-            raise IOError(2, 'Connect failed')
+            raise VPPIOError(2, 'Connect failed')
         self.vpp_dictionary_maxid = self.transport.msg_table_max_index()
         self._register_functions(do_async=do_async)
 
         # Initialise control ping
         crc = self.messages['control_ping'].crc
         self.control_ping_index = self.transport.get_msg_index(
         self.vpp_dictionary_maxid = self.transport.msg_table_max_index()
         self._register_functions(do_async=do_async)
 
         # Initialise control ping
         crc = self.messages['control_ping'].crc
         self.control_ping_index = self.transport.get_msg_index(
-            ('control_ping' + '_' + crc[2:]).encode())
+            ('control_ping' + '_' + crc[2:]))
         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()
         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()
+        else:
+            self.event_thread = None
         return rv
 
     def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
         return rv
 
     def connect(self, name, chroot_prefix=None, do_async=False, rx_qlen=32):
@@ -412,7 +578,8 @@ class VPP():
     def disconnect(self):
         """Detach from VPP."""
         rv = self.transport.disconnect()
     def disconnect(self):
         """Detach from VPP."""
         rv = self.transport.disconnect()
-        self.message_queue.put("terminate event thread")
+        if self.event_thread is not None:
+            self.message_queue.put("terminate event thread")
         return rv
 
     def msg_handler_sync(self, msg):
         return rv
 
     def msg_handler_sync(self, msg):
@@ -434,12 +601,33 @@ class VPP():
             # No context -> async notification that we feed to the callback
             self.message_queue.put_nowait(r)
         else:
             # 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')
+            raise VPPIOError(2, 'RPC reply message received in event handler')
+
+    def has_context(self, msg):
+        if len(msg) < 10:
+            return False
+
+        header = VPPType('header_with_context', [['u16', 'msgid'],
+                                                 ['u32', 'client_index'],
+                                                 ['u32', 'context']])
 
 
-    def decode_incoming_msg(self, msg):
+        (i, ci, context), size = header.unpack(msg, 0)
+        if self.id_names[i] == 'rx_thread_exit':
+            return
+
+        #
+        # Decode message and returns a tuple.
+        #
+        msgobj = self.id_msgdef[i]
+        if 'context' in msgobj.field_by_name and context >= 0:
+            return True
+        return False
+
+    def decode_incoming_msg(self, msg, no_type_conversion=False):
         if not msg:
         if not msg:
-            self.logger.warning('vpp_api.read failed')
+            logger.warning('vpp_api.read failed')
             return
             return
+
         (i, ci), size = self.header.unpack(msg, 0)
         if self.id_names[i] == 'rx_thread_exit':
             return
         (i, ci), size = self.header.unpack(msg, 0)
         if self.id_names[i] == 'rx_thread_exit':
             return
@@ -449,9 +637,9 @@ class VPP():
         #
         msgobj = self.id_msgdef[i]
         if not msgobj:
         #
         msgobj = self.id_msgdef[i]
         if not msgobj:
-            raise IOError(2, 'Reply message undefined')
+            raise VPPIOError(2, 'Reply message undefined')
 
 
-        r, size = msgobj.unpack(msg)
+        r, size = msgobj.unpack(msg, ntc=no_type_conversion)
         return r
 
     def msg_handler_async(self, msg):
         return r
 
     def msg_handler_async(self, msg):
@@ -477,10 +665,28 @@ class VPP():
     def validate_args(self, msg, kwargs):
         d = set(kwargs.keys()) - set(msg.field_by_name.keys())
         if d:
     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))
+            raise VPPValueError('Invalid argument {} to {}'
+                                .format(list(d), msg.name))
 
 
-    def _call_vpp(self, i, msg, multipart, **kwargs):
+    def _add_stat(self, name, ms):
+        if not name in self.stats:
+            self.stats[name] = {'max': ms, 'count': 1, 'avg': ms}
+        else:
+            if ms > self.stats[name]['max']:
+                self.stats[name]['max'] = ms
+            self.stats[name]['count'] += 1
+            n = self.stats[name]['count']
+            self.stats[name]['avg'] = self.stats[name]['avg'] * (n - 1) / n + ms / n
+
+    def get_stats(self):
+        s = '\n=== API PAPI STATISTICS ===\n'
+        s += '{:<30} {:>4} {:>6} {:>6}\n'.format('message', 'cnt', 'avg', 'max')
+        for n in sorted(self.stats.items(), key=lambda v: v[1]['avg'], reverse=True):
+            s += '{:<30} {:>4} {:>6.2f} {:>6.2f}\n'.format(n[0], n[1]['count'],
+                                                           n[1]['avg'], n[1]['max'])
+        return s
+
+    def _call_vpp(self, i, msgdef, service, **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
@@ -495,7 +701,7 @@ class VPP():
         the response.  It will raise an IOError exception if there was
         no response within the timeout window.
         """
         the response.  It will raise an IOError exception if there was
         no response within the timeout window.
         """
-
+        ts = time.time()
         if 'context' not in kwargs:
             context = self.get_context()
             kwargs['context'] = context
         if 'context' not in kwargs:
             context = self.get_context()
             kwargs['context'] = context
@@ -503,55 +709,86 @@ class VPP():
             context = kwargs['context']
         kwargs['_vl_msg_id'] = i
 
             context = kwargs['context']
         kwargs['_vl_msg_id'] = i
 
+        no_type_conversion = kwargs.pop('_no_type_conversion', False)
+        timeout = kwargs.pop('_timeout', None)
+
         try:
             if self.transport.socket_index:
                 kwargs['client_index'] = self.transport.socket_index
         except AttributeError:
             pass
         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.validate_args(msgdef, kwargs)
+
+        s = 'Calling {}({})'.format(msgdef.name,
+            ','.join(['{!r}:{!r}'.format(k, v) for k, v in kwargs.items()]))
+        self.logger.debug(s)
+
+        b = msgdef.pack(kwargs)
         self.transport.suspend()
 
         self.transport.write(b)
 
         self.transport.suspend()
 
         self.transport.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)
+        msgreply = service['reply']
+        stream = True if 'stream' in service else False
+        if stream:
+            if 'stream_msg' in service:
+                # New service['reply'] = _reply and service['stream_message'] = _details
+                stream_message = service['stream_msg']
+                modern =True
+            else:
+                # Old  service['reply'] = _details
+                stream_message = msgreply
+                msgreply = 'control_ping_reply'
+                modern = False
+                # 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):
 
         # Block until we get a reply.
         rl = []
         while (True):
-            msg = self.transport.read()
-            if not msg:
-                raise IOError(2, 'VPP API client: read failed')
-            r = self.decode_incoming_msg(msg)
+            r = self.read_blocking(no_type_conversion, timeout)
+            if r is None:
+                raise VPPIOError(2, 'VPP API client: read failed')
             msgname = type(r).__name__
             if context not in r or r.context == 0 or context != r.context:
                 # Message being queued
                 self.message_queue.put_nowait(r)
                 continue
             msgname = type(r).__name__
             if context not in r or r.context == 0 or context != r.context:
                 # Message being queued
                 self.message_queue.put_nowait(r)
                 continue
-
-            if not multipart:
+            if msgname != msgreply and (stream and (msgname != stream_message)):
+                print('REPLY MISMATCH', msgreply, msgname, stream_message, stream)
+            if not stream:
                 rl = r
                 break
                 rl = r
                 break
-            if msgname == 'control_ping_reply':
+            if msgname == msgreply:
+                if modern: # Return both reply and list
+                    rl = r, rl
                 break
 
             rl.append(r)
 
         self.transport.resume()
 
                 break
 
             rl.append(r)
 
         self.transport.resume()
 
+        s = 'Return value: {!r}'.format(r)
+        if len(s) > 80:
+            s = s[:80] + "..."
+        self.logger.debug(s)
+        te = time.time()
+        self._add_stat(msgdef.name, (te - ts) * 1000)
         return rl
 
     def _call_vpp_async(self, i, msg, **kwargs):
         return rl
 
     def _call_vpp_async(self, i, msg, **kwargs):
-        """Given a message, send the message and await a reply.
+        """Given a message, send the message and return the context.
 
         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.
 
         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.
+
+        The reply message(s) will be delivered later to the registered callback.
+        The returned context will help with assigning which call
+        the reply belongs to.
         """
         if 'context' not in kwargs:
             context = self.get_context()
         """
         if 'context' not in kwargs:
             context = self.get_context()
@@ -567,6 +804,35 @@ class VPP():
         b = msg.pack(kwargs)
 
         self.transport.write(b)
         b = msg.pack(kwargs)
 
         self.transport.write(b)
+        return context
+
+    def read_blocking(self, no_type_conversion=False, timeout=None):
+        """Get next received message from transport within timeout, decoded.
+
+        Note that notifications have context zero
+        and are not put into receive queue (at least for socket transport),
+        use async_thread with registered callback for processing them.
+
+        If no message appears in the queue within timeout, return None.
+
+        Optionally, type conversion can be skipped,
+        as some of conversions are into less precise types.
+
+        When r is the return value of this, the caller can get message name as:
+            msgname = type(r).__name__
+        and context number (type long) as:
+            context = r.context
+
+        :param no_type_conversion: If false, type conversions are applied.
+        :type no_type_conversion: bool
+        :returns: Decoded message, or None if no message (within timeout).
+        :rtype: Whatever VPPType.unpack returns, depends on no_type_conversion.
+        :raises VppTransportShmemIOError if timed out.
+        """
+        msg = self.transport.read(timeout=timeout)
+        if not msg:
+            return None
+        return self.decode_incoming_msg(msg, no_type_conversion)
 
     def register_event_callback(self, callback):
         """Register a callback for async messages.
 
     def register_event_callback(self, callback):
         """Register a callback for async messages.
@@ -601,5 +867,57 @@ class VPP():
             if self.event_callback:
                 self.event_callback(msgname, r)
 
             if self.event_callback:
                 self.event_callback(msgname, r)
 
+    def validate_message_table(self, namecrctable):
+        """Take a dictionary of name_crc message names
+        and returns an array of missing messages"""
+
+        missing_table = []
+        for name_crc in namecrctable:
+            i = self.transport.get_msg_index(name_crc)
+            if i <= 0:
+                missing_table.append(name_crc)
+        return missing_table
+
+    def dump_message_table(self):
+        """Return VPPs API message table as name_crc dictionary"""
+        return self.transport.message_table
+
+    def dump_message_table_filtered(self, msglist):
+        """Return VPPs API message table as name_crc dictionary,
+        filtered by message name list."""
+
+        replies = [self.services[n]['reply'] for n in msglist]
+        message_table_filtered = {}
+        for name in msglist + replies:
+            for k,v in self.transport.message_table.items():
+                if k.startswith(name):
+                    message_table_filtered[k] = v
+                    break
+        return message_table_filtered
+
+    def __repr__(self):
+        return "<VPPApiClient apifiles=%s, testmode=%s, async_thread=%s, " \
+               "logger=%s, read_timeout=%s, use_socket=%s, " \
+               "server_address='%s'>" % (
+                   self._apifiles, self.testmode, self.async_thread,
+                   self.logger, self.read_timeout, self.use_socket,
+                   self.server_address)
+
+    def details_iter(self, f, **kwargs):
+        cursor = 0
+        while True:
+            kwargs['cursor'] = cursor
+            rv, details = f(**kwargs)
+            #
+            # Convert to yield from details when we only support python 3
+            #
+            for d in details:
+                yield d
+            if rv.retval == 0 or rv.retval != -165:
+                break
+            cursor = rv.cursor
+
+# Provide the old name for backward compatibility.
+VPP = VPPApiClient
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4