API: Use string type instead of u8.

The new string type is modelled after string in proto3.
It is always variable length.

Change-Id: I64884067e28a80072c8dac31b7c7c82d6e306051
Signed-off-by: Ole Troan <ot@cisco.com>
Signed-off-by: Michal Cmarada <mcmarada@cisco.com>
Signed-off-by: Ole Troan <ot@cisco.com>

3 files changed, 80 insertions, 17 deletions

diff --git a/src/vpp-api/python/vpp_papi/vpp_papi.py b/src/vpp-api/python/vpp_papi/vpp_papi.py
index 32abe14da94..4de257c6924 100644
--- a/src/vpp-api/python/vpp_papi/vpp_papi.py
+++ b/src/vpp-api/python/vpp_papi/vpp_papi.py
@@ -29,6 +29,8 @@ import atexit
 from . vpp_serializer import VPPType, VPPEnumType, VPPUnionType, BaseTypes
 from . vpp_serializer import VPPMessage, vpp_get_type, VPPTypeAlias
 
+logger = logging.getLogger(__name__)
+
 if sys.version[0] == '2':
     import Queue as queue
 else:
@@ -63,6 +65,19 @@ else:
         return d.items()
 
 
+def call_logger(msgdef, kwargs):
+    s = 'Calling {}('.format(msgdef.name)
+    for k, v in kwargs.items():
+        s += '{}:{} '.format(k, v)
+    s += ')'
+    return s
+
+
+def return_logger(r):
+    s = 'Return from {}'.format(r)
+    return s
+
+
 class VppApiDynamicMethodHolder(object):
     pass
 
@@ -493,10 +508,31 @@ class VPP(object):
         else:
             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']])
+
+        (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:
             self.logger.warning('vpp_api.read failed')
             return
+
         (i, ci), size = self.header.unpack(msg, 0)
         if self.id_names[i] == 'rx_thread_exit':
             return
@@ -537,7 +573,7 @@ class VPP(object):
             raise VPPValueError('Invalid argument {} to {}'
                                 .format(list(d), msg.name))
 
-    def _call_vpp(self, i, msg, multipart, **kwargs):
+    def _call_vpp(self, i, msgdef, multipart, **kwargs):
         """Given a message, send the message and await a reply.
 
         msgdef - the message packing definition
@@ -567,8 +603,11 @@ class VPP(object):
                 kwargs['client_index'] = self.transport.socket_index
         except AttributeError:
             pass
-        self.validate_args(msg, kwargs)
-        b = msg.pack(kwargs)
+        self.validate_args(msgdef, kwargs)
+
+        logging.debug(call_logger(msgdef, kwargs))
+
+        b = msgdef.pack(kwargs)
         self.transport.suspend()
 
         self.transport.write(b)
@@ -601,6 +640,7 @@ class VPP(object):
 
         self.transport.resume()
 
+        logger.debug(return_logger(rl))
         return rl
 
     def _call_vpp_async(self, i, msg, **kwargs):
diff --git a/src/vpp-api/python/vpp_papi/vpp_serializer.py b/src/vpp-api/python/vpp_papi/vpp_serializer.py
index 5dce03b6188..418c0243402 100644
--- a/src/vpp-api/python/vpp_papi/vpp_serializer.py
+++ b/src/vpp-api/python/vpp_papi/vpp_serializer.py
@@ -59,6 +59,7 @@ def conversion_unpacker(data, field_type):
 class BaseTypes(object):
     def __init__(self, type, elements=0):
         base_types = {'u8': '>B',
+                      'string': '>s',
                       'u16': '>H',
                       'u32': '>I',
                       'i32': '>i',
@@ -67,13 +68,11 @@ class BaseTypes(object):
                       'bool': '>?',
                       'header': '>HI'}
 
-        if elements > 0 and type == 'u8':
+        if elements > 0 and (type == 'u8' or type == 'string'):
             self.packer = struct.Struct('>%ss' % elements)
         else:
             self.packer = struct.Struct(base_types[type])
         self.size = self.packer.size
-        logger.debug('Adding {} with format: {}'
-                     .format(type, base_types[type]))
 
     def pack(self, data, kwargs=None):
         if not data:  # Default to zero if not specified
@@ -84,10 +83,32 @@ class BaseTypes(object):
         return self.packer.unpack_from(data, offset)[0], self.packer.size
 
 
+class String(object):
+    def __init__(self):
+        self.name = 'string'
+        self.size = 1
+        self.length_field_packer = BaseTypes('u32')
+
+    def pack(self, list, kwargs=None):
+        if not list:
+            return self.length_field_packer.pack(0) + b""
+        return self.length_field_packer.pack(len(list)) + list.encode('utf8')
+
+    def unpack(self, data, offset=0, result=None, ntc=False):
+        length, length_field_size = self.length_field_packer.unpack(data,
+                                                                    offset)
+        if length == 0:
+            return b'', 0
+        p = BaseTypes('u8', length)
+        x, size = p.unpack(data, offset + length_field_size)
+        x2 = x.split(b'\0',1)[0]
+        return (x2.decode('utf8'), size + length_field_size)
+
+
 types = {'u8': BaseTypes('u8'), 'u16': BaseTypes('u16'),
          'u32': BaseTypes('u32'), 'i32': BaseTypes('i32'),
          'u64': BaseTypes('u64'), 'f64': BaseTypes('f64'),
-         'bool': BaseTypes('bool')}
+         'bool': BaseTypes('bool'), 'string': String()}
 
 
 def vpp_get_type(name):
@@ -107,6 +128,7 @@ class FixedList_u8(object):
         self.num = num
         self.packer = BaseTypes(field_type, num)
         self.size = self.packer.size
+        self.field_type = field_type
 
     def pack(self, data, kwargs=None):
         """Packs a fixed length bytestring. Left-pads with zeros
@@ -128,6 +150,10 @@ class FixedList_u8(object):
                 'Invalid array length for "{}" got {}'
                 ' expected {}'
                 .format(self.name, len(data[offset:]), self.num))
+        if self.field_type == 'string':
+            s = self.packer.unpack(data, offset)
+            s2 = s[0].split(b'\0', 1)[0]
+            return (s2.decode('utf-8'), self.num)
         return self.packer.unpack(data, offset)
 
 
@@ -164,6 +190,7 @@ class FixedList(object):
 class VLAList(object):
     def __init__(self, name, field_type, len_field_name, index):
         self.name = name
+        self.field_type = field_type
         self.index = index
         self.packer = types[field_type]
         self.size = self.packer.size
@@ -179,6 +206,7 @@ class VLAList(object):
         b = bytes()
 
         # u8 array
+
         if self.packer.size == 1:
             return bytearray(list)
 
@@ -249,7 +277,6 @@ class VPPEnumType(object):
             e_hash[ename] = evalue
         self.enum = IntEnum(name, e_hash)
         types[name] = self
-        logger.debug('Adding enum {}'.format(name))
 
     def __getattr__(self, name):
         return self.enum[name]
@@ -290,7 +317,6 @@ class VPPUnionType(object):
 
         types[name] = self
         self.tuple = collections.namedtuple(name, fields, rename=True)
-        logger.debug('Adding union {}'.format(name))
 
     # Union of variable length?
     def pack(self, data, kwargs=None):
@@ -381,7 +407,7 @@ class VPPType(object):
                 if list_elements == 0:
                     p = VLAList_legacy(f_name, f_type)
                     self.packers.append(p)
-                elif f_type == 'u8':
+                elif f_type == 'u8' or f_type == 'string':
                     p = FixedList_u8(f_name, f_type, list_elements)
                     self.packers.append(p)
                     size += p.size
@@ -390,10 +416,9 @@ class VPPType(object):
                     self.packers.append(p)
                     size += p.size
             elif len(f) == 4:  # Variable length list
-                    # Find index of length field
-                    length_index = self.fields.index(f[3])
-                    p = VLAList(f_name, f_type, f[3], length_index)
-                    self.packers.append(p)
+                length_index = self.fields.index(f[3])
+                p = VLAList(f_name, f_type, f[3], length_index)
+                self.packers.append(p)
             else:
                 self.packers.append(types[f_type])
                 size += types[f_type].size
@@ -401,7 +426,6 @@ class VPPType(object):
         self.size = size
         self.tuple = collections.namedtuple(name, self.fields, rename=True)
         types[name] = self
-        logger.debug('Adding type {}'.format(name))
 
     def pack(self, data, kwargs=None):
         if not kwargs:
diff --git a/src/vpp-api/python/vpp_papi/vpp_transport_socket.py b/src/vpp-api/python/vpp_papi/vpp_transport_socket.py
index 393e2e9c9c1..4341cad3e90 100644
--- a/src/vpp-api/python/vpp_papi/vpp_transport_socket.py
+++ b/src/vpp-api/python/vpp_papi/vpp_transport_socket.py
@@ -59,8 +59,7 @@ class VppTransport(object):
                         return
                     # Put either to local queue or if context == 0
                     # callback queue
-                    r = self.parent.decode_incoming_msg(msg)
-                    if hasattr(r, 'context') and r.context > 0:
+                    if self.parent.has_context(msg):
                         self.q.put(msg)
                     else:
                         self.parent.msg_handler_async(msg)