Python API: Add enum and union support.

As well as a rewrite of the encoders/decoders to make it more readable and extensible.
(Re-commit after fix to verify build.)

Change-Id: Ic244d3cebe070bb2570491f8a24f4a1e203f889a
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 343 insertions, 0 deletions

diff --git a/src/vpp-api/python/vpp_papi/vpp_serializer.py b/src/vpp-api/python/vpp_papi/vpp_serializer.py
new file mode 100644
index 00000000000..7f5c5ace2dc
--- /dev/null
+++ b/src/vpp-api/python/vpp_papi/vpp_serializer.py
@@ -0,0 +1,343 @@
+#
+# Copyright (c) 2018 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.
+#
+
+import struct
+import collections
+from enum import IntEnum
+import logging
+
+#
+# Set log-level in application by doing e.g.:
+# logger = logging.getLogger('vpp_serializer')
+# logger.setLevel(logging.DEBUG)
+#
+logger = logging.getLogger(__name__)
+
+
+class BaseTypes():
+    def __init__(self, type, elements=0):
+        base_types = {'u8': '>B',
+                      'u16': '>H',
+                      'u32': '>I',
+                      'i32': '>i',
+                      'u64': '>Q',
+                      'f64': '>d',
+                      'header': '>HI'}
+
+        if elements > 0 and type == 'u8':
+            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):
+        logger.debug("Data: {} Format: {}".format(data, self.packer.format))
+        return self.packer.pack(data)
+
+    def unpack(self, data, offset, result=None):
+        logger.debug("@ {} Format: {}".format(offset, self.packer.format))
+        return self.packer.unpack_from(data, offset)[0]
+
+
+types = {}
+types['u8'] = BaseTypes('u8')
+types['u16'] = BaseTypes('u16')
+types['u32'] = BaseTypes('u32')
+types['i32'] = BaseTypes('i32')
+types['u64'] = BaseTypes('u64')
+types['f64'] = BaseTypes('f64')
+
+
+class FixedList_u8():
+    def __init__(self, name, field_type, num):
+        self.name = name
+        self.num = num
+        self.packer = BaseTypes(field_type, num)
+        self.size = self.packer.size
+
+    def pack(self, list, kwargs):
+        """Packs a fixed length bytestring. Left-pads with zeros
+        if input data is too short."""
+        logger.debug("Data: {}".format(list))
+
+        if len(list) > self.num:
+            raise ValueError('Fixed list length error for "{}", got: {}'
+                             ' expected: {}'
+                             .format(self.name, len(list), self.num))
+        return self.packer.pack(list)
+
+    def unpack(self, data, offset=0, result=None):
+        if len(data[offset:]) < self.num:
+            raise ValueError('Invalid array length for "{}" got {}'
+                             ' expected {}'
+                             .format(self.name, len(data), self.num))
+        return self.packer.unpack(data, offset)
+
+
+class FixedList():
+    def __init__(self, name, field_type, num):
+        self.num = num
+        self.packer = types[field_type]
+        self.size = self.packer.size * num
+
+    def pack(self, list, kwargs):
+        logger.debug("Data: {}".format(list))
+
+        if len(list) != self.num:
+            raise ValueError('Fixed list length error, got: {} expected: {}'
+                             .format(len(list), self.num))
+        b = bytes()
+        for e in list:
+            b += self.packer.pack(e)
+        return b
+
+    def unpack(self, data, offset=0, result=None):
+        # Return a list of arguments
+        result = []
+        for e in range(self.num):
+            x = self.packer.unpack(data, offset)
+            result.append(x)
+            offset += self.packer.size
+        return result
+
+
+class VLAList():
+    def __init__(self, name, field_type, len_field_name, index):
+        self.index = index
+        self.packer = types[field_type]
+        self.size = self.packer.size
+        self.length_field = len_field_name
+
+    def pack(self, list, kwargs=None):
+        logger.debug("Data: {}".format(list))
+        if len(list) != kwargs[self.length_field]:
+            raise ValueError('Variable length error, got: {} expected: {}'
+                             .format(len(list), kwargs[self.length_field]))
+        b = bytes()
+
+        # u8 array
+        if self.packer.size == 1:
+            return bytearray(list)
+
+        for e in list:
+            b += self.packer.pack(e)
+        return b
+
+    def unpack(self, data, offset=0, result=None):
+        logger.debug("Data: {} @ {} Result: {}"
+                     .format(list, offset, result[self.index]))
+        # Return a list of arguments
+
+        # u8 array
+        if self.packer.size == 1:
+            if result[self.index] == 0:
+                return b''
+            p = BaseTypes('u8', result[self.index])
+            r = p.unpack(data, offset)
+            return r
+
+        r = []
+        for e in range(result[self.index]):
+            x = self.packer.unpack(data, offset)
+            r.append(x)
+            offset += self.packer.size
+        return r
+
+
+class VLAList_legacy():
+    def __init__(self, name, field_type):
+        self.packer = types[field_type]
+        self.size = self.packer.size
+
+    def pack(self, list, kwargs=None):
+        logger.debug("Data: {}".format(list))
+
+        if self.packer.size == 1:
+            return bytes(list)
+
+        b = bytes()
+        for e in list:
+            b += self.packer.pack(e)
+        return b
+
+    def unpack(self, data, offset=0, result=None):
+        # Return a list of arguments
+        if (len(data) - offset) % self.packer.size:
+            raise ValueError('Legacy Variable Length Array length mismatch.')
+        elements = int((len(data) - offset) / self.packer.size)
+        r = []
+        logger.debug("Legacy VLA: {} elements of size {}"
+                     .format(elements, self.packer.size))
+        for e in range(elements):
+            x = self.packer.unpack(data, offset)
+            r.append(x)
+            offset += self.packer.size
+        return r
+
+
+class VPPEnumType():
+    def __init__(self, name, msgdef):
+        self.size = types['u32'].size
+        e_hash = {}
+        for f in msgdef:
+            if type(f) is dict and 'enumtype' in f:
+                if f['enumtype'] != 'u32':
+                    raise NotImplementedError
+                continue
+            ename, evalue = f
+            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]
+
+    def pack(self, data, kwargs=None):
+        logger.debug("Data: {}".format(data))
+        return types['u32'].pack(data, kwargs)
+
+    def unpack(self, data, offset=0, result=None):
+        x = types['u32'].unpack(data, offset)
+        return self.enum(x)
+
+
+class VPPUnionType():
+    def __init__(self, name, msgdef):
+        self.name = name
+        self.size = 0
+        self.maxindex = 0
+        fields = []
+        self.packers = collections.OrderedDict()
+        for i, f in enumerate(msgdef):
+            if type(f) is dict and 'crc' in f:
+                self.crc = f['crc']
+                continue
+            f_type, f_name = f
+            if f_type not in types:
+                logger.debug('Unknown union type {}'.format(f_type))
+                raise ValueError('Unknown message type {}'.format(f_type))
+            fields.append(f_name)
+            size = types[f_type].size
+            self.packers[f_name] = types[f_type]
+            if size > self.size:
+                self.size = size
+                self.maxindex = i
+
+        types[name] = self
+        self.tuple = collections.namedtuple(name, fields, rename=True)
+        logger.debug('Adding union {}'.format(name))
+
+    def pack(self, data, kwargs=None):
+        logger.debug("Data: {}".format(data))
+        for k, v in data.items():
+            logger.debug("Key: {} Value: {}".format(k, v))
+            b = self.packers[k].pack(v, kwargs)
+            offset = self.size - self.packers[k].size
+            break
+        r = bytearray(self.size)
+        r[offset:] = b
+        return r
+
+    def unpack(self, data, offset=0, result=None):
+        r = []
+        for k, p in self.packers.items():
+            union_offset = self.size - p.size
+            r.append(p.unpack(data, offset + union_offset))
+        return self.tuple._make(r)
+
+
+class VPPType():
+    # Set everything up to be able to pack / unpack
+    def __init__(self, name, msgdef):
+        self.name = name
+        self.msgdef = msgdef
+        self.packers = []
+        self.fields = []
+        self.fieldtypes = []
+        self.field_by_name = {}
+        size = 0
+        for i, f in enumerate(msgdef):
+            if type(f) is dict and 'crc' in f:
+                self.crc = f['crc']
+                continue
+            f_type, f_name = f[:2]
+            self.fields.append(f_name)
+            self.field_by_name[f_name] = None
+            self.fieldtypes.append(f_type)
+            if f_type not in types:
+                logger.debug('Unknown type {}'.format(f_type))
+                raise ValueError('Unknown message type {}'.format(f_type))
+            if len(f) == 3:  # list
+                list_elements = f[2]
+                if list_elements == 0:
+                    p = VLAList_legacy(f_name, f_type)
+                    self.packers.append(p)
+                elif f_type == 'u8':
+                    p = FixedList_u8(f_name, f_type, list_elements)
+                    self.packers.append(p)
+                    size += p.size
+                else:
+                    p = FixedList(f_name, f_type, list_elements)
+                    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)
+            else:
+                self.packers.append(types[f_type])
+                size += types[f_type].size
+
+        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:
+            kwargs = data
+        logger.debug("Data: {}".format(data))
+        b = bytes()
+        for i, a in enumerate(self.fields):
+            if a not in data:
+                logger.debug("Argument {} not given, defaulting to 0"
+                             .format(a))
+                b += b'\x00' * self.packers[i].size
+                continue
+
+            if isinstance(self.packers[i], VPPType):
+                b += self.packers[i].pack(data[a], kwargs[a])
+            else:
+                b += self.packers[i].pack(data[a], kwargs)
+        return b
+
+    def unpack(self, data, offset=0, result=None):
+        # Return a list of arguments
+        result = []
+        for p in self.packers:
+            x = p.unpack(data, offset, result)
+            if type(x) is tuple and len(x) == 1:
+                x = x[0]
+            result.append(x)
+            offset += p.size
+        return self.tuple._make(result)
+
+
+class VPPMessage(VPPType):
+    pass