#!/usr/bin/python
'''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.'''
-nanopb_version = "nanopb-0.2.3"
+nanopb_version = "nanopb-0.2.4-dev"
try:
import google.protobuf.descriptor_pb2 as descriptor
import time
import os.path
-# Values are tuple (c type, pb type)
+# Values are tuple (c type, pb type, encoded size)
FieldD = descriptor.FieldDescriptorProto
datatypes = {
- FieldD.TYPE_BOOL: ('bool', 'BOOL'),
- FieldD.TYPE_DOUBLE: ('double', 'DOUBLE'),
- FieldD.TYPE_FIXED32: ('uint32_t', 'FIXED32'),
- FieldD.TYPE_FIXED64: ('uint64_t', 'FIXED64'),
- FieldD.TYPE_FLOAT: ('float', 'FLOAT'),
- FieldD.TYPE_INT32: ('int32_t', 'INT32'),
- FieldD.TYPE_INT64: ('int64_t', 'INT64'),
- FieldD.TYPE_SFIXED32: ('int32_t', 'SFIXED32'),
- FieldD.TYPE_SFIXED64: ('int64_t', 'SFIXED64'),
- FieldD.TYPE_SINT32: ('int32_t', 'SINT32'),
- FieldD.TYPE_SINT64: ('int64_t', 'SINT64'),
- FieldD.TYPE_UINT32: ('uint32_t', 'UINT32'),
- FieldD.TYPE_UINT64: ('uint64_t', 'UINT64')
+ FieldD.TYPE_BOOL: ('bool', 'BOOL', 1),
+ FieldD.TYPE_DOUBLE: ('double', 'DOUBLE', 8),
+ FieldD.TYPE_FIXED32: ('uint32_t', 'FIXED32', 4),
+ FieldD.TYPE_FIXED64: ('uint64_t', 'FIXED64', 8),
+ FieldD.TYPE_FLOAT: ('float', 'FLOAT', 4),
+ FieldD.TYPE_INT32: ('int32_t', 'INT32', 5),
+ FieldD.TYPE_INT64: ('int64_t', 'INT64', 10),
+ FieldD.TYPE_SFIXED32: ('int32_t', 'SFIXED32', 4),
+ FieldD.TYPE_SFIXED64: ('int64_t', 'SFIXED64', 8),
+ FieldD.TYPE_SINT32: ('int32_t', 'SINT32', 5),
+ FieldD.TYPE_SINT64: ('int64_t', 'SINT64', 10),
+ FieldD.TYPE_UINT32: ('uint32_t', 'UINT32', 5),
+ FieldD.TYPE_UINT64: ('uint64_t', 'UINT64', 10)
}
class Names:
raise NotImplementedError("Lookup of non-absolute type names is not supported")
return Names(type_name[1:].split('.'))
+def varint_max_size(max_value):
+ '''Returns the maximum number of bytes a varint can take when encoded.'''
+ for i in range(1, 11):
+ if (max_value >> (i * 7)) == 0:
+ return i
+ raise ValueError("Value too large for varint: " + str(max_value))
+
+assert varint_max_size(0) == 1
+assert varint_max_size(127) == 1
+assert varint_max_size(128) == 2
+
class Enum:
def __init__(self, names, desc, enum_options):
'''desc is EnumDescriptorProto'''
self.max_size = None
self.max_count = None
self.array_decl = ""
+ self.enc_size = None
# Parse field options
if field_options.HasField("max_size"):
# Decide the C data type to use in the struct.
if datatypes.has_key(desc.type):
- self.ctype, self.pbtype = datatypes[desc.type]
+ self.ctype, self.pbtype, self.enc_size = datatypes[desc.type]
elif desc.type == FieldD.TYPE_ENUM:
self.pbtype = 'ENUM'
self.ctype = names_from_type_name(desc.type_name)
if self.default is not None:
self.default = self.ctype + self.default
+ self.enc_size = 5 # protoc rejects enum values > 32 bits
elif desc.type == FieldD.TYPE_STRING:
self.pbtype = 'STRING'
if self.max_size is None:
else:
self.ctype = 'char'
self.array_decl += '[%d]' % self.max_size
+ self.enc_size = varint_max_size(self.max_size) + self.max_size
elif desc.type == FieldD.TYPE_BYTES:
self.pbtype = 'BYTES'
if self.max_size is None:
can_be_static = False
else:
self.ctype = self.struct_name + self.name + 't'
+ self.enc_size = varint_max_size(self.max_size) + self.max_size
elif desc.type == FieldD.TYPE_MESSAGE:
self.pbtype = 'MESSAGE'
self.ctype = self.submsgname = names_from_type_name(desc.type_name)
+ self.enc_size = None # Needs to be filled in after the message type is available
else:
raise NotImplementedError(desc.type)
return max(self.tag, self.max_size, self.max_count)
+ def encoded_size(self, allmsgs):
+ '''Return the maximum size that this field can take when encoded,
+ including the field tag. If the size cannot be determined, returns
+ None.'''
+
+ if self.allocation != 'STATIC':
+ return None
+
+ encsize = self.enc_size
+ if self.pbtype == 'MESSAGE':
+ for msg in allmsgs:
+ if msg.name == self.submsgname:
+ encsize = msg.encoded_size(allmsgs)
+ if encsize is None:
+ return None # Submessage size is indeterminate
+ encsize += varint_max_size(encsize) # submsg length is encoded also
+ break
+ else:
+ # Submessage cannot be found, this currently occurs when
+ # the submessage type is defined in a different file.
+ return None
+
+ if encsize is None:
+ raise RuntimeError("Could not determine encoded size for %s.%s"
+ % (self.struct_name, self.name))
+
+ encsize += varint_max_size(self.tag << 3) # Tag + wire type
+
+ if self.rules == 'REPEATED':
+ # Decoders must be always able to handle unpacked arrays.
+ # Therefore we have to reserve space for it, even though
+ # we emit packed arrays ourselves.
+ encsize *= self.max_count
+
+ return encsize
+
class ExtensionRange(Field):
def __init__(self, struct_name, range_start, field_options):
def tags(self):
return ''
+
+ def encoded_size(self, allmsgs):
+ # We exclude extensions from the count, because they cannot be known
+ # until runtime. Other option would be to return None here, but this
+ # way the value remains useful if extensions are not used.
+ return 0
class ExtensionField(Field):
def __init__(self, struct_name, desc, field_options):
result += ' PB_LAST_FIELD\n};'
return result
+ def encoded_size(self, allmsgs):
+ '''Return the maximum size that this message can take when encoded.
+ If the size cannot be determined, returns None.
+ '''
+ size = 0
+ for field in self.fields:
+ fsize = field.encoded_size(allmsgs)
+ if fsize is None:
+ return None
+ size += fsize
+
+ return size
# ---------------------------------------------------------------------------
yield '/* Struct field encoding specification for nanopb */\n'
for msg in messages:
yield msg.fields_declaration() + '\n'
+ yield '\n'
- yield '\n#ifdef __cplusplus\n'
+ yield '/* Maximum encoded size of messages (where known) */\n'
+ for msg in messages:
+ msize = msg.encoded_size(messages)
+ if msize is not None:
+ identifier = '%s_size' % msg.name
+ yield '#define %-40s %d\n' % (identifier, msize)
+ yield '\n'
+
+ yield '#ifdef __cplusplus\n'
yield '} /* extern "C" */\n'
yield '#endif\n'
Code Review / apps / agl-service-can-low-level.git / blobdiff