+ 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
+
+ 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
+
+ # Include submessage length prefix
+ encsize += varint_max_size(encsize.upperlimit())
+ break
+ else:
+ # Submessage cannot be found, this currently occurs when
+ # the submessage type is defined in a different file.
+ # Instead of direct numeric value, reference the size that
+ # has been #defined in the other file.
+ encsize = EncodedSize(self.submsgname + 'size')
+
+ # We will have to make a conservative assumption on the length
+ # prefix size, though.
+ encsize += 5
+
+ elif self.enc_size is None:
+ raise RuntimeError("Could not determine encoded size for %s.%s"
+ % (self.struct_name, self.name))
+ else:
+ encsize = EncodedSize(self.enc_size)
+
+ 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):
+ '''Implements a special pb_extension_t* field in an extensible message
+ structure. The range_start signifies the index at which the extensions
+ start. Not necessarily all tags above this are extensions, it is merely
+ a speed optimization.
+ '''
+ self.tag = range_start
+ self.struct_name = struct_name
+ self.name = 'extensions'
+ self.pbtype = 'EXTENSION'
+ self.rules = 'OPTIONAL'
+ self.allocation = 'CALLBACK'
+ self.ctype = 'pb_extension_t'
+ self.array_decl = ''
+ self.default = None
+ self.max_size = 0
+ self.max_count = 0
+
+ def __str__(self):
+ return ' pb_extension_t *extensions;'
+
+ def types(self):
+ return None
+
+ 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 EncodedSize(0)
+
+class ExtensionField(Field):
+ def __init__(self, struct_name, desc, field_options):
+ self.fullname = struct_name + desc.name
+ self.extendee_name = names_from_type_name(desc.extendee)
+ Field.__init__(self, self.fullname + 'struct', desc, field_options)
+
+ if self.rules != 'OPTIONAL':
+ self.skip = True
+ else:
+ self.skip = False
+ self.rules = 'OPTEXT'
+
+ def tags(self):
+ '''Return the #define for the tag number of this field.'''
+ identifier = '%s_tag' % self.fullname
+ return '#define %-40s %d\n' % (identifier, self.tag)
+
+ def extension_decl(self):
+ '''Declaration of the extension type in the .pb.h file'''
+ if self.skip:
+ msg = '/* Extension field %s was skipped because only "optional"\n' % self.fullname
+ msg +=' type of extension fields is currently supported. */\n'
+ return msg
+
+ return 'extern const pb_extension_type_t %s;\n' % self.fullname