The binary toolset consists of a tool that translates the VSS YAML specification to the binary file format (see below),
and two libraries that provides methods that are likely to be needed by a server that manages the VSS tree, one written in C, and one in Go.
The translation tool can be invoked via the make file available on the VSS repo (https://github.com/COVESA/vehicle_signal_specification):
$ make binary
or, by invoking all tools:
$ make all
To run the binary tool without using the make file, the binary tool libray must first be built in the binary directory:
$ gcc -shared -o binarytool.so -fPIC binarytool.c
then the vspec2binary.py is executed in the root directory:
$ vspec2binary.py -i:./spec/VehicleSignalSpecification.id ./spec/VehicleSignalSpecification.vspec vss_rel_.binary
where vss_rel_.binary is the tre file in binary format.
Current version is found at https://github.com/COVESA/vehicle_signal_specification/blob/master/VERSION.
The two libraries provides the same set of methods, such as:
- to read the file into memory,
- to write it back to file,
- to search the tree for a given path (with usage of wildcard in the path expression),
- to create a JSON file of the leaf node paths of the VSS tree,
- to traverse the tree (up/down/left/right),
- and more.
Each library is also complemented with a testparser that uses the library to traverse the tree, make searches to it, etc.
A textbased UI presents the different options, with following results.
To build the testparser from the c_parser directory:
$ cc testparser.c cparserlib.c -o ctestparser
When starting it, the path to the binary file must be provided. If started from the c_parser directory:
$ ./ctestparser ../../vss_rel_.binary
To build the testparser from the go_parser directory:
$ go build testparser.go -o gotestparser
When starting it, the path to the binary file must be provided. If started from the go_parser directory:
$ ./gotestparser ../../vss_rel_.binary
The binary node file format is as follows:
Name | Datatype | #bytes
---------------------------------------
NameLen | uint8 | 1
Name | chararray | NameLen
NodeTypeLen | uint8 | 1
NodeType | chararray | NodeTypeLen
UuidLen | uint8 | 1
Uuid | chararray | UuidLen
DescrLen | uint8 | 1
Description | chararray | DescrLen
DatatypeLen | uint8 | 1
Datatype | chararray | DatatypeLen
MinLen | uint8 | 1
Min | chararray | MinLen
MaxLen | uint8 | 1
Max | chararray | MaxLen
UnitLen | uint8 | 1
Unit | chararray | UnitLen
AllowedLen | uint8 | 1
Allowed | chararray | AllowedLen
DefaultLen | uint8 | 1
Default | chararray | AllowedLen
ValidateLen | uint8 | 1
Validate | chararray | ValidateLen
Children | uint8 | 1
The Allowed string contains an array of allowed, each Allowed is preceeded by two characters holding the size of the Allowed sub-string.
The size is in hex format, with values from "01" to "FF". An example is "03abc0A012345678902cd" which contains the three Alloweds "abc", "0123456789", and "cd".
The nodes are written into the file in the order given by an iterative method as shown in the following pseudocode.
def traverseAndWriteNode(thisNode):
writeNode(thisNode)
for i = 0 ; i < thisNode.Children ; i++:
traverseAndWriteNode(thisNode.Child[i])
When reading the file the same iterative pattern must be used to generate the correct VSS tree, as is the case for all the described tools.