Struct Dbc 

pub struct Dbc { /* private fields */ }

Represents a complete DBC (CAN database) file.

A Dbc contains:

• An optional version string
• A list of nodes (ECUs)
• A collection of messages with their signals

Examples

use dbc_rs::Dbc;

let dbc_content = r#"VERSION "1.0"

BU_: ECM TCM

BO_ 256 EngineData : 8 ECM
 SG_ RPM : 0|16@0+ (0.25,0) [0|8000] "rpm" TCM
"#;

let dbc = Dbc::parse(dbc_content)?;
println!("Parsed {} messages", dbc.messages().len());

Implementations

impl Dbc

pub fn version(&self) -> Option<&Version>

Get the version of the DBC file

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse("VERSION \"1.0\"\n\nBU_: ECM\n\nBO_ 256 Engine : 8 ECM")?;
if let Some(version) = dbc.version() {
    // Version is available
    let _ = version.as_str();
}

pub fn nodes(&self) -> &Nodes

Get a reference to the nodes collection

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse("VERSION \"1.0\"\n\nBU_: ECM TCM\n\nBO_ 256 Engine : 8 ECM")?;
let nodes = dbc.nodes();
assert_eq!(nodes.len(), 2);
// Iterate over nodes
let mut iter = nodes.iter();
assert_eq!(iter.next(), Some("ECM"));
assert_eq!(iter.next(), Some("TCM"));
assert_eq!(iter.next(), None);

pub fn messages(&self) -> &Messages

Get a reference to the messages collection

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse("VERSION \"1.0\"\n\nBU_: ECM\n\nBO_ 256 Engine : 8 ECM")?;
let messages = dbc.messages();
assert_eq!(messages.len(), 1);
let message = messages.at(0).unwrap();
assert_eq!(message.name(), "Engine");
assert_eq!(message.id(), 256);

pub fn value_descriptions(&self) -> &ValueDescriptionsMap

Get value descriptions for a specific signal

Value descriptions map numeric signal values to human-readable text. Returns None if the signal has no value descriptions.

Global Value Descriptions: According to the Vector DBC specification, a message_id of -1 (0xFFFFFFFF) in a VAL_ statement means the value descriptions apply to all signals with that name in ANY message. This method will first check for a message-specific entry, then fall back to a global entry if one exists.

Examples

if let Some(value_descriptions) = dbc.value_descriptions_for_signal(100, "Gear") {
    if let Some(desc) = value_descriptions.get(0) {
        println!("Value 0 means: {}", desc);
    }
}

Get a reference to the value descriptions list

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse(r#"VERSION "1.0"

BU_: ECM

BO_ 100 Engine : 8 ECM
 SG_ Gear : 0|8@1+ (1,0) [0|5] "" *

VAL_ 100 Gear 0 "Park" 1 "Drive" ;"#)?;
let value_descriptions_list = dbc.value_descriptions();
assert_eq!(value_descriptions_list.len(), 1);

pub fn value_descriptions_for_signal( &self, message_id: u32, signal_name: &str, ) -> Option<&ValueDescriptions>

pub fn extended_multiplexing_for_message( &self, message_id: u32, ) -> Vec<ExtendedMultiplexing, { MAX_EXTENDED_MULTIPLEXING }>

Get extended multiplexing entries for a specific message

Extended multiplexing (SG_MUL_VAL_) entries define which multiplexer switch values activate specific multiplexed signals. This method returns all extended multiplexing entries for the given message ID.

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse(r#"VERSION "1.0"

BU_: ECM

BO_ 500 ComplexMux : 8 ECM
 SG_ Mux1 M : 0|8@1+ (1,0) [0|255] ""
 SG_ Signal_A m0 : 16|16@1+ (0.1,0) [0|100] ""

SG_MUL_VAL_ 500 Signal_A Mux1 0-5,10-15 ;
"#)?;
let extended = dbc.extended_multiplexing_for_message(500);
assert_eq!(extended.len(), 1);

impl Dbc

Decoding functionality for DBC structures

pub fn decode( &self, id: u32, payload: &[u8], ) -> Result<Vec<(&str, f64, Option<&str>), { MAX_SIGNALS_PER_MESSAGE }>>

Decode a CAN message payload using the message ID to find the corresponding message definition.

This is a high-performance method for decoding CAN messages in no_std environments. It finds the message by ID, then decodes all signals in the message from the payload bytes.

Arguments

• id - The CAN message ID to look up
• payload - The CAN message payload bytes (up to 64 bytes for CAN FD)

Returns

• Ok(Vec<...>) - A vector of (signal_name, physical_value) pairs
• Err(Error) - If the message ID is not found, payload length doesn’t match DLC, or signal decoding fails

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse(r#"VERSION "1.0"

BU_: ECM

BO_ 256 Engine : 8 ECM
 SG_ RPM : 0|16@1+ (0.25,0) [0|8000] "rpm" *
"#)?;

// Decode a CAN message with RPM value of 2000 (raw: 8000 = 0x1F40)
let payload = [0x40, 0x1F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00];
let decoded = dbc.decode(256, &payload)?;
assert_eq!(decoded.len(), 1);
assert_eq!(decoded[0].0, "RPM");
assert_eq!(decoded[0].1, 2000.0);
assert_eq!(decoded[0].2, Some("rpm"));

High-performance CAN message decoding optimized for throughput.

Performance optimizations:

• O(1) or O(log n) message lookup via feature-flagged index (heapless/alloc)
• Inlined hot paths
• Direct error construction (no closure allocation)
• Early validation to avoid unnecessary work
• Optimized signal decoding loop

impl Dbc

pub fn parse(data: &str) -> Result<Self>

Parse a DBC file from a string slice

Examples

use dbc_rs::Dbc;

let dbc_content = r#"VERSION "1.0"

BU_: ECM

BO_ 256 EngineData : 8 ECM
 SG_ RPM : 0|16@0+ (0.25,0) [0|8000] "rpm""#;

let dbc = Dbc::parse(dbc_content)?;
assert_eq!(dbc.messages().len(), 1);

pub fn parse_bytes(data: &[u8]) -> Result<Self>

Parse a DBC file from a byte slice

Examples

use dbc_rs::Dbc;

let dbc_bytes = b"VERSION \"1.0\"\n\nBU_: ECM\n\nBO_ 256 Engine : 8 ECM";
let dbc = Dbc::parse_bytes(dbc_bytes)?;
println!("Parsed {} messages", dbc.messages().len());

impl Dbc

pub fn to_dbc_string(&self) -> String

Serialize this DBC to a DBC format string

Examples

use dbc_rs::Dbc;

let dbc = Dbc::parse("VERSION \"1.0\"\n\nBU_: ECM\n\nBO_ 256 Engine : 8 ECM")?;
let dbc_string = dbc.to_dbc_string();
// The string can be written to a file or used elsewhere
assert!(dbc_string.contains("VERSION"));

Trait Implementations

impl Debug for Dbc

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Dbc

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.