blob: 589dfc3143be3f0e3d8097c82da6ec81c5ad65b2 [file] [log] [blame]
pub mod gap_types {
pub static COMPLETE_LOCAL_NAME: u8 = 0x09;
pub static SERVICE_DATA: u8 = 0x16;
pub static UUID: u8 = 0x02;
pub static FLAGS: u8 = 0x01;
}
pub mod flags {
pub static LE_GENERAL_DISCOVERABLE: u8 = 0x01;
}
pub struct BlePayload {
bytes: [u8; 39],
occupied: usize,
}
impl BlePayload {
pub fn add(&mut self, kind: u8, content: &[u8]) -> Result<(), ()> {
self.check_can_write_num_bytes(content.len() + 2)?;
self.bytes[self.occupied] = (content.len() + 1) as u8;
self.bytes[self.occupied + 1] = kind;
let write = &mut self.bytes[self.occupied + 2..(self.occupied + content.len() + 2)];
write.copy_from_slice(content);
self.occupied += 2 + content.len();
Ok(())
}
pub fn add_flag(&mut self, flag: u8) -> Result<(), ()> {
self.check_can_write_num_bytes(3)?;
self.bytes[self.occupied] = 2;
self.bytes[self.occupied + 1] = gap_types::FLAGS;
self.bytes[self.occupied + 2] = flag;
self.occupied += 3;
Ok(())
}
pub fn add_service_payload(&mut self, uuid: [u8; 2], content: &[u8]) -> Result<(), ()> {
self.check_can_write_num_bytes(4 + content.len())?;
self.bytes[self.occupied] = (content.len() + 3) as u8;
self.bytes[self.occupied + 1] = gap_types::SERVICE_DATA;
self.bytes[self.occupied + 2] = uuid[0];
self.bytes[self.occupied + 3] = uuid[1];
let write = &mut self.bytes[self.occupied + 4..(self.occupied + content.len() + 4)];
write.copy_from_slice(content);
self.occupied += 4 + content.len();
Ok(())
}
fn check_can_write_num_bytes(&self, number: usize) -> Result<(), ()> {
if self.occupied + number <= self.bytes.len() {
Ok(())
} else {
Err(())
}
}
}
impl Default for BlePayload {
fn default() -> Self {
BlePayload {
bytes: [0; 39],
occupied: 0,
}
}
}
impl AsRef<[u8]> for BlePayload {
fn as_ref(&self) -> &[u8] {
&self.bytes[0..self.occupied]
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_add() {
let mut pld = BlePayload::default();
pld.add(1, &[2]).unwrap();
assert_eq!(pld.as_ref().len(), 3);
assert_eq!(pld.as_ref(), &mut [2, 1, 2])
}
#[test]
fn test_add_service_payload() {
let mut pld = BlePayload::default();
pld.add_service_payload([1, 2], &[2]).unwrap();
assert_eq!(pld.as_ref(), &[4, 0x16, 1, 2, 2])
}
#[test]
fn test_add_service_payload_two_times() {
let mut pld = BlePayload::default();
pld.add_service_payload([1, 2], &[2]).unwrap();
pld.add_service_payload([1, 2], &[2, 3]).unwrap();
assert_eq!(pld.as_ref(), &[4, 0x16, 1, 2, 2, 5, 0x16, 1, 2, 2, 3])
}
#[test]
fn big_data_causes_error() {
let mut pld = BlePayload::default();
assert!(pld.add_service_payload([1, 2], &[0; 36]).is_err());
}
#[test]
fn initial_size_is_zero() {
let pld = BlePayload::default();
assert_eq!(pld.as_ref().len(), 0);
}
}