esp32-nimble 0.12.0

A wrapper for the ESP32 NimBLE Bluetooth stack.
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use crate::{
    BLEError, Signal, ble,
    utilities::{OsMBuf, as_void_ptr, voidp_to_ref},
};
use esp_idf_svc::sys as esp_idf_sys;

pub struct BLEWriter {
    conn_handle: u16,
    handle: u16,
    signal: Signal<u32>,
}

impl BLEWriter {
    pub fn new(conn_handle: u16, handle: u16) -> Self {
        Self {
            conn_handle,
            handle,
            signal: Signal::new(),
        }
    }

    pub async fn write_value(&mut self, data: &[u8], response: bool) -> Result<(), BLEError> {
        unsafe {
            // ble_att_mtu() returns 0 for a closed connection
            let mtu = esp_idf_sys::ble_att_mtu(self.conn_handle);
            if mtu == 0 {
                return BLEError::convert(esp_idf_sys::BLE_HS_ENOTCONN as _);
            }
            let mtu = { mtu - 3 } as usize;

            if !response && data.len() <= mtu {
                return ble!(esp_idf_sys::ble_gattc_write_no_rsp_flat(
                    self.conn_handle,
                    self.handle,
                    data.as_ptr() as _,
                    data.len() as _
                ));
            }

            if data.len() <= mtu {
                ble!(esp_idf_sys::ble_gattc_write_flat(
                    self.conn_handle,
                    self.handle,
                    data.as_ptr() as _,
                    data.len() as _,
                    Some(Self::on_write_cb),
                    as_void_ptr(self),
                ))?;
            } else {
                let om = OsMBuf::from_flat(data);
                ble!(esp_idf_sys::ble_gattc_write_long(
                    self.conn_handle,
                    self.handle,
                    0,
                    om.0,
                    Some(Self::on_write_cb),
                    as_void_ptr(self),
                ))?;
            }

            ble!(self.signal.wait().await)?;
        }

        Ok(())
    }

    extern "C" fn on_write_cb(
        conn_handle: u16,
        error: *const esp_idf_sys::ble_gatt_error,
        _service: *mut esp_idf_sys::ble_gatt_attr,
        arg: *mut core::ffi::c_void,
    ) -> i32 {
        let writer = unsafe { voidp_to_ref::<Self>(arg) };
        if writer.conn_handle != conn_handle {
            return 0;
        }

        writer.signal.signal(unsafe { (*error).status as _ });
        0
    }
}