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extern crate libc;
mod ffi;
use std::ffi::{CStr, CString};
use std::marker::PhantomData;
use libc::{wchar_t, size_t, c_int};
pub type HidError = &'static str;
pub type HidResult<T> = Result<T, HidError>;
const STRING_BUF_LEN: usize = 128;
pub struct HidApi {
devices: Vec<HidDeviceInfo>,
}
static mut hid_api_lock: bool = false;
impl HidApi {
pub fn new() -> HidResult<Self> {
if unsafe { !hid_api_lock } {
unsafe {
if ffi::hid_init() == -1 {
return Err("Failed to init hid");
}
hid_api_lock = true;
}
Ok(HidApi { devices: unsafe { HidApi::get_hid_device_info_vector() } })
} else {
Err("HidApi already in use")
}
}
pub fn refresh_devices(&mut self) {
self.devices = unsafe { HidApi::get_hid_device_info_vector() };
}
unsafe fn get_hid_device_info_vector() -> Vec<HidDeviceInfo> {
let mut device_vector = Vec::with_capacity(8);
let enumeration = ffi::hid_enumerate(0, 0);
{
let mut current_device = enumeration;
if !current_device.is_null() {
'do_while: loop {
device_vector.push(conv_hid_device_info(current_device));
if (*current_device).next.is_null() {
break 'do_while;
} else {
current_device = (*current_device).next;
}
}
}
}
ffi::hid_free_enumeration(enumeration);
device_vector
}
pub fn devices(&self) -> Vec<HidDeviceInfo> {
self.devices.clone()
}
pub fn open(&self, vid: u16, pid: u16) -> HidResult<HidDevice> {
let device = unsafe { ffi::hid_open(vid, pid, std::ptr::null()) };
if device.is_null() {
Err("Unable to open hid device")
} else {
Ok(HidDevice {
_hid_device: device,
phantom: PhantomData,
})
}
}
pub fn open_serial(&self, vid: u16, pid: u16, sn: &str) -> HidResult<HidDevice> {
let device = unsafe { ffi::hid_open(vid, pid, std::mem::transmute(sn.as_ptr())) };
if device.is_null() {
Err("Unable to open hid device")
} else {
Ok(HidDevice {
_hid_device: device,
phantom: PhantomData,
})
}
}
pub fn open_path(&self, device_path: &str) -> HidResult<HidDevice> {
let cstr = CString::new(device_path).unwrap();
let device = unsafe { ffi::hid_open_path(cstr.as_ptr()) };
if device.is_null() {
Err("Unable to open hid device")
} else {
Ok(HidDevice {
_hid_device: device,
phantom: PhantomData,
})
}
}
}
impl Drop for HidApi {
fn drop(&mut self) {
unsafe {
ffi::hid_exit();
hid_api_lock = false;
}
}
}
unsafe fn wchar_to_string(wstr: *const wchar_t) -> HidResult<String> {
if wstr.is_null() {
return Err("Null pointer!");
}
let mut char_vector: Vec<char> = Vec::with_capacity(8);
let mut index: isize = 0;
while *wstr.offset(index) != 0 {
use std::char;
char_vector.push(match char::from_u32(*wstr.offset(index) as u32) {
Some(ch) => ch,
None => return Err("Unable to add next char"),
});
index += 1;
}
Ok(char_vector.into_iter().collect())
}
unsafe fn conv_hid_device_info(src: *mut ffi::HidDeviceInfo) -> HidDeviceInfo {
HidDeviceInfo {
path: std::str::from_utf8(CStr::from_ptr((*src).path).to_bytes()).unwrap().to_owned(),
vendor_id: (*src).vendor_id,
product_id: (*src).product_id,
serial_number: wchar_to_string((*src).serial_number).ok(),
release_number: (*src).release_number,
manufacturer_string: wchar_to_string((*src).manufacturer_string).ok(),
product_string: wchar_to_string((*src).product_string).ok(),
usage_page: (*src).usage_page,
usage: (*src).usage,
interface_number: (*src).interface_number,
}
}
#[derive(Debug, Clone)]
pub struct HidDeviceInfo {
pub path: String,
pub vendor_id: u16,
pub product_id: u16,
pub serial_number: Option<String>,
pub release_number: u16,
pub manufacturer_string: Option<String>,
pub product_string: Option<String>,
pub usage_page: u16,
pub usage: u16,
pub interface_number: i32,
}
pub struct HidDevice<'a> {
_hid_device: *mut ffi::HidDevice,
phantom: PhantomData<&'a ()>,
}
impl<'a> Drop for HidDevice<'a> {
fn drop(&mut self) {
unsafe { ffi::hid_close(self._hid_device) };
}
}
impl<'a> HidDevice<'a> {
fn check_size(&self, res: i32) -> HidResult<usize> {
if res == -1 {
match self.check_error() {
Ok(err) => {
if err.is_empty() {
Err("Undetected error")
} else {
println!("{:?}", err);
Err("Detected error")
}
}
Err(_) => {
Err("Failed to retrieve error message")
}
}
} else {
Ok(res as usize)
}
}
pub fn check_error(&self) -> HidResult<String> {
unsafe { wchar_to_string(ffi::hid_error(self._hid_device)) }
}
pub fn write(&self, data: &[u8]) -> HidResult<usize> {
if data.len() == 0 {
return Err("Data must contain at least one byte");
}
let res = unsafe { ffi::hid_write(self._hid_device, data.as_ptr(), data.len() as size_t) };
self.check_size(res)
}
pub fn read(&self, buf: &mut [u8]) -> HidResult<usize> {
let res = unsafe { ffi::hid_read(self._hid_device, buf.as_mut_ptr(), buf.len() as size_t) };
self.check_size(res)
}
pub fn read_timeout(&self, buf: &mut [u8], timeout: i32) -> HidResult<usize> {
let res = unsafe {
ffi::hid_read_timeout(self._hid_device,
buf.as_mut_ptr(),
buf.len() as size_t,
timeout)
};
self.check_size(res)
}
pub fn send_feature_report(&self, data: &[u8]) -> HidResult<()> {
if data.len() == 0 {
return Err("Data must contain at least one byte");
}
let res = unsafe {
ffi::hid_send_feature_report(self._hid_device, data.as_ptr(), data.len() as size_t)
};
let res = try!(self.check_size(res));
if res != data.len() {
Err("Failed to send feature report completely")
} else {
Ok(())
}
}
pub fn get_feature_report(&self, buf: &mut [u8]) -> HidResult<usize> {
let res = unsafe {
ffi::hid_get_feature_report(self._hid_device, buf.as_mut_ptr(), buf.len() as size_t)
};
self.check_size(res)
}
pub fn set_blocking_mode(&self, blocking: bool) -> HidResult<()> {
let res = unsafe {
ffi::hid_set_nonblocking(self._hid_device, if blocking { 0i32 } else { 1i32 })
};
if res == -1 {
Err("Failed to set blocking mode")
} else {
Ok(())
}
}
pub fn get_manufacturer_string(&self) -> HidResult<String> {
let mut buf = [0 as wchar_t; STRING_BUF_LEN];
let res = unsafe {
ffi::hid_get_manufacturer_string(self._hid_device,
buf.as_mut_ptr(),
STRING_BUF_LEN as size_t)
};
let res = try!(self.check_size(res));
unsafe { wchar_to_string(buf[..res].as_ptr()) }
}
pub fn get_product_string(&self) -> HidResult<String> {
let mut buf = [0 as wchar_t; STRING_BUF_LEN];
let res = unsafe {
ffi::hid_get_product_string(self._hid_device,
buf.as_mut_ptr(),
STRING_BUF_LEN as size_t)
};
let res = try!(self.check_size(res));
unsafe { wchar_to_string(buf[..res].as_ptr()) }
}
pub fn get_serial_number_string(&self) -> HidResult<String> {
let mut buf = [0 as wchar_t; STRING_BUF_LEN];
let res = unsafe {
ffi::hid_get_serial_number_string(self._hid_device,
buf.as_mut_ptr(),
STRING_BUF_LEN as size_t)
};
let res = try!(self.check_size(res));
unsafe { wchar_to_string(buf[..res].as_ptr()) }
}
pub fn get_indexed_string(&self, index: i32) -> HidResult<String> {
let mut buf = [0 as wchar_t; STRING_BUF_LEN];
let res = unsafe {
ffi::hid_get_indexed_string(self._hid_device,
index as c_int,
buf.as_mut_ptr(),
STRING_BUF_LEN)
};
let res = try!(self.check_size(res));
unsafe { wchar_to_string(buf[..res].as_ptr()) }
}
}
#[test]
fn smoke() {
let api = HidApi::new().unwrap();
for device in &api.devices() {
println!("{:#?}", device);
}
}