implemented more functionality for embedded_io

This commit is contained in:
Djeeberjr 2025-08-08 13:03:47 +02:00
parent 54d35ebbec
commit c6d7ca79d0
2 changed files with 97 additions and 57 deletions

View File

@ -6,12 +6,12 @@ use crate::{
embedded_io::{error::MB85RCErrorType, head::Head},
};
pub struct EmbedIODev<T: I2c> {
pub struct EmbedIODev<T: I2c, const N: u64> {
dev: crate::MB85RC<T>,
head: Head,
head: Head<N>,
}
impl<T: I2c> EmbedIODev<T> {
impl<T: I2c, const N: u64> EmbedIODev<T, N> {
pub fn new(mb85rc: MB85RC<T>) -> Self {
Self {
dev: mb85rc,
@ -20,42 +20,59 @@ impl<T: I2c> EmbedIODev<T> {
}
}
impl<T: I2c> ErrorType for EmbedIODev<T> {
impl<T: I2c, const N: u64> ErrorType for EmbedIODev<T, N> {
type Error = MB85RCErrorType<T::Error>;
}
impl<T: I2c> Read for EmbedIODev<T> {
impl<T: I2c, const N: u64> Read for EmbedIODev<T, N> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::Error> {
self.dev
.sequential_read(&self.head.memory_address().unwrap(), buf)
.map_err(MB85RCErrorType::I2c)
.map(|_| {
self.head.advance(buf.len());
buf.len()
})
match self.head.memory_address() {
Some(addr) => self
.dev
.sequential_read(&addr, buf)
.map_err(MB85RCErrorType::I2c)
.map(|_| {
self.head.advance(buf.len());
buf.len()
}),
None => Err(MB85RCErrorType::InvalidPosition),
}
}
}
impl<T: I2c> Write for EmbedIODev<T> {
impl<T: I2c, const N: u64> Write for EmbedIODev<T, N> {
fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
// From trait doc: Implementations must not return Ok(0) unless buf is empty.
if buf.is_empty() {
return Ok(0);
}
// match self.head.memory_address() {
// Some(addr) => self
// .dev
// .write_page(&addr, buf)
// .map_err(MB85RCErrorType::I2c)
// .map(|_| {
// self.head.advance(buf.len());
// buf.len()
// }),
// None => Err(MB85RCErrorType::InvalidPosition),
// }
todo!()
}
fn flush(&mut self) -> Result<(), Self::Error> {
todo!()
// We can't really flush here.
Ok(())
}
}
impl<T: I2c> Seek for EmbedIODev<T> {
impl<T: I2c, const N: u64> Seek for EmbedIODev<T, N> {
fn seek(&mut self, pos: embedded_io::SeekFrom) -> Result<u64, Self::Error> {
self.head
.seek(pos)
.map_err(|_| MB85RCErrorType::InvalidPosition)?;
.ok_or(MB85RCErrorType::InvalidPosition)?;
Ok(self.head.into())
}
}

View File

@ -1,28 +1,34 @@
use embedded_io::SeekFrom;
/// moveable Read/Write head
/// Capped at `N`
/// Does not allow overflow
#[derive(Clone, Copy, Default)]
pub struct Head(u64);
pub struct Head<const N: u64>(u64);
impl Head {
impl<const N: u64> Head<N> {
pub fn new() -> Self {
Self(0)
}
pub fn seek(&mut self, pos: SeekFrom) -> Result<u64, ()> {
pub fn seek(&mut self, pos: SeekFrom) -> Option<u64> {
match pos {
SeekFrom::Start(offset) => {
self.0 = offset;
Ok(self.0)
}
SeekFrom::Start(offset) => match self.0.checked_add(offset).filter(|&sum| sum <= N) {
Some(new_pos) => {
self.0 = new_pos;
Some(new_pos)
}
None => None,
},
SeekFrom::End(offset) => {
// Do not allow seek over the end
if offset > 0 {
return Err(());
return None;
}
self.0 = u64::MAX - offset.unsigned_abs();
self.0 = N - offset.unsigned_abs();
Ok(self.0)
Some(self.0)
}
SeekFrom::Current(offset) => {
let new_pos = if offset > 0 {
@ -33,21 +39,31 @@ impl Head {
match new_pos {
Some(pos) => {
self.0 = pos;
Ok(self.0)
if pos > N {
None
} else {
self.0 = pos;
Some(self.0)
}
}
None => Err(()),
None => None,
}
}
}
}
/// Move the head forward when reading files.
/// Expected to not overflow. If it does it is capped at `u64::MAX`.
/// Expected to not overflow. If it does it is capped at `N`.
pub fn advance(&mut self, bytes: usize) {
match u64::try_from(bytes) {
Ok(offset) => self.0 += offset,
Err(_) => self.0 = u64::MAX,
match self.0.checked_add(bytes as u64) {
Some(sum) => {
if sum > N {
self.0 = N
} else {
self.0 = sum;
}
}
None => self.0 = N,
}
}
@ -65,8 +81,8 @@ impl Head {
}
}
impl From<Head> for u64 {
fn from(head: Head) -> Self {
impl<const N: u64> From<Head<N>> for u64 {
fn from(head: Head<N>) -> Self {
head.0
}
}
@ -77,87 +93,94 @@ mod tests {
#[test]
fn create() {
let head = Head::new();
let head: Head<65_535> = Head::new();
let inner: u64 = head.into();
assert_eq!(inner, 0u64);
}
#[test]
fn seek_start() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let res = head.seek(SeekFrom::Start(1337));
let inner: u64 = head.into();
assert_eq!(inner, 1337u64);
assert_eq!(res, Ok(inner));
assert_eq!(res, Some(inner));
}
#[test]
fn seek_current_forward() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let _ = head.seek(SeekFrom::Start(1337));
let res = head.seek(SeekFrom::Current(3));
let inner: u64 = head.into();
assert_eq!(inner, 1340u64);
assert_eq!(res, Ok(inner));
assert_eq!(res, Some(inner));
}
#[test]
fn seek_current_back() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let _ = head.seek(SeekFrom::Start(1337));
let res = head.seek(SeekFrom::Current(-337));
let inner: u64 = head.into();
assert_eq!(inner, 1000u64);
assert_eq!(res, Ok(inner));
assert_eq!(res, Some(inner));
}
#[test]
fn seek_current_zero() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let _ = head.seek(SeekFrom::Start(1337));
let res = head.seek(SeekFrom::Current(0));
let inner: u64 = head.into();
assert_eq!(inner, 1337u64);
assert_eq!(res, Ok(inner));
assert_eq!(res, Some(inner));
}
#[test]
fn seek_end() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let res = head.seek(SeekFrom::End(-10));
let inner: u64 = head.into();
assert_eq!(inner, u64::MAX - 10);
assert_eq!(res, Ok(inner));
assert_eq!(inner, 65_535 - 10);
assert_eq!(res, Some(inner));
}
#[test]
fn seek_end_overflow() {
let mut head: Head<65_535> = Head::new();
let res = head.seek(SeekFrom::End(10));
assert!(res.is_none());
}
#[test]
fn seek_invalid_overflow() {
let mut head = Head::new();
let _ = head.seek(SeekFrom::Start(u64::MAX - 5));
let mut head: Head<65_535> = Head::new();
let _ = head.seek(SeekFrom::Start(65_535 - 5));
let res = head.seek(SeekFrom::Current(10));
assert!(res.is_err());
assert!(res.is_none());
}
#[test]
fn seek_invalid_underflow() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let res = head.seek(SeekFrom::Current(-1));
assert!(res.is_err());
assert!(res.is_none());
}
#[test]
fn convert_zero() {
let head = Head::new();
let head: Head<65_535> = Head::new();
let addr = head.memory_address();
assert_eq!(addr, Some([0, 0]));
@ -165,7 +188,7 @@ mod tests {
#[test]
fn convert_1_byte() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let _ = head.seek(SeekFrom::Start(50));
let addr = head.memory_address();
@ -175,7 +198,7 @@ mod tests {
#[test]
fn convert_2_bytes() {
let mut head = Head::new();
let mut head: Head<65_535> = Head::new();
let _ = head.seek(SeekFrom::Start(260));
let addr = head.memory_address();
@ -185,8 +208,8 @@ mod tests {
#[test]
fn convert_invalid() {
let mut head = Head::new();
let _ = head.seek(SeekFrom::Start(u16::MAX as u64 + 1));
let mut head: Head<4_294_967_295> = Head::new(); // Needs to be more then u16::MAX
let _ = head.seek(SeekFrom::Start(65_536)); // One more then u16::MAX
let addr = head.memory_address();
assert!(addr.is_none());