From 83959b26914d9681d108816e25032b4020c244fb Mon Sep 17 00:00:00 2001
From: Simon Renblad <srenblad@m-labs.hk>
Date: Mon, 29 Jul 2024 17:54:35 +0800
Subject: [PATCH] libconfig rewrites

---
 libconfig/src/lib.rs       | 34 +++++++++++++++++++++----------
 libconfig/src/sd_reader.rs | 41 ++++++++++++++++++--------------------
 2 files changed, 43 insertions(+), 32 deletions(-)

diff --git a/libconfig/src/lib.rs b/libconfig/src/lib.rs
index f1bf1b1..670d227 100644
--- a/libconfig/src/lib.rs
+++ b/libconfig/src/lib.rs
@@ -3,7 +3,6 @@ extern crate alloc;
 
 use core::fmt;
 use alloc::{string::FromUtf8Error, string::String, vec::Vec, rc::Rc};
-use core_io::{self as io, BufRead, BufReader, Read, Write, Seek, SeekFrom};
 use libboard_zynq::sdio;
 
 pub mod sd_reader;
@@ -13,7 +12,7 @@ pub mod bootgen;
 #[derive(Debug)]
 pub enum Error<'a> {
     SdError(sdio::sd_card::CardInitializationError),
-    IoError(io::Error),
+    IoError(sd_reader::SdReader::Error),
     Utf8Error(FromUtf8Error),
     KeyNotFoundError(&'a str),
     NoConfig,
@@ -39,8 +38,8 @@ impl<'a> From<sdio::sd_card::CardInitializationError> for Error<'a> {
     }
 }
 
-impl<'a> From<io::Error> for Error<'a> {
-    fn from(error: io::Error) -> Self {
+impl<'a> From<sd_reader::SdReader::Error> for Error<'a> {
+    fn from(error: sd_reader::SdReader::Error) -> Self {
         Error::IoError(error)
     }
 }
@@ -57,14 +56,29 @@ fn parse_config<'a>(
     file: fatfs::File<sd_reader::SdReader>,
 ) -> Result<'a, ()> {
     let prefix = [key, "="].concat().to_ascii_lowercase();
-    for line in BufReader::new(file).lines() {
-        let line = line?.to_ascii_lowercase();
-        if line.starts_with(&prefix) {
-            buffer.extend(line[prefix.len()..].as_bytes());
-            return Ok(());
+    let mut file_buf: Vec<u8> = Vec::new();
+    loop {
+        match memchr::memchr(b'\n', &file_buf) {
+            Some(i) => {
+                let s = String::from_utf8(&file_buf[..=i])
+                if s.starts_with(&prefix) {
+                    buffer.extend_from_slice(&file_buf[..=i]);
+                    return Ok(())
+                } else {
+                    file.consume(i + 1)
+                }
+            }
+            None => {
+                let s = String::from_utf8(file_buf)
+                if s.starts_with(&prefix) {
+                    buffer.extend_from_slice(file_buf);
+                    return Ok(())
+                } else {
+                    return Err(Error::KeyNotFoundError(key))
+                }
+            }
         }
     }
-    Err(Error::KeyNotFoundError(key))
 }
 
 pub struct Config {
diff --git a/libconfig/src/sd_reader.rs b/libconfig/src/sd_reader.rs
index fc93304..7293c91 100644
--- a/libconfig/src/sd_reader.rs
+++ b/libconfig/src/sd_reader.rs
@@ -188,6 +188,25 @@ impl SdReader {
     fn cmd_error_to_io_error(_: CmdTransferError) -> Self::Error {
         Self::Error::Other("Command transfer error")
     }
+     fn fill_buf(&mut self) -> Result<&[u8], Self::Error> {
+         if self.index == BLOCK_SIZE {
+             // flush the buffer if it is dirty before overwriting it with new data
+             if self.dirty {
+                 self.flush()?;
+             }
+             // reload buffer
+             self.sd
+                 .read_block(self.byte_addr / (BLOCK_SIZE as u32), 1, &mut self.buffer)
+                 .map_err(cmd_error_to_io_error)?;
+             self.index = (self.byte_addr as usize) % BLOCK_SIZE;
+         }
+         Ok(&self.buffer[self.index..])
+     }
+ 
+     fn consume(&mut self, amt: usize) {
+         self.index += amt;
+         self.byte_addr += amt as u32;
+     }
 }
 
 
@@ -217,28 +236,6 @@ impl Read for SdReader {
     }
 }
 
-// impl BufRead for SdReader {
-//     fn fill_buf(&mut self) -> Result<&[u8], Self::Error> {
-//         if self.index == BLOCK_SIZE {
-//             // flush the buffer if it is dirty before overwriting it with new data
-//             if self.dirty {
-//                 self.flush()?;
-//             }
-//             // reload buffer
-//             self.sd
-//                 .read_block(self.byte_addr / (BLOCK_SIZE as u32), 1, &mut self.buffer)
-//                 .map_err(cmd_error_to_io_error)?;
-//             self.index = (self.byte_addr as usize) % BLOCK_SIZE;
-//         }
-//         Ok(&self.buffer[self.index..])
-//     }
-// 
-//     fn consume(&mut self, amt: usize) {
-//         self.index += amt;
-//         self.byte_addr += amt as u32;
-//     }
-// }
-
 impl Write for SdReader {
     fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
         let (a, b, c) = self.block_align(buf);