Config: implemented config struct.

src/runtime/src/config.rs

@@ -1,65 +1,96 @@
-use log::info;
+use crate::sd_reader;
 use core::fmt;
-use alloc::{vec::Vec, string::String, string::FromUtf8Error};
-use core_io as io;
+use alloc::{string::FromUtf8Error, string::String, vec::Vec};
+use core_io::{self as io, BufRead, BufReader, Read};
 
 use libboard_zynq::sdio;
 
-use crate::sd_reader;
-
 #[derive(Debug)]
-pub enum Error {
+pub enum Error<'a> {
     SdError(sdio::sd_card::CardInitializationError),
     IoError(io::Error),
     Utf8Error(FromUtf8Error),
+    ConfigNotFound(&'a str),
 }
 
-pub type Result<T> = core::result::Result<T, Error>;
+pub type Result<'a, T> = core::result::Result<T, Error<'a>>;
 
-impl fmt::Display for Error {
+impl<'a> fmt::Display for Error<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            Error::SdError(error)   => write!(f, "SD error: {:?}", error), // TODO: Display for CardInitializationError?
+            Error::SdError(error) => write!(f, "SD error: {}", error),
             Error::IoError(error) => write!(f, "I/O error: {}", error),
             Error::Utf8Error(error) => write!(f, "UTF-8 error: {}", error),
+            Error::ConfigNotFound(name) => write!(f, "Config `{}` not found", name),
         }
     }
 }
 
-impl From<sdio::sd_card::CardInitializationError> for Error {
+impl<'a> From<sdio::sd_card::CardInitializationError> for Error<'a> {
     fn from(error: sdio::sd_card::CardInitializationError) -> Self {
         Error::SdError(error)
     }
 }
 
-impl From<io::Error> for Error {
+impl<'a> From<io::Error> for Error<'a> {
     fn from(error: io::Error) -> Self {
         Error::IoError(error)
     }
 }
 
-impl From<FromUtf8Error> for Error {
+impl<'a> From<FromUtf8Error> for Error<'a> {
     fn from(error: FromUtf8Error) -> Self {
         Error::Utf8Error(error)
     }
 }
 
-pub fn read(key: &str) -> Result<Vec<u8>> {
+fn parse_config<'a>(
+    key: &'a str,
+    buffer: &mut Vec<u8>,
+    file: fatfs::File<sd_reader::SdReader>,
+) -> Result<'a, ()> {
+    let prefix = [key, "="].concat();
+    for line in BufReader::new(file).lines() {
+        let line = line?;
+        if line.starts_with(&prefix) {
+            buffer.extend(line[prefix.len()..].as_bytes());
+            return Ok(());
+        }
+    }
+    Err(Error::ConfigNotFound(key))
+}
+
+pub struct Config {
+    fs: fatfs::FileSystem<sd_reader::SdReader>,
+}
+
+impl Config {
+    pub fn new() -> Result<'static, Self> {
         let sdio = sdio::SDIO::sdio0(true);
-    let mut sd = sdio::sd_card::SdCard::from_sdio(sdio)?;
-    let reader = sd_reader::SdReader::new(&mut sd);
+        if !sdio.is_card_inserted() {
+            Err(sdio::sd_card::CardInitializationError::NoCardInserted)?;
+        }
+        let sd = sdio::sd_card::SdCard::from_sdio(sdio)?;
+        let reader = sd_reader::SdReader::new(sd);
 
         let fs = reader.mount_fatfs(sd_reader::PartitionEntry::Entry1)?;
-    let root_dir = fs.root_dir();
-    for entry in root_dir.iter() {
-        if let Ok(entry) = entry {
-            let bytes = entry.short_file_name_as_bytes();
-            info!("{}", core::str::from_utf8(bytes).unwrap());
+        Ok(Config { fs })
     }
-    }
-    Err(sdio::sd_card::CardInitializationError::NoCardInserted)? // TODO
-}
 
-pub fn read_str(key: &str) -> Result<String> {
-    Ok(String::from_utf8(read(key)?)?)
+    fn read<'b>(&mut self, key: &'b str) -> Result<'b, Vec<u8>> {
+        let root_dir = self.fs.root_dir();
+        let mut buffer: Vec<u8> = Vec::new();
+        match root_dir.open_file(&["/CONFIG/", key, ".BIN"].concat()) {
+            Ok(mut f) => f.read_to_end(&mut buffer).map(|v| ())?,
+            Err(_) => match root_dir.open_file("/CONFIG.TXT") {
+                Ok(f) => parse_config(key, &mut buffer, f)?,
+                Err(_) => return Err(Error::ConfigNotFound(key)),
+            },
+        };
+        Ok(buffer)
+    }
+
+    pub fn read_str<'b>(&mut self, key: &'b str) -> Result<'b, String> {
+        Ok(String::from_utf8(self.read(key)?)?)
+    }
 }