moved low-level code into fat-bits subcrate

src/iter.rs

@@ -1,52 +0,0 @@
-use std::io::Read;
-
-use crate::subslice::SubSlice;
-use crate::utils::replace;
-use crate::{FatFs, SliceLike};
-
-pub struct ClusterChainReader<'a, S: SliceLike> {
-    sub_slice: SubSlice<'a, S>,
-
-    next_cluster: Option<u32>,
-}
-
-impl<'a, S: SliceLike> ClusterChainReader<'a, S> {
-    pub fn new(fat_fs: &'a FatFs<S>, first_cluster: u32) -> ClusterChainReader<'a, S> {
-        let next_cluster = fat_fs.next_cluster(first_cluster).unwrap_or(None);
-
-        let sub_slice = fat_fs.cluster_as_subslice(first_cluster);
-
-        ClusterChainReader {
-            sub_slice,
-            next_cluster,
-        }
-    }
-
-    fn next_cluster(&mut self) -> bool {
-        let Some(next_cluster) = self.next_cluster else {
-            return false;
-        };
-
-        replace(&mut self.sub_slice, |sub_slice| {
-            let fat_fs = sub_slice.release();
-
-            self.next_cluster = fat_fs.next_cluster(next_cluster).unwrap_or(None);
-
-            fat_fs.cluster_as_subslice(next_cluster)
-        });
-
-        true
-    }
-}
-
-impl<'a, S: SliceLike> Read for ClusterChainReader<'a, S> {
-    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
-        if self.sub_slice.is_empty() {
-            if !self.next_cluster() {
-                return Ok(0);
-            }
-        }
-
-        self.sub_slice.read(buf)
-    }
-}