FileChunks: save offset instead of chunk index

src/sharry/file/chunks.rs

@@ -8,7 +8,7 @@ use log::error;
 
 pub struct FileChunks<'t> {
     file_path: &'t Path,
-    chunk_index: u64,
+    offset: u64,
     chunk_size: usize,
 }
 
@@ -16,15 +16,15 @@ impl<'t> FileChunks<'t> {
     pub(super) fn new(path: &'t Path, chunk_size: usize) -> Self {
         Self {
             file_path: path,
-            chunk_index: 0,
+            offset: 0,
             chunk_size,
         }
     }
 
-    pub fn seek(self, chunk_index: u64) -> Self {
+    pub fn seek(self, offset: u64) -> Self {
         Self {
             file_path: self.file_path,
-            chunk_index,
+            offset,
             chunk_size: self.chunk_size,
         }
     }
@@ -34,15 +34,10 @@ impl Iterator for FileChunks<'_> {
     type Item = Chunk;
 
     fn next(&mut self) -> Option<Self::Item> {
-        let offset = self.chunk_index
-            * u64::try_from(self.chunk_size)
-                .inspect_err(|e| error!("Error converting to u64: {e}"))
-                .ok()?;
-
         let mut f = File::open(self.file_path)
             .inspect_err(|e| error!("Error opening file: {e}"))
             .ok()?;
-        f.seek(SeekFrom::Start(offset)).ok()?;
+        f.seek(SeekFrom::Start(self.offset)).ok()?;
 
         let mut bytes = vec![0; self.chunk_size];
         let read_len = (f.read(&mut bytes))
@@ -50,9 +45,17 @@ impl Iterator for FileChunks<'_> {
             .ok()?;
         bytes.truncate(read_len);
 
-        self.chunk_index += 1;
+        let read_len: u64 = read_len
+            .try_into()
+            .inspect_err(|e| error!("Error converting to u64: {e}"))
+            .ok()?;
+        self.offset += read_len;
 
-        Some(Self::Item { offset, bytes }).filter(|c| !c.bytes.is_empty())
+        Some(Self::Item {
+            offset: self.offset,
+            bytes,
+        })
+        .filter(|c| !c.bytes.is_empty())
     }
 }