[pbs-devel] [RFC pxar 2/20] fix #3174: decoder: factor out skip_bytes from skip_entry

[Christian Ebner <c.ebner@proxmox.com>]

Allows to skip bytes independently of the current entries header, as is
implemented by skip_entry.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
---
 src/decoder/mod.rs | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
index d1fb911..2ca263b 100644
--- a/src/decoder/mod.rs
+++ b/src/decoder/mod.rs
@@ -562,20 +562,25 @@ impl<I: SeqRead> DecoderImpl<I> {
     // These utilize additional information and hence are not part of the `dyn SeqRead` impl.
     //
 
-    async fn skip_entry(&mut self, offset: u64) -> io::Result<()> {
-        let mut len = self.current_header.content_size() - offset;
+    async fn skip_bytes(&mut self, len: usize) -> io::Result<()> {
+        let mut remaining = len;
         let scratch = scratch_buffer();
-        while len >= (scratch.len() as u64) {
+        while remaining >= scratch.len() {
             seq_read_exact(&mut self.input, scratch).await?;
-            len -= scratch.len() as u64;
+            remaining -= scratch.len();
         }
-        let len = len as usize;
-        if len > 0 {
-            seq_read_exact(&mut self.input, &mut scratch[..len]).await?;
+        if remaining > 0 {
+            seq_read_exact(&mut self.input, &mut scratch[..remaining]).await?;
         }
         Ok(())
     }
 
+    async fn skip_entry(&mut self, offset: u64) -> io::Result<()> {
+        let len =
+            usize::try_from(self.current_header.content_size() - offset).map_err(io_err_other)?;
+        self.skip_bytes(len).await
+    }
+
     async fn read_entry_as_bytes(&mut self) -> io::Result<Vec<u8>> {
         let size = usize::try_from(self.current_header.content_size()).map_err(io_err_other)?;
         let data = seq_read_exact_data(&mut self.input, size).await?;
-- 
2.39.2