perf: remove redundant BufReaders for decompressing tar archives

Author: kskalski

runtime/src/snapshot_utils.rs

@@ -2313,14 +2313,15 @@ fn untar_snapshot_create_shared_buffer(
             })
             .unwrap()
     };
+    // Apply buffered reader for decoders that do not buffer internally.
     match archive_format {
         ArchiveFormat::TarBzip2 => SharedBuffer::new(BzDecoder::new(BufReader::new(open_file()))),
-        ArchiveFormat::TarGzip => SharedBuffer::new(GzDecoder::new(BufReader::new(open_file()))),
+        ArchiveFormat::TarGzip => SharedBuffer::new(GzDecoder::new(open_file())),
         ArchiveFormat::TarZstd { .. } => SharedBuffer::new(
-            zstd::stream::read::Decoder::new(BufReader::new(open_file())).unwrap(),
+            zstd::stream::read::Decoder::new(open_file()).unwrap(),
         ),
         ArchiveFormat::TarLz4 => {
-            SharedBuffer::new(lz4::Decoder::new(BufReader::new(open_file())).unwrap())
+            SharedBuffer::new(lz4::Decoder::new(open_file()).unwrap())
         }
         ArchiveFormat::Tar => SharedBuffer::new(BufReader::new(open_file())),
     }