Use a buffered reader for incbin

Iterating via `bytes()` on a file is inefficient as the default
implementation calls `read` on each byte, which can be costly on bytes
which are not in memory like files. This is extra important for
statements like `incbin` as included files can be rather big.

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/xixanta/src/assembler.rs b/lib/xixanta/src/assembler.rs
index 5b01db8..6fc0cc1 100644
--- a/lib/xixanta/src/assembler.rs
+++ b/lib/xixanta/src/assembler.rs
@@ -8,7 +8,7 @@ use crate::SourceInfo;
 use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::fs::File;
-use std::io::Read;
+use std::io::{BufReader, Read};
 use std::ops::Neg;
 
 /// The mode in which a literal is expressed.
@@ -1497,7 +1497,8 @@ impl<'a> Assembler<'a> {
         }
 
         // And finally just push each byte from the given file as a fill bundle.
-        for byte in file.bytes() {
+        let reader = BufReader::new(file);
+        for byte in reader.bytes() {
             match byte {
                 Ok(b) => self.push_bundle(Bundle::fill(b), node)?,
                 Err(_) => break,