From ecee4f3b3bdc7eacf411ef4743942bdaccc971a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Hoen?=
 <45117380+JeromeHoen@users.noreply.github.com>
Date: Fri, 24 Feb 2023 16:30:58 +0100
Subject: [PATCH] Performance improvements

binary_to_u32 and bitslice_to_vec perf improvements
---
 src/lib.rs | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 76ec001..f8b4587 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -154,24 +154,18 @@ fn get_row_indexes(buf: &[u8], field: &QvdFieldHeader, record_byte_size: usize)
     indexes
 }
 
-// Slow
 fn binary_to_u32(binary: Vec<u8>) -> u32 {
     let mut sum: u32 = 0;
     for bit in binary {
-        sum <<= 1;
-        sum += bit as u32;
+        sum = (sum << 1) | (bit as u32);
     }
     sum
 }
 
-// Slow
 fn bitslice_to_vec(bitslice: &BitSlice<Msb0, u8>) -> Vec<u8> {
-    let mut v: Vec<u8> = Vec::new();
-    for bit in bitslice {
-        let val = match bit {
-            true => 1,
-            false => 0,
-        };
+    let mut v: Vec<u8> = Vec::with_capacity(bitslice.len());
+    for bit in bitslice.iter() {
+        let val = if *bit { 1 } else { 0 };
         v.push(val);
     }
     v