From dd2ace77f652510a680fdfd21a08361cbb905702 Mon Sep 17 00:00:00 2001
From: Cong-Cong <dacongsama@live.com>
Date: Thu, 2 Jan 2025 10:13:47 +0800
Subject: [PATCH] perf: current_value use usize

---
 src/decoder.rs | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/src/decoder.rs b/src/decoder.rs
index 46229241..c92fdfa3 100644
--- a/src/decoder.rs
+++ b/src/decoder.rs
@@ -36,7 +36,7 @@ pub(crate) struct MappingsDecoder<'a> {
   current_data: [u32; 5],
   current_data_pos: usize,
   // current_value will include a sign bit at bit 0
-  current_value: i64,
+  current_value: usize,
   current_value_pos: usize,
   generated_line: u32,
 }
@@ -103,23 +103,20 @@ impl Iterator for MappingsDecoder<'_> {
         }
       } else if (value & CONTINUATION_BIT) == 0 {
         // last sextet
-        self.current_value |= (value as i64) << self.current_value_pos;
-        let final_value = if (self.current_value & 1) != 0 {
-          -(self.current_value >> 1)
-        } else {
-          self.current_value >> 1
-        };
+        self.current_value |= (value as usize) << self.current_value_pos;
         if self.current_data_pos < 5 {
-          self.current_data[self.current_data_pos] =
-            (self.current_data[self.current_data_pos] as i64 + final_value)
-              as u32;
+          self.current_data[self.current_data_pos] = if (self.current_value & 1) != 0 {
+            self.current_data[self.current_data_pos] as usize - (self.current_value >> 1)
+          } else {
+            self.current_data[self.current_data_pos] as usize + (self.current_value >> 1)
+          } as u32;
         }
         self.current_data_pos += 1;
         self.current_value_pos = 0;
         self.current_value = 0;
       } else {
         self.current_value |=
-          ((value & DATA_MASK) as i64) << self.current_value_pos;
+          ((value & DATA_MASK) as usize) << self.current_value_pos;
         self.current_value_pos += 5;
       }
     }