From cc32dd207530e0e9a202c01d832e808525f808d9 Mon Sep 17 00:00:00 2001
From: CJ van den Berg <cj@vdbonline.com>
Date: Thu, 12 Mar 2026 20:08:19 +0100
Subject: [PATCH] refactor: optimize decodeUIntLength to iterate instead of
 recursing

---
 src/cbor.zig | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/src/cbor.zig b/src/cbor.zig
index 52c40f9..8ae94d1 100644
--- a/src/cbor.zig
+++ b/src/cbor.zig
@@ -339,21 +339,12 @@ pub fn decodeType(iter: *[]const u8) error{TooShort}!CborType {
     return .{ .type = type_, .minor = bits.minor, .major = bits.major };
 }
 
-fn decodeUIntLengthRecurse(iter: *[]const u8, length: usize, acc: u64) error{TooShort}!u64 {
-    if (iter.len < 1)
-        return error.TooShort;
-    const v: u8 = iter.*[0];
-    iter.* = iter.*[1..];
-    var i = acc | v;
-    if (length == 1)
-        return i;
-    i <<= 8;
-    // return @call(.always_tail, decodeUIntLengthRecurse, .{ iter, length - 1, i });  FIXME: @call(.always_tail) seems broken as of 0.11.0-dev.2964+e9cbdb2cf
-    return decodeUIntLengthRecurse(iter, length - 1, i);
-}
-
-fn decodeUIntLength(iter: *[]const u8, length: usize) !u64 {
-    return decodeUIntLengthRecurse(iter, length, 0);
+fn decodeUIntLength(iter: *[]const u8, length: usize) error{TooShort}!u64 {
+    if (iter.len < length) return error.TooShort;
+    var acc: u64 = 0;
+    for (iter.*[0..length]) |byte| acc = (acc << 8) | byte;
+    iter.* = iter.*[length..];
+    return acc;
 }
 
 fn decodePInt(iter: *[]const u8, minor: u5) error{ TooShort, InvalidPIntType }!u64 {