From 98f3c055f9bd9203ef10fdfee50b1960f0932fa0 Mon Sep 17 00:00:00 2001
From: Xiaoyu Lu <xiaoyux.lu@intel.com>
Date: Tue, 29 Dec 2020 16:12:07 +0800
Subject: [PATCH] efi-str add string compare

---
 efi-str/src/lib.rs    |  8 ++++++++
 efi-str/src/os_str.rs | 16 ++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/efi-str/src/lib.rs b/efi-str/src/lib.rs
index 29762668..277c82c4 100644
--- a/efi-str/src/lib.rs
+++ b/efi-str/src/lib.rs
@@ -1,5 +1,7 @@
 #![cfg_attr(not(test), no_std)]
 
+#![feature(unicode_internals)]
+
 pub mod encoder;
 
 #[macro_use]
@@ -28,5 +30,11 @@ mod tests {
         assert_eq!(path_osstr_nul, "中国\0");
         assert_ne!(path_osstr, path_osstr_nul);
         assert_ne!("中1", path_osstr);
+
+        let str_lower = "hi";
+        let str_upper = [0x48, 0x49];
+        let str_upper = OsStr::from_u16_slice(&str_upper);
+
+        assert_eq!(str_upper.eq_ignore_ascii_case(str_lower), true);
     }
 }
diff --git a/efi-str/src/os_str.rs b/efi-str/src/os_str.rs
index 4f11acb6..59ebc8af 100644
--- a/efi-str/src/os_str.rs
+++ b/efi-str/src/os_str.rs
@@ -1,5 +1,6 @@
 use core::fmt;
 use core::slice::Iter;
+use core::unicode::conversions;
 
 pub struct OsStr([u16]);
 
@@ -92,6 +93,21 @@ impl OsStr {
         }
         res
     }
+
+    pub fn eq_ignore_ascii_case(&self, other: &str) -> bool {
+        if self.0.len() == other.chars().count() {
+            let mut i = 0;
+            for c in other.chars() {
+                if conversions::to_lower(c)[0] as u32 == self.0[i] as u32 || conversions::to_upper(c)[0] as u32 == self.0[i] as u32 {
+                    i += 1;
+                } else {
+                    return false;
+                }
+            }
+            return true;
+        }
+        return false;
+    }
 }
 
 impl fmt::Debug for &OsStr {