From 738235574f32690f186e4734636434641093c2ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?H=C3=BCseyin=20ASLIT=C3=9CRK?= <asliturk@hotmail.com>
Date: Wed, 20 May 2020 21:20:43 +0300
Subject: [PATCH] AK: StringUtils, add "convert_to_uint_from_hex" method

New method to convert hex string unsigned integer.
---
 AK/StringUtils.cpp | 32 ++++++++++++++++++++++++++++++++
 AK/StringUtils.h   |  2 +-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/AK/StringUtils.cpp b/AK/StringUtils.cpp
index 7f6c6f4a97..4bd2b7aada 100644
--- a/AK/StringUtils.cpp
+++ b/AK/StringUtils.cpp
@@ -143,6 +143,38 @@ unsigned convert_to_uint(const StringView& str, bool& ok)
     return value;
 }
 
+unsigned convert_to_uint_from_hex(const StringView& str, bool& ok)
+{
+    if (str.is_empty()) {
+        ok = false;
+        return 0;
+    }
+
+    unsigned value = 0;
+    const auto count = str.length();
+
+    for (size_t i = 0; i < count; i++) {
+        char digit = str[i];
+        u8 digit_val;
+
+        if (digit >= '0' && digit <= '9') {
+            digit_val = digit - '0';
+        } else if (digit >= 'a' && digit <= 'f') {
+            digit_val = 10 + (digit - 'a');
+        } else if (digit >= 'A' && digit <= 'F') {
+            digit_val = 10 + (digit - 'A');
+        } else {
+            ok = false;
+            return 0;
+        }
+
+        value = (value << 4) + digit_val;
+    }
+
+    ok = true;
+    return value;
+}
+
 static inline char to_lowercase(char c)
 {
     if (c >= 'A' && c <= 'Z')
diff --git a/AK/StringUtils.h b/AK/StringUtils.h
index f4b433b8ef..7e9007f102 100644
--- a/AK/StringUtils.h
+++ b/AK/StringUtils.h
@@ -41,8 +41,8 @@ namespace StringUtils {
 bool matches(const StringView& str, const StringView& mask, CaseSensitivity = CaseSensitivity::CaseInsensitive);
 int convert_to_int(const StringView&, bool& ok);
 unsigned convert_to_uint(const StringView&, bool& ok);
+unsigned convert_to_uint_from_hex(const StringView&, bool& ok);
 bool equals_ignoring_case(const StringView&, const StringView&);
-
 }
 
 }