From c1d165a8c2678c31aced5e1d46231d9996b0774a Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Mon, 4 Apr 2022 11:08:08 -0400
Subject: [PATCH] Make ParseHex use string_view

---
 src/util/strencodings.cpp | 30 +++++++++++-------------------
 src/util/strencodings.h   |  3 +--
 2 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
index 940fa90da21..f5288eca179 100644
--- a/src/util/strencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -81,32 +81,24 @@ bool IsHexNumber(const std::string& str)
     return (str.size() > starting_location);
 }
 
-std::vector<unsigned char> ParseHex(const char* psz)
+std::vector<unsigned char> ParseHex(std::string_view str)
 {
     // convert hex dump to vector
     std::vector<unsigned char> vch;
-    while (true)
-    {
-        while (IsSpace(*psz))
-            psz++;
-        signed char c = HexDigit(*psz++);
-        if (c == (signed char)-1)
-            break;
-        auto n{uint8_t(c << 4)};
-        c = HexDigit(*psz++);
-        if (c == (signed char)-1)
-            break;
-        n |= c;
-        vch.push_back(n);
+    auto it = str.begin();
+    while (it != str.end() && it + 1 != str.end()) {
+        if (IsSpace(*it)) {
+            ++it;
+            continue;
+        }
+        auto c1 = HexDigit(*(it++));
+        auto c2 = HexDigit(*(it++));
+        if (c1 < 0 || c2 < 0) break;
+        vch.push_back(uint8_t(c1 << 4) | c2);
     }
     return vch;
 }
 
-std::vector<unsigned char> ParseHex(const std::string& str)
-{
-    return ParseHex(str.c_str());
-}
-
 void SplitHostPort(std::string in, uint16_t& portOut, std::string& hostOut)
 {
     size_t colon = in.find_last_of(':');
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
index 1f83fa3ffa6..0e72466fc3a 100644
--- a/src/util/strencodings.h
+++ b/src/util/strencodings.h
@@ -55,8 +55,7 @@ enum class ByteUnit : uint64_t {
 * @return           A new string without unsafe chars
 */
 std::string SanitizeString(const std::string& str, int rule = SAFE_CHARS_DEFAULT);
-std::vector<unsigned char> ParseHex(const char* psz);
-std::vector<unsigned char> ParseHex(const std::string& str);
+std::vector<unsigned char> ParseHex(std::string_view str);
 signed char HexDigit(char c);
 /* Returns true if each character in str is a hex character, and has an even
  * number of hex digits.*/