From 7d8dfe2fafc703709891c37c7504f63e4e5dbcd0 Mon Sep 17 00:00:00 2001
From: Hodlinator <172445034+hodlinator@users.noreply.github.com>
Date: Thu, 11 Jul 2024 22:38:43 +0200
Subject: [PATCH] refactor: Add base_blob::SetHex(std::string_view)

Also consolidates other SetHex() overloads to call it.
---
 src/uint256.cpp | 34 ++++++++++++----------------------
 src/uint256.h   | 15 +++++++++++++--
 2 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/src/uint256.cpp b/src/uint256.cpp
index 7f81c3c448a9b9..1efcff51e7956a 100644
--- a/src/uint256.cpp
+++ b/src/uint256.cpp
@@ -18,39 +18,31 @@ std::string base_blob<BITS>::GetHex() const
 }
 
 template <unsigned int BITS>
-void base_blob<BITS>::SetHex(const char* psz)
+void base_blob<BITS>::SetHex(std::string_view str)
 {
     std::fill(m_data.begin(), m_data.end(), 0);
 
-    // skip leading spaces
-    while (IsSpace(*psz))
-        psz++;
-
-    // skip 0x
-    if (psz[0] == '0' && ToLower(psz[1]) == 'x')
-        psz += 2;
+    str = util::LeftTrimStringView(str);
+    str = util::RemovePrefixView(str, "0x");
 
     // hex string to uint
     size_t digits = 0;
-    while (::HexDigit(psz[digits]) != -1)
-        digits++;
+    for (const char c : str) {
+        if (::HexDigit(c) == -1)
+            break;
+        ++digits;
+    }
     unsigned char* p1 = m_data.data();
     unsigned char* pend = p1 + WIDTH;
     while (digits > 0 && p1 < pend) {
-        *p1 = ::HexDigit(psz[--digits]);
+        *p1 = ::HexDigit(str[--digits]);
         if (digits > 0) {
-            *p1 |= ((unsigned char)::HexDigit(psz[--digits]) << 4);
+            *p1 |= ((unsigned char)::HexDigit(str[--digits]) << 4);
             p1++;
         }
     }
 }
 
-template <unsigned int BITS>
-void base_blob<BITS>::SetHex(const std::string& str)
-{
-    SetHex(str.c_str());
-}
-
 template <unsigned int BITS>
 std::string base_blob<BITS>::ToString() const
 {
@@ -60,14 +52,12 @@ std::string base_blob<BITS>::ToString() const
 // Explicit instantiations for base_blob<160>
 template std::string base_blob<160>::GetHex() const;
 template std::string base_blob<160>::ToString() const;
-template void base_blob<160>::SetHex(const char*);
-template void base_blob<160>::SetHex(const std::string&);
+template void base_blob<160>::SetHex(std::string_view);
 
 // Explicit instantiations for base_blob<256>
 template std::string base_blob<256>::GetHex() const;
 template std::string base_blob<256>::ToString() const;
-template void base_blob<256>::SetHex(const char*);
-template void base_blob<256>::SetHex(const std::string&);
+template void base_blob<256>::SetHex(std::string_view);
 
 const uint256 uint256::ZERO(0);
 const uint256 uint256::ONE(1);
diff --git a/src/uint256.h b/src/uint256.h
index d35b3a66fa59f0..6e6b387e8b5018 100644
--- a/src/uint256.h
+++ b/src/uint256.h
@@ -58,8 +58,9 @@ class base_blob
     friend constexpr bool operator<(const base_blob& a, const base_blob& b) { return a.Compare(b) < 0; }
 
     std::string GetHex() const;
-    void SetHex(const char* psz);
-    void SetHex(const std::string& str);
+    void SetHex(std::string_view str);
+    inline void SetHex(const char* psz) { SetHex(std::string_view{psz}); }
+    inline void SetHex(const std::string& str) { SetHex(std::string_view{str}); }
     std::string ToString() const;
 
     constexpr const unsigned char* data() const { return m_data.data(); }
@@ -132,5 +133,15 @@ inline uint256 uint256S(const std::string& str)
     rv.SetHex(str);
     return rv;
 }
+/* uint256 from std::string_view.
+ * This is a separate function because the constructor uint256(std::string_view str) can result
+ * in dangerously catching uint256(0) via std::string_view(const char*).
+ */
+inline uint256 uint256S(std::string_view str)
+{
+    uint256 rv;
+    rv.SetHex(str);
+    return rv;
+}
 
 #endif // BITCOIN_UINT256_H