refactor: use string_view to pass string literals to Parse{Hash,Hex}

as string_view is optimized to be trivially copiable, and in these use cases we
only perform read operations on the passed object.

These utility methods are called by quite a few RPCs and tests, as well as by each other.

$ git grep "ParseHashV\|ParseHashO\|ParseHexV\|ParseHexO" | wc -l
61

1 files changed, 5 insertions, 4 deletions

diff --git a/src/rpc/util.h b/src/rpc/util.h
index 392540ffad..addf9000d0 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -26,6 +26,7 @@
 #include <map>
 #include <optional>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <utility>
 #include <variant>
@@ -91,10 +92,10 @@ void RPCTypeCheckObj(const UniValue& o,
  * Utilities: convert hex-encoded Values
  * (throws error if not hex).
  */
-uint256 ParseHashV(const UniValue& v, std::string strName);
-uint256 ParseHashO(const UniValue& o, std::string strKey);
-std::vector<unsigned char> ParseHexV(const UniValue& v, std::string strName);
-std::vector<unsigned char> ParseHexO(const UniValue& o, std::string strKey);
+uint256 ParseHashV(const UniValue& v, std::string_view name);
+uint256 ParseHashO(const UniValue& o, std::string_view strKey);
+std::vector<unsigned char> ParseHexV(const UniValue& v, std::string_view name);
+std::vector<unsigned char> ParseHexO(const UniValue& o, std::string_view strKey);
 
 /**
  * Validate and return a CAmount from a UniValue number or string.