From e3858e81dcddf10c89529d684b451f244cb365de Mon Sep 17 00:00:00 2001
From: Rubidium <rubidium@openttd.org>
Date: Sun, 20 Apr 2025 23:08:19 +0200
Subject: [PATCH] Codechange: use std::string_view over const std::string& for
 finding files

---
 src/fileio.cpp    | 12 ++++++------
 src/fileio_func.h |  6 +++---
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/fileio.cpp b/src/fileio.cpp
index 3d05b2a3c5..14106c61c0 100644
--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -118,7 +118,7 @@ static void FillValidSearchPaths(bool only_local_path)
  * @param subdir the subdirectory to look in
  * @return true if and only if the file can be opened
  */
-bool FioCheckFileExists(const std::string &filename, Subdirectory subdir)
+bool FioCheckFileExists(std::string_view filename, Subdirectory subdir)
 {
 	auto f = FioFOpenFile(filename, "rb", subdir);
 	return f.has_value();
@@ -141,7 +141,7 @@ bool FileExists(const std::string &filename)
  * @param filename Filename to look for.
  * @return String containing the path if the path was found, else an empty string.
  */
-std::string FioFindFullPath(Subdirectory subdir, const std::string &filename)
+std::string FioFindFullPath(Subdirectory subdir, std::string_view filename)
 {
 	assert(subdir < NUM_SUBDIRS);
 
@@ -180,7 +180,7 @@ std::string FioFindDirectory(Subdirectory subdir)
 	return _personal_dir;
 }
 
-static std::optional<FileHandle> FioFOpenFileSp(const std::string &filename, const char *mode, Searchpath sp, Subdirectory subdir, size_t *filesize)
+static std::optional<FileHandle> FioFOpenFileSp(std::string_view filename, const char *mode, Searchpath sp, Subdirectory subdir, size_t *filesize)
 {
 #if defined(_WIN32)
 	/* fopen is implemented as a define with ellipses for
@@ -195,7 +195,7 @@ static std::optional<FileHandle> FioFOpenFileSp(const std::string &filename, con
 	if (subdir == NO_DIRECTORY) {
 		buf = filename;
 	} else {
-		buf = _searchpaths[sp] + _subdirs[subdir] + filename;
+		buf = fmt::format("{}{}{}", _searchpaths[sp], _subdirs[subdir], filename);
 	}
 
 	auto f = FileHandle::Open(buf, mode);
@@ -239,7 +239,7 @@ static std::optional<FileHandle> FioFOpenFileTar(const TarFileListEntry &entry,
  * @param subdir Subdirectory to open.
  * @return File handle of the opened file, or \c nullptr if the file is not available.
  */
-std::optional<FileHandle> FioFOpenFile(const std::string &filename, const char *mode, Subdirectory subdir, size_t *filesize)
+std::optional<FileHandle> FioFOpenFile(std::string_view filename, const char *mode, Subdirectory subdir, size_t *filesize)
 {
 	std::optional<FileHandle> f = std::nullopt;
 	assert(subdir < NUM_SUBDIRS || subdir == NO_DIRECTORY);
@@ -252,7 +252,7 @@ std::optional<FileHandle> FioFOpenFile(const std::string &filename, const char *
 	/* We can only use .tar in case of data-dir, and read-mode */
 	if (!f.has_value() && mode[0] == 'r' && subdir != NO_DIRECTORY) {
 		/* Filenames in tars are always forced to be lowercase */
-		std::string resolved_name = filename;
+		std::string resolved_name{filename};
 		strtolower(resolved_name);
 
 		/* Resolve ".." */
diff --git a/src/fileio_func.h b/src/fileio_func.h
index 2b65924a33..34a2b2f1a2 100644
--- a/src/fileio_func.h
+++ b/src/fileio_func.h
@@ -13,9 +13,9 @@
 #include "core/enum_type.hpp"
 #include "fileio_type.h"
 
-std::optional<FileHandle> FioFOpenFile(const std::string &filename, const char *mode, Subdirectory subdir, size_t *filesize = nullptr);
-bool FioCheckFileExists(const std::string &filename, Subdirectory subdir);
-std::string FioFindFullPath(Subdirectory subdir, const std::string &filename);
+std::optional<FileHandle> FioFOpenFile(std::string_view filename, const char *mode, Subdirectory subdir, size_t *filesize = nullptr);
+bool FioCheckFileExists(std::string_view filename, Subdirectory subdir);
+std::string FioFindFullPath(Subdirectory subdir, std::string_view filename);
 std::string FioGetDirectory(Searchpath sp, Subdirectory subdir);
 std::string FioFindDirectory(Subdirectory subdir);
 void FioCreateDirectory(const std::string &name);