Merge pull request #768 from lioncash/string-view

file_util, vfs: Use std::string_view where applicable

src/common/file_util.cpp

@@ -792,66 +792,80 @@ void SplitFilename83(const std::string& filename, std::array<char, 9>& short_nam
     }
 }
 
-std::vector<std::string> SplitPathComponents(const std::string& filename) {
-    auto copy(filename);
+std::vector<std::string> SplitPathComponents(std::string_view filename) {
+    std::string copy(filename);
     std::replace(copy.begin(), copy.end(), '\\', '/');
     std::vector<std::string> out;
 
-    std::stringstream stream(filename);
+    std::stringstream stream(copy);
     std::string item;
-    while (std::getline(stream, item, '/'))
+    while (std::getline(stream, item, '/')) {
         out.push_back(std::move(item));
+    }
 
     return out;
 }
 
-std::string GetParentPath(const std::string& path) {
-    auto out = path;
-    const auto name_bck_index = out.find_last_of('\\');
-    const auto name_fwd_index = out.find_last_of('/');
+std::string_view GetParentPath(std::string_view path) {
+    const auto name_bck_index = path.rfind('\\');
+    const auto name_fwd_index = path.rfind('/');
     size_t name_index;
-    if (name_bck_index == std::string::npos || name_fwd_index == std::string::npos)
-        name_index = std::min<size_t>(name_bck_index, name_fwd_index);
-    else
-        name_index = std::max<size_t>(name_bck_index, name_fwd_index);
 
-    return out.erase(name_index);
+    if (name_bck_index == std::string_view::npos || name_fwd_index == std::string_view::npos) {
+        name_index = std::min(name_bck_index, name_fwd_index);
+    } else {
+        name_index = std::max(name_bck_index, name_fwd_index);
+    }
+
+    return path.substr(0, name_index);
 }
 
-std::string GetPathWithoutTop(std::string path) {
-    if (path.empty())
-        return "";
+std::string_view GetPathWithoutTop(std::string_view path) {
+    if (path.empty()) {
+        return path;
+    }
+
     while (path[0] == '\\' || path[0] == '/') {
-        path = path.substr(1);
-        if (path.empty())
-            return "";
+        path.remove_suffix(1);
+        if (path.empty()) {
+            return path;
+        }
     }
-    const auto name_bck_index = path.find_first_of('\\');
-    const auto name_fwd_index = path.find_first_of('/');
+
+    const auto name_bck_index = path.find('\\');
+    const auto name_fwd_index = path.find('/');
     return path.substr(std::min(name_bck_index, name_fwd_index) + 1);
 }
 
-std::string GetFilename(std::string path) {
-    std::replace(path.begin(), path.end(), '\\', '/');
-    auto name_index = path.find_last_of('/');
-    if (name_index == std::string::npos)
-        return "";
+std::string_view GetFilename(std::string_view path) {
+    const auto name_index = path.find_last_of("\\/");
+
+    if (name_index == std::string_view::npos) {
+        return {};
+    }
+
     return path.substr(name_index + 1);
 }
 
-std::string GetExtensionFromFilename(const std::string& name) {
-    size_t index = name.find_last_of('.');
-    if (index == std::string::npos)
-        return "";
+std::string_view GetExtensionFromFilename(std::string_view name) {
+    const size_t index = name.rfind('.');
+
+    if (index == std::string_view::npos) {
+        return {};
+    }
 
     return name.substr(index + 1);
 }
 
-std::string RemoveTrailingSlash(const std::string& path) {
-    if (path.empty())
+std::string_view RemoveTrailingSlash(std::string_view path) {
+    if (path.empty()) {
         return path;
-    if (path.back() == '\\' || path.back() == '/')
-        return path.substr(0, path.size() - 1);
+    }
+
+    if (path.back() == '\\' || path.back() == '/') {
+        path.remove_suffix(1);
+        return path;
+    }
 
     return path;
 }

src/common/file_util.h

@@ -9,6 +9,7 @@
 #include <fstream>
 #include <functional>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <vector>
 #include "common/common_types.h"
@@ -151,22 +152,22 @@ void SplitFilename83(const std::string& filename, std::array<char, 9>& short_nam
 
 // Splits the path on '/' or '\' and put the components into a vector
 // i.e. "C:\Users\Yuzu\Documents\save.bin" becomes {"C:", "Users", "Yuzu", "Documents", "save.bin" }
-std::vector<std::string> SplitPathComponents(const std::string& filename);
+std::vector<std::string> SplitPathComponents(std::string_view filename);
 
 // Gets all of the text up to the last '/' or '\' in the path.
-std::string GetParentPath(const std::string& path);
+std::string_view GetParentPath(std::string_view path);
 
 // Gets all of the text after the first '/' or '\' in the path.
-std::string GetPathWithoutTop(std::string path);
+std::string_view GetPathWithoutTop(std::string_view path);
 
 // Gets the filename of the path
-std::string GetFilename(std::string path);
+std::string_view GetFilename(std::string_view path);
 
 // Gets the extension of the filename
-std::string GetExtensionFromFilename(const std::string& name);
+std::string_view GetExtensionFromFilename(std::string_view name);
 
 // Removes the final '/' or '\' if one exists
-std::string RemoveTrailingSlash(const std::string& path);
+std::string_view RemoveTrailingSlash(std::string_view path);
 
 // Creates a new vector containing indices [first, last) from the original.
 template <typename T>

src/core/file_sys/vfs.cpp

@@ -13,7 +13,7 @@ namespace FileSys {
 VfsFile::~VfsFile() = default;
 
 std::string VfsFile::GetExtension() const {
-    return FileUtil::GetExtensionFromFilename(GetName());
+    return std::string(FileUtil::GetExtensionFromFilename(GetName()));
 }
 
 VfsDirectory::~VfsDirectory() = default;
@@ -46,64 +46,80 @@ size_t VfsFile::WriteBytes(const std::vector<u8>& data, size_t offset) {
     return Write(data.data(), data.size(), offset);
 }
 
-std::shared_ptr<VfsFile> VfsDirectory::GetFileRelative(const std::string& path) const {
+std::shared_ptr<VfsFile> VfsDirectory::GetFileRelative(std::string_view path) const {
     auto vec = FileUtil::SplitPathComponents(path);
     vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
               vec.end());
-    if (vec.empty())
+    if (vec.empty()) {
         return nullptr;
-    if (vec.size() == 1)
+    }
+
+    if (vec.size() == 1) {
         return GetFile(vec[0]);
+    }
+
     auto dir = GetSubdirectory(vec[0]);
     for (size_t component = 1; component < vec.size() - 1; ++component) {
-        if (dir == nullptr)
+        if (dir == nullptr) {
             return nullptr;
+        }
+
         dir = dir->GetSubdirectory(vec[component]);
     }
-    if (dir == nullptr)
+
+    if (dir == nullptr) {
         return nullptr;
+    }
+
     return dir->GetFile(vec.back());
 }
 
-std::shared_ptr<VfsFile> VfsDirectory::GetFileAbsolute(const std::string& path) const {
-    if (IsRoot())
+std::shared_ptr<VfsFile> VfsDirectory::GetFileAbsolute(std::string_view path) const {
+    if (IsRoot()) {
         return GetFileRelative(path);
+    }
 
     return GetParentDirectory()->GetFileAbsolute(path);
 }
 
-std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryRelative(const std::string& path) const {
+std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryRelative(std::string_view path) const {
     auto vec = FileUtil::SplitPathComponents(path);
     vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
               vec.end());
-    if (vec.empty())
+    if (vec.empty()) {
         // TODO(DarkLordZach): Return this directory if path is '/' or similar. Can't currently
         // because of const-ness
         return nullptr;
+    }
+
     auto dir = GetSubdirectory(vec[0]);
     for (size_t component = 1; component < vec.size(); ++component) {
-        if (dir == nullptr)
+        if (dir == nullptr) {
             return nullptr;
+        }
+
         dir = dir->GetSubdirectory(vec[component]);
     }
+
     return dir;
 }
 
-std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryAbsolute(const std::string& path) const {
-    if (IsRoot())
+std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryAbsolute(std::string_view path) const {
+    if (IsRoot()) {
         return GetDirectoryRelative(path);
+    }
 
     return GetParentDirectory()->GetDirectoryAbsolute(path);
 }
 
-std::shared_ptr<VfsFile> VfsDirectory::GetFile(const std::string& name) const {
+std::shared_ptr<VfsFile> VfsDirectory::GetFile(std::string_view name) const {
     const auto& files = GetFiles();
     const auto iter = std::find_if(files.begin(), files.end(),
                                    [&name](const auto& file1) { return name == file1->GetName(); });
     return iter == files.end() ? nullptr : *iter;
 }
 
-std::shared_ptr<VfsDirectory> VfsDirectory::GetSubdirectory(const std::string& name) const {
+std::shared_ptr<VfsDirectory> VfsDirectory::GetSubdirectory(std::string_view name) const {
     const auto& subs = GetSubdirectories();
     const auto iter = std::find_if(subs.begin(), subs.end(),
                                    [&name](const auto& file1) { return name == file1->GetName(); });
@@ -128,77 +144,96 @@ size_t VfsDirectory::GetSize() const {
     return file_total + subdir_total;
 }
 
-std::shared_ptr<VfsFile> VfsDirectory::CreateFileRelative(const std::string& path) {
+std::shared_ptr<VfsFile> VfsDirectory::CreateFileRelative(std::string_view path) {
     auto vec = FileUtil::SplitPathComponents(path);
     vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
               vec.end());
-    if (vec.empty())
+    if (vec.empty()) {
         return nullptr;
-    if (vec.size() == 1)
+    }
+
+    if (vec.size() == 1) {
         return CreateFile(vec[0]);
+    }
+
     auto dir = GetSubdirectory(vec[0]);
     if (dir == nullptr) {
         dir = CreateSubdirectory(vec[0]);
-        if (dir == nullptr)
+        if (dir == nullptr) {
             return nullptr;
+        }
     }
 
     return dir->CreateFileRelative(FileUtil::GetPathWithoutTop(path));
 }
 
-std::shared_ptr<VfsFile> VfsDirectory::CreateFileAbsolute(const std::string& path) {
-    if (IsRoot())
+std::shared_ptr<VfsFile> VfsDirectory::CreateFileAbsolute(std::string_view path) {
+    if (IsRoot()) {
         return CreateFileRelative(path);
+    }
+
     return GetParentDirectory()->CreateFileAbsolute(path);
 }
 
-std::shared_ptr<VfsDirectory> VfsDirectory::CreateDirectoryRelative(const std::string& path) {
+std::shared_ptr<VfsDirectory> VfsDirectory::CreateDirectoryRelative(std::string_view path) {
     auto vec = FileUtil::SplitPathComponents(path);
     vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
               vec.end());
-    if (vec.empty())
+    if (vec.empty()) {
         return nullptr;
-    if (vec.size() == 1)
+    }
+
+    if (vec.size() == 1) {
         return CreateSubdirectory(vec[0]);
+    }
+
     auto dir = GetSubdirectory(vec[0]);
     if (dir == nullptr) {
         dir = CreateSubdirectory(vec[0]);
-        if (dir == nullptr)
+        if (dir == nullptr) {
             return nullptr;
+        }
     }
+
     return dir->CreateDirectoryRelative(FileUtil::GetPathWithoutTop(path));
 }
 
-std::shared_ptr<VfsDirectory> VfsDirectory::CreateDirectoryAbsolute(const std::string& path) {
-    if (IsRoot())
+std::shared_ptr<VfsDirectory> VfsDirectory::CreateDirectoryAbsolute(std::string_view path) {
+    if (IsRoot()) {
         return CreateDirectoryRelative(path);
+    }
+
     return GetParentDirectory()->CreateDirectoryAbsolute(path);
 }
 
-bool VfsDirectory::DeleteSubdirectoryRecursive(const std::string& name) {
+bool VfsDirectory::DeleteSubdirectoryRecursive(std::string_view name) {
     auto dir = GetSubdirectory(name);
-    if (dir == nullptr)
+    if (dir == nullptr) {
         return false;
+    }
 
     bool success = true;
     for (const auto& file : dir->GetFiles()) {
-        if (!DeleteFile(file->GetName()))
+        if (!DeleteFile(file->GetName())) {
             success = false;
+        }
     }
 
     for (const auto& sdir : dir->GetSubdirectories()) {
-        if (!dir->DeleteSubdirectoryRecursive(sdir->GetName()))
+        if (!dir->DeleteSubdirectoryRecursive(sdir->GetName())) {
             success = false;
+        }
     }
 
     return success;
 }
 
-bool VfsDirectory::Copy(const std::string& src, const std::string& dest) {
+bool VfsDirectory::Copy(std::string_view src, std::string_view dest) {
     const auto f1 = GetFile(src);
     auto f2 = CreateFile(dest);
-    if (f1 == nullptr || f2 == nullptr)
+    if (f1 == nullptr || f2 == nullptr) {
         return false;
+    }
 
     if (!f2->Resize(f1->GetSize())) {
         DeleteFile(dest);
@@ -216,23 +251,23 @@ bool ReadOnlyVfsDirectory::IsReadable() const {
     return true;
 }
 
-std::shared_ptr<VfsDirectory> ReadOnlyVfsDirectory::CreateSubdirectory(const std::string& name) {
+std::shared_ptr<VfsDirectory> ReadOnlyVfsDirectory::CreateSubdirectory(std::string_view name) {
     return nullptr;
 }
 
-std::shared_ptr<VfsFile> ReadOnlyVfsDirectory::CreateFile(const std::string& name) {
+std::shared_ptr<VfsFile> ReadOnlyVfsDirectory::CreateFile(std::string_view name) {
     return nullptr;
 }
 
-bool ReadOnlyVfsDirectory::DeleteSubdirectory(const std::string& name) {
+bool ReadOnlyVfsDirectory::DeleteSubdirectory(std::string_view name) {
     return false;
 }
 
-bool ReadOnlyVfsDirectory::DeleteFile(const std::string& name) {
+bool ReadOnlyVfsDirectory::DeleteFile(std::string_view name) {
     return false;
 }
 
-bool ReadOnlyVfsDirectory::Rename(const std::string& name) {
+bool ReadOnlyVfsDirectory::Rename(std::string_view name) {
     return false;
 }
 } // namespace FileSys

src/core/file_sys/vfs.h

@@ -6,11 +6,11 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <vector>
 #include "boost/optional.hpp"
 #include "common/common_types.h"
-#include "common/file_util.h"
 
 namespace FileSys {
 struct VfsFile;
@@ -112,7 +112,7 @@ struct VfsFile : NonCopyable {
     }
 
     // Renames the file to name. Returns whether or not the operation was successsful.
-    virtual bool Rename(const std::string& name) = 0;
+    virtual bool Rename(std::string_view name) = 0;
 };
 
 // A class representing a directory in an abstract filesystem.
@@ -121,27 +121,27 @@ struct VfsDirectory : NonCopyable {
 
     // Retrives the file located at path as if the current directory was root. Returns nullptr if
     // not found.
-    virtual std::shared_ptr<VfsFile> GetFileRelative(const std::string& path) const;
+    virtual std::shared_ptr<VfsFile> GetFileRelative(std::string_view path) const;
     // Calls GetFileRelative(path) on the root of the current directory.
-    virtual std::shared_ptr<VfsFile> GetFileAbsolute(const std::string& path) const;
+    virtual std::shared_ptr<VfsFile> GetFileAbsolute(std::string_view path) const;
 
     // Retrives the directory located at path as if the current directory was root. Returns nullptr
     // if not found.
-    virtual std::shared_ptr<VfsDirectory> GetDirectoryRelative(const std::string& path) const;
+    virtual std::shared_ptr<VfsDirectory> GetDirectoryRelative(std::string_view path) const;
     // Calls GetDirectoryRelative(path) on the root of the current directory.
-    virtual std::shared_ptr<VfsDirectory> GetDirectoryAbsolute(const std::string& path) const;
+    virtual std::shared_ptr<VfsDirectory> GetDirectoryAbsolute(std::string_view path) const;
 
     // Returns a vector containing all of the files in this directory.
     virtual std::vector<std::shared_ptr<VfsFile>> GetFiles() const = 0;
     // Returns the file with filename matching name. Returns nullptr if directory dosen't have a
     // file with name.
-    virtual std::shared_ptr<VfsFile> GetFile(const std::string& name) const;
+    virtual std::shared_ptr<VfsFile> GetFile(std::string_view name) const;
 
     // Returns a vector containing all of the subdirectories in this directory.
     virtual std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const = 0;
     // Returns the directory with name matching name. Returns nullptr if directory dosen't have a
     // directory with name.
-    virtual std::shared_ptr<VfsDirectory> GetSubdirectory(const std::string& name) const;
+    virtual std::shared_ptr<VfsDirectory> GetSubdirectory(std::string_view name) const;
 
     // Returns whether or not the directory can be written to.
     virtual bool IsWritable() const = 0;
@@ -161,53 +161,56 @@ struct VfsDirectory : NonCopyable {
 
     // Creates a new subdirectory with name name. Returns a pointer to the new directory or nullptr
     // if the operation failed.
-    virtual std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) = 0;
+    virtual std::shared_ptr<VfsDirectory> CreateSubdirectory(std::string_view name) = 0;
     // Creates a new file with name name. Returns a pointer to the new file or nullptr if the
     // operation failed.
-    virtual std::shared_ptr<VfsFile> CreateFile(const std::string& name) = 0;
+    virtual std::shared_ptr<VfsFile> CreateFile(std::string_view name) = 0;
 
     // Creates a new file at the path relative to this directory. Also creates directories if
     // they do not exist and is supported by this implementation. Returns nullptr on any failure.
-    virtual std::shared_ptr<VfsFile> CreateFileRelative(const std::string& path);
+    virtual std::shared_ptr<VfsFile> CreateFileRelative(std::string_view path);
 
     // Creates a new file at the path relative to root of this directory. Also creates directories
     // if they do not exist and is supported by this implementation. Returns nullptr on any failure.
-    virtual std::shared_ptr<VfsFile> CreateFileAbsolute(const std::string& path);
+    virtual std::shared_ptr<VfsFile> CreateFileAbsolute(std::string_view path);
 
     // Creates a new directory at the path relative to this directory. Also creates directories if
     // they do not exist and is supported by this implementation. Returns nullptr on any failure.
-    virtual std::shared_ptr<VfsDirectory> CreateDirectoryRelative(const std::string& path);
+    virtual std::shared_ptr<VfsDirectory> CreateDirectoryRelative(std::string_view path);
 
     // Creates a new directory at the path relative to root of this directory. Also creates
     // directories if they do not exist and is supported by this implementation. Returns nullptr on
     // any failure.
-    virtual std::shared_ptr<VfsDirectory> CreateDirectoryAbsolute(const std::string& path);
+    virtual std::shared_ptr<VfsDirectory> CreateDirectoryAbsolute(std::string_view path);
 
     // Deletes the subdirectory with name and returns true on success.
-    virtual bool DeleteSubdirectory(const std::string& name) = 0;
+    virtual bool DeleteSubdirectory(std::string_view name) = 0;
     // Deletes all subdirectories and files of subdirectory with name recirsively and then deletes
     // the subdirectory. Returns true on success.
-    virtual bool DeleteSubdirectoryRecursive(const std::string& name);
+    virtual bool DeleteSubdirectoryRecursive(std::string_view name);
     // Returnes whether or not the file with name name was deleted successfully.
-    virtual bool DeleteFile(const std::string& name) = 0;
+    virtual bool DeleteFile(std::string_view name) = 0;
 
     // Returns whether or not this directory was renamed to name.
-    virtual bool Rename(const std::string& name) = 0;
+    virtual bool Rename(std::string_view name) = 0;
 
     // Returns whether or not the file with name src was successfully copied to a new file with name
     // dest.
-    virtual bool Copy(const std::string& src, const std::string& dest);
+    virtual bool Copy(std::string_view src, std::string_view dest);
 
     // Interprets the file with name file instead as a directory of type directory.
     // The directory must have a constructor that takes a single argument of type
     // std::shared_ptr<VfsFile>. Allows to reinterpret container files (i.e NCA, zip, XCI, etc) as a
     // subdirectory in one call.
     template <typename Directory>
-    bool InterpretAsDirectory(const std::string& file) {
+    bool InterpretAsDirectory(std::string_view file) {
         auto file_p = GetFile(file);
-        if (file_p == nullptr)
+
+        if (file_p == nullptr) {
             return false;
-        return ReplaceFileWithSubdirectory(file, std::make_shared<Directory>(file_p));
+        }
+
+        return ReplaceFileWithSubdirectory(file_p, std::make_shared<Directory>(file_p));
     }
 
 protected:
@@ -221,10 +224,10 @@ protected:
 struct ReadOnlyVfsDirectory : public VfsDirectory {
     bool IsWritable() const override;
     bool IsReadable() const override;
-    std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) override;
-    std::shared_ptr<VfsFile> CreateFile(const std::string& name) override;
-    bool DeleteSubdirectory(const std::string& name) override;
-    bool DeleteFile(const std::string& name) override;
-    bool Rename(const std::string& name) override;
+    std::shared_ptr<VfsDirectory> CreateSubdirectory(std::string_view name) override;
+    std::shared_ptr<VfsFile> CreateFile(std::string_view name) override;
+    bool DeleteSubdirectory(std::string_view name) override;
+    bool DeleteFile(std::string_view name) override;
+    bool Rename(std::string_view name) override;
 };
 } // namespace FileSys

src/core/file_sys/vfs_offset.cpp

@@ -80,7 +80,7 @@ size_t OffsetVfsFile::WriteBytes(const std::vector<u8>& data, size_t r_offset) {
     return file->Write(data.data(), TrimToFit(data.size(), r_offset), offset + r_offset);
 }
 
-bool OffsetVfsFile::Rename(const std::string& name) {
+bool OffsetVfsFile::Rename(std::string_view name) {
     return file->Rename(name);
 }
 

src/core/file_sys/vfs_offset.h

@@ -4,6 +4,9 @@
 
 #pragma once
 
+#include <memory>
+#include <string_view>
+
 #include "core/file_sys/vfs.h"
 
 namespace FileSys {
@@ -30,7 +33,7 @@ struct OffsetVfsFile : public VfsFile {
     bool WriteByte(u8 data, size_t offset) override;
     size_t WriteBytes(const std::vector<u8>& data, size_t offset) override;
 
-    bool Rename(const std::string& name) override;
+    bool Rename(std::string_view name) override;
 
     size_t GetOffset() const;
 

src/core/file_sys/vfs_real.cpp

@@ -72,12 +72,15 @@ size_t RealVfsFile::Write(const u8* data, size_t length, size_t offset) {
     return backing.WriteBytes(data, length);
 }
 
-bool RealVfsFile::Rename(const std::string& name) {
-    const auto out = FileUtil::Rename(GetName(), name);
-    path = parent_path + DIR_SEP + name;
+bool RealVfsFile::Rename(std::string_view name) {
+    std::string name_str(name.begin(), name.end());
+    const auto out = FileUtil::Rename(GetName(), name_str);
+
+    path = (parent_path + DIR_SEP).append(name);
     path_components = parent_components;
-    path_components.push_back(name);
+    path_components.push_back(std::move(name_str));
     backing = FileUtil::IOFile(path, PermissionsToCharArray(perms).c_str());
+
     return out;
 }
 
@@ -135,36 +138,54 @@ std::shared_ptr<VfsDirectory> RealVfsDirectory::GetParentDirectory() const {
     return std::make_shared<RealVfsDirectory>(parent_path, perms);
 }
 
-std::shared_ptr<VfsDirectory> RealVfsDirectory::CreateSubdirectory(const std::string& name) {
-    if (!FileUtil::CreateDir(path + DIR_SEP + name))
+std::shared_ptr<VfsDirectory> RealVfsDirectory::CreateSubdirectory(std::string_view name) {
+    const std::string subdir_path = (path + DIR_SEP).append(name);
+
+    if (!FileUtil::CreateDir(subdir_path)) {
         return nullptr;
-    subdirectories.emplace_back(std::make_shared<RealVfsDirectory>(path + DIR_SEP + name, perms));
+    }
+
+    subdirectories.emplace_back(std::make_shared<RealVfsDirectory>(subdir_path, perms));
     return subdirectories.back();
 }
 
-std::shared_ptr<VfsFile> RealVfsDirectory::CreateFile(const std::string& name) {
-    if (!FileUtil::CreateEmptyFile(path + DIR_SEP + name))
+std::shared_ptr<VfsFile> RealVfsDirectory::CreateFile(std::string_view name) {
+    const std::string file_path = (path + DIR_SEP).append(name);
+
+    if (!FileUtil::CreateEmptyFile(file_path)) {
         return nullptr;
-    files.emplace_back(std::make_shared<RealVfsFile>(path + DIR_SEP + name, perms));
+    }
+
+    files.emplace_back(std::make_shared<RealVfsFile>(file_path, perms));
     return files.back();
 }
 
-bool RealVfsDirectory::DeleteSubdirectory(const std::string& name) {
-    return FileUtil::DeleteDirRecursively(path + DIR_SEP + name);
+bool RealVfsDirectory::DeleteSubdirectory(std::string_view name) {
+    const std::string subdir_path = (path + DIR_SEP).append(name);
+
+    return FileUtil::DeleteDirRecursively(subdir_path);
 }
 
-bool RealVfsDirectory::DeleteFile(const std::string& name) {
-    auto file = GetFile(name);
-    if (file == nullptr)
+bool RealVfsDirectory::DeleteFile(std::string_view name) {
+    const auto file = GetFile(name);
+
+    if (file == nullptr) {
         return false;
+    }
+
     files.erase(std::find(files.begin(), files.end(), file));
+
     auto real_file = std::static_pointer_cast<RealVfsFile>(file);
     real_file->Close();
-    return FileUtil::Delete(path + DIR_SEP + name);
+
+    const std::string file_path = (path + DIR_SEP).append(name);
+    return FileUtil::Delete(file_path);
 }
 
-bool RealVfsDirectory::Rename(const std::string& name) {
-    return FileUtil::Rename(path, parent_path + DIR_SEP + name);
+bool RealVfsDirectory::Rename(std::string_view name) {
+    const std::string new_name = (parent_path + DIR_SEP).append(name);
+
+    return FileUtil::Rename(path, new_name);
 }
 
 bool RealVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {

src/core/file_sys/vfs_real.h

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <string_view>
+
 #include "common/file_util.h"
 #include "core/file_sys/mode.h"
 #include "core/file_sys/vfs.h"
@@ -24,7 +26,7 @@ struct RealVfsFile : public VfsFile {
     bool IsReadable() const override;
     size_t Read(u8* data, size_t length, size_t offset) const override;
     size_t Write(const u8* data, size_t length, size_t offset) override;
-    bool Rename(const std::string& name) override;
+    bool Rename(std::string_view name) override;
 
 private:
     bool Close();
@@ -47,11 +49,11 @@ struct RealVfsDirectory : public VfsDirectory {
     bool IsReadable() const override;
     std::string GetName() const override;
     std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
-    std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) override;
-    std::shared_ptr<VfsFile> CreateFile(const std::string& name) override;
-    bool DeleteSubdirectory(const std::string& name) override;
-    bool DeleteFile(const std::string& name) override;
-    bool Rename(const std::string& name) override;
+    std::shared_ptr<VfsDirectory> CreateSubdirectory(std::string_view name) override;
+    std::shared_ptr<VfsFile> CreateFile(std::string_view name) override;
+    bool DeleteSubdirectory(std::string_view name) override;
+    bool DeleteFile(std::string_view name) override;
+    bool Rename(std::string_view name) override;
 
 protected:
     bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;

src/core/hle/service/filesystem/filesystem.cpp

@@ -24,7 +24,7 @@ namespace Service::FileSystem {
 constexpr u64 EMULATED_SD_REPORTED_SIZE = 32000000000;
 
 static FileSys::VirtualDir GetDirectoryRelativeWrapped(FileSys::VirtualDir base,
-                                                       const std::string& dir_name) {
+                                                       std::string_view dir_name) {
     if (dir_name.empty() || dir_name == "." || dir_name == "/" || dir_name == "\\")
         return base;
 

src/core/loader/loader.cpp

@@ -49,7 +49,8 @@ FileType GuessFromFilename(const std::string& name) {
     if (name == "main")
         return FileType::DeconstructedRomDirectory;
 
-    const std::string extension = Common::ToLower(FileUtil::GetExtensionFromFilename(name));
+    const std::string extension =
+        Common::ToLower(std::string(FileUtil::GetExtensionFromFilename(name)));
 
     if (extension == "elf")
         return FileType::ELF;