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Merge pull request #10729 from liamwhite/windows-is-a-meme

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vfs_real: add file LRU cache for open file limits
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bunnei 2023-06-14 18:32:25 -07:00 committed by GitHub
commit ce0510913a
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2 changed files with 127 additions and 108 deletions
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205
src/core/file_sys/vfs_real.cpp
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@ -25,6 +25,8 @@ namespace FS = Common::FS;
namespace {
constexpr size_t MaxOpenFiles = 512;
constexpr FS::FileAccessMode ModeFlagsToFileAccessMode(Mode mode) {
switch (mode) {
case Mode::Read:
@ -73,28 +75,30 @@ VfsEntryType RealVfsFilesystem::GetEntryType(std::string_view path_) const {
VirtualFile RealVfsFilesystem::OpenFile(std::string_view path_, Mode perms) {
const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
if (const auto weak_iter = cache.find(path); weak_iter != cache.cend()) {
const auto& weak = weak_iter->second;
if (!weak.expired()) {
return std::shared_ptr<RealVfsFile>(new RealVfsFile(*this, weak.lock(), path, perms));
if (auto it = cache.find(path); it != cache.end()) {
if (auto file = it->second.lock(); file) {
return file;
}
}
auto backing = FS::FileOpen(path, ModeFlagsToFileAccessMode(perms), FS::FileType::BinaryFile);
if (!backing) {
if (!FS::Exists(path) || !FS::IsFile(path)) {
return nullptr;
}
cache.insert_or_assign(path, std::move(backing));
auto reference = std::make_unique<FileReference>();
this->InsertReferenceIntoList(*reference);
// Cannot use make_shared as RealVfsFile constructor is private
return std::shared_ptr<RealVfsFile>(new RealVfsFile(*this, backing, path, perms));
auto file =
std::shared_ptr<RealVfsFile>(new RealVfsFile(*this, std::move(reference), path, perms));
cache[path] = file;
return file;
}
VirtualFile RealVfsFilesystem::CreateFile(std::string_view path_, Mode perms) {
const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
cache.erase(path);
// Current usages of CreateFile expect to delete the contents of an existing file.
if (FS::IsFile(path)) {
FS::IOFile temp{path, FS::FileAccessMode::Write, FS::FileType::BinaryFile};
@ -123,51 +127,22 @@ VirtualFile RealVfsFilesystem::CopyFile(std::string_view old_path_, std::string_
VirtualFile RealVfsFilesystem::MoveFile(std::string_view old_path_, std::string_view new_path_) {
const auto old_path = FS::SanitizePath(old_path_, FS::DirectorySeparator::PlatformDefault);
const auto new_path = FS::SanitizePath(new_path_, FS::DirectorySeparator::PlatformDefault);
const auto cached_file_iter = cache.find(old_path);
if (cached_file_iter != cache.cend()) {
auto file = cached_file_iter->second.lock();
if (!cached_file_iter->second.expired()) {
file->Close();
}
if (!FS::RenameFile(old_path, new_path)) {
return nullptr;
}
cache.erase(old_path);
file->Open(new_path, FS::FileAccessMode::Read, FS::FileType::BinaryFile);
if (file->IsOpen()) {
cache.insert_or_assign(new_path, std::move(file));
} else {
LOG_ERROR(Service_FS, "Failed to open path {} in order to re-cache it", new_path);
}
} else {
ASSERT(false);
cache.erase(old_path);
cache.erase(new_path);
if (!FS::RenameFile(old_path, new_path)) {
return nullptr;
}
return OpenFile(new_path, Mode::ReadWrite);
}
bool RealVfsFilesystem::DeleteFile(std::string_view path_) {
const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
const auto cached_iter = cache.find(path);
if (cached_iter != cache.cend()) {
if (!cached_iter->second.expired()) {
cached_iter->second.lock()->Close();
}
cache.erase(path);
}
cache.erase(path);
return FS::RemoveFile(path);
}
VirtualDir RealVfsFilesystem::OpenDirectory(std::string_view path_, Mode perms) {
const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
// Cannot use make_shared as RealVfsDirectory constructor is private
return std::shared_ptr<RealVfsDirectory>(new RealVfsDirectory(*this, path, perms));
}
@ -176,7 +151,6 @@ VirtualDir RealVfsFilesystem::CreateDirectory(std::string_view path_, Mode perms
if (!FS::CreateDirs(path)) {
return nullptr;
}
// Cannot use make_shared as RealVfsDirectory constructor is private
return std::shared_ptr<RealVfsDirectory>(new RealVfsDirectory(*this, path, perms));
}
@ -194,73 +168,102 @@ VirtualDir RealVfsFilesystem::MoveDirectory(std::string_view old_path_,
if (!FS::RenameDir(old_path, new_path)) {
return nullptr;
}
for (auto& kv : cache) {
// If the path in the cache doesn't start with old_path, then bail on this file.
if (kv.first.rfind(old_path, 0) != 0) {
continue;
}
const auto file_old_path =
FS::SanitizePath(kv.first, FS::DirectorySeparator::PlatformDefault);
auto file_new_path = FS::SanitizePath(new_path + '/' + kv.first.substr(old_path.size()),
FS::DirectorySeparator::PlatformDefault);
const auto& cached = cache[file_old_path];
if (cached.expired()) {
continue;
}
auto file = cached.lock();
cache.erase(file_old_path);
file->Open(file_new_path, FS::FileAccessMode::Read, FS::FileType::BinaryFile);
if (file->IsOpen()) {
cache.insert_or_assign(std::move(file_new_path), std::move(file));
} else {
LOG_ERROR(Service_FS, "Failed to open path {} in order to re-cache it", file_new_path);
}
}
return OpenDirectory(new_path, Mode::ReadWrite);
}
bool RealVfsFilesystem::DeleteDirectory(std::string_view path_) {
const auto path = FS::SanitizePath(path_, FS::DirectorySeparator::PlatformDefault);
for (auto& kv : cache) {
// If the path in the cache doesn't start with path, then bail on this file.
if (kv.first.rfind(path, 0) != 0) {
continue;
}
const auto& entry = cache[kv.first];
if (!entry.expired()) {
entry.lock()->Close();
}
cache.erase(kv.first);
}
return FS::RemoveDirRecursively(path);
}
RealVfsFile::RealVfsFile(RealVfsFilesystem& base_, std::shared_ptr<FS::IOFile> backing_,
const std::string& path_, Mode perms_)
: base(base_), backing(std::move(backing_)), path(path_), parent_path(FS::GetParentPath(path_)),
path_components(FS::SplitPathComponents(path_)), perms(perms_) {}
void RealVfsFilesystem::RefreshReference(const std::string& path, Mode perms,
FileReference& reference) {
// Temporarily remove from list.
this->RemoveReferenceFromList(reference);
RealVfsFile::~RealVfsFile() = default;
// Restore file if needed.
if (!reference.file) {
this->EvictSingleReference();
reference.file =
FS::FileOpen(path, ModeFlagsToFileAccessMode(perms), FS::FileType::BinaryFile);
if (reference.file) {
num_open_files++;
}
}
// Reinsert into list.
this->InsertReferenceIntoList(reference);
}
void RealVfsFilesystem::DropReference(std::unique_ptr<FileReference>&& reference) {
// Remove from list.
this->RemoveReferenceFromList(*reference);
// Close the file.
if (reference->file) {
reference->file.reset();
num_open_files--;
}
}
void RealVfsFilesystem::EvictSingleReference() {
if (num_open_files < MaxOpenFiles || open_references.empty()) {
return;
}
// Get and remove from list.
auto& reference = open_references.back();
this->RemoveReferenceFromList(reference);
// Close the file.
if (reference.file) {
reference.file.reset();
num_open_files--;
}
// Reinsert into closed list.
this->InsertReferenceIntoList(reference);
}
void RealVfsFilesystem::InsertReferenceIntoList(FileReference& reference) {
if (reference.file) {
open_references.push_front(reference);
} else {
closed_references.push_front(reference);
}
}
void RealVfsFilesystem::RemoveReferenceFromList(FileReference& reference) {
if (reference.file) {
open_references.erase(open_references.iterator_to(reference));
} else {
closed_references.erase(closed_references.iterator_to(reference));
}
}
RealVfsFile::RealVfsFile(RealVfsFilesystem& base_, std::unique_ptr<FileReference> reference_,
const std::string& path_, Mode perms_)
: base(base_), reference(std::move(reference_)), path(path_),
parent_path(FS::GetParentPath(path_)), path_components(FS::SplitPathComponents(path_)),
perms(perms_) {}
RealVfsFile::~RealVfsFile() {
base.DropReference(std::move(reference));
}
std::string RealVfsFile::GetName() const {
return path_components.back();
}
std::size_t RealVfsFile::GetSize() const {
return backing->GetSize();
base.RefreshReference(path, perms, *reference);
return reference->file ? reference->file->GetSize() : 0;
}
bool RealVfsFile::Resize(std::size_t new_size) {
return backing->SetSize(new_size);
base.RefreshReference(path, perms, *reference);
return reference->file ? reference->file->SetSize(new_size) : false;
}
VirtualDir RealVfsFile::GetContainingDirectory() const {
@ -276,27 +279,25 @@ bool RealVfsFile::IsReadable() const {
}
std::size_t RealVfsFile::Read(u8* data, std::size_t length, std::size_t offset) const {
if (!backing->Seek(static_cast<s64>(offset))) {
base.RefreshReference(path, perms, *reference);
if (!reference->file || !reference->file->Seek(static_cast<s64>(offset))) {
return 0;
}
return backing->ReadSpan(std::span{data, length});
return reference->file->ReadSpan(std::span{data, length});
}
std::size_t RealVfsFile::Write(const u8* data, std::size_t length, std::size_t offset) {
if (!backing->Seek(static_cast<s64>(offset))) {
base.RefreshReference(path, perms, *reference);
if (!reference->file || !reference->file->Seek(static_cast<s64>(offset))) {
return 0;
}
return backing->WriteSpan(std::span{data, length});
return reference->file->WriteSpan(std::span{data, length});
}
bool RealVfsFile::Rename(std::string_view name) {
return base.MoveFile(path, parent_path + '/' + std::string(name)) != nullptr;
}
void RealVfsFile::Close() {
backing->Close();
}
// TODO(DarkLordZach): MSVC would not let me combine the following two functions using 'if
// constexpr' because there is a compile error in the branch not used.

30
src/core/file_sys/vfs_real.h
View File

@ -3,8 +3,9 @@
#pragma once
#include <map>
#include <string_view>
#include <boost/container/flat_map.hpp>
#include "common/intrusive_list.h"
#include "core/file_sys/mode.h"
#include "core/file_sys/vfs.h"
@ -14,6 +15,11 @@ class IOFile;
namespace FileSys {
struct FileReference : public Common::IntrusiveListBaseNode<FileReference> {
std::shared_ptr<Common::FS::IOFile> file{};
};
class RealVfsFile;
class RealVfsFilesystem : public VfsFilesystem {
public:
RealVfsFilesystem();
@ -35,7 +41,21 @@ public:
bool DeleteDirectory(std::string_view path) override;
private:
boost::container::flat_map<std::string, std::weak_ptr<Common::FS::IOFile>> cache;
using ReferenceListType = Common::IntrusiveListBaseTraits<FileReference>::ListType;
std::map<std::string, std::weak_ptr<VfsFile>, std::less<>> cache;
ReferenceListType open_references;
ReferenceListType closed_references;
size_t num_open_files{};
private:
friend class RealVfsFile;
void RefreshReference(const std::string& path, Mode perms, FileReference& reference);
void DropReference(std::unique_ptr<FileReference>&& reference);
void EvictSingleReference();
private:
void InsertReferenceIntoList(FileReference& reference);
void RemoveReferenceFromList(FileReference& reference);
};
// An implementation of VfsFile that represents a file on the user's computer.
@ -57,13 +77,11 @@ public:
bool Rename(std::string_view name) override;
private:
RealVfsFile(RealVfsFilesystem& base, std::shared_ptr<Common::FS::IOFile> backing,
RealVfsFile(RealVfsFilesystem& base, std::unique_ptr<FileReference> reference,
const std::string& path, Mode perms = Mode::Read);
void Close();
RealVfsFilesystem& base;
std::shared_ptr<Common::FS::IOFile> backing;
std::unique_ptr<FileReference> reference;
std::string path;
std::string parent_path;
std::vector<std::string> path_components;