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authorMorph <39850852+Morph1984@users.noreply.github.com>2021-05-26 01:32:56 +0200
committerGitHub <noreply@github.com>2021-05-26 01:32:56 +0200
commit065867e2c24e9856c360fc2d6b9a86c92aedc43e (patch)
tree7964e85ef4f01a3c2b8f44e850f37b384405b930 /src/common/fs/file.h
parentMerge pull request #6349 from german77/suppress_config_warning (diff)
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-rw-r--r--src/common/fs/file.h450
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diff --git a/src/common/fs/file.h b/src/common/fs/file.h
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+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <cstdio>
+#include <filesystem>
+#include <fstream>
+#include <span>
+#include <type_traits>
+#include <vector>
+
+#include "common/concepts.h"
+#include "common/fs/fs_types.h"
+#include "common/fs/fs_util.h"
+
+namespace Common::FS {
+
+enum class SeekOrigin {
+ SetOrigin, // Seeks from the start of the file.
+ CurrentPosition, // Seeks from the current file pointer position.
+ End, // Seeks from the end of the file.
+};
+
+/**
+ * Opens a file stream at path with the specified open mode.
+ *
+ * @param file_stream Reference to file stream
+ * @param path Filesystem path
+ * @param open_mode File stream open mode
+ */
+template <typename FileStream>
+void OpenFileStream(FileStream& file_stream, const std::filesystem::path& path,
+ std::ios_base::openmode open_mode) {
+ file_stream.open(path, open_mode);
+}
+
+#ifdef _WIN32
+template <typename FileStream, typename Path>
+void OpenFileStream(FileStream& file_stream, const Path& path, std::ios_base::openmode open_mode) {
+ if constexpr (IsChar<typename Path::value_type>) {
+ file_stream.open(ToU8String(path), open_mode);
+ } else {
+ file_stream.open(std::filesystem::path{path}, open_mode);
+ }
+}
+#endif
+
+/**
+ * Reads an entire file at path and returns a string of the contents read from the file.
+ * If the filesystem object at path is not a file, this function returns an empty string.
+ *
+ * @param path Filesystem path
+ * @param type File type
+ *
+ * @returns A string of the contents read from the file.
+ */
+[[nodiscard]] std::string ReadStringFromFile(const std::filesystem::path& path, FileType type);
+
+#ifdef _WIN32
+template <typename Path>
+[[nodiscard]] std::string ReadStringFromFile(const Path& path, FileType type) {
+ if constexpr (IsChar<typename Path::value_type>) {
+ return ReadStringFromFile(ToU8String(path), type);
+ } else {
+ return ReadStringFromFile(std::filesystem::path{path}, type);
+ }
+}
+#endif
+
+/**
+ * Writes a string to a file at path and returns the number of characters successfully written.
+ * If an file already exists at path, its contents will be erased.
+ * If the filesystem object at path is not a file, this function returns 0.
+ *
+ * @param path Filesystem path
+ * @param type File type
+ *
+ * @returns Number of characters successfully written.
+ */
+[[nodiscard]] size_t WriteStringToFile(const std::filesystem::path& path, FileType type,
+ std::string_view string);
+
+#ifdef _WIN32
+template <typename Path>
+[[nodiscard]] size_t WriteStringToFile(const Path& path, FileType type, std::string_view string) {
+ if constexpr (IsChar<typename Path::value_type>) {
+ return WriteStringToFile(ToU8String(path), type, string);
+ } else {
+ return WriteStringToFile(std::filesystem::path{path}, type, string);
+ }
+}
+#endif
+
+/**
+ * Appends a string to a file at path and returns the number of characters successfully written.
+ * If a file does not exist at path, WriteStringToFile is called instead.
+ * If the filesystem object at path is not a file, this function returns 0.
+ *
+ * @param path Filesystem path
+ * @param type File type
+ *
+ * @returns Number of characters successfully written.
+ */
+[[nodiscard]] size_t AppendStringToFile(const std::filesystem::path& path, FileType type,
+ std::string_view string);
+
+#ifdef _WIN32
+template <typename Path>
+[[nodiscard]] size_t AppendStringToFile(const Path& path, FileType type, std::string_view string) {
+ if constexpr (IsChar<typename Path::value_type>) {
+ return AppendStringToFile(ToU8String(path), type, string);
+ } else {
+ return AppendStringToFile(std::filesystem::path{path}, type, string);
+ }
+}
+#endif
+
+class IOFile final : NonCopyable {
+public:
+ IOFile();
+
+ explicit IOFile(const std::string& path, FileAccessMode mode,
+ FileType type = FileType::BinaryFile,
+ FileShareFlag flag = FileShareFlag::ShareReadOnly);
+
+ explicit IOFile(std::string_view path, FileAccessMode mode,
+ FileType type = FileType::BinaryFile,
+ FileShareFlag flag = FileShareFlag::ShareReadOnly);
+
+ /**
+ * An IOFile is a lightweight wrapper on C Library file operations.
+ * Automatically closes an open file on the destruction of an IOFile object.
+ *
+ * @param path Filesystem path
+ * @param mode File access mode
+ * @param type File type, default is BinaryFile. Use TextFile to open the file as a text file
+ * @param flag (Windows only) File-share access flag, default is ShareReadOnly
+ */
+ explicit IOFile(const std::filesystem::path& path, FileAccessMode mode,
+ FileType type = FileType::BinaryFile,
+ FileShareFlag flag = FileShareFlag::ShareReadOnly);
+
+ virtual ~IOFile();
+
+ IOFile(IOFile&& other) noexcept;
+ IOFile& operator=(IOFile&& other) noexcept;
+
+ /**
+ * Gets the path of the file.
+ *
+ * @returns The path of the file.
+ */
+ [[nodiscard]] std::filesystem::path GetPath() const;
+
+ /**
+ * Gets the access mode of the file.
+ *
+ * @returns The access mode of the file.
+ */
+ [[nodiscard]] FileAccessMode GetAccessMode() const;
+
+ /**
+ * Gets the type of the file.
+ *
+ * @returns The type of the file.
+ */
+ [[nodiscard]] FileType GetType() const;
+
+ /**
+ * Opens a file at path with the specified file access mode.
+ * This function behaves differently depending on the FileAccessMode.
+ * These behaviors are documented in each enum value of FileAccessMode.
+ *
+ * @param path Filesystem path
+ * @param mode File access mode
+ * @param type File type, default is BinaryFile. Use TextFile to open the file as a text file
+ * @param flag (Windows only) File-share access flag, default is ShareReadOnly
+ */
+ void Open(const std::filesystem::path& path, FileAccessMode mode,
+ FileType type = FileType::BinaryFile,
+ FileShareFlag flag = FileShareFlag::ShareReadOnly);
+
+#ifdef _WIN32
+ template <typename Path>
+ [[nodiscard]] void Open(const Path& path, FileAccessMode mode,
+ FileType type = FileType::BinaryFile,
+ FileShareFlag flag = FileShareFlag::ShareReadOnly) {
+ using ValueType = typename Path::value_type;
+ if constexpr (IsChar<ValueType>) {
+ Open(ToU8String(path), mode, type, flag);
+ } else {
+ Open(std::filesystem::path{path}, mode, type, flag);
+ }
+ }
+#endif
+
+ /// Closes the file if it is opened.
+ void Close();
+
+ /**
+ * Checks whether the file is open.
+ * Use this to check whether the calls to Open() or Close() succeeded.
+ *
+ * @returns True if the file is open, false otherwise.
+ */
+ [[nodiscard]] bool IsOpen() const;
+
+ /**
+ * Helper function which deduces the value type of a contiguous STL container used in ReadSpan.
+ * If T is not a contiguous STL container as defined by the concept IsSTLContainer, this calls
+ * ReadObject and T must be a trivially copyable object.
+ *
+ * See ReadSpan for more details if T is a contiguous container.
+ * See ReadObject for more details if T is a trivially copyable object.
+ *
+ * @tparam T Contiguous container or trivially copyable object
+ *
+ * @param data Container of T::value_type data or reference to object
+ *
+ * @returns Count of T::value_type data or objects successfully read.
+ */
+ template <typename T>
+ [[nodiscard]] size_t Read(T& data) const {
+ if constexpr (IsSTLContainer<T>) {
+ using ContiguousType = typename T::value_type;
+ static_assert(std::is_trivially_copyable_v<ContiguousType>,
+ "Data type must be trivially copyable.");
+ return ReadSpan<ContiguousType>(data);
+ } else {
+ return ReadObject(data) ? 1 : 0;
+ }
+ }
+
+ /**
+ * Helper function which deduces the value type of a contiguous STL container used in WriteSpan.
+ * If T is not a contiguous STL container as defined by the concept IsSTLContainer, this calls
+ * WriteObject and T must be a trivially copyable object.
+ *
+ * See WriteSpan for more details if T is a contiguous container.
+ * See WriteObject for more details if T is a trivially copyable object.
+ *
+ * @tparam T Contiguous container or trivially copyable object
+ *
+ * @param data Container of T::value_type data or const reference to object
+ *
+ * @returns Count of T::value_type data or objects successfully written.
+ */
+ template <typename T>
+ [[nodiscard]] size_t Write(const T& data) const {
+ if constexpr (IsSTLContainer<T>) {
+ using ContiguousType = typename T::value_type;
+ static_assert(std::is_trivially_copyable_v<ContiguousType>,
+ "Data type must be trivially copyable.");
+ return WriteSpan<ContiguousType>(data);
+ } else {
+ static_assert(std::is_trivially_copyable_v<T>, "Data type must be trivially copyable.");
+ return WriteObject(data) ? 1 : 0;
+ }
+ }
+
+ /**
+ * Reads a span of T data from a file sequentially.
+ * This function reads from the current position of the file pointer and
+ * advances it by the (count of T * sizeof(T)) bytes successfully read.
+ *
+ * Failures occur when:
+ * - The file is not open
+ * - The opened file lacks read permissions
+ * - Attempting to read beyond the end-of-file
+ *
+ * @tparam T Data type
+ *
+ * @param data Span of T data
+ *
+ * @returns Count of T data successfully read.
+ */
+ template <typename T>
+ [[nodiscard]] size_t ReadSpan(std::span<T> data) const {
+ static_assert(std::is_trivially_copyable_v<T>, "Data type must be trivially copyable.");
+
+ if (!IsOpen()) {
+ return 0;
+ }
+
+ return std::fread(data.data(), sizeof(T), data.size(), file);
+ }
+
+ /**
+ * Writes a span of T data to a file sequentially.
+ * This function writes from the current position of the file pointer and
+ * advances it by the (count of T * sizeof(T)) bytes successfully written.
+ *
+ * Failures occur when:
+ * - The file is not open
+ * - The opened file lacks write permissions
+ *
+ * @tparam T Data type
+ *
+ * @param data Span of T data
+ *
+ * @returns Count of T data successfully written.
+ */
+ template <typename T>
+ [[nodiscard]] size_t WriteSpan(std::span<const T> data) const {
+ static_assert(std::is_trivially_copyable_v<T>, "Data type must be trivially copyable.");
+
+ if (!IsOpen()) {
+ return 0;
+ }
+
+ return std::fwrite(data.data(), sizeof(T), data.size(), file);
+ }
+
+ /**
+ * Reads a T object from a file sequentially.
+ * This function reads from the current position of the file pointer and
+ * advances it by the sizeof(T) bytes successfully read.
+ *
+ * Failures occur when:
+ * - The file is not open
+ * - The opened file lacks read permissions
+ * - Attempting to read beyond the end-of-file
+ *
+ * @tparam T Data type
+ *
+ * @param object Reference to object
+ *
+ * @returns True if the object is successfully read from the file, false otherwise.
+ */
+ template <typename T>
+ [[nodiscard]] bool ReadObject(T& object) const {
+ static_assert(std::is_trivially_copyable_v<T>, "Data type must be trivially copyable.");
+ static_assert(!std::is_pointer_v<T>, "T must not be a pointer to an object.");
+
+ if (!IsOpen()) {
+ return false;
+ }
+
+ return std::fread(&object, sizeof(T), 1, file) == 1;
+ }
+
+ /**
+ * Writes a T object to a file sequentially.
+ * This function writes from the current position of the file pointer and
+ * advances it by the sizeof(T) bytes successfully written.
+ *
+ * Failures occur when:
+ * - The file is not open
+ * - The opened file lacks write permissions
+ *
+ * @tparam T Data type
+ *
+ * @param object Const reference to object
+ *
+ * @returns True if the object is successfully written to the file, false otherwise.
+ */
+ template <typename T>
+ [[nodiscard]] bool WriteObject(const T& object) const {
+ static_assert(std::is_trivially_copyable_v<T>, "Data type must be trivially copyable.");
+ static_assert(!std::is_pointer_v<T>, "T must not be a pointer to an object.");
+
+ if (!IsOpen()) {
+ return false;
+ }
+
+ return std::fwrite(&object, sizeof(T), 1, file) == 1;
+ }
+
+ /**
+ * Specialized function to read a string of a given length from a file sequentially.
+ * This function writes from the current position of the file pointer and
+ * advances it by the number of characters successfully read.
+ * The size of the returned string may not match length if not all bytes are successfully read.
+ *
+ * @param length Length of the string
+ *
+ * @returns A string read from the file.
+ */
+ [[nodiscard]] std::string ReadString(size_t length) const;
+
+ /**
+ * Specialized function to write a string to a file sequentially.
+ * This function writes from the current position of the file pointer and
+ * advances it by the number of characters successfully written.
+ *
+ * @param string Span of const char backed std::string or std::string_view
+ *
+ * @returns Number of characters successfully written.
+ */
+ [[nodiscard]] size_t WriteString(std::span<const char> string) const;
+
+ /**
+ * Flushes any unwritten buffered data into the file.
+ *
+ * @returns True if the flush was successful, false otherwise.
+ */
+ [[nodiscard]] bool Flush() const;
+
+ /**
+ * Resizes the file to a given size.
+ * If the file is resized to a smaller size, the remainder of the file is discarded.
+ * If the file is resized to a larger size, the new area appears as if zero-filled.
+ *
+ * Failures occur when:
+ * - The file is not open
+ *
+ * @param size File size in bytes
+ *
+ * @returns True if the file resize succeeded, false otherwise.
+ */
+ [[nodiscard]] bool SetSize(u64 size) const;
+
+ /**
+ * Gets the size of the file.
+ *
+ * Failures occur when:
+ * - The file is not open
+ *
+ * @returns The file size in bytes of the file. Returns 0 on failure.
+ */
+ [[nodiscard]] u64 GetSize() const;
+
+ /**
+ * Moves the current position of the file pointer with the specified offset and seek origin.
+ *
+ * @param offset Offset from seek origin
+ * @param origin Seek origin
+ *
+ * @returns True if the file pointer has moved to the specified offset, false otherwise.
+ */
+ [[nodiscard]] bool Seek(s64 offset, SeekOrigin origin = SeekOrigin::SetOrigin) const;
+
+ /**
+ * Gets the current position of the file pointer.
+ *
+ * @returns The current position of the file pointer.
+ */
+ [[nodiscard]] s64 Tell() const;
+
+private:
+ std::filesystem::path file_path;
+ FileAccessMode file_access_mode;
+ FileType file_type;
+
+ std::FILE* file = nullptr;
+};
+
+} // namespace Common::FS