From 2c049ae06dbbdfff7542c23ca4d748879f4beb71 Mon Sep 17 00:00:00 2001 From: FearlessTobi Date: Thu, 18 Jan 2024 23:08:37 +0100 Subject: fs: Add path class --- src/core/file_sys/fs_string_util.h | 241 +++++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 src/core/file_sys/fs_string_util.h (limited to 'src/core/file_sys/fs_string_util.h') diff --git a/src/core/file_sys/fs_string_util.h b/src/core/file_sys/fs_string_util.h new file mode 100644 index 000000000..68114e72c --- /dev/null +++ b/src/core/file_sys/fs_string_util.h @@ -0,0 +1,241 @@ +// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project +// SPDX-License-Identifier: GPL-2.0-or-later + +#pragma once + +#include "common/assert.h" + +namespace FileSys { + +template +constexpr int Strlen(const T* str) { + ASSERT(str != nullptr); + + int length = 0; + while (*str++) { + ++length; + } + + return length; +} + +template +constexpr int Strnlen(const T* str, int count) { + ASSERT(str != nullptr); + ASSERT(count >= 0); + + int length = 0; + while (count-- && *str++) { + ++length; + } + + return length; +} + +template +constexpr int Strncmp(const T* lhs, const T* rhs, int count) { + ASSERT(lhs != nullptr); + ASSERT(rhs != nullptr); + ASSERT(count >= 0); + + if (count == 0) { + return 0; + } + + T l, r; + do { + l = *(lhs++); + r = *(rhs++); + } while (l && (l == r) && (--count)); + + return l - r; +} + +template +static constexpr int Strlcpy(T* dst, const T* src, int count) { + ASSERT(dst != nullptr); + ASSERT(src != nullptr); + + const T* cur = src; + if (count > 0) { + while ((--count) && *cur) { + *(dst++) = *(cur++); + } + *dst = 0; + } + + while (*cur) { + cur++; + } + + return static_cast(cur - src); +} + +/* std::size() does not support zero-size C arrays. We're fixing that. */ +template +constexpr auto size(const C& c) -> decltype(c.size()) { + return std::size(c); +} + +template +constexpr std::size_t size(const C& c) { + if constexpr (sizeof(C) == 0) { + return 0; + } else { + return std::size(c); + } +} + +enum CharacterEncodingResult { + CharacterEncodingResult_Success = 0, + CharacterEncodingResult_InsufficientLength = 1, + CharacterEncodingResult_InvalidFormat = 2, +}; + +namespace impl { + +class CharacterEncodingHelper { +public: + static constexpr int8_t Utf8NBytesInnerTable[0x100 + 1] = { + -1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 7, 8, + }; + + static constexpr char GetUtf8NBytes(size_t i) { + return static_cast(Utf8NBytesInnerTable[1 + i]); + } +}; + +} // namespace impl + +constexpr inline CharacterEncodingResult ConvertCharacterUtf8ToUtf32(u32* dst, const char* src) { + /* Check pre-conditions. */ + ASSERT(dst != nullptr); + ASSERT(src != nullptr); + + /* Perform the conversion. */ + const auto* p = src; + switch (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[0]))) { + case 1: + *dst = static_cast(p[0]); + return CharacterEncodingResult_Success; + case 2: + if ((static_cast(p[0]) & 0x1E) != 0) { + if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[1])) == + 0) { + *dst = (static_cast(p[0] & 0x1F) << 6) | (static_cast(p[1] & 0x3F) << 0); + return CharacterEncodingResult_Success; + } + } + break; + case 3: + if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[1])) == 0 && + impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[2])) == 0) { + const u32 c = (static_cast(p[0] & 0xF) << 12) | + (static_cast(p[1] & 0x3F) << 6) | + (static_cast(p[2] & 0x3F) << 0); + if ((c & 0xF800) != 0 && (c & 0xF800) != 0xD800) { + *dst = c; + return CharacterEncodingResult_Success; + } + } + return CharacterEncodingResult_InvalidFormat; + case 4: + if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[1])) == 0 && + impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[2])) == 0 && + impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[3])) == 0) { + const u32 c = + (static_cast(p[0] & 0x7) << 18) | (static_cast(p[1] & 0x3F) << 12) | + (static_cast(p[2] & 0x3F) << 6) | (static_cast(p[3] & 0x3F) << 0); + if (c >= 0x10000 && c < 0x110000) { + *dst = c; + return CharacterEncodingResult_Success; + } + } + return CharacterEncodingResult_InvalidFormat; + default: + break; + } + + /* We failed to convert. */ + return CharacterEncodingResult_InvalidFormat; +} + +constexpr inline CharacterEncodingResult PickOutCharacterFromUtf8String(char* dst, + const char** str) { + /* Check pre-conditions. */ + ASSERT(dst != nullptr); + ASSERT(str != nullptr); + ASSERT(*str != nullptr); + + /* Clear the output. */ + dst[0] = 0; + dst[1] = 0; + dst[2] = 0; + dst[3] = 0; + + /* Perform the conversion. */ + const auto* p = *str; + u32 c = static_cast(*p); + switch (impl::CharacterEncodingHelper::GetUtf8NBytes(c)) { + case 1: + dst[0] = (*str)[0]; + ++(*str); + break; + case 2: + if ((p[0] & 0x1E) != 0) { + if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[1])) == + 0) { + c = (static_cast(p[0] & 0x1F) << 6) | (static_cast(p[1] & 0x3F) << 0); + dst[0] = (*str)[0]; + dst[1] = (*str)[1]; + (*str) += 2; + break; + } + } + return CharacterEncodingResult_InvalidFormat; + case 3: + if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[1])) == 0 && + impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[2])) == 0) { + c = (static_cast(p[0] & 0xF) << 12) | (static_cast(p[1] & 0x3F) << 6) | + (static_cast(p[2] & 0x3F) << 0); + if ((c & 0xF800) != 0 && (c & 0xF800) != 0xD800) { + dst[0] = (*str)[0]; + dst[1] = (*str)[1]; + dst[2] = (*str)[2]; + (*str) += 3; + break; + } + } + return CharacterEncodingResult_InvalidFormat; + case 4: + if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[1])) == 0 && + impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[2])) == 0 && + impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast(p[3])) == 0) { + c = (static_cast(p[0] & 0x7) << 18) | (static_cast(p[1] & 0x3F) << 12) | + (static_cast(p[2] & 0x3F) << 6) | (static_cast(p[3] & 0x3F) << 0); + if (c >= 0x10000 && c < 0x110000) { + dst[0] = (*str)[0]; + dst[1] = (*str)[1]; + dst[2] = (*str)[2]; + dst[3] = (*str)[3]; + (*str) += 4; + break; + } + } + return CharacterEncodingResult_InvalidFormat; + default: + return CharacterEncodingResult_InvalidFormat; + } + + return CharacterEncodingResult_Success; +} + +} // namespace FileSys -- cgit v1.2.3