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author | Vitaly Novichkov <admin@wohlnet.ru> | 2018-06-24 21:48:02 +0300 |
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committer | Vitaly Novichkov <admin@wohlnet.ru> | 2018-06-24 21:48:02 +0300 |
commit | e3a353a6b84b47ad4204b110249bc74b16554985 (patch) | |
tree | 2dbc8cc9489557d7136a83b88905bbf52db91d07 /src/file_reader.hpp | |
parent | aaa70d5425a6c3130daa34053bd17d9165f571db (diff) | |
parent | 76eb1a12ef6e6a3f8c7f6c0a226fc5b35dd99536 (diff) | |
download | libADLMIDI-e3a353a6b84b47ad4204b110249bc74b16554985.tar.gz libADLMIDI-e3a353a6b84b47ad4204b110249bc74b16554985.tar.bz2 libADLMIDI-e3a353a6b84b47ad4204b110249bc74b16554985.zip |
Merge branch 'master' into stable
Diffstat (limited to 'src/file_reader.hpp')
-rw-r--r-- | src/file_reader.hpp | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/src/file_reader.hpp b/src/file_reader.hpp new file mode 100644 index 0000000..7d13262 --- /dev/null +++ b/src/file_reader.hpp @@ -0,0 +1,300 @@ +/* + * FileAndMemoryReader - a tiny helper to utify file reading from a disk and memory block + * + * Copyright (c) 2015-2018 Vitaly Novichkov <admin@wohlnet.ru> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#pragma once +#ifndef FILE_AND_MEM_READER_HHHH +#define FILE_AND_MEM_READER_HHHH + +#include <string> // std::string +#include <cstdio> // std::fopen, std::fread, std::fseek, std::ftell, std::fclose, std::feof +#include <stdint.h> // uint*_t +#include <stddef.h> // size_t and friends +#ifdef _WIN32 +#define NOMINMAX 1 +#include <cstring> // std::strlen +#include <windows.h> // MultiByteToWideChar +#endif + +/** + * @brief A little class gives able to read filedata from disk and also from a memory segment + */ +class FileAndMemReader +{ + //! Currently loaded filename (empty for a memory blocks) + std::string m_file_name; + //! File reader descriptor + std::FILE *m_fp; + + //! Memory pointer descriptor + const void *m_mp; + //! Size of memory block + size_t m_mp_size; + //! Cursor position in the memory block + size_t m_mp_tell; + +public: + /** + * @brief Relation direction + */ + enum relTo + { + //! At begin position + SET = SEEK_SET, + //! At current position + CUR = SEEK_CUR, + //! At end position + END = SEEK_END + }; + + /** + * @brief C.O.: It's a constructor! + */ + FileAndMemReader() : + m_fp(NULL), + m_mp(NULL), + m_mp_size(0), + m_mp_tell(0) + {} + + /** + * @brief C.O.: It's a destructor! + */ + ~FileAndMemReader() + { + close(); + } + + /** + * @brief Open file from a disk + * @param path Path to the file in UTF-8 (even on Windows!) + */ + void openFile(const char *path) + { + if(m_fp) + this->close();//Close previously opened file first! +#if !defined(_WIN32) || defined(__WATCOMC__) + m_fp = std::fopen(path, "rb"); +#else + wchar_t widePath[MAX_PATH]; + int size = MultiByteToWideChar(CP_UTF8, 0, path, static_cast<int>(std::strlen(path)), widePath, MAX_PATH); + widePath[size] = '\0'; + m_fp = _wfopen(widePath, L"rb"); +#endif + m_file_name = path; + m_mp = NULL; + m_mp_size = 0; + m_mp_tell = 0; + } + + /** + * @brief Open file from memory block + * @param mem Pointer to the memory block + * @param lenght Size of given block + */ + void openData(const void *mem, size_t lenght) + { + if(m_fp) + this->close();//Close previously opened file first! + m_fp = NULL; + m_mp = mem; + m_mp_size = lenght; + m_mp_tell = 0; + } + + /** + * @brief Seek to given position + * @param pos Offset or position + * @param rel_to Relation (at begin, at current, or at end) + */ + void seek(long pos, int rel_to) + { + if(!this->isValid()) + return; + + if(m_fp)//If a file + { + std::fseek(m_fp, pos, rel_to); + } + else//If a memory block + { + switch(rel_to) + { + case SET: + m_mp_tell = static_cast<size_t>(pos); + break; + + case END: + m_mp_tell = m_mp_size - static_cast<size_t>(pos); + break; + + case CUR: + m_mp_tell = m_mp_tell + static_cast<size_t>(pos); + break; + } + + if(m_mp_tell > m_mp_size) + m_mp_tell = m_mp_size; + } + } + + /** + * @brief Seek to given position (unsigned integer 64 as relation. Negative values not supported) + * @param pos Offset or position + * @param rel_to Relation (at begin, at current, or at end) + */ + inline void seeku(uint64_t pos, int rel_to) + { + this->seek(static_cast<long>(pos), rel_to); + } + + /** + * @brief Read the buffer from a file + * @param buf Pointer to the destination memory block + * @param num Number of elements + * @param size Size of one element + * @return Size + */ + size_t read(void *buf, size_t num, size_t size) + { + if(!this->isValid()) + return 0; + if(m_fp) + return std::fread(buf, num, size, m_fp); + else + { + size_t pos = 0; + size_t maxSize = static_cast<size_t>(size * num); + + while((pos < maxSize) && (m_mp_tell < m_mp_size)) + { + reinterpret_cast<uint8_t *>(buf)[pos] = reinterpret_cast<const uint8_t *>(m_mp)[m_mp_tell]; + m_mp_tell++; + pos++; + } + + return pos / num; + } + } + + /** + * @brief Get one byte and seek forward + * @return Readed byte or EOF (a.k.a. -1) + */ + int getc() + { + if(!this->isValid()) + return -1; + if(m_fp)//If a file + { + return std::getc(m_fp); + } + else //If a memory block + { + if(m_mp_tell >= m_mp_size) + return -1; + int x = reinterpret_cast<const uint8_t *>(m_mp)[m_mp_tell]; + m_mp_tell++; + return x; + } + } + + /** + * @brief Returns current offset of cursor in a file + * @return Offset position + */ + size_t tell() + { + if(!this->isValid()) + return 0; + if(m_fp)//If a file + return static_cast<size_t>(std::ftell(m_fp)); + else//If a memory block + return m_mp_tell; + } + + /** + * @brief Close the file + */ + void close() + { + if(m_fp) + std::fclose(m_fp); + + m_fp = NULL; + m_mp = NULL; + m_mp_size = 0; + m_mp_tell = 0; + } + + /** + * @brief Is file instance valid + * @return true if vaild + */ + bool isValid() + { + return (m_fp) || (m_mp); + } + + /** + * @brief Is End Of File? + * @return true if end of file was reached + */ + bool eof() + { + if(!this->isValid()) + return true; + if(m_fp) + return (std::feof(m_fp) != 0); + else + return m_mp_tell >= m_mp_size; + } + + /** + * @brief Get a current file name + * @return File name of currently loaded file + */ + const std::string &fileName() + { + return m_file_name; + } + + /** + * @brief Retrieve file size + * @return Size of file in bytes + */ + size_t fileSize() + { + if(!this->isValid()) + return 0; + if(!m_fp) + return m_mp_size; //Size of memory block is well known + size_t old_pos = this->tell(); + seek(0l, FileAndMemReader::END); + size_t file_size = this->tell(); + seek(static_cast<long>(old_pos), FileAndMemReader::SET); + return file_size; + } +}; + +#endif /* FILE_AND_MEM_READER_HHHH */ |