mirror of
https://github.com/ZDoom/qzdoom.git
synced 2024-12-16 07:21:28 +00:00
301 lines
7.6 KiB
C++
301 lines
7.6 KiB
C++
|
/*
|
||
|
* 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 */
|