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// license:BSD-3-Clause
// copyright-holders:Aaron Giles
//============================================================
//
// minifile.c - Minimal core file access functions
//
//============================================================
#include "osdcore.h"
#include <cassert>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <string>
#include <stdio.h> // for fileno
#include <unistd.h> // for ftruncate
namespace {
class std_osd_file : public osd_file
{
public:
std_osd_file(FILE *f) : m_file(f) { assert(m_file); }
//============================================================
// osd_close
//============================================================
virtual ~std_osd_file() override
{
// close the file handle
if (m_file) std::fclose(m_file);
}
//============================================================
// osd_read
//============================================================
virtual error read(void *buffer, std::uint64_t offset, std::uint32_t length, std::uint32_t &actual) override
{
// seek to the new location; note that most fseek implementations are limited to 32 bits
if (std::fseek(m_file, offset, SEEK_SET) < 0)
return error::FAILURE;
// perform the read
std::size_t const count = std::fread(buffer, 1, length, m_file);
actual = count;
return error::NONE;
}
//============================================================
// osd_write
//============================================================
virtual error write(const void *buffer, std::uint64_t offset, std::uint32_t length, std::uint32_t &actual) override
{
// seek to the new location; note that most fseek implementations are limited to 32 bits
if (std::fseek(m_file, offset, SEEK_SET) < 0)
return error::FAILURE;
// perform the write
std::size_t const count = std::fwrite(buffer, 1, length, m_file);
actual = count;
return error::NONE;
}
//============================================================
// osd_truncate
//============================================================
error truncate(std::uint64_t offset) override
{
return (ftruncate(fileno(m_file), offset) < 0) ? error::FAILURE : error::NONE;
}
//============================================================
// osd_fflush
//============================================================
virtual error flush() override
{
return (std::fflush(m_file) == EOF) ? error::FAILURE : error::NONE;
}
private:
FILE *m_file;
};
} // anonymous namespace
//============================================================
// osd_open
//============================================================
osd_file::error osd_file::open(std::string const &path, std::uint32_t openflags, ptr &file, std::uint64_t &filesize)
{
// based on the flags, choose a mode
const char *mode;
if (openflags & OPEN_FLAG_WRITE)
{
if (openflags & OPEN_FLAG_READ)
mode = (openflags & OPEN_FLAG_CREATE) ? "w+b" : "r+b";
else
mode = "wb";
}
else if (openflags & OPEN_FLAG_READ)
mode = "rb";
else
return error::INVALID_ACCESS;
// open the file
FILE *const fileptr = std::fopen(path.c_str(), mode);
if (!fileptr)
return error::NOT_FOUND;
// get the size -- note that most fseek/ftell implementations are limited to 32 bits
long length;
if ((std::fseek(fileptr, 0, SEEK_END) < 0) ||
((length = std::ftell(fileptr)) < 0) ||
(std::fseek(fileptr, 0, SEEK_SET) < 0))
{
std::fclose(fileptr);
return error::FAILURE;
}
try
{
file = std::make_unique<std_osd_file>(fileptr);
filesize = std::int64_t(length);
return error::NONE;
}
catch (...)
{
std::fclose(fileptr);
return error::OUT_OF_MEMORY;
}
}
//============================================================
// osd_openpty
//============================================================
osd_file::error osd_file::openpty(ptr &file, std::string &name)
{
return error::FAILURE;
}
//============================================================
// osd_rmfile
//============================================================
osd_file::error osd_file::remove(std::string const &filename)
{
return (std::remove(filename.c_str()) < 0) ? error::FAILURE : error::NONE;
}
//============================================================
// osd_get_physical_drive_geometry
//============================================================
bool osd_get_physical_drive_geometry(const char *filename, uint32_t *cylinders, uint32_t *heads, uint32_t *sectors, uint32_t *bps)
{
// there is no standard way of doing this, so we always return false, indicating
// that a given path is not a physical drive
return false;
}
//============================================================
// osd_uchar_from_osdchar
//============================================================
int osd_uchar_from_osdchar(char32_t *uchar, const char *osdchar, size_t count)
{
// we assume a standard 1:1 mapping of characters to the first 256 unicode characters
*uchar = (uint8_t)*osdchar;
return 1;
}
//============================================================
// osd_stat
//============================================================
osd_directory_entry *osd_stat(const std::string &path)
{
osd_directory_entry *result = nullptr;
// create an osd_directory_entry; be sure to make sure that the caller can
// free all resources by just freeing the resulting osd_directory_entry
result = (osd_directory_entry *)osd_malloc_array(sizeof(*result) + path.length() + 1);
strcpy((char *)(result + 1), path.c_str());
result->name = (char *)(result + 1);
result->type = ENTTYPE_NONE;
result->size = 0;
FILE *f = std::fopen(path.c_str(), "rb");
if (f != nullptr)
{
std::fseek(f, 0, SEEK_END);
result->type = ENTTYPE_FILE;
result->size = std::ftell(f);
std::fclose(f);
}
return result;
}
//============================================================
// osd_get_full_path
//============================================================
osd_file::error osd_get_full_path(std::string &dst, std::string const &path)
{
// derive the full path of the file in an allocated string
// for now just fake it since we don't presume any underlying file system
dst = path;
return osd_file::error::NONE;
}
//============================================================
// osd_is_absolute_path
//============================================================
bool osd_is_absolute_path(std::string const &path)
{
// assume no for everything
return false;
}
//============================================================
// osd_get_volume_name
//============================================================
const char *osd_get_volume_name(int idx)
{
// we don't expose volumes
return nullptr;
}
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