67 lines
1.5 KiB
C++
67 lines
1.5 KiB
C++
// (C) 2018-2023 by Folkert van Heusden
|
|
// Released under MIT license
|
|
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "disk_backend_file.h"
|
|
#include "log.h"
|
|
|
|
|
|
disk_backend_file::disk_backend_file(const std::string & filename) :
|
|
filename(filename)
|
|
{
|
|
}
|
|
|
|
disk_backend_file::~disk_backend_file()
|
|
{
|
|
close(fd);
|
|
}
|
|
|
|
bool disk_backend_file::begin()
|
|
{
|
|
fd = open(filename.c_str(), O_RDWR);
|
|
|
|
if (fd == -1) {
|
|
DOLOG(ll_error, true, "disk_backend_file: cannot open \"%s\": %s", filename.c_str(), strerror(errno));
|
|
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool disk_backend_file::read(const off_t offset, const size_t n, uint8_t *const target)
|
|
{
|
|
DOLOG(debug, false, "disk_backend_file::read: read %zu bytes from offset %zu", n, offset);
|
|
|
|
#if defined(_WIN32) // hope for the best
|
|
if (lseek(fd, offset, SEEK_SET) == -1)
|
|
return false;
|
|
|
|
return ::read(fd, target, n) == ssize_t(n);
|
|
#else
|
|
ssize_t rc = pread(fd, target, n, offset);
|
|
if (rc != ssize_t(n)) {
|
|
DOLOG(debug, false, "disk_backend_file::read: read failure. expected %zu bytes, got %zd", n, rc);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
#endif
|
|
}
|
|
|
|
bool disk_backend_file::write(const off_t offset, const size_t n, const uint8_t *const from)
|
|
{
|
|
DOLOG(debug, false, "disk_backend_file::write: write %zu bytes to offset %zu", n, offset);
|
|
|
|
#if defined(_WIN32) // hope for the best
|
|
if (lseek(fd, offset, SEEK_SET) == -1)
|
|
return false;
|
|
|
|
return ::write(fd, from, n) == ssize_t(n);
|
|
#else
|
|
return pwrite(fd, from, n, offset) == ssize_t(n);
|
|
#endif
|
|
}
|