jes/src/core/File.cc

124 lines
2.2 KiB
C++

#include "File.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef _WIN32
#define JES_O_BINARY O_BINARY
#else
#define JES_O_BINARY 0
#endif
/**
* Open a file.
*
* @param[in] filename The filename.
* @param[in] writing Whether to open for writing.
*/
bool File::open(const char * filename, bool writing)
{
int fd;
if (writing)
{
/* TODO: handle mode */
fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC | JES_O_BINARY, 0644);
}
else
{
fd = ::open(filename, O_RDONLY | JES_O_BINARY);
}
if (fd < 0)
{
return false;
}
m_fd = fd;
return true;
}
/**
* Close the file.
*/
void File::close()
{
if (m_fd >= 0)
{
::close(m_fd);
m_fd = -1;
}
}
/**
* Get the file's size.
*
* This function will reset the file position to the beginning of the file.
*
* @return The file's size, or -1 on error.
*/
size_t File::get_size()
{
if (m_fd >= 0)
{
off_t o = lseek(m_fd, 0, SEEK_END);
lseek(m_fd, 0, SEEK_SET);
return o;
}
return -1;
}
/**
* Read from the file.
*
* @param[in] buf Memory buffer to read into. Must be large enough to hold
* size bytes.
* @param[in] size Number of bytes to read.
*
* @retval false The file failed to read.
* @retval true The file was read successfully.
*/
bool File::read(uint8_t * buf, size_t size)
{
size_t n_bytes_read = 0u;
for (;;)
{
off_t rd_size = ::read(m_fd, &buf[n_bytes_read], size - n_bytes_read);
if (rd_size <= 0)
break;
n_bytes_read += (size_t)rd_size;
if (n_bytes_read >= size)
break;
}
if (n_bytes_read != size)
{
return false;
}
return true;
}
bool File::write(const uint8_t * buf, size_t size)
{
if (size <= 0)
return true;
size_t n_bytes_written = 0u;
for (;;)
{
off_t write_size = ::write(m_fd, &buf[n_bytes_written], size - n_bytes_written);
if (write_size <= 0)
break;
n_bytes_written += (size_t)write_size;
if (n_bytes_written >= size)
break;
}
if (n_bytes_written != size)
{
return false;
}
return true;
}