fxos/lib/util.cpp

98 lines
1.9 KiB
C++

#include <fxos/util.h>
#include <cstdlib>
#include <cstring>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
/* Empty buffer initialized with given byte */
Buffer::Buffer(size_t size, int fill)
{
m_data = malloc(size);
if(!m_data) throw std::bad_alloc();
m_size = size;
memset(m_data, fill, size);
m_path = "(anonymous)";
}
/* Buffer initialized from file */
Buffer::Buffer(std::string filepath, ssize_t size, int fill)
{
char const *path = filepath.c_str();
int fd = open(path, O_RDONLY);
if(!fd) throw std::runtime_error(format("cannot open '%s'", path));
struct stat statbuf;
ssize_t x = fstat(fd, &statbuf);
if(x < 0)
{
close(fd);
throw std::runtime_error(format("cannot stat '%s'", path));
}
m_size = (size < 0) ? statbuf.st_size : size;
size_t size_to_read = std::min(m_size, (size_t)statbuf.st_size);
m_data = malloc(m_size);
if(!m_data) throw std::bad_alloc();
/* Read buffer and fill whatever is left */
memset(m_data, fill, m_size);
x = read(fd, m_data, size_to_read);
close(fd);
if(x != (ssize_t)size_to_read)
{
throw std::runtime_error(format(
"error while reading '%s'", path));
}
m_path = filepath;
}
/* Create a buffer by copying another buffer */
Buffer::Buffer(Buffer const &other):
Buffer(other.size(), 0x00)
{
}
/* Create a buffer by copying and resizing another buffer */
Buffer::Buffer(Buffer const &other, size_t new_size, int fill):
Buffer(new_size, fill)
{
memcpy(m_data, other.data(), std::min(new_size, other.size()));
}
/* Free allocated data, obviously */
Buffer::~Buffer()
{
free(m_data);
}
/* Buffer size */
size_t Buffer::size() const noexcept
{
return m_size;
}
/* Buffer data */
char *Buffer::data() noexcept
{
return static_cast<char *>(m_data);
}
char const *Buffer::data() const noexcept
{
return static_cast<char const *>(m_data);
}
/* File path */
std::string Buffer::path() const noexcept
{
return m_path;
}