#include "y16t_internal.h"
#include <errno.h>
#include <unistd.h>

__attribute__((nonnull))
static ssize_t y16t_pall_hret(const ssize_t tmp, size_t *dnb)
{
	if(tmp > 0) {
		*dnb += tmp;
		return tmp;
	} else if(!tmp) {
		return -EIO;
	} else {
		return -errno;
	}
}

ssize_t y16t_pread_all(const int fd, void *buf, size_t nbyte, off_t offset)
{
	size_t dnb = 0;
	while(nbyte) {
		const ssize_t tmp = y16t_pall_hret(pread(
			fd,
			buf    + dnb,
			nbyte  - dnb,
			offset + dnb), &dnb);
		switch(tmp) {
		  case -EINTR:
			continue;
		  default:
		  	if(tmp > 0) continue;
		  	return tmp;
		}
	}
	return (ssize_t)dnb;
}

ssize_t y16t_pwrite_all(const int fd, const void *buf, size_t nbyte, off_t offset)
{
	size_t dnb = 0;
	while(nbyte) {
		const ssize_t tmp = y16t_pall_hret(pwrite(
			fd,
			buf    + dnb,
			nbyte  - dnb,
			offset + dnb), &dnb);
		switch(tmp) {
		  case -EINTR:
			continue;
		  default:
		  	if(tmp > 0) continue;
		  	return tmp;
		}
	}
	return (ssize_t)dnb;
}