source: trunk/minix/commands/i386/mtools-3.9.7/force_io.c@ 10

/*
 * Force I/O to be done to complete transfer length
 *
 * written by:
 *
 * Alain L. Knaff                       
 * alain@linux.lu
 *
 */

#include "sysincludes.h"
#include "msdos.h"
#include "stream.h"

static int force_io(Stream_t *Stream,
                    char *buf, mt_off_t start, size_t len,
                    int (*io)(Stream_t *, char *, mt_off_t, size_t))
{
        int ret;
        int done=0;
        
        while(len){
                ret = io(Stream, buf, start, len);
                if ( ret <= 0 ){
                        if (done)
                                return done;
                        else
                                return ret;
                }
                start += ret;
                done += ret;
                len -= ret;
                buf += ret;
        }
        return done;
}

int force_write(Stream_t *Stream, char *buf, mt_off_t start, size_t len)
{
        return force_io(Stream, buf, start, len,
                                        Stream->Class->write);
}

int force_read(Stream_t *Stream, char *buf, mt_off_t start, size_t len)
{
        return force_io(Stream, buf, start, len,
                                        Stream->Class->read);
}