shifter.c

#include "shifter.h"
#include <string.h>
void shifter_init(struct shifter *sh, uint8_t *buf, int bufsize) {
  memset(sh, 0, sizeof(struct shifter));
  sh->buf = buf;
  sh->bufsize = bufsize;
}
 
void shift_into_uint8(struct shifter *sh, uint8_t b) {
  if (sh->error) {
    return;
  }
  if (sh->validbytes >= (sh->bufsize - 1)) {
    sh->error = 1;
    return;
  }
  sh->buf[sh->validbytes] = b;
  sh->validbytes++;
}
void shift_into_uint32(struct shifter *sh, uint32_t b) {
  int i;
 
  for (i = 0; i < 4; i++) {
    uint32_t x = b;
    x = x & 0xFF;
    shift_into_uint8(sh, x);
    b = b >> 8;
  }
}
void shift_into_uint64(struct shifter *sh, uint64_t b) {
  int i;
 
  for (i = 0; i < 8; i++) {
    uint64_t x = b;
    x = x & 0xFF;
    shift_into_uint8(sh, x);
    b = b >> 8;
  }
}
// if non-zero an error occured on this shifter
int shift_error(struct shifter *sh) {
  return sh->error;
}
int shift_size(struct shifter *sh) {
  return sh->validbytes;
}