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#include "interface.h"
#include "internals.h"
#include "id-errno.h"
#include "debug.h"
unsigned int extract_unsigned_pnum(struct id_cookie *cookie, int start_bit, int *err)
{
unsigned int value=0;
unsigned int bit_offset=0;
unsigned char bits;
unsigned char ch;
int oor;
*err = ID_EOK;
for (;;) {
ch = id_fetch_byte(cookie->mem_ptr, cookie->offset++, &oor);
if (oor != ID_EOK) {
*err = oor;
id_error("extract runs oor");
return 0;
}
if (ch & (1<<(start_bit-1))) {
/* more to go, accumulate bits */
bits = ch & ((1<<(start_bit - 1)) - 1);
value |= (bits << bit_offset);
bit_offset += start_bit-1;
start_bit = 8;
} else {
/* last byte of number */
bits = ch & ((1<<(start_bit - 1)) - 1);
value |= (bits << bit_offset);
break;
}
}
return value;
}
int extract_signed_pnum(struct id_cookie *cookie, int start_bit, int *err)
{
int value=0;
unsigned int bit_offset=0;
unsigned char bits;
unsigned char ch;
int oor;
*err = ID_EOK;
for (;;) {
ch = id_fetch_byte(cookie->mem_ptr, cookie->offset++, &oor);
if (oor != ID_EOK) {
*err = oor;
id_error("extract runs oor");
return 0;
}
if (ch & (1<<(start_bit-1))) {
/* more to go, accumulate bits */
bits = ch & ((1<<(start_bit - 1)) - 1);
value |= (bits << bit_offset);
bit_offset += start_bit-1;
start_bit = 8;
} else {
/* last byte of number */
bits = ch & ((1<<(start_bit - 2)) - 1);
value |= (bits << bit_offset);
if (ch & (1<<(start_bit - 2)))
value = -value;
break;
}
}
return value;
}
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