marshal_load

static VALUE
time_mload(VALUE time, VALUE str)
{
    struct time_object *tobj;
    unsigned long p, s;
    time_t sec;
    long usec;
    unsigned char *buf;
    struct tm tm;
    int i, gmt;
    long nsec;
    VALUE submicro;

    time_modify(time);

    submicro = rb_attr_get(str, id_submicro);
    if (submicro != Qnil) {
        st_delete(rb_generic_ivar_table(str), (st_data_t*)&id_submicro, 0);
    }
    rb_copy_generic_ivar(time, str);

    StringValue(str);
    buf = (unsigned char *)RSTRING_PTR(str);
    if (RSTRING_LEN(str) != 8) {
        rb_raise(rb_eTypeError, "marshaled time format differ");
    }

    p = s = 0;
    for (i=0; i<4; i++) {
        p |= buf[i]<<(8*i);
    }
    for (i=4; i<8; i++) {
        s |= buf[i]<<(8*(i-4));
    }

    if ((p & (1UL<<31)) == 0) {
        gmt = 0;
        sec = p;
        usec = s;
        nsec = usec * 1000;
    }
    else {
        p &= ~(1UL<<31);
        gmt        = (p >> 30) & 0x1;
        tm.tm_year = (p >> 14) & 0xffff;
        tm.tm_mon  = (p >> 10) & 0xf;
        tm.tm_mday = (p >>  5) & 0x1f;
        tm.tm_hour =  p        & 0x1f;
        tm.tm_min  = (s >> 26) & 0x3f;
        tm.tm_sec  = (s >> 20) & 0x3f;
        tm.tm_isdst = 0;

        sec = make_time_t(&tm, Qtrue);
        usec = (long)(s & 0xfffff);
        nsec = usec * 1000;

        if (submicro != Qnil) {
            unsigned char *ptr;
            long len;
            int digit;
            ptr = (unsigned char*)StringValuePtr(submicro);
            len = RSTRING_LEN(submicro);
            if (0 < len) {
                if (10 <= (digit = ptr[0] >> 4)) goto end_submicro;
                nsec += digit * 100;
                if (10 <= (digit = ptr[0] & 0xf)) goto end_submicro;
                nsec += digit * 10;
            }
            if (1 < len) {
                if (10 <= (digit = ptr[1] >> 4)) goto end_submicro;
                nsec += digit;
            }
end_submicro: ;
        }
    }
    time_overflow_p(&sec, &nsec);

    GetTimeval(time, tobj);
    tobj->tm_got = 0;
    tobj->gmt = gmt;
    tobj->ts.tv_sec = sec;
    tobj->ts.tv_nsec = nsec;

    return time;
}