#ifndef PLCB_UTIL_H_
#define PLCB_UTIL_H_

/* This file contains various conversion functions and macros */

/*this stuff converts from SVs to int64_t (signed and unsigned) depending
 on the perl*/

/*XXX:
12:54 < LeoNerd> mordy: Namely,   my ( $hi, $lo ) = unpack "L> L>", $packed_64bit;
                 my $num = Math::BigInt->new( $hi ); $num >>= 32; $num |= $lo;
                 return $num;
12:55 < mordy> what about vice versa? or would i change my C interface to accept 2
               32 bit integers and piece them back together there?
12:55 < LeoNerd> mordy: That might be simplest.
*/

#ifdef PLCB_PERL64
#define plcb_sv_to_u64(sv) SvUV(sv)
#define plcb_sv_to_64(sv) (int64_t)(plcb_sv_to_u64(sv))
#define plcb_sv_from_u64(sv, num) (sv_setuv(sv, num))
#define plcb_sv_from_u64_new(nump) newSVuv( (*nump) )

#define plcb_cas_from_sv(sv, cas_p, lenvar) \
    (SvIOK(sv)) \
    ? cas_p = (uint64_t*)&(SvIVX(sv)) \
    : (uint64_t*)die("Expected valid (UV) cas. IOK not true")

#else

static inline uint64_t plcb_sv_to_u64(SV *in)
{
    char *sv_blob;
    STRLEN blob_len;
    uint64_t ret;
    
    if(SvIOK(in)) {
        /*Numeric*/
        return SvUV(in);
    }
    
    sv_blob = SvPV(in, blob_len);
    if(blob_len != 8) {
        die("expected 8-byte data string. Got %d", blob_len);
    }
    ret = *(uint64_t*)sv_blob;
    return ret;
}
#define plcb_sv_to_64(sv) ((int64_t)(plcb_sv_to_u64(sv)))

#define plcb_sv_from_u64(sv, num) \
    (sv_setpvn(sv, (const char const*)&(num), 8))

#define plcb_sv_from_u64_new(nump) \
    newSVpv((const char* const)(nump), 8)

/*Extract a packed 8 byte blob from an SV into a CAS value*/

#define plcb_cas_from_sv(sv, cas_p, lenvar) \
    ((cas_p) = (uint64_t*)SvPV(sv, lenvar))  \
    ? (\
        (lenvar == 8) \
            ? (cas_p) \
            : (void*)die("Expected 8-byte CAS. Got %d", lenvar) \
        ) \
    : (void*)die("CAS specified, but is null")
    
#endif /*PLCB_PERL64*/

/*assertively extract a non-null key from an SV, together with its length*/

#define plcb_get_str_or_die(ksv, charvar, lenvar, diespec) \
    (charvar = SvPV(ksv, lenvar)) \
        ? ( (lenvar) ? charvar : (void*)die("Got zero-length %s", diespec) ) \
        : (void*)die("Got NULL %s", diespec)


#define PLCB_TIME_ABS_OFFSET

#ifdef PLCB_TIME_ABS_OFFSET
#define PLCB_UEXP2EXP(cbexp, uexp, now) \
    cbexp = ((uexp) \
        ? ((now) \
            ? (now + uexp) \
            : (time(NULL)) + uexp) \
        : 0)

#else

/*Memcached protocol states that a time offset greater than 30 days is taken
 to be an epoch time. We hide this from perl by simply generating our own
 epoch time based on the user's time*/

#define PLCB_UEXP2EXP(cbexp, uexp, now) \
    cbexp = ((uexp) \
        ? ((uexp > (30*24*60*60)) \
            ? ((now) \
                ? (now + uexp) \
                : (time(NULL) + uexp)) \
            : uexp) \
        : 0)
#endif


#endif /* PLCB_UTIL_H_ */