CBOR-XS/XS.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <float.h>

#include "ecb.h"

#define F_SHRINK         0x00000200UL
#define F_ALLOW_UNKNOWN  0x00002000UL

#define INIT_SIZE   32 // initial scalar size to be allocated

#define SB do {
#define SE } while (0)

#define IN_RANGE_INC(type,val,beg,end) \
  ((unsigned type)((unsigned type)(val) - (unsigned type)(beg)) \
  <= (unsigned type)((unsigned type)(end) - (unsigned type)(beg)))

#define ERR_NESTING_EXCEEDED "cbor text or perl structure exceeds maximum nesting level (max_depth set too low?)"

#ifdef USE_ITHREADS
# define CBOR_SLOW 1
# define CBOR_STASH (cbor_stash ? cbor_stash : gv_stashpv ("CBOR::XS", 1))
#else
# define CBOR_SLOW 0
# define CBOR_STASH cbor_stash
#endif

static HV *cbor_stash, *cbor_boolean_stash, *cbor_tagged_stash; // CBOR::XS::
static SV *cbor_true, *cbor_false;

typedef struct {
  U32 flags;
  U32 max_depth;
  STRLEN max_size;
} CBOR;

ecb_inline void
cbor_init (CBOR *cbor)
{
  Zero (cbor, 1, CBOR);
  cbor->max_depth = 512;
}

/////////////////////////////////////////////////////////////////////////////
// utility functions

ecb_inline SV *
get_bool (const char *name)
{
  SV *sv = get_sv (name, 1);

  SvREADONLY_on (sv);
  SvREADONLY_on (SvRV (sv));

  return sv;
}

ecb_inline void
shrink (SV *sv)
{
  sv_utf8_downgrade (sv, 1);

  if (SvLEN (sv) > SvCUR (sv) + 1)
    {
#ifdef SvPV_shrink_to_cur
      SvPV_shrink_to_cur (sv);
#elif defined (SvPV_renew)
      SvPV_renew (sv, SvCUR (sv) + 1);
#endif
    }
}

/////////////////////////////////////////////////////////////////////////////
// fp hell

//TODO

/////////////////////////////////////////////////////////////////////////////
// encoder

// structure used for encoding CBOR
typedef struct
{
  char *cur;  // SvPVX (sv) + current output position
  char *end;  // SvEND (sv)
  SV *sv;     // result scalar
  CBOR cbor;
  U32 depth;  // recursion level
} enc_t;

ecb_inline void
need (enc_t *enc, STRLEN len)
{
  if (ecb_expect_false (enc->cur + len >= enc->end))
    {
      STRLEN cur = enc->cur - (char *)SvPVX (enc->sv);
      SvGROW (enc->sv, cur + (len < (cur >> 2) ? cur >> 2 : len) + 1);
      enc->cur = SvPVX (enc->sv) + cur;
      enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
    }
}

ecb_inline void
encode_ch (enc_t *enc, char ch)
{
  need (enc, 1);
  *enc->cur++ = ch;
}

static void
encode_uint (enc_t *enc, int major, UV len)
{
   need (enc, 9);

   if (len < 24)
      *enc->cur++ = major | len;
   else if (len <= 0xff)
     {
       *enc->cur++ = major | 24;
       *enc->cur++ = len;
     }
   else if (len <= 0xffff)
     {
       *enc->cur++ = major | 25;
       *enc->cur++ = len >> 8;
       *enc->cur++ = len;
     }
   else if (len <= 0xffffffff)
     {
       *enc->cur++ = major | 26;
       *enc->cur++ = len >> 24;
       *enc->cur++ = len >> 16;
       *enc->cur++ = len >>  8;
       *enc->cur++ = len;
     }
   else
     {
       *enc->cur++ = major | 27;
       *enc->cur++ = len >> 56;
       *enc->cur++ = len >> 48;
       *enc->cur++ = len >> 40;
       *enc->cur++ = len >> 32;
       *enc->cur++ = len >> 24;
       *enc->cur++ = len >> 16;
       *enc->cur++ = len >>  8;
       *enc->cur++ = len;
     }
}

static void
encode_str (enc_t *enc, int utf8, char *str, STRLEN len)
{
  encode_uint (enc, utf8 ? 0x60 : 0x40, len);
  need (enc, len);
  memcpy (enc->cur, str, len);
  enc->cur += len;
}

static void encode_sv (enc_t *enc, SV *sv);

static void
encode_av (enc_t *enc, AV *av)
{
  int i, len = av_len (av);

  if (enc->depth >= enc->cbor.max_depth)
    croak (ERR_NESTING_EXCEEDED);

  ++enc->depth;

  encode_uint (enc, 0x80, len + 1);

  for (i = 0; i <= len; ++i)
    {
      SV **svp = av_fetch (av, i, 0);
      encode_sv (enc, svp ? *svp : &PL_sv_undef);
    }

  --enc->depth;
}

static void
encode_hv (enc_t *enc, HV *hv)
{
  HE *he;

  if (enc->depth >= enc->cbor.max_depth)
    croak (ERR_NESTING_EXCEEDED);

  ++enc->depth;

  int pairs = hv_iterinit (hv);
  int mg = SvMAGICAL (hv);

  if (mg)
    encode_ch (enc, 0xa0 | 31);
  else
    encode_uint (enc, 0xa0, pairs);

  while ((he = hv_iternext (hv)))
    {
      if (HeKLEN (he) == HEf_SVKEY)
        encode_sv (enc, HeSVKEY (he));
      else
        encode_str (enc, HeKUTF8 (he), HeKEY (he), HeKLEN (he));

      encode_sv (enc, ecb_expect_false (mg) ? hv_iterval (hv, he) : HeVAL (he));
    }

  if (mg)
    encode_ch (enc, 0xe0 | 31);

  --enc->depth;
}

// encode objects, arrays and special \0=false and \1=true values.
static void
encode_rv (enc_t *enc, SV *sv)
{
  svtype svt;

  SvGETMAGIC (sv);
  svt = SvTYPE (sv);

  if (ecb_expect_false (SvOBJECT (sv)))
    {
      HV *boolean_stash = !CBOR_SLOW || cbor_boolean_stash
                          ? cbor_boolean_stash
                          : gv_stashpv ("CBOR::XS::Boolean", 1);
      HV *tagged_stash  = !CBOR_SLOW || cbor_tagged_stash
                          ? cbor_tagged_stash
                          : gv_stashpv ("CBOR::XS::Tagged" , 1);

      if (SvSTASH (sv) == boolean_stash)
        encode_ch (enc, SvIV (sv) ? 0xe0 | 21 : 0xe0 | 20);
      else if (SvSTASH (sv) == tagged_stash)
        {
          if (svt != SVt_PVAV)
            croak ("encountered CBOR::XS::Tagged object that isn't an array");

          encode_uint (enc, 0xc0, SvUV (*av_fetch ((AV *)sv, 0, 1)));
          encode_sv (enc, *av_fetch ((AV *)sv, 1, 1));
        }
      else
        {
          // we re-bless the reference to get overload and other niceties right
          GV *to_cbor = gv_fetchmethod_autoload (SvSTASH (sv), "TO_CBOR", 0);

          if (to_cbor)
            {
              dSP;

              ENTER; SAVETMPS; PUSHMARK (SP);
              XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));

              // calling with G_SCALAR ensures that we always get a 1 return value
              PUTBACK;
              call_sv ((SV *)GvCV (to_cbor), G_SCALAR);
              SPAGAIN;

              // catch this surprisingly common error
              if (SvROK (TOPs) && SvRV (TOPs) == sv)
                croak ("%s::TO_CBOR method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));

              sv = POPs;
              PUTBACK;

              encode_sv (enc, sv);

              FREETMPS; LEAVE;
            }
          else
            croak ("encountered object '%s', but no TO_CBOR method available on it",
                   SvPV_nolen (sv_2mortal (newRV_inc (sv))));
        }
    }
  else if (svt == SVt_PVHV)
    encode_hv (enc, (HV *)sv);
  else if (svt == SVt_PVAV)
    encode_av (enc, (AV *)sv);
  else if (svt < SVt_PVAV)
    {
      STRLEN len = 0;
      char *pv = svt ? SvPV (sv, len) : 0;

      if (len == 1 && *pv == '1')
        encode_ch (enc, 0xe0 | 21);
      else if (len == 1 && *pv == '0')
        encode_ch (enc, 0xe0 | 20);
      else if (enc->cbor.flags & F_ALLOW_UNKNOWN)
        encode_ch (enc, 0xe0 | 23);
      else
        croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
               SvPV_nolen (sv_2mortal (newRV_inc (sv))));
    }
  else if (enc->cbor.flags & F_ALLOW_UNKNOWN)
    encode_ch (enc, 0xe0 | 23);
  else
    croak ("encountered %s, but CBOR can only represent references to arrays or hashes",
           SvPV_nolen (sv_2mortal (newRV_inc (sv))));
}

static void
encode_nv (enc_t *enc, SV *sv)
{
  double nv = SvNVX (sv);

  need (enc, 9);

  if (ecb_expect_false (nv == (U32)nv))
    encode_uint (enc, 0x00, (U32)nv);
  //TODO: maybe I32?
  else if (ecb_expect_false (nv == (float)nv))
    {
      uint32_t fp = ecb_float_to_binary32 (nv);

      *enc->cur++ = 0xe0 | 26;

      if (!ecb_big_endian ())
        fp = ecb_bswap32 (fp);

      memcpy (enc->cur, &fp, 4);
      enc->cur += 4;
    }
  else
    {
      uint64_t fp = ecb_double_to_binary64 (nv);

      *enc->cur++ = 0xe0 | 27;

      if (!ecb_big_endian ())
        fp = ecb_bswap64 (fp);

      memcpy (enc->cur, &fp, 8);
      enc->cur += 8;
    }
}

static void
encode_sv (enc_t *enc, SV *sv)
{
  SvGETMAGIC (sv);

  if (SvPOKp (sv))
    {
      STRLEN len;
      char *str = SvPV (sv, len);
      encode_str (enc, SvUTF8 (sv), str, len);
    }
  else if (SvNOKp (sv))
    encode_nv (enc, sv);
  else if (SvIOKp (sv))
    {
      if (SvIsUV (sv))
        encode_uint (enc, 0x00, SvUVX (sv));
      else if (SvIVX (sv) >= 0)
        encode_uint (enc, 0x00, SvIVX (sv));
      else
        encode_uint (enc, 0x20, -(SvIVX (sv) + 1));
    }
  else if (SvROK (sv))
    encode_rv (enc, SvRV (sv));
  else if (!SvOK (sv))
    encode_ch (enc, 0xe0 | 22);
  else if (enc->cbor.flags & F_ALLOW_UNKNOWN)
    encode_ch (enc, 0xe0 | 23);
  else
    croak ("encountered perl type (%s,0x%x) that CBOR cannot handle, check your input data",
           SvPV_nolen (sv), (unsigned int)SvFLAGS (sv));
}

static SV *
encode_cbor (SV *scalar, CBOR *cbor)
{
  enc_t enc;

  enc.cbor      = *cbor;
  enc.sv        = sv_2mortal (NEWSV (0, INIT_SIZE));
  enc.cur       = SvPVX (enc.sv);
  enc.end       = SvEND (enc.sv);
  enc.depth     = 0;

  SvPOK_only (enc.sv);
  encode_sv (&enc, scalar);

  SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
  *SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings

  if (enc.cbor.flags & F_SHRINK)
    shrink (enc.sv);

  return enc.sv;
}

/////////////////////////////////////////////////////////////////////////////
// decoder

// structure used for decoding CBOR
typedef struct
{
  U8 *cur; // current parser pointer
  U8 *end; // end of input string
  const char *err; // parse error, if != 0
  CBOR cbor;
  U32 depth; // recursion depth
  U32 maxdepth; // recursion depth limit
} dec_t;

#define ERR(reason) SB if (!dec->err) dec->err = reason; goto fail; SE

#define WANT(len) if (ecb_expect_false (dec->cur + len > dec->end)) ERR ("unexpected end of CBOR data")

#define DEC_INC_DEPTH if (++dec->depth > dec->cbor.max_depth) ERR (ERR_NESTING_EXCEEDED)
#define DEC_DEC_DEPTH --dec->depth

static UV
decode_uint (dec_t *dec)
{
  switch (*dec->cur & 31)
    {
      case  0: case  1: case  2: case  3: case  4: case  5: case  6: case  7:
      case  8: case  9: case 10: case 11: case 12: case 13: case 14: case 15:
      case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23:
        return *dec->cur++ & 31;

      case 24:
        WANT (2);
        dec->cur += 2;
        return dec->cur[-1];

      case 25:
        WANT (3);
        dec->cur += 3;
        return (((UV)dec->cur[-2]) <<  8)
             |  ((UV)dec->cur[-1]);

      case 26:
        WANT (5);
        dec->cur += 5;
        return (((UV)dec->cur[-4]) << 24)
             | (((UV)dec->cur[-3]) << 16)
             | (((UV)dec->cur[-2]) <<  8)
             |  ((UV)dec->cur[-1]);

      case 27:
        WANT (9);
        dec->cur += 9;
        return (((UV)dec->cur[-8]) << 56)
             | (((UV)dec->cur[-7]) << 48)
             | (((UV)dec->cur[-6]) << 40)
             | (((UV)dec->cur[-5]) << 32)
             | (((UV)dec->cur[-4]) << 24)
             | (((UV)dec->cur[-3]) << 16)
             | (((UV)dec->cur[-2]) <<  8)
             |  ((UV)dec->cur[-1]);

      default:
        ERR ("corrupted CBOR data (unsupported integer minor encoding)");
    }

fail:
  return 0;
}

static SV *decode_sv (dec_t *dec);

static SV *
decode_av (dec_t *dec)
{
  AV *av = newAV ();

  DEC_INC_DEPTH;

  if ((*dec->cur & 31) == 31)
    {
      ++dec->cur;

      for (;;)
        {
          WANT (1);

          if (*dec->cur == (0xe0 | 31))
            {
              ++dec->cur;
              break;
            }

          av_push (av, decode_sv (dec));
        }
    }
  else
    {
      int i, len = decode_uint (dec);

      av_fill (av, len - 1);

      for (i = 0; i < len; ++i)
        AvARRAY (av)[i] = decode_sv (dec);
    }

  DEC_DEC_DEPTH;
  return newRV_noinc ((SV *)av);

fail:
  SvREFCNT_dec (av);
  DEC_DEC_DEPTH;
  return &PL_sv_undef;
}

static SV *
decode_hv (dec_t *dec)
{
  HV *hv = newHV ();

  DEC_INC_DEPTH;

  if ((*dec->cur & 31) == 31)
    {
      ++dec->cur;

      for (;;)
        {
          WANT (1);

          if (*dec->cur == (0xe0 | 31))
            {
              ++dec->cur;
              break;
            }

          SV *k = decode_sv (dec);
          SV *v = decode_sv (dec);

          hv_store_ent (hv, k, v, 0);
        }
    }
  else
    {
      int len = decode_uint (dec);

      while (len--)
        {
          SV *k = decode_sv (dec);
          SV *v = decode_sv (dec);

          hv_store_ent (hv, k, v, 0);
        }
    }

  DEC_DEC_DEPTH;
  return newRV_noinc ((SV *)hv);

fail:
  SvREFCNT_dec (hv);
  DEC_DEC_DEPTH;
  return &PL_sv_undef;
}

static SV *
decode_str (dec_t *dec, int utf8)
{
  SV *sv = 0;

  if ((*dec->cur & 31) == 31)
    {
      ++dec->cur;

      sv = newSVpvn ("", 0);

      // not very fast, and certainly not robust against illegal input
      for (;;)
        {
          WANT (1);

          if (*dec->cur == (0xe0 | 31))
            {
              ++dec->cur;
              break;
            }

          sv_catsv (sv, decode_sv (dec));
        }
    }
  else
    {
      STRLEN len = decode_uint (dec);

      WANT (len);
      sv = newSVpvn (dec->cur, len);
      dec->cur += len;
    }

  if (utf8)
    SvUTF8_on (sv);

  return sv;

fail:
  SvREFCNT_dec (sv);
  return &PL_sv_undef;
}

static SV *
decode_tagged (dec_t *dec)
{
  UV tag = decode_uint (dec);
  SV *sv = decode_sv (dec);

  if (tag == 55799) // 2.4.5 Self-Describe CBOR
    return sv;

  AV *av = newAV ();
  av_push (av, newSVuv (tag));
  av_push (av, sv);
  return newRV_noinc ((SV *)av);
}

static SV *
decode_sv (dec_t *dec)
{
  WANT (1);

  switch (*dec->cur >> 5)
    {
      case 0: // unsigned int
        return newSVuv (decode_uint (dec));
      case 1: // negative int
        return newSViv (-1 - (IV)decode_uint (dec));
      case 2: // octet string
        return decode_str (dec, 0);
      case 3: // utf-8 string
        return decode_str (dec, 1);
      case 4: // array
        return decode_av (dec);
      case 5: // map
        return decode_hv (dec);
      case 6: // tag
        return decode_tagged (dec);
      case 7: // misc
        switch (*dec->cur++ & 31)
          {
            case 20:
#if CBOR_SLOW
              cbor_false = get_bool ("CBOR::XS::false");
#endif
              return newSVsv (cbor_false);
            case 21:
#if CBOR_SLOW
              cbor_true = get_bool ("CBOR::XS::true");
#endif
              return newSVsv (cbor_true);
            case 22:
              return newSVsv (&PL_sv_undef);

            case 25:
              {
                WANT (2);

                uint16_t fp = (dec->cur[0] << 8) | dec->cur[1];
                dec->cur += 2;

                return newSVnv (ecb_binary16_to_float (fp));
              }

            case 26:
              {
                uint32_t fp;
                WANT (4);
                memcpy (&fp, dec->cur, 4);
                dec->cur += 4;

                if (!ecb_big_endian ())
                  fp = ecb_bswap32 (fp);

                return newSVnv (ecb_binary32_to_float (fp));
              }

            case 27:
              {
                uint64_t fp;
                WANT (8);
                memcpy (&fp, dec->cur, 8);
                dec->cur += 8;

                if (!ecb_big_endian ())
                  fp = ecb_bswap64 (fp);

                return newSVnv (ecb_binary64_to_double (fp));
              }

            // 0..19 unassigned
            // 24 reserved + unassigned (reserved values are not encodable)
            default:
              ERR ("corrupted CBOR data (reserved/unassigned major 7 value)");
          }

        break;
  }

fail:
  return &PL_sv_undef;
}

static SV *
decode_cbor (SV *string, CBOR *cbor, char **offset_return)
{
  dec_t dec;
  SV *sv;

  /* work around bugs in 5.10 where manipulating magic values
   * makes perl ignore the magic in subsequent accesses.
   * also make a copy of non-PV values, to get them into a clean
   * state (SvPV should do that, but it's buggy, see below).
   */
  /*SvGETMAGIC (string);*/
  if (SvMAGICAL (string) || !SvPOK (string))
    string = sv_2mortal (newSVsv (string));

  SvUPGRADE (string, SVt_PV);

  /* work around a bug in perl 5.10, which causes SvCUR to fail an
   * assertion with -DDEBUGGING, although SvCUR is documented to
   * return the xpv_cur field which certainly exists after upgrading.
   * according to nicholas clark, calling SvPOK fixes this.
   * But it doesn't fix it, so try another workaround, call SvPV_nolen
   * and hope for the best.
   * Damnit, SvPV_nolen still trips over yet another assertion. This
   * assertion business is seriously broken, try yet another workaround
   * for the broken -DDEBUGGING.
   */
  {
#ifdef DEBUGGING
    STRLEN offset = SvOK (string) ? sv_len (string) : 0;
#else
    STRLEN offset = SvCUR (string);
#endif

    if (offset > cbor->max_size && cbor->max_size)
      croak ("attempted decode of CBOR text of %lu bytes size, but max_size is set to %lu",
             (unsigned long)SvCUR (string), (unsigned long)cbor->max_size);
  }

  sv_utf8_downgrade (string, 0);

  dec.cbor  = *cbor;
  dec.cur   = (U8 *)SvPVX (string);
  dec.end   = (U8 *)SvEND (string);
  dec.err   = 0;
  dec.depth = 0;

  sv = decode_sv (&dec);

  if (offset_return)
    *offset_return = dec.cur;

  if (!(offset_return || !sv))
    if (dec.cur != dec.end && !dec.err)
      dec.err = "garbage after CBOR object";

  if (dec.err)
    {
      SvREFCNT_dec (sv);
      croak ("%s, at offset %d (octet 0x%02x)", dec.err, dec.cur - (U8 *)SvPVX (string), (int)(uint8_t)*dec.cur);
    }

  sv = sv_2mortal (sv);

  return sv;
}

/////////////////////////////////////////////////////////////////////////////
// XS interface functions

MODULE = CBOR::XS               PACKAGE = CBOR::XS

BOOT:
{
        cbor_stash         = gv_stashpv ("CBOR::XS"         , 1);
        cbor_boolean_stash = gv_stashpv ("CBOR::XS::Boolean", 1);
        cbor_tagged_stash  = gv_stashpv ("CBOR::XS::Tagged" , 1);

        cbor_true  = get_bool ("CBOR::XS::true");
        cbor_false = get_bool ("CBOR::XS::false");
}

PROTOTYPES: DISABLE

void CLONE (...)
        CODE:
        cbor_stash         = 0;
        cbor_boolean_stash = 0;
        cbor_tagged_stash  = 0;

void new (char *klass)
        PPCODE:
{
        SV *pv = NEWSV (0, sizeof (CBOR));
        SvPOK_only (pv);
        cbor_init ((CBOR *)SvPVX (pv));
        XPUSHs (sv_2mortal (sv_bless (
           newRV_noinc (pv),
           strEQ (klass, "CBOR::XS") ? CBOR_STASH : gv_stashpv (klass, 1)
        )));
}

void shrink (CBOR *self, int enable = 1)
        ALIAS:
        shrink          = F_SHRINK
        allow_unknown   = F_ALLOW_UNKNOWN
        PPCODE:
{
        if (enable)
          self->flags |=  ix;
        else
          self->flags &= ~ix;

        XPUSHs (ST (0));
}

void get_shrink (CBOR *self)
        ALIAS:
        get_shrink          = F_SHRINK
        get_allow_unknown   = F_ALLOW_UNKNOWN
        PPCODE:
        XPUSHs (boolSV (self->flags & ix));

void max_depth (CBOR *self, U32 max_depth = 0x80000000UL)
        PPCODE:
        self->max_depth = max_depth;
        XPUSHs (ST (0));

U32 get_max_depth (CBOR *self)
        CODE:
        RETVAL = self->max_depth;
        OUTPUT:
        RETVAL

void max_size (CBOR *self, U32 max_size = 0)
        PPCODE:
        self->max_size = max_size;
        XPUSHs (ST (0));

int get_max_size (CBOR *self)
        CODE:
        RETVAL = self->max_size;
        OUTPUT:
        RETVAL

#if 0 //TODO

void filter_cbor_object (CBOR *self, SV *cb = &PL_sv_undef)
        PPCODE:
{
        SvREFCNT_dec (self->cb_object);
        self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;

        XPUSHs (ST (0));
}

void filter_cbor_single_key_object (CBOR *self, SV *key, SV *cb = &PL_sv_undef)
        PPCODE:
{
        if (!self->cb_sk_object)
          self->cb_sk_object = newHV ();

        if (SvOK (cb))
          hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
        else
          {
            hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);

            if (!HvKEYS (self->cb_sk_object))
              {
                SvREFCNT_dec (self->cb_sk_object);
                self->cb_sk_object = 0;
              }
          }

        XPUSHs (ST (0));
}

#endif

void encode (CBOR *self, SV *scalar)
        PPCODE:
        PUTBACK; scalar = encode_cbor (scalar, self); SPAGAIN;
        XPUSHs (scalar);

void decode (CBOR *self, SV *cborstr)
        PPCODE:
        PUTBACK; cborstr = decode_cbor (cborstr, self, 0); SPAGAIN;
        XPUSHs (cborstr);

void decode_prefix (CBOR *self, SV *cborstr)
        PPCODE:
{
        SV *sv;
        char *offset;
        PUTBACK; sv = decode_cbor (cborstr, self, &offset); SPAGAIN;
        EXTEND (SP, 2);
        PUSHs (sv);
        PUSHs (sv_2mortal (newSVuv (offset - SvPVX (cborstr))));
}

#if 0

void DESTROY (CBOR *self)
        CODE:
        SvREFCNT_dec (self->cb_sk_object);
        SvREFCNT_dec (self->cb_object);

#endif

PROTOTYPES: ENABLE

void encode_cbor (SV *scalar)
        PPCODE:
{
        CBOR cbor;
        cbor_init (&cbor);
        PUTBACK; scalar = encode_cbor (scalar, &cbor); SPAGAIN;
        XPUSHs (scalar);
}

void decode_cbor (SV *cborstr)
        PPCODE:
{
        CBOR cbor;
        cbor_init (&cbor);
        PUTBACK; cborstr = decode_cbor (cborstr, &cbor, 0); SPAGAIN;
        XPUSHs (cborstr);
}

Revision:	1.6
Committed:	Sat Oct 26 22:25:47 2013 UTC (10 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.5:	+49 -262 lines
Log Message:	* empty log message *
#	Content
1	#include "EXTERN.h"
2	#include "perl.h"
3	#include "XSUB.h"
4
5	#include <assert.h>
6	#include <string.h>
7	#include <stdlib.h>
8	#include <stdio.h>
9	#include <limits.h>
10	#include <float.h>
11
12	#include "ecb.h"
13
14	#define F_SHRINK 0x00000200UL
15	#define F_ALLOW_UNKNOWN 0x00002000UL
16
17	#define INIT_SIZE 32 // initial scalar size to be allocated
18
19	#define SB do {
20	#define SE } while (0)
21
22	#define IN_RANGE_INC(type,val,beg,end) \
23	((unsigned type)((unsigned type)(val) - (unsigned type)(beg)) \
24	<= (unsigned type)((unsigned type)(end) - (unsigned type)(beg)))
25
26	#define ERR_NESTING_EXCEEDED "cbor text or perl structure exceeds maximum nesting level (max_depth set too low?)"
27
28	#ifdef USE_ITHREADS
29	# define CBOR_SLOW 1
30	# define CBOR_STASH (cbor_stash ? cbor_stash : gv_stashpv ("CBOR::XS", 1))
31	#else
32	# define CBOR_SLOW 0
33	# define CBOR_STASH cbor_stash
34	#endif
35
36	static HV cbor_stash, cbor_boolean_stash, *cbor_tagged_stash; // CBOR::XS::
37	static SV cbor_true, cbor_false;
38
39	typedef struct {
40	U32 flags;
41	U32 max_depth;
42	STRLEN max_size;
43	} CBOR;
44
45	ecb_inline void
46	cbor_init (CBOR *cbor)
47	{
48	Zero (cbor, 1, CBOR);
49	cbor->max_depth = 512;
50	}
51
52	/////////////////////////////////////////////////////////////////////////////
53	// utility functions
54
55	ecb_inline SV *
56	get_bool (const char *name)
57	{
58	SV *sv = get_sv (name, 1);
59
60	SvREADONLY_on (sv);
61	SvREADONLY_on (SvRV (sv));
62
63	return sv;
64	}
65
66	ecb_inline void
67	shrink (SV *sv)
68	{
69	sv_utf8_downgrade (sv, 1);
70
71	if (SvLEN (sv) > SvCUR (sv) + 1)
72	{
73	#ifdef SvPV_shrink_to_cur
74	SvPV_shrink_to_cur (sv);
75	#elif defined (SvPV_renew)
76	SvPV_renew (sv, SvCUR (sv) + 1);
77	#endif
78	}
79	}
80
81	/////////////////////////////////////////////////////////////////////////////
82	// fp hell
83
84	//TODO
85
86	/////////////////////////////////////////////////////////////////////////////
87	// encoder
88
89	// structure used for encoding CBOR
90	typedef struct
91	{
92	char *cur; // SvPVX (sv) + current output position
93	char *end; // SvEND (sv)
94	SV *sv; // result scalar
95	CBOR cbor;
96	U32 depth; // recursion level
97	} enc_t;
98
99	ecb_inline void
100	need (enc_t *enc, STRLEN len)
101	{
102	if (ecb_expect_false (enc->cur + len >= enc->end))
103	{
104	STRLEN cur = enc->cur - (char *)SvPVX (enc->sv);
105	SvGROW (enc->sv, cur + (len < (cur >> 2) ? cur >> 2 : len) + 1);
106	enc->cur = SvPVX (enc->sv) + cur;
107	enc->end = SvPVX (enc->sv) + SvLEN (enc->sv) - 1;
108	}
109	}
110
111	ecb_inline void
112	encode_ch (enc_t *enc, char ch)
113	{
114	need (enc, 1);
115	*enc->cur++ = ch;
116	}
117
118	static void
119	encode_uint (enc_t *enc, int major, UV len)
120	{
121	need (enc, 9);
122
123	if (len < 24)
124	*enc->cur++ = major \| len;
125	else if (len <= 0xff)
126	{
127	*enc->cur++ = major \| 24;
128	*enc->cur++ = len;
129	}
130	else if (len <= 0xffff)
131	{
132	*enc->cur++ = major \| 25;
133	*enc->cur++ = len >> 8;
134	*enc->cur++ = len;
135	}
136	else if (len <= 0xffffffff)
137	{
138	*enc->cur++ = major \| 26;
139	*enc->cur++ = len >> 24;
140	*enc->cur++ = len >> 16;
141	*enc->cur++ = len >> 8;
142	*enc->cur++ = len;
143	}
144	else
145	{
146	*enc->cur++ = major \| 27;
147	*enc->cur++ = len >> 56;
148	*enc->cur++ = len >> 48;
149	*enc->cur++ = len >> 40;
150	*enc->cur++ = len >> 32;
151	*enc->cur++ = len >> 24;
152	*enc->cur++ = len >> 16;
153	*enc->cur++ = len >> 8;
154	*enc->cur++ = len;
155	}
156	}
157
158	static void
159	encode_str (enc_t enc, int utf8, char str, STRLEN len)
160	{
161	encode_uint (enc, utf8 ? 0x60 : 0x40, len);
162	need (enc, len);
163	memcpy (enc->cur, str, len);
164	enc->cur += len;
165	}
166
167	static void encode_sv (enc_t enc, SV sv);
168
169	static void
170	encode_av (enc_t enc, AV av)
171	{
172	int i, len = av_len (av);
173
174	if (enc->depth >= enc->cbor.max_depth)
175	croak (ERR_NESTING_EXCEEDED);
176
177	++enc->depth;
178
179	encode_uint (enc, 0x80, len + 1);
180
181	for (i = 0; i <= len; ++i)
182	{
183	SV **svp = av_fetch (av, i, 0);
184	encode_sv (enc, svp ? *svp : &PL_sv_undef);
185	}
186
187	--enc->depth;
188	}
189
190	static void
191	encode_hv (enc_t enc, HV hv)
192	{
193	HE *he;
194
195	if (enc->depth >= enc->cbor.max_depth)
196	croak (ERR_NESTING_EXCEEDED);
197
198	++enc->depth;
199
200	int pairs = hv_iterinit (hv);
201	int mg = SvMAGICAL (hv);
202
203	if (mg)
204	encode_ch (enc, 0xa0 \| 31);
205	else
206	encode_uint (enc, 0xa0, pairs);
207
208	while ((he = hv_iternext (hv)))
209	{
210	if (HeKLEN (he) == HEf_SVKEY)
211	encode_sv (enc, HeSVKEY (he));
212	else
213	encode_str (enc, HeKUTF8 (he), HeKEY (he), HeKLEN (he));
214
215	encode_sv (enc, ecb_expect_false (mg) ? hv_iterval (hv, he) : HeVAL (he));
216	}
217
218	if (mg)
219	encode_ch (enc, 0xe0 \| 31);
220
221	--enc->depth;
222	}
223
224	// encode objects, arrays and special \0=false and \1=true values.
225	static void
226	encode_rv (enc_t enc, SV sv)
227	{
228	svtype svt;
229
230	SvGETMAGIC (sv);
231	svt = SvTYPE (sv);
232
233	if (ecb_expect_false (SvOBJECT (sv)))
234	{
235	HV *boolean_stash = !CBOR_SLOW \|\| cbor_boolean_stash
236	? cbor_boolean_stash
237	: gv_stashpv ("CBOR::XS::Boolean", 1);
238	HV *tagged_stash = !CBOR_SLOW \|\| cbor_tagged_stash
239	? cbor_tagged_stash
240	: gv_stashpv ("CBOR::XS::Tagged" , 1);
241
242	if (SvSTASH (sv) == boolean_stash)
243	encode_ch (enc, SvIV (sv) ? 0xe0 \| 21 : 0xe0 \| 20);
244	else if (SvSTASH (sv) == tagged_stash)
245	{
246	if (svt != SVt_PVAV)
247	croak ("encountered CBOR::XS::Tagged object that isn't an array");
248
249	encode_uint (enc, 0xc0, SvUV (av_fetch ((AV )sv, 0, 1)));
250	encode_sv (enc, av_fetch ((AV )sv, 1, 1));
251	}
252	else
253	{
254	// we re-bless the reference to get overload and other niceties right
255	GV *to_cbor = gv_fetchmethod_autoload (SvSTASH (sv), "TO_CBOR", 0);
256
257	if (to_cbor)
258	{
259	dSP;
260
261	ENTER; SAVETMPS; PUSHMARK (SP);
262	XPUSHs (sv_bless (sv_2mortal (newRV_inc (sv)), SvSTASH (sv)));
263
264	// calling with G_SCALAR ensures that we always get a 1 return value
265	PUTBACK;
266	call_sv ((SV *)GvCV (to_cbor), G_SCALAR);
267	SPAGAIN;
268
269	// catch this surprisingly common error
270	if (SvROK (TOPs) && SvRV (TOPs) == sv)
271	croak ("%s::TO_CBOR method returned same object as was passed instead of a new one", HvNAME (SvSTASH (sv)));
272
273	sv = POPs;
274	PUTBACK;
275
276	encode_sv (enc, sv);
277
278	FREETMPS; LEAVE;
279	}
280	else
281	croak ("encountered object '%s', but no TO_CBOR method available on it",
282	SvPV_nolen (sv_2mortal (newRV_inc (sv))));
283	}
284	}
285	else if (svt == SVt_PVHV)
286	encode_hv (enc, (HV *)sv);
287	else if (svt == SVt_PVAV)
288	encode_av (enc, (AV *)sv);
289	else if (svt < SVt_PVAV)
290	{
291	STRLEN len = 0;
292	char *pv = svt ? SvPV (sv, len) : 0;
293
294	if (len == 1 && *pv == '1')
295	encode_ch (enc, 0xe0 \| 21);
296	else if (len == 1 && *pv == '0')
297	encode_ch (enc, 0xe0 \| 20);
298	else if (enc->cbor.flags & F_ALLOW_UNKNOWN)
299	encode_ch (enc, 0xe0 \| 23);
300	else
301	croak ("cannot encode reference to scalar '%s' unless the scalar is 0 or 1",
302	SvPV_nolen (sv_2mortal (newRV_inc (sv))));
303	}
304	else if (enc->cbor.flags & F_ALLOW_UNKNOWN)
305	encode_ch (enc, 0xe0 \| 23);
306	else
307	croak ("encountered %s, but CBOR can only represent references to arrays or hashes",
308	SvPV_nolen (sv_2mortal (newRV_inc (sv))));
309	}
310
311	static void
312	encode_nv (enc_t enc, SV sv)
313	{
314	double nv = SvNVX (sv);
315
316	need (enc, 9);
317
318	if (ecb_expect_false (nv == (U32)nv))
319	encode_uint (enc, 0x00, (U32)nv);
320	//TODO: maybe I32?
321	else if (ecb_expect_false (nv == (float)nv))
322	{
323	uint32_t fp = ecb_float_to_binary32 (nv);
324
325	*enc->cur++ = 0xe0 \| 26;
326
327	if (!ecb_big_endian ())
328	fp = ecb_bswap32 (fp);
329
330	memcpy (enc->cur, &fp, 4);
331	enc->cur += 4;
332	}
333	else
334	{
335	uint64_t fp = ecb_double_to_binary64 (nv);
336
337	*enc->cur++ = 0xe0 \| 27;
338
339	if (!ecb_big_endian ())
340	fp = ecb_bswap64 (fp);
341
342	memcpy (enc->cur, &fp, 8);
343	enc->cur += 8;
344	}
345	}
346
347	static void
348	encode_sv (enc_t enc, SV sv)
349	{
350	SvGETMAGIC (sv);
351
352	if (SvPOKp (sv))
353	{
354	STRLEN len;
355	char *str = SvPV (sv, len);
356	encode_str (enc, SvUTF8 (sv), str, len);
357	}
358	else if (SvNOKp (sv))
359	encode_nv (enc, sv);
360	else if (SvIOKp (sv))
361	{
362	if (SvIsUV (sv))
363	encode_uint (enc, 0x00, SvUVX (sv));
364	else if (SvIVX (sv) >= 0)
365	encode_uint (enc, 0x00, SvIVX (sv));
366	else
367	encode_uint (enc, 0x20, -(SvIVX (sv) + 1));
368	}
369	else if (SvROK (sv))
370	encode_rv (enc, SvRV (sv));
371	else if (!SvOK (sv))
372	encode_ch (enc, 0xe0 \| 22);
373	else if (enc->cbor.flags & F_ALLOW_UNKNOWN)
374	encode_ch (enc, 0xe0 \| 23);
375	else
376	croak ("encountered perl type (%s,0x%x) that CBOR cannot handle, check your input data",
377	SvPV_nolen (sv), (unsigned int)SvFLAGS (sv));
378	}
379
380	static SV *
381	encode_cbor (SV scalar, CBOR cbor)
382	{
383	enc_t enc;
384
385	enc.cbor = *cbor;
386	enc.sv = sv_2mortal (NEWSV (0, INIT_SIZE));
387	enc.cur = SvPVX (enc.sv);
388	enc.end = SvEND (enc.sv);
389	enc.depth = 0;
390
391	SvPOK_only (enc.sv);
392	encode_sv (&enc, scalar);
393
394	SvCUR_set (enc.sv, enc.cur - SvPVX (enc.sv));
395	*SvEND (enc.sv) = 0; // many xs functions expect a trailing 0 for text strings
396
397	if (enc.cbor.flags & F_SHRINK)
398	shrink (enc.sv);
399
400	return enc.sv;
401	}
402
403	/////////////////////////////////////////////////////////////////////////////
404	// decoder
405
406	// structure used for decoding CBOR
407	typedef struct
408	{
409	U8 *cur; // current parser pointer
410	U8 *end; // end of input string
411	const char *err; // parse error, if != 0
412	CBOR cbor;
413	U32 depth; // recursion depth
414	U32 maxdepth; // recursion depth limit
415	} dec_t;
416
417	#define ERR(reason) SB if (!dec->err) dec->err = reason; goto fail; SE
418
419	#define WANT(len) if (ecb_expect_false (dec->cur + len > dec->end)) ERR ("unexpected end of CBOR data")
420
421	#define DEC_INC_DEPTH if (++dec->depth > dec->cbor.max_depth) ERR (ERR_NESTING_EXCEEDED)
422	#define DEC_DEC_DEPTH --dec->depth
423
424	static UV
425	decode_uint (dec_t *dec)
426	{
427	switch (*dec->cur & 31)
428	{
429	case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
430	case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15:
431	case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23:
432	return *dec->cur++ & 31;
433
434	case 24:
435	WANT (2);
436	dec->cur += 2;
437	return dec->cur[-1];
438
439	case 25:
440	WANT (3);
441	dec->cur += 3;
442	return (((UV)dec->cur[-2]) << 8)
443	\| ((UV)dec->cur[-1]);
444
445	case 26:
446	WANT (5);
447	dec->cur += 5;
448	return (((UV)dec->cur[-4]) << 24)
449	\| (((UV)dec->cur[-3]) << 16)
450	\| (((UV)dec->cur[-2]) << 8)
451	\| ((UV)dec->cur[-1]);
452
453	case 27:
454	WANT (9);
455	dec->cur += 9;
456	return (((UV)dec->cur[-8]) << 56)
457	\| (((UV)dec->cur[-7]) << 48)
458	\| (((UV)dec->cur[-6]) << 40)
459	\| (((UV)dec->cur[-5]) << 32)
460	\| (((UV)dec->cur[-4]) << 24)
461	\| (((UV)dec->cur[-3]) << 16)
462	\| (((UV)dec->cur[-2]) << 8)
463	\| ((UV)dec->cur[-1]);
464
465	default:
466	ERR ("corrupted CBOR data (unsupported integer minor encoding)");
467	}
468
469	fail:
470	return 0;
471	}
472
473	static SV decode_sv (dec_t dec);
474
475	static SV *
476	decode_av (dec_t *dec)
477	{
478	AV *av = newAV ();
479
480	DEC_INC_DEPTH;
481
482	if ((*dec->cur & 31) == 31)
483	{
484	++dec->cur;
485
486	for (;;)
487	{
488	WANT (1);
489
490	if (*dec->cur == (0xe0 \| 31))
491	{
492	++dec->cur;
493	break;
494	}
495
496	av_push (av, decode_sv (dec));
497	}
498	}
499	else
500	{
501	int i, len = decode_uint (dec);
502
503	av_fill (av, len - 1);
504
505	for (i = 0; i < len; ++i)
506	AvARRAY (av)[i] = decode_sv (dec);
507	}
508
509	DEC_DEC_DEPTH;
510	return newRV_noinc ((SV *)av);
511
512	fail:
513	SvREFCNT_dec (av);
514	DEC_DEC_DEPTH;
515	return &PL_sv_undef;
516	}
517
518	static SV *
519	decode_hv (dec_t *dec)
520	{
521	HV *hv = newHV ();
522
523	DEC_INC_DEPTH;
524
525	if ((*dec->cur & 31) == 31)
526	{
527	++dec->cur;
528
529	for (;;)
530	{
531	WANT (1);
532
533	if (*dec->cur == (0xe0 \| 31))
534	{
535	++dec->cur;
536	break;
537	}
538
539	SV *k = decode_sv (dec);
540	SV *v = decode_sv (dec);
541
542	hv_store_ent (hv, k, v, 0);
543	}
544	}
545	else
546	{
547	int len = decode_uint (dec);
548
549	while (len--)
550	{
551	SV *k = decode_sv (dec);
552	SV *v = decode_sv (dec);
553
554	hv_store_ent (hv, k, v, 0);
555	}
556	}
557
558	DEC_DEC_DEPTH;
559	return newRV_noinc ((SV *)hv);
560
561	fail:
562	SvREFCNT_dec (hv);
563	DEC_DEC_DEPTH;
564	return &PL_sv_undef;
565	}
566
567	static SV *
568	decode_str (dec_t *dec, int utf8)
569	{
570	SV *sv = 0;
571
572	if ((*dec->cur & 31) == 31)
573	{
574	++dec->cur;
575
576	sv = newSVpvn ("", 0);
577
578	// not very fast, and certainly not robust against illegal input
579	for (;;)
580	{
581	WANT (1);
582
583	if (*dec->cur == (0xe0 \| 31))
584	{
585	++dec->cur;
586	break;
587	}
588
589	sv_catsv (sv, decode_sv (dec));
590	}
591	}
592	else
593	{
594	STRLEN len = decode_uint (dec);
595
596	WANT (len);
597	sv = newSVpvn (dec->cur, len);
598	dec->cur += len;
599	}
600
601	if (utf8)
602	SvUTF8_on (sv);
603
604	return sv;
605
606	fail:
607	SvREFCNT_dec (sv);
608	return &PL_sv_undef;
609	}
610
611	static SV *
612	decode_tagged (dec_t *dec)
613	{
614	UV tag = decode_uint (dec);
615	SV *sv = decode_sv (dec);
616
617	if (tag == 55799) // 2.4.5 Self-Describe CBOR
618	return sv;
619
620	AV *av = newAV ();
621	av_push (av, newSVuv (tag));
622	av_push (av, sv);
623	return newRV_noinc ((SV *)av);
624	}
625
626	static SV *
627	decode_sv (dec_t *dec)
628	{
629	WANT (1);
630
631	switch (*dec->cur >> 5)
632	{
633	case 0: // unsigned int
634	return newSVuv (decode_uint (dec));
635	case 1: // negative int
636	return newSViv (-1 - (IV)decode_uint (dec));
637	case 2: // octet string
638	return decode_str (dec, 0);
639	case 3: // utf-8 string
640	return decode_str (dec, 1);
641	case 4: // array
642	return decode_av (dec);
643	case 5: // map
644	return decode_hv (dec);
645	case 6: // tag
646	return decode_tagged (dec);
647	case 7: // misc
648	switch (*dec->cur++ & 31)
649	{
650	case 20:
651	#if CBOR_SLOW
652	cbor_false = get_bool ("CBOR::XS::false");
653	#endif
654	return newSVsv (cbor_false);
655	case 21:
656	#if CBOR_SLOW
657	cbor_true = get_bool ("CBOR::XS::true");
658	#endif
659	return newSVsv (cbor_true);
660	case 22:
661	return newSVsv (&PL_sv_undef);
662
663	case 25:
664	{
665	WANT (2);
666
667	uint16_t fp = (dec->cur[0] << 8) \| dec->cur[1];
668	dec->cur += 2;
669
670	return newSVnv (ecb_binary16_to_float (fp));
671	}
672
673	case 26:
674	{
675	uint32_t fp;
676	WANT (4);
677	memcpy (&fp, dec->cur, 4);
678	dec->cur += 4;
679
680	if (!ecb_big_endian ())
681	fp = ecb_bswap32 (fp);
682
683	return newSVnv (ecb_binary32_to_float (fp));
684	}
685
686	case 27:
687	{
688	uint64_t fp;
689	WANT (8);
690	memcpy (&fp, dec->cur, 8);
691	dec->cur += 8;
692
693	if (!ecb_big_endian ())
694	fp = ecb_bswap64 (fp);
695
696	return newSVnv (ecb_binary64_to_double (fp));
697	}
698
699	// 0..19 unassigned
700	// 24 reserved + unassigned (reserved values are not encodable)
701	default:
702	ERR ("corrupted CBOR data (reserved/unassigned major 7 value)");
703	}
704
705	break;
706	}
707
708	fail:
709	return &PL_sv_undef;
710	}
711
712	static SV *
713	decode_cbor (SV string, CBOR cbor, char **offset_return)
714	{
715	dec_t dec;
716	SV *sv;
717
718	/* work around bugs in 5.10 where manipulating magic values
719	* makes perl ignore the magic in subsequent accesses.
720	* also make a copy of non-PV values, to get them into a clean
721	* state (SvPV should do that, but it's buggy, see below).
722	*/
723	/SvGETMAGIC (string);/
724	if (SvMAGICAL (string) \|\| !SvPOK (string))
725	string = sv_2mortal (newSVsv (string));
726
727	SvUPGRADE (string, SVt_PV);
728
729	/* work around a bug in perl 5.10, which causes SvCUR to fail an
730	* assertion with -DDEBUGGING, although SvCUR is documented to
731	* return the xpv_cur field which certainly exists after upgrading.
732	* according to nicholas clark, calling SvPOK fixes this.
733	* But it doesn't fix it, so try another workaround, call SvPV_nolen
734	* and hope for the best.
735	* Damnit, SvPV_nolen still trips over yet another assertion. This
736	* assertion business is seriously broken, try yet another workaround
737	* for the broken -DDEBUGGING.
738	*/
739	{
740	#ifdef DEBUGGING
741	STRLEN offset = SvOK (string) ? sv_len (string) : 0;
742	#else
743	STRLEN offset = SvCUR (string);
744	#endif
745
746	if (offset > cbor->max_size && cbor->max_size)
747	croak ("attempted decode of CBOR text of %lu bytes size, but max_size is set to %lu",
748	(unsigned long)SvCUR (string), (unsigned long)cbor->max_size);
749	}
750
751	sv_utf8_downgrade (string, 0);
752
753	dec.cbor = *cbor;
754	dec.cur = (U8 *)SvPVX (string);
755	dec.end = (U8 *)SvEND (string);
756	dec.err = 0;
757	dec.depth = 0;
758
759	sv = decode_sv (&dec);
760
761	if (offset_return)
762	*offset_return = dec.cur;
763
764	if (!(offset_return \|\| !sv))
765	if (dec.cur != dec.end && !dec.err)
766	dec.err = "garbage after CBOR object";
767
768	if (dec.err)
769	{
770	SvREFCNT_dec (sv);
771	croak ("%s, at offset %d (octet 0x%02x)", dec.err, dec.cur - (U8 )SvPVX (string), (int)(uint8_t)dec.cur);
772	}
773
774	sv = sv_2mortal (sv);
775
776	return sv;
777	}
778
779	/////////////////////////////////////////////////////////////////////////////
780	// XS interface functions
781
782	MODULE = CBOR::XS PACKAGE = CBOR::XS
783
784	BOOT:
785	{
786	cbor_stash = gv_stashpv ("CBOR::XS" , 1);
787	cbor_boolean_stash = gv_stashpv ("CBOR::XS::Boolean", 1);
788	cbor_tagged_stash = gv_stashpv ("CBOR::XS::Tagged" , 1);
789
790	cbor_true = get_bool ("CBOR::XS::true");
791	cbor_false = get_bool ("CBOR::XS::false");
792	}
793
794	PROTOTYPES: DISABLE
795
796	void CLONE (...)
797	CODE:
798	cbor_stash = 0;
799	cbor_boolean_stash = 0;
800	cbor_tagged_stash = 0;
801
802	void new (char *klass)
803	PPCODE:
804	{
805	SV *pv = NEWSV (0, sizeof (CBOR));
806	SvPOK_only (pv);
807	cbor_init ((CBOR *)SvPVX (pv));
808	XPUSHs (sv_2mortal (sv_bless (
809	newRV_noinc (pv),
810	strEQ (klass, "CBOR::XS") ? CBOR_STASH : gv_stashpv (klass, 1)
811	)));
812	}
813
814	void shrink (CBOR *self, int enable = 1)
815	ALIAS:
816	shrink = F_SHRINK
817	allow_unknown = F_ALLOW_UNKNOWN
818	PPCODE:
819	{
820	if (enable)
821	self->flags \|= ix;
822	else
823	self->flags &= ~ix;
824
825	XPUSHs (ST (0));
826	}
827
828	void get_shrink (CBOR *self)
829	ALIAS:
830	get_shrink = F_SHRINK
831	get_allow_unknown = F_ALLOW_UNKNOWN
832	PPCODE:
833	XPUSHs (boolSV (self->flags & ix));
834
835	void max_depth (CBOR *self, U32 max_depth = 0x80000000UL)
836	PPCODE:
837	self->max_depth = max_depth;
838	XPUSHs (ST (0));
839
840	U32 get_max_depth (CBOR *self)
841	CODE:
842	RETVAL = self->max_depth;
843	OUTPUT:
844	RETVAL
845
846	void max_size (CBOR *self, U32 max_size = 0)
847	PPCODE:
848	self->max_size = max_size;
849	XPUSHs (ST (0));
850
851	int get_max_size (CBOR *self)
852	CODE:
853	RETVAL = self->max_size;
854	OUTPUT:
855	RETVAL
856
857	#if 0 //TODO
858
859	void filter_cbor_object (CBOR self, SV cb = &PL_sv_undef)
860	PPCODE:
861	{
862	SvREFCNT_dec (self->cb_object);
863	self->cb_object = SvOK (cb) ? newSVsv (cb) : 0;
864
865	XPUSHs (ST (0));
866	}
867
868	void filter_cbor_single_key_object (CBOR self, SV key, SV *cb = &PL_sv_undef)
869	PPCODE:
870	{
871	if (!self->cb_sk_object)
872	self->cb_sk_object = newHV ();
873
874	if (SvOK (cb))
875	hv_store_ent (self->cb_sk_object, key, newSVsv (cb), 0);
876	else
877	{
878	hv_delete_ent (self->cb_sk_object, key, G_DISCARD, 0);
879
880	if (!HvKEYS (self->cb_sk_object))
881	{
882	SvREFCNT_dec (self->cb_sk_object);
883	self->cb_sk_object = 0;
884	}
885	}
886
887	XPUSHs (ST (0));
888	}
889
890	#endif
891
892	void encode (CBOR self, SV scalar)
893	PPCODE:
894	PUTBACK; scalar = encode_cbor (scalar, self); SPAGAIN;
895	XPUSHs (scalar);
896
897	void decode (CBOR self, SV cborstr)
898	PPCODE:
899	PUTBACK; cborstr = decode_cbor (cborstr, self, 0); SPAGAIN;
900	XPUSHs (cborstr);
901
902	void decode_prefix (CBOR self, SV cborstr)
903	PPCODE:
904	{
905	SV *sv;
906	char *offset;
907	PUTBACK; sv = decode_cbor (cborstr, self, &offset); SPAGAIN;
908	EXTEND (SP, 2);
909	PUSHs (sv);
910	PUSHs (sv_2mortal (newSVuv (offset - SvPVX (cborstr))));
911	}
912
913	#if 0
914
915	void DESTROY (CBOR *self)
916	CODE:
917	SvREFCNT_dec (self->cb_sk_object);
918	SvREFCNT_dec (self->cb_object);
919
920	#endif
921
922	PROTOTYPES: ENABLE
923
924	void encode_cbor (SV *scalar)
925	PPCODE:
926	{
927	CBOR cbor;
928	cbor_init (&cbor);
929	PUTBACK; scalar = encode_cbor (scalar, &cbor); SPAGAIN;
930	XPUSHs (scalar);
931	}
932
933	void decode_cbor (SV *cborstr)
934	PPCODE:
935	{
936	CBOR cbor;
937	cbor_init (&cbor);
938	PUTBACK; cborstr = decode_cbor (cborstr, &cbor, 0); SPAGAIN;
939	XPUSHs (cborstr);
940	}
941