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Sourcecode: postgresql-8.4 version File versions  Download package

hstore_gist.c

/*
 * $PostgreSQL: pgsql/contrib/hstore/hstore_gist.c,v 1.10 2009/06/11 14:48:51 momjian Exp $
 */
#include "postgres.h"

#include "access/gist.h"
#include "access/itup.h"
#include "access/skey.h"
#include "crc32.h"

#include "hstore.h"

/* bigint defines */
#define BITBYTE 8
#define SIGLENINT  4                /* >122 => key will toast, so very slow!!! */
#define SIGLEN    ( sizeof(int)*SIGLENINT )
#define SIGLENBIT (SIGLEN*BITBYTE)

typedef char BITVEC[SIGLEN];
typedef char *BITVECP;

#define SIGPTR(x)  ( (BITVECP) ARR_DATA_PTR(x) )


#define LOOPBYTE \
                  for(i=0;i<SIGLEN;i++)

#define LOOPBIT \
                  for(i=0;i<SIGLENBIT;i++)

/* beware of multiple evaluation of arguments to these macros! */
#define GETBYTE(x,i) ( *( (BITVECP)(x) + (int)( (i) / BITBYTE ) ) )
#define GETBITBYTE(x,i) ( (*((char*)(x)) >> (i)) & 0x01 )
#define CLRBIT(x,i)   GETBYTE(x,i) &= ~( 0x01 << ( (i) % BITBYTE ) )
#define SETBIT(x,i)   GETBYTE(x,i) |=  ( 0x01 << ( (i) % BITBYTE ) )
#define GETBIT(x,i) ( (GETBYTE(x,i) >> ( (i) % BITBYTE )) & 0x01 )
#define HASHVAL(val) (((unsigned int)(val)) % SIGLENBIT)
#define HASH(sign, val) SETBIT((sign), HASHVAL(val))

00040 typedef struct
{
      int32       vl_len_;          /* varlena header (do not touch directly!) */
      int4        flag;
      char        data[1];
} GISTTYPE;

#define ALLISTRUE       0x04

#define ISALLTRUE(x)    ( ((GISTTYPE*)x)->flag & ALLISTRUE )

#define GTHDRSIZE       (VARHDRSZ + sizeof(int4))
#define CALCGTSIZE(flag) ( GTHDRSIZE+(((flag) & ALLISTRUE) ? 0 : SIGLEN) )

#define GETSIGN(x)            ( (BITVECP)( (char*)x+GTHDRSIZE ) )

#define SUMBIT(val) (         \
      GETBITBYTE((val),0) + \
      GETBITBYTE((val),1) + \
      GETBITBYTE((val),2) + \
      GETBITBYTE((val),3) + \
      GETBITBYTE((val),4) + \
      GETBITBYTE((val),5) + \
      GETBITBYTE((val),6) + \
      GETBITBYTE((val),7)   \
)

#define GETENTRY(vec,pos) ((GISTTYPE *) DatumGetPointer((vec)->vector[(pos)].key))

#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )

PG_FUNCTION_INFO_V1(ghstore_in);
Datum       ghstore_in(PG_FUNCTION_ARGS);

PG_FUNCTION_INFO_V1(ghstore_out);
Datum       ghstore_out(PG_FUNCTION_ARGS);


Datum
ghstore_in(PG_FUNCTION_ARGS)
{
      elog(ERROR, "Not implemented");
      PG_RETURN_DATUM(0);
}

Datum
ghstore_out(PG_FUNCTION_ARGS)
{
      elog(ERROR, "Not implemented");
      PG_RETURN_DATUM(0);
}

PG_FUNCTION_INFO_V1(ghstore_consistent);
PG_FUNCTION_INFO_V1(ghstore_compress);
PG_FUNCTION_INFO_V1(ghstore_decompress);
PG_FUNCTION_INFO_V1(ghstore_penalty);
PG_FUNCTION_INFO_V1(ghstore_picksplit);
PG_FUNCTION_INFO_V1(ghstore_union);
PG_FUNCTION_INFO_V1(ghstore_same);

Datum       ghstore_consistent(PG_FUNCTION_ARGS);
Datum       ghstore_compress(PG_FUNCTION_ARGS);
Datum       ghstore_decompress(PG_FUNCTION_ARGS);
Datum       ghstore_penalty(PG_FUNCTION_ARGS);
Datum       ghstore_picksplit(PG_FUNCTION_ARGS);
Datum       ghstore_union(PG_FUNCTION_ARGS);
Datum       ghstore_same(PG_FUNCTION_ARGS);

Datum
ghstore_compress(PG_FUNCTION_ARGS)
{
      GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
      GISTENTRY  *retval = entry;

      if (entry->leafkey)
      {
            GISTTYPE   *res = (GISTTYPE *) palloc0(CALCGTSIZE(0));
            HStore         *toastedval = (HStore *) DatumGetPointer(entry->key);
            HStore         *val = (HStore *) DatumGetPointer(PG_DETOAST_DATUM(entry->key));
            HEntry         *ptr = ARRPTR(val);
            char     *words = STRPTR(val);

            SET_VARSIZE(res, CALCGTSIZE(0));

            while (ptr - ARRPTR(val) < val->size)
            {
                  int               h;

                  h = crc32_sz((char *) (words + ptr->pos), ptr->keylen);
                  HASH(GETSIGN(res), h);
                  if (!ptr->valisnull)
                  {
                        h = crc32_sz((char *) (words + ptr->pos + ptr->keylen), ptr->vallen);
                        HASH(GETSIGN(res), h);
                  }
                  ptr++;
            }

            if (val != toastedval)
                  pfree(val);

            retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
            gistentryinit(*retval, PointerGetDatum(res),
                                entry->rel, entry->page,
                                entry->offset,
                                FALSE);
      }
      else if (!ISALLTRUE(DatumGetPointer(entry->key)))
      {
            int4        i;
            GISTTYPE   *res;
            BITVECP           sign = GETSIGN(DatumGetPointer(entry->key));

            LOOPBYTE
            {
                  if ((sign[i] & 0xff) != 0xff)
                        PG_RETURN_POINTER(retval);
            }

            res = (GISTTYPE *) palloc(CALCGTSIZE(ALLISTRUE));
            SET_VARSIZE(res, CALCGTSIZE(ALLISTRUE));
            res->flag = ALLISTRUE;

            retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
            gistentryinit(*retval, PointerGetDatum(res),
                                entry->rel, entry->page,
                                entry->offset,
                                FALSE);
      }

      PG_RETURN_POINTER(retval);
}

Datum
ghstore_decompress(PG_FUNCTION_ARGS)
{
      GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
      GISTENTRY  *retval;
      HStore         *key;

      key = (HStore *) PG_DETOAST_DATUM(entry->key);

      if (key != (HStore *) DatumGetPointer(entry->key))
      {
            /* need to pass back the decompressed item */
            retval = palloc(sizeof(GISTENTRY));
            gistentryinit(*retval, PointerGetDatum(key),
                                entry->rel, entry->page, entry->offset, entry->leafkey);
            PG_RETURN_POINTER(retval);
      }
      else
      {
            /* we can return the entry as-is */
            PG_RETURN_POINTER(entry);
      }
}

Datum
ghstore_same(PG_FUNCTION_ARGS)
{
      GISTTYPE   *a = (GISTTYPE *) PG_GETARG_POINTER(0);
      GISTTYPE   *b = (GISTTYPE *) PG_GETARG_POINTER(1);
      bool     *result = (bool *) PG_GETARG_POINTER(2);

      if (ISALLTRUE(a) && ISALLTRUE(b))
            *result = true;
      else if (ISALLTRUE(a))
            *result = false;
      else if (ISALLTRUE(b))
            *result = false;
      else
      {
            int4        i;
            BITVECP           sa = GETSIGN(a),
                              sb = GETSIGN(b);

            *result = true;
            LOOPBYTE
            {
                  if (sa[i] != sb[i])
                  {
                        *result = false;
                        break;
                  }
            }
      }
      PG_RETURN_POINTER(result);
}

static int4
sizebitvec(BITVECP sign)
{
      int4        size = 0,
                        i;

      LOOPBYTE
      {
            size += SUMBIT(sign);
            sign = (BITVECP) (((char *) sign) + 1);
      }
      return size;
}

static int
hemdistsign(BITVECP a, BITVECP b)
{
      int               i,
                        dist = 0;

      LOOPBIT
      {
            if (GETBIT(a, i) != GETBIT(b, i))
                  dist++;
      }
      return dist;
}

static int
hemdist(GISTTYPE *a, GISTTYPE *b)
{
      if (ISALLTRUE(a))
      {
            if (ISALLTRUE(b))
                  return 0;
            else
                  return SIGLENBIT - sizebitvec(GETSIGN(b));
      }
      else if (ISALLTRUE(b))
            return SIGLENBIT - sizebitvec(GETSIGN(a));

      return hemdistsign(GETSIGN(a), GETSIGN(b));
}

static int4
unionkey(BITVECP sbase, GISTTYPE *add)
{
      int4        i;
      BITVECP           sadd = GETSIGN(add);

      if (ISALLTRUE(add))
            return 1;
      LOOPBYTE
            sbase[i] |= sadd[i];
      return 0;
}

Datum
ghstore_union(PG_FUNCTION_ARGS)
{
      GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
      int4        len = entryvec->n;

      int            *size = (int *) PG_GETARG_POINTER(1);
      BITVEC            base;
      int4        i;
      int4        flag = 0;
      GISTTYPE   *result;

      MemSet((void *) base, 0, sizeof(BITVEC));
      for (i = 0; i < len; i++)
      {
            if (unionkey(base, GETENTRY(entryvec, i)))
            {
                  flag = ALLISTRUE;
                  break;
            }
      }

      len = CALCGTSIZE(flag);
      result = (GISTTYPE *) palloc(len);
      SET_VARSIZE(result, len);
      result->flag = flag;
      if (!ISALLTRUE(result))
            memcpy((void *) GETSIGN(result), (void *) base, sizeof(BITVEC));
      *size = len;

      PG_RETURN_POINTER(result);
}

Datum
ghstore_penalty(PG_FUNCTION_ARGS)
{
      GISTENTRY  *origentry = (GISTENTRY *) PG_GETARG_POINTER(0); /* always ISSIGNKEY */
      GISTENTRY  *newentry = (GISTENTRY *) PG_GETARG_POINTER(1);
      float    *penalty = (float *) PG_GETARG_POINTER(2);
      GISTTYPE   *origval = (GISTTYPE *) DatumGetPointer(origentry->key);
      GISTTYPE   *newval = (GISTTYPE *) DatumGetPointer(newentry->key);

      *penalty = hemdist(origval, newval);
      PG_RETURN_POINTER(penalty);
}


00333 typedef struct
{
      OffsetNumber pos;
      int4        cost;
} SPLITCOST;

static int
comparecost(const void *a, const void *b)
{
      return ((SPLITCOST *) a)->cost - ((SPLITCOST *) b)->cost;
}


Datum
ghstore_picksplit(PG_FUNCTION_ARGS)
{
      GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
      OffsetNumber maxoff = entryvec->n - 2;

      GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
      OffsetNumber k,
                        j;
      GISTTYPE   *datum_l,
                     *datum_r;
      BITVECP           union_l,
                        union_r;
      int4        size_alpha,
                        size_beta;
      int4        size_waste,
                        waste = -1;
      int4        nbytes;
      OffsetNumber seed_1 = 0,
                        seed_2 = 0;
      OffsetNumber *left,
                     *right;
      BITVECP           ptr;
      int               i;
      SPLITCOST  *costvector;
      GISTTYPE   *_k,
                     *_j;

      nbytes = (maxoff + 2) * sizeof(OffsetNumber);
      v->spl_left = (OffsetNumber *) palloc(nbytes);
      v->spl_right = (OffsetNumber *) palloc(nbytes);

      for (k = FirstOffsetNumber; k < maxoff; k = OffsetNumberNext(k))
      {
            _k = GETENTRY(entryvec, k);
            for (j = OffsetNumberNext(k); j <= maxoff; j = OffsetNumberNext(j))
            {
                  size_waste = hemdist(_k, GETENTRY(entryvec, j));
                  if (size_waste > waste)
                  {
                        waste = size_waste;
                        seed_1 = k;
                        seed_2 = j;
                  }
            }
      }

      left = v->spl_left;
      v->spl_nleft = 0;
      right = v->spl_right;
      v->spl_nright = 0;

      if (seed_1 == 0 || seed_2 == 0)
      {
            seed_1 = 1;
            seed_2 = 2;
      }

      /* form initial .. */
      if (ISALLTRUE(GETENTRY(entryvec, seed_1)))
      {
            datum_l = (GISTTYPE *) palloc(GTHDRSIZE);
            SET_VARSIZE(datum_l, GTHDRSIZE);
            datum_l->flag = ALLISTRUE;
      }
      else
      {
            datum_l = (GISTTYPE *) palloc(GTHDRSIZE + SIGLEN);
            SET_VARSIZE(datum_l, GTHDRSIZE + SIGLEN);
            datum_l->flag = 0;
            memcpy((void *) GETSIGN(datum_l), (void *) GETSIGN(GETENTRY(entryvec, seed_1)), sizeof(BITVEC))
                  ;
      }
      if (ISALLTRUE(GETENTRY(entryvec, seed_2)))
      {
            datum_r = (GISTTYPE *) palloc(GTHDRSIZE);
            SET_VARSIZE(datum_r, GTHDRSIZE);
            datum_r->flag = ALLISTRUE;
      }
      else
      {
            datum_r = (GISTTYPE *) palloc(GTHDRSIZE + SIGLEN);
            SET_VARSIZE(datum_r, GTHDRSIZE + SIGLEN);
            datum_r->flag = 0;
            memcpy((void *) GETSIGN(datum_r), (void *) GETSIGN(GETENTRY(entryvec, seed_2)), sizeof(BITVEC));
      }

      maxoff = OffsetNumberNext(maxoff);
      /* sort before ... */
      costvector = (SPLITCOST *) palloc(sizeof(SPLITCOST) * maxoff);
      for (j = FirstOffsetNumber; j <= maxoff; j = OffsetNumberNext(j))
      {
            costvector[j - 1].pos = j;
            _j = GETENTRY(entryvec, j);
            size_alpha = hemdist(datum_l, _j);
            size_beta = hemdist(datum_r, _j);
            costvector[j - 1].cost = abs(size_alpha - size_beta);
      }
      qsort((void *) costvector, maxoff, sizeof(SPLITCOST), comparecost);

      union_l = GETSIGN(datum_l);
      union_r = GETSIGN(datum_r);

      for (k = 0; k < maxoff; k++)
      {
            j = costvector[k].pos;
            if (j == seed_1)
            {
                  *left++ = j;
                  v->spl_nleft++;
                  continue;
            }
            else if (j == seed_2)
            {
                  *right++ = j;
                  v->spl_nright++;
                  continue;
            }
            _j = GETENTRY(entryvec, j);
            size_alpha = hemdist(datum_l, _j);
            size_beta = hemdist(datum_r, _j);

            if (size_alpha < size_beta + WISH_F(v->spl_nleft, v->spl_nright, 0.0001))
            {
                  if (ISALLTRUE(datum_l) || ISALLTRUE(_j))
                  {
                        if (!ISALLTRUE(datum_l))
                              MemSet((void *) union_l, 0xff, sizeof(BITVEC));
                  }
                  else
                  {
                        ptr = GETSIGN(_j);
                        LOOPBYTE
                              union_l[i] |= ptr[i];
                  }
                  *left++ = j;
                  v->spl_nleft++;
            }
            else
            {
                  if (ISALLTRUE(datum_r) || ISALLTRUE(_j))
                  {
                        if (!ISALLTRUE(datum_r))
                              MemSet((void *) union_r, 0xff, sizeof(BITVEC));
                  }
                  else
                  {
                        ptr = GETSIGN(_j);
                        LOOPBYTE
                              union_r[i] |= ptr[i];
                  }
                  *right++ = j;
                  v->spl_nright++;
            }
      }

      *right = *left = FirstOffsetNumber;
      pfree(costvector);

      v->spl_ldatum = PointerGetDatum(datum_l);
      v->spl_rdatum = PointerGetDatum(datum_r);

      PG_RETURN_POINTER(v);
}


Datum
ghstore_consistent(PG_FUNCTION_ARGS)
{
      GISTTYPE   *entry = (GISTTYPE *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
      StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);

      /* Oid            subtype = PG_GETARG_OID(3); */
      bool     *recheck = (bool *) PG_GETARG_POINTER(4);
      bool        res = true;
      BITVECP           sign;

      /* All cases served by this function are inexact */
      *recheck = true;

      if (ISALLTRUE(entry))
            PG_RETURN_BOOL(true);

      sign = GETSIGN(entry);

      if (strategy == HStoreContainsStrategyNumber || strategy == 13 /* hack for old strats */ )
      {
            HStore         *query = PG_GETARG_HS(1);
            HEntry         *qe = ARRPTR(query);
            char     *qv = STRPTR(query);

            while (res && qe - ARRPTR(query) < query->size)
            {
                  int               crc = crc32_sz((char *) (qv + qe->pos), qe->keylen);

                  if (GETBIT(sign, HASHVAL(crc)))
                  {
                        if (!qe->valisnull)
                        {
                              crc = crc32_sz((char *) (qv + qe->pos + qe->keylen), qe->vallen);
                              if (!GETBIT(sign, HASHVAL(crc)))
                                    res = false;
                        }
                  }
                  else
                        res = false;
                  qe++;
            }
      }
      else if (strategy == HStoreExistsStrategyNumber)
      {
            text     *query = PG_GETARG_TEXT_P(1);
            int               crc = crc32_sz(VARDATA(query), VARSIZE(query) - VARHDRSZ);

            res = (GETBIT(sign, HASHVAL(crc))) ? true : false;
      }
      else
            elog(ERROR, "Unsupported strategy number: %d", strategy);

      PG_RETURN_BOOL(res);
}

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