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postgresql/contrib/intarray/_int_gist.c
Peter Eisentraut 2eb4a831e5 Change TRUE/FALSE to true/false 
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources.  The upper case spellings are only used
in some files/modules.  So standardize on the standard spellings.

The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.

In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-11-08 11:37:28 -05:00

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/*
* contrib/intarray/_int_gist.c
*/
#include "postgres.h"
#include <limits.h>
#include "access/gist.h"
#include "access/stratnum.h"
#include "_int.h"
#define GETENTRY(vec,pos) ((ArrayType *) DatumGetPointer((vec)->vector[(pos)].key))
/*
** GiST support methods
*/
PG_FUNCTION_INFO_V1(g_int_consistent);
PG_FUNCTION_INFO_V1(g_int_compress);
PG_FUNCTION_INFO_V1(g_int_decompress);
PG_FUNCTION_INFO_V1(g_int_penalty);
PG_FUNCTION_INFO_V1(g_int_picksplit);
PG_FUNCTION_INFO_V1(g_int_union);
PG_FUNCTION_INFO_V1(g_int_same);
/*
** The GiST Consistent method for _intments
** Should return false if for all data items x below entry,
** the predicate x op query == false, where op is the oper
** corresponding to strategy in the pg_amop table.
*/
Datum
g_int_consistent(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
ArrayType *query = PG_GETARG_ARRAYTYPE_P_COPY(1);
StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
/* Oid subtype = PG_GETARG_OID(3); */
bool *recheck = (bool *) PG_GETARG_POINTER(4);
bool retval;
/* this is exact except for RTSameStrategyNumber */
*recheck = (strategy == RTSameStrategyNumber);
if (strategy == BooleanSearchStrategy)
{
retval = execconsistent((QUERYTYPE *) query,
(ArrayType *) DatumGetPointer(entry->key),
GIST_LEAF(entry));
pfree(query);
PG_RETURN_BOOL(retval);
}
/* sort query for fast search, key is already sorted */
CHECKARRVALID(query);
PREPAREARR(query);
switch (strategy)
{
case RTOverlapStrategyNumber:
retval = inner_int_overlap((ArrayType *) DatumGetPointer(entry->key),
query);
break;
case RTSameStrategyNumber:
if (GIST_LEAF(entry))
DirectFunctionCall3(g_int_same,
entry->key,
PointerGetDatum(query),
PointerGetDatum(&retval));
else
retval = inner_int_contains((ArrayType *) DatumGetPointer(entry->key),
query);
break;
case RTContainsStrategyNumber:
case RTOldContainsStrategyNumber:
retval = inner_int_contains((ArrayType *) DatumGetPointer(entry->key),
query);
break;
case RTContainedByStrategyNumber:
case RTOldContainedByStrategyNumber:
if (GIST_LEAF(entry))
retval = inner_int_contains(query,
(ArrayType *) DatumGetPointer(entry->key));
else
retval = inner_int_overlap((ArrayType *) DatumGetPointer(entry->key),
query);
break;
default:
retval = false;
}
pfree(query);
PG_RETURN_BOOL(retval);
}
Datum
g_int_union(PG_FUNCTION_ARGS)
{
GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
int *size = (int *) PG_GETARG_POINTER(1);
int32 i,
*ptr;
ArrayType *res;
int totlen = 0;
for (i = 0; i < entryvec->n; i++)
{
ArrayType *ent = GETENTRY(entryvec, i);
CHECKARRVALID(ent);
totlen += ARRNELEMS(ent);
}
res = new_intArrayType(totlen);
ptr = ARRPTR(res);
for (i = 0; i < entryvec->n; i++)
{
ArrayType *ent = GETENTRY(entryvec, i);
int nel;
nel = ARRNELEMS(ent);
memcpy(ptr, ARRPTR(ent), nel * sizeof(int32));
ptr += nel;
}
QSORT(res, 1);
res = _int_unique(res);
*size = VARSIZE(res);
PG_RETURN_POINTER(res);
}
/*
** GiST Compress and Decompress methods
*/
Datum
g_int_compress(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
GISTENTRY *retval;
ArrayType *r;
int len;
int *dr;
int i,
min,
cand;
if (entry->leafkey)
{
r = DatumGetArrayTypePCopy(entry->key);
CHECKARRVALID(r);
PREPAREARR(r);
if (ARRNELEMS(r) >= 2 * MAXNUMRANGE)
elog(NOTICE, "input array is too big (%d maximum allowed, %d current), use gist__intbig_ops opclass instead",
2 * MAXNUMRANGE - 1, ARRNELEMS(r));
retval = palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(r),
entry->rel, entry->page, entry->offset, false);
PG_RETURN_POINTER(retval);
}
/*
* leaf entries never compress one more time, only when entry->leafkey
* ==true, so now we work only with internal keys
*/
r = DatumGetArrayTypeP(entry->key);
CHECKARRVALID(r);
if (ARRISEMPTY(r))
{
if (r != (ArrayType *) DatumGetPointer(entry->key))
pfree(r);
PG_RETURN_POINTER(entry);
}
if ((len = ARRNELEMS(r)) >= 2 * MAXNUMRANGE)
{ /* compress */
if (r == (ArrayType *) DatumGetPointer(entry->key))
r = DatumGetArrayTypePCopy(entry->key);
r = resize_intArrayType(r, 2 * (len));
dr = ARRPTR(r);
for (i = len - 1; i >= 0; i--)
dr[2 * i] = dr[2 * i + 1] = dr[i];
len *= 2;
cand = 1;
while (len > MAXNUMRANGE * 2)
{
min = INT_MAX;
for (i = 2; i < len; i += 2)
if (min > (dr[i] - dr[i - 1]))
{
min = (dr[i] - dr[i - 1]);
cand = i;
}
memmove((void *) &dr[cand - 1], (void *) &dr[cand + 1], (len - cand - 1) * sizeof(int32));
len -= 2;
}
r = resize_intArrayType(r, len);
retval = palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(r),
entry->rel, entry->page, entry->offset, false);
PG_RETURN_POINTER(retval);
}
else
PG_RETURN_POINTER(entry);
}
Datum
g_int_decompress(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
GISTENTRY *retval;
ArrayType *r;
int *dr,
lenr;
ArrayType *in;
int lenin;
int *din;
int i,
j;
in = DatumGetArrayTypeP(entry->key);
CHECKARRVALID(in);
if (ARRISEMPTY(in))
{
if (in != (ArrayType *) DatumGetPointer(entry->key))
{
retval = palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(in),
entry->rel, entry->page, entry->offset, false);
PG_RETURN_POINTER(retval);
}
PG_RETURN_POINTER(entry);
}
lenin = ARRNELEMS(in);
if (lenin < 2 * MAXNUMRANGE)
{ /* not compressed value */
if (in != (ArrayType *) DatumGetPointer(entry->key))
{
retval = palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(in),
entry->rel, entry->page, entry->offset, false);
PG_RETURN_POINTER(retval);
}
PG_RETURN_POINTER(entry);
}
din = ARRPTR(in);
lenr = internal_size(din, lenin);
r = new_intArrayType(lenr);
dr = ARRPTR(r);
for (i = 0; i < lenin; i += 2)
for (j = din[i]; j <= din[i + 1]; j++)
if ((!i) || *(dr - 1) != j)
*dr++ = j;
if (in != (ArrayType *) DatumGetPointer(entry->key))
pfree(in);
retval = palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(r),
entry->rel, entry->page, entry->offset, false);
PG_RETURN_POINTER(retval);
}
/*
** The GiST Penalty method for _intments
*/
Datum
g_int_penalty(PG_FUNCTION_ARGS)
{
GISTENTRY *origentry = (GISTENTRY *) PG_GETARG_POINTER(0);
GISTENTRY *newentry = (GISTENTRY *) PG_GETARG_POINTER(1);
float *result = (float *) PG_GETARG_POINTER(2);
ArrayType *ud;
float tmp1,
tmp2;
ud = inner_int_union((ArrayType *) DatumGetPointer(origentry->key),
(ArrayType *) DatumGetPointer(newentry->key));
rt__int_size(ud, &tmp1);
rt__int_size((ArrayType *) DatumGetPointer(origentry->key), &tmp2);
*result = tmp1 - tmp2;
pfree(ud);
PG_RETURN_POINTER(result);
}
Datum
g_int_same(PG_FUNCTION_ARGS)
{
ArrayType *a = PG_GETARG_ARRAYTYPE_P(0);
ArrayType *b = PG_GETARG_ARRAYTYPE_P(1);
bool *result = (bool *) PG_GETARG_POINTER(2);
int32 n = ARRNELEMS(a);
int32 *da,
*db;
CHECKARRVALID(a);
CHECKARRVALID(b);
if (n != ARRNELEMS(b))
{
*result = false;
PG_RETURN_POINTER(result);
}
*result = true;
da = ARRPTR(a);
db = ARRPTR(b);
while (n--)
{
if (*da++ != *db++)
{
*result = false;
break;
}
}
PG_RETURN_POINTER(result);
}
/*****************************************************************
** Common GiST Method
*****************************************************************/
typedef struct
{
OffsetNumber pos;
float cost;
} SPLITCOST;
static int
comparecost(const void *a, const void *b)
{
if (((const SPLITCOST *) a)->cost == ((const SPLITCOST *) b)->cost)
return 0;
else
return (((const SPLITCOST *) a)->cost > ((const SPLITCOST *) b)->cost) ? 1 : -1;
}
/*
** The GiST PickSplit method for _intments
** We use Guttman's poly time split algorithm
*/
Datum
g_int_picksplit(PG_FUNCTION_ARGS)
{
GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
OffsetNumber i,
j;
ArrayType *datum_alpha,
*datum_beta;
ArrayType *datum_l,
*datum_r;
ArrayType *union_d,
*union_dl,
*union_dr;
ArrayType *inter_d;
bool firsttime;
float size_alpha,
size_beta,
size_union,
size_inter;
float size_waste,
waste;
float size_l,
size_r;
int nbytes;
OffsetNumber seed_1 = 0,
seed_2 = 0;
OffsetNumber *left,
*right;
OffsetNumber maxoff;
SPLITCOST *costvector;
#ifdef GIST_DEBUG
elog(DEBUG3, "--------picksplit %d", entryvec->n);
#endif
maxoff = entryvec->n - 2;
nbytes = (maxoff + 2) * sizeof(OffsetNumber);
v->spl_left = (OffsetNumber *) palloc(nbytes);
v->spl_right = (OffsetNumber *) palloc(nbytes);
firsttime = true;
waste = 0.0;
for (i = FirstOffsetNumber; i < maxoff; i = OffsetNumberNext(i))
{
datum_alpha = GETENTRY(entryvec, i);
for (j = OffsetNumberNext(i); j <= maxoff; j = OffsetNumberNext(j))
{
datum_beta = GETENTRY(entryvec, j);
/* compute the wasted space by unioning these guys */
/* size_waste = size_union - size_inter; */
union_d = inner_int_union(datum_alpha, datum_beta);
rt__int_size(union_d, &size_union);
inter_d = inner_int_inter(datum_alpha, datum_beta);
rt__int_size(inter_d, &size_inter);
size_waste = size_union - size_inter;
pfree(union_d);
pfree(inter_d);
/*
* are these a more promising split that what we've already seen?
*/
if (size_waste > waste || firsttime)
{
waste = size_waste;
seed_1 = i;
seed_2 = j;
firsttime = false;
}
}
}
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;
}
datum_alpha = GETENTRY(entryvec, seed_1);
datum_l = copy_intArrayType(datum_alpha);
rt__int_size(datum_l, &size_l);
datum_beta = GETENTRY(entryvec, seed_2);
datum_r = copy_intArrayType(datum_beta);
rt__int_size(datum_r, &size_r);
maxoff = OffsetNumberNext(maxoff);
/*
* sort entries
*/
costvector = (SPLITCOST *) palloc(sizeof(SPLITCOST) * maxoff);
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
{
costvector[i - 1].pos = i;
datum_alpha = GETENTRY(entryvec, i);
union_d = inner_int_union(datum_l, datum_alpha);
rt__int_size(union_d, &size_alpha);
pfree(union_d);
union_d = inner_int_union(datum_r, datum_alpha);
rt__int_size(union_d, &size_beta);
pfree(union_d);
costvector[i - 1].cost = Abs((size_alpha - size_l) - (size_beta - size_r));
}
qsort((void *) costvector, maxoff, sizeof(SPLITCOST), comparecost);
/*
* Now split up the regions between the two seeds. An important property
* of this split algorithm is that the split vector v has the indices of
* items to be split in order in its left and right vectors. We exploit
* this property by doing a merge in the code that actually splits the
* page.
*
* For efficiency, we also place the new index tuple in this loop. This is
* handled at the very end, when we have placed all the existing tuples
* and i == maxoff + 1.
*/
for (j = 0; j < maxoff; j++)
{
i = costvector[j].pos;
/*
* If we've already decided where to place this item, just put it on
* the right list. Otherwise, we need to figure out which page needs
* the least enlargement in order to store the item.
*/
if (i == seed_1)
{
*left++ = i;
v->spl_nleft++;
continue;
}
else if (i == seed_2)
{
*right++ = i;
v->spl_nright++;
continue;
}
/* okay, which page needs least enlargement? */
datum_alpha = GETENTRY(entryvec, i);
union_dl = inner_int_union(datum_l, datum_alpha);
union_dr = inner_int_union(datum_r, datum_alpha);
rt__int_size(union_dl, &size_alpha);
rt__int_size(union_dr, &size_beta);
/* pick which page to add it to */
if (size_alpha - size_l < size_beta - size_r + WISH_F(v->spl_nleft, v->spl_nright, 0.01))
{
pfree(datum_l);
pfree(union_dr);
datum_l = union_dl;
size_l = size_alpha;
*left++ = i;
v->spl_nleft++;
}
else
{
pfree(datum_r);
pfree(union_dl);
datum_r = union_dr;
size_r = size_beta;
*right++ = i;
v->spl_nright++;
}
}
pfree(costvector);
*right = *left = FirstOffsetNumber;
v->spl_ldatum = PointerGetDatum(datum_l);
v->spl_rdatum = PointerGetDatum(datum_r);
PG_RETURN_POINTER(v);
}
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