postgresql/contrib/ltree/_ltree_gist.c

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2023-05-09 21:11:15 +00:00
/*
* contrib/ltree/_ltree_gist.c
*
*
* GiST support for ltree[]
* Teodor Sigaev <teodor@stack.net>
*/
#include "postgres.h"
#include "access/gist.h"
#include "access/reloptions.h"
#include "access/stratnum.h"
#include "crc32.h"
#include "ltree.h"
#include "port/pg_bitutils.h"
PG_FUNCTION_INFO_V1(_ltree_compress);
PG_FUNCTION_INFO_V1(_ltree_same);
PG_FUNCTION_INFO_V1(_ltree_union);
PG_FUNCTION_INFO_V1(_ltree_penalty);
PG_FUNCTION_INFO_V1(_ltree_picksplit);
PG_FUNCTION_INFO_V1(_ltree_consistent);
PG_FUNCTION_INFO_V1(_ltree_gist_options);
#define GETENTRY(vec,pos) ((ltree_gist *) DatumGetPointer((vec)->vector[(pos)].key))
#define NEXTVAL(x) ( (ltree*)( (char*)(x) + INTALIGN( VARSIZE(x) ) ) )
#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
static void
hashing(BITVECP sign, ltree *t, int siglen)
{
int tlen = t->numlevel;
ltree_level *cur = LTREE_FIRST(t);
int hash;
while (tlen > 0)
{
hash = ltree_crc32_sz(cur->name, cur->len);
AHASH(sign, hash, siglen);
cur = LEVEL_NEXT(cur);
tlen--;
}
}
Datum
_ltree_compress(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
GISTENTRY *retval = entry;
int siglen = LTREE_GET_ASIGLEN();
if (entry->leafkey)
{ /* ltree */
ltree_gist *key;
ArrayType *val = DatumGetArrayTypeP(entry->key);
int num = ArrayGetNItems(ARR_NDIM(val), ARR_DIMS(val));
ltree *item = (ltree *) ARR_DATA_PTR(val);
if (ARR_NDIM(val) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
if (array_contains_nulls(val))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array must not contain nulls")));
key = ltree_gist_alloc(false, NULL, siglen, NULL, NULL);
while (num > 0)
{
hashing(LTG_SIGN(key), item, siglen);
num--;
item = NEXTVAL(item);
}
retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(key),
entry->rel, entry->page,
entry->offset, false);
}
else if (!LTG_ISALLTRUE(entry->key))
{
int32 i;
ltree_gist *key;
BITVECP sign = LTG_SIGN(DatumGetPointer(entry->key));
ALOOPBYTE(siglen)
{
if ((sign[i] & 0xff) != 0xff)
PG_RETURN_POINTER(retval);
}
key = ltree_gist_alloc(true, sign, siglen, NULL, NULL);
retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(key),
entry->rel, entry->page,
entry->offset, false);
}
PG_RETURN_POINTER(retval);
}
Datum
_ltree_same(PG_FUNCTION_ARGS)
{
ltree_gist *a = (ltree_gist *) PG_GETARG_POINTER(0);
ltree_gist *b = (ltree_gist *) PG_GETARG_POINTER(1);
bool *result = (bool *) PG_GETARG_POINTER(2);
int siglen = LTREE_GET_ASIGLEN();
if (LTG_ISALLTRUE(a) && LTG_ISALLTRUE(b))
*result = true;
else if (LTG_ISALLTRUE(a))
*result = false;
else if (LTG_ISALLTRUE(b))
*result = false;
else
{
int32 i;
BITVECP sa = LTG_SIGN(a),
sb = LTG_SIGN(b);
*result = true;
ALOOPBYTE(siglen)
{
if (sa[i] != sb[i])
{
*result = false;
break;
}
}
}
PG_RETURN_POINTER(result);
}
static int32
unionkey(BITVECP sbase, ltree_gist *add, int siglen)
{
int32 i;
BITVECP sadd = LTG_SIGN(add);
if (LTG_ISALLTRUE(add))
return 1;
ALOOPBYTE(siglen)
sbase[i] |= sadd[i];
return 0;
}
Datum
_ltree_union(PG_FUNCTION_ARGS)
{
GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
int *size = (int *) PG_GETARG_POINTER(1);
int siglen = LTREE_GET_ASIGLEN();
int32 i;
ltree_gist *result = ltree_gist_alloc(false, NULL, siglen, NULL, NULL);
BITVECP base = LTG_SIGN(result);
for (i = 0; i < entryvec->n; i++)
{
if (unionkey(base, GETENTRY(entryvec, i), siglen))
{
result->flag |= LTG_ALLTRUE;
SET_VARSIZE(result, LTG_HDRSIZE);
break;
}
}
*size = VARSIZE(result);
PG_RETURN_POINTER(result);
}
static int32
sizebitvec(BITVECP sign, int siglen)
{
return pg_popcount((const char *) sign, siglen);
}
static int
hemdistsign(BITVECP a, BITVECP b, int siglen)
{
int i,
diff,
dist = 0;
ALOOPBYTE(siglen)
{
diff = (unsigned char) (a[i] ^ b[i]);
/* Using the popcount functions here isn't likely to win */
dist += pg_number_of_ones[diff];
}
return dist;
}
static int
hemdist(ltree_gist *a, ltree_gist *b, int siglen)
{
if (LTG_ISALLTRUE(a))
{
if (LTG_ISALLTRUE(b))
return 0;
else
return ASIGLENBIT(siglen) - sizebitvec(LTG_SIGN(b), siglen);
}
else if (LTG_ISALLTRUE(b))
return ASIGLENBIT(siglen) - sizebitvec(LTG_SIGN(a), siglen);
return hemdistsign(LTG_SIGN(a), LTG_SIGN(b), siglen);
}
Datum
_ltree_penalty(PG_FUNCTION_ARGS)
{
ltree_gist *origval = (ltree_gist *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
ltree_gist *newval = (ltree_gist *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
float *penalty = (float *) PG_GETARG_POINTER(2);
int siglen = LTREE_GET_ASIGLEN();
*penalty = hemdist(origval, newval, siglen);
PG_RETURN_POINTER(penalty);
}
typedef struct
{
OffsetNumber pos;
int32 cost;
} SPLITCOST;
static int
comparecost(const void *a, const void *b)
{
return ((const SPLITCOST *) a)->cost - ((const SPLITCOST *) b)->cost;
}
Datum
_ltree_picksplit(PG_FUNCTION_ARGS)
{
GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
int siglen = LTREE_GET_ASIGLEN();
OffsetNumber k,
j;
ltree_gist *datum_l,
*datum_r;
BITVECP union_l,
union_r;
int32 size_alpha,
size_beta;
int32 size_waste,
waste = -1;
int32 nbytes;
OffsetNumber seed_1 = 0,
seed_2 = 0;
OffsetNumber *left,
*right;
OffsetNumber maxoff;
BITVECP ptr;
int i;
SPLITCOST *costvector;
ltree_gist *_k,
*_j;
maxoff = entryvec->n - 2;
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), siglen);
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 .. */
datum_l = ltree_gist_alloc(LTG_ISALLTRUE(GETENTRY(entryvec, seed_1)),
LTG_SIGN(GETENTRY(entryvec, seed_1)),
siglen, NULL, NULL);
datum_r = ltree_gist_alloc(LTG_ISALLTRUE(GETENTRY(entryvec, seed_2)),
LTG_SIGN(GETENTRY(entryvec, seed_2)),
siglen, NULL, NULL);
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, siglen);
size_beta = hemdist(datum_r, _j, siglen);
costvector[j - 1].cost = Abs(size_alpha - size_beta);
}
qsort((void *) costvector, maxoff, sizeof(SPLITCOST), comparecost);
union_l = LTG_SIGN(datum_l);
union_r = LTG_SIGN(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, siglen);
size_beta = hemdist(datum_r, _j, siglen);
if (size_alpha < size_beta + WISH_F(v->spl_nleft, v->spl_nright, 0.00001))
{
if (LTG_ISALLTRUE(datum_l) || LTG_ISALLTRUE(_j))
{
if (!LTG_ISALLTRUE(datum_l))
MemSet((void *) union_l, 0xff, siglen);
}
else
{
ptr = LTG_SIGN(_j);
ALOOPBYTE(siglen)
union_l[i] |= ptr[i];
}
*left++ = j;
v->spl_nleft++;
}
else
{
if (LTG_ISALLTRUE(datum_r) || LTG_ISALLTRUE(_j))
{
if (!LTG_ISALLTRUE(datum_r))
MemSet((void *) union_r, 0xff, siglen);
}
else
{
ptr = LTG_SIGN(_j);
ALOOPBYTE(siglen)
union_r[i] |= ptr[i];
}
*right++ = j;
v->spl_nright++;
}
}
*right = *left = FirstOffsetNumber;
v->spl_ldatum = PointerGetDatum(datum_l);
v->spl_rdatum = PointerGetDatum(datum_r);
PG_RETURN_POINTER(v);
}
static bool
gist_te(ltree_gist *key, ltree *query, int siglen)
{
ltree_level *curq = LTREE_FIRST(query);
BITVECP sign = LTG_SIGN(key);
int qlen = query->numlevel;
unsigned int hv;
if (LTG_ISALLTRUE(key))
return true;
while (qlen > 0)
{
hv = ltree_crc32_sz(curq->name, curq->len);
if (!GETBIT(sign, AHASHVAL(hv, siglen)))
return false;
curq = LEVEL_NEXT(curq);
qlen--;
}
return true;
}
typedef struct LtreeSignature
{
BITVECP sign;
int siglen;
} LtreeSignature;
static bool
checkcondition_bit(void *cxt, ITEM *val)
{
LtreeSignature *sig = cxt;
return (FLG_CANLOOKSIGN(val->flag)) ? GETBIT(sig->sign, AHASHVAL(val->val, sig->siglen)) : true;
}
static bool
gist_qtxt(ltree_gist *key, ltxtquery *query, int siglen)
{
LtreeSignature sig;
if (LTG_ISALLTRUE(key))
return true;
sig.sign = LTG_SIGN(key);
sig.siglen = siglen;
return ltree_execute(GETQUERY(query),
&sig, false,
checkcondition_bit);
}
static bool
gist_qe(ltree_gist *key, lquery *query, int siglen)
{
lquery_level *curq = LQUERY_FIRST(query);
BITVECP sign = LTG_SIGN(key);
int qlen = query->numlevel;
if (LTG_ISALLTRUE(key))
return true;
while (qlen > 0)
{
if (curq->numvar && LQL_CANLOOKSIGN(curq))
{
bool isexist = false;
int vlen = curq->numvar;
lquery_variant *curv = LQL_FIRST(curq);
while (vlen > 0)
{
if (GETBIT(sign, AHASHVAL(curv->val, siglen)))
{
isexist = true;
break;
}
curv = LVAR_NEXT(curv);
vlen--;
}
if (!isexist)
return false;
}
curq = LQL_NEXT(curq);
qlen--;
}
return true;
}
static bool
_arrq_cons(ltree_gist *key, ArrayType *_query, int siglen)
{
lquery *query = (lquery *) ARR_DATA_PTR(_query);
int num = ArrayGetNItems(ARR_NDIM(_query), ARR_DIMS(_query));
if (ARR_NDIM(_query) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
if (array_contains_nulls(_query))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array must not contain nulls")));
while (num > 0)
{
if (gist_qe(key, query, siglen))
return true;
num--;
query = (lquery *) NEXTVAL(query);
}
return false;
}
Datum
_ltree_consistent(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
void *query = (void *) PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
/* Oid subtype = PG_GETARG_OID(3); */
bool *recheck = (bool *) PG_GETARG_POINTER(4);
int siglen = LTREE_GET_ASIGLEN();
ltree_gist *key = (ltree_gist *) DatumGetPointer(entry->key);
bool res = false;
/* All cases served by this function are inexact */
*recheck = true;
switch (strategy)
{
case 10:
case 11:
res = gist_te(key, (ltree *) query, siglen);
break;
case 12:
case 13:
res = gist_qe(key, (lquery *) query, siglen);
break;
case 14:
case 15:
res = gist_qtxt(key, (ltxtquery *) query, siglen);
break;
case 16:
case 17:
res = _arrq_cons(key, (ArrayType *) query, siglen);
break;
default:
/* internal error */
elog(ERROR, "unrecognized StrategyNumber: %d", strategy);
}
PG_FREE_IF_COPY(query, 1);
PG_RETURN_BOOL(res);
}
Datum
_ltree_gist_options(PG_FUNCTION_ARGS)
{
local_relopts *relopts = (local_relopts *) PG_GETARG_POINTER(0);
init_local_reloptions(relopts, sizeof(LtreeGistOptions));
add_local_int_reloption(relopts, "siglen", "signature length",
LTREE_ASIGLEN_DEFAULT, 1, LTREE_ASIGLEN_MAX,
offsetof(LtreeGistOptions, siglen));
PG_RETURN_VOID();
}