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postgresql/contrib/ltree/ltree_op.c

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/*
* op function for ltree
* Teodor Sigaev <teodor@stack.net>
* contrib/ltree/ltree_op.c
*/
#include "postgres.h"
#include <ctype.h>
#include "access/htup_details.h"
#include "catalog/pg_statistic.h"
#include "common/hashfn.h"
#include "ltree.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/selfuncs.h"
PG_MODULE_MAGIC;
/* compare functions */
PG_FUNCTION_INFO_V1(ltree_cmp);
PG_FUNCTION_INFO_V1(ltree_lt);
PG_FUNCTION_INFO_V1(ltree_le);
PG_FUNCTION_INFO_V1(ltree_eq);
PG_FUNCTION_INFO_V1(ltree_ne);
PG_FUNCTION_INFO_V1(ltree_ge);
PG_FUNCTION_INFO_V1(ltree_gt);
PG_FUNCTION_INFO_V1(hash_ltree);
PG_FUNCTION_INFO_V1(hash_ltree_extended);
PG_FUNCTION_INFO_V1(nlevel);
PG_FUNCTION_INFO_V1(ltree_isparent);
PG_FUNCTION_INFO_V1(ltree_risparent);
PG_FUNCTION_INFO_V1(subltree);
PG_FUNCTION_INFO_V1(subpath);
PG_FUNCTION_INFO_V1(ltree_index);
PG_FUNCTION_INFO_V1(ltree_addltree);
PG_FUNCTION_INFO_V1(ltree_addtext);
PG_FUNCTION_INFO_V1(ltree_textadd);
PG_FUNCTION_INFO_V1(lca);
PG_FUNCTION_INFO_V1(ltree2text);
PG_FUNCTION_INFO_V1(text2ltree);
PG_FUNCTION_INFO_V1(ltreeparentsel);
int
ltree_compare(const ltree *a, const ltree *b)
{
ltree_level *al = LTREE_FIRST(a);
ltree_level *bl = LTREE_FIRST(b);
int an = a->numlevel;
int bn = b->numlevel;
while (an > 0 && bn > 0)
{
int res;
if ((res = memcmp(al->name, bl->name, Min(al->len, bl->len))) == 0)
{
if (al->len != bl->len)
return (al->len - bl->len) * 10 * (an + 1);
}
else
{
if (res < 0)
res = -1;
else
res = 1;
return res * 10 * (an + 1);
}
an--;
bn--;
al = LEVEL_NEXT(al);
bl = LEVEL_NEXT(bl);
}
return (a->numlevel - b->numlevel) * 10 * (an + 1);
}
#define RUNCMP \
ltree *a = PG_GETARG_LTREE_P(0); \
ltree *b = PG_GETARG_LTREE_P(1); \
int res = ltree_compare(a,b); \
PG_FREE_IF_COPY(a,0); \
PG_FREE_IF_COPY(b,1)
Datum
ltree_cmp(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_INT32(res);
}
Datum
ltree_lt(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_BOOL(res < 0);
}
Datum
ltree_le(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_BOOL(res <= 0);
}
Datum
ltree_eq(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_BOOL(res == 0);
}
Datum
ltree_ge(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_BOOL(res >= 0);
}
Datum
ltree_gt(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_BOOL(res > 0);
}
Datum
ltree_ne(PG_FUNCTION_ARGS)
{
RUNCMP;
PG_RETURN_BOOL(res != 0);
}
/* Compute a hash for the ltree */
Datum
hash_ltree(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(0);
uint32 result = 1;
int an = a->numlevel;
ltree_level *al = LTREE_FIRST(a);
while (an > 0)
{
uint32 levelHash = DatumGetUInt32(hash_any((unsigned char *) al->name, al->len));
/*
* Combine hash values of successive elements by multiplying the
* current value by 31 and adding on the new element's hash value.
*
* This method is borrowed from hash_array(), which see for further
* commentary.
*/
result = (result << 5) - result + levelHash;
an--;
al = LEVEL_NEXT(al);
}
PG_FREE_IF_COPY(a, 0);
PG_RETURN_UINT32(result);
}
/* Compute an extended hash for the ltree */
Datum
hash_ltree_extended(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(0);
const uint64 seed = PG_GETARG_INT64(1);
uint64 result = 1;
int an = a->numlevel;
ltree_level *al = LTREE_FIRST(a);
/*
* If the path has length zero, return 1 + seed to ensure that the low 32
* bits of the result match hash_ltree when the seed is 0, as required by
* the hash index support functions, but to also return a different value
* when there is a seed.
*/
if (an == 0)
{
PG_FREE_IF_COPY(a, 0);
PG_RETURN_UINT64(result + seed);
}
while (an > 0)
{
uint64 levelHash = DatumGetUInt64(hash_any_extended((unsigned char *) al->name, al->len, seed));
result = (result << 5) - result + levelHash;
an--;
al = LEVEL_NEXT(al);
}
PG_FREE_IF_COPY(a, 0);
PG_RETURN_UINT64(result);
}
Datum
nlevel(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(0);
int res = a->numlevel;
PG_FREE_IF_COPY(a, 0);
PG_RETURN_INT32(res);
}
bool
inner_isparent(const ltree *c, const ltree *p)
{
ltree_level *cl = LTREE_FIRST(c);
ltree_level *pl = LTREE_FIRST(p);
int pn = p->numlevel;
if (pn > c->numlevel)
return false;
while (pn > 0)
{
if (cl->len != pl->len)
return false;
if (memcmp(cl->name, pl->name, cl->len) != 0)
return false;
pn--;
cl = LEVEL_NEXT(cl);
pl = LEVEL_NEXT(pl);
}
return true;
}
Datum
ltree_isparent(PG_FUNCTION_ARGS)
{
ltree *c = PG_GETARG_LTREE_P(1);
ltree *p = PG_GETARG_LTREE_P(0);
bool res = inner_isparent(c, p);
PG_FREE_IF_COPY(c, 1);
PG_FREE_IF_COPY(p, 0);
PG_RETURN_BOOL(res);
}
Datum
ltree_risparent(PG_FUNCTION_ARGS)
{
ltree *c = PG_GETARG_LTREE_P(0);
ltree *p = PG_GETARG_LTREE_P(1);
bool res = inner_isparent(c, p);
PG_FREE_IF_COPY(c, 0);
PG_FREE_IF_COPY(p, 1);
PG_RETURN_BOOL(res);
}
static ltree *
inner_subltree(ltree *t, int32 startpos, int32 endpos)
{
char *start = NULL,
*end = NULL;
ltree_level *ptr = LTREE_FIRST(t);
ltree *res;
int i;
if (startpos < 0 || endpos < 0 || startpos >= t->numlevel || startpos > endpos)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid positions")));
if (endpos > t->numlevel)
endpos = t->numlevel;
start = end = (char *) ptr;
for (i = 0; i < endpos; i++)
{
if (i == startpos)
start = (char *) ptr;
if (i == endpos - 1)
{
end = (char *) LEVEL_NEXT(ptr);
break;
}
ptr = LEVEL_NEXT(ptr);
}
res = (ltree *) palloc0(LTREE_HDRSIZE + (end - start));
SET_VARSIZE(res, LTREE_HDRSIZE + (end - start));
res->numlevel = endpos - startpos;
memcpy(LTREE_FIRST(res), start, end - start);
return res;
}
Datum
subltree(PG_FUNCTION_ARGS)
{
ltree *t = PG_GETARG_LTREE_P(0);
ltree *res = inner_subltree(t, PG_GETARG_INT32(1), PG_GETARG_INT32(2));
PG_FREE_IF_COPY(t, 0);
PG_RETURN_POINTER(res);
}
Datum
subpath(PG_FUNCTION_ARGS)
{
ltree *t = PG_GETARG_LTREE_P(0);
int32 start = PG_GETARG_INT32(1);
int32 len = (fcinfo->nargs == 3) ? PG_GETARG_INT32(2) : 0;
int32 end;
ltree *res;
end = start + len;
if (start < 0)
{
start = t->numlevel + start;
end = start + len;
}
if (start < 0)
{ /* start > t->numlevel */
start = t->numlevel + start;
end = start + len;
}
if (len < 0)
end = t->numlevel + len;
else if (len == 0)
end = (fcinfo->nargs == 3) ? start : 0xffff;
res = inner_subltree(t, start, end);
PG_FREE_IF_COPY(t, 0);
PG_RETURN_POINTER(res);
}
static ltree *
ltree_concat(ltree *a, ltree *b)
{
ltree *r;
int numlevel = (int) a->numlevel + b->numlevel;
if (numlevel > LTREE_MAX_LEVELS)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("number of ltree levels (%d) exceeds the maximum allowed (%d)",
numlevel, LTREE_MAX_LEVELS)));
r = (ltree *) palloc0(VARSIZE(a) + VARSIZE(b) - LTREE_HDRSIZE);
SET_VARSIZE(r, VARSIZE(a) + VARSIZE(b) - LTREE_HDRSIZE);
r->numlevel = (uint16) numlevel;
memcpy(LTREE_FIRST(r), LTREE_FIRST(a), VARSIZE(a) - LTREE_HDRSIZE);
memcpy(((char *) LTREE_FIRST(r)) + VARSIZE(a) - LTREE_HDRSIZE,
LTREE_FIRST(b),
VARSIZE(b) - LTREE_HDRSIZE);
return r;
}
Datum
ltree_addltree(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(0);
ltree *b = PG_GETARG_LTREE_P(1);
ltree *r;
r = ltree_concat(a, b);
PG_FREE_IF_COPY(a, 0);
PG_FREE_IF_COPY(b, 1);
PG_RETURN_POINTER(r);
}
Datum
ltree_addtext(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(0);
text *b = PG_GETARG_TEXT_PP(1);
char *s;
ltree *r,
*tmp;
s = text_to_cstring(b);
tmp = (ltree *) DatumGetPointer(DirectFunctionCall1(ltree_in,
PointerGetDatum(s)));
pfree(s);
r = ltree_concat(a, tmp);
pfree(tmp);
PG_FREE_IF_COPY(a, 0);
PG_FREE_IF_COPY(b, 1);
PG_RETURN_POINTER(r);
}
Datum
ltree_index(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(0);
ltree *b = PG_GETARG_LTREE_P(1);
int start = (fcinfo->nargs == 3) ? PG_GETARG_INT32(2) : 0;
int i,
j;
ltree_level *startptr,
*aptr,
*bptr;
bool found = false;
if (start < 0)
{
if (-start >= a->numlevel)
start = 0;
else
start = (int) (a->numlevel) + start;
}
if (a->numlevel - start < b->numlevel || a->numlevel == 0 || b->numlevel == 0)
{
PG_FREE_IF_COPY(a, 0);
PG_FREE_IF_COPY(b, 1);
PG_RETURN_INT32(-1);
}
startptr = LTREE_FIRST(a);
for (i = 0; i <= a->numlevel - b->numlevel; i++)
{
if (i >= start)
{
aptr = startptr;
bptr = LTREE_FIRST(b);
for (j = 0; j < b->numlevel; j++)
{
if (!(aptr->len == bptr->len && memcmp(aptr->name, bptr->name, aptr->len) == 0))
break;
aptr = LEVEL_NEXT(aptr);
bptr = LEVEL_NEXT(bptr);
}
if (j == b->numlevel)
{
found = true;
break;
}
}
startptr = LEVEL_NEXT(startptr);
}
if (!found)
i = -1;
PG_FREE_IF_COPY(a, 0);
PG_FREE_IF_COPY(b, 1);
PG_RETURN_INT32(i);
}
Datum
ltree_textadd(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE_P(1);
text *b = PG_GETARG_TEXT_PP(0);
char *s;
ltree *r,
*tmp;
s = text_to_cstring(b);
tmp = (ltree *) DatumGetPointer(DirectFunctionCall1(ltree_in,
PointerGetDatum(s)));
pfree(s);
r = ltree_concat(tmp, a);
pfree(tmp);
PG_FREE_IF_COPY(a, 1);
PG_FREE_IF_COPY(b, 0);
PG_RETURN_POINTER(r);
}
/*
* Common code for variants of lca(), find longest common ancestor of inputs
*
* Returns NULL if there is no common ancestor, ie, the longest common
* prefix is empty.
*/
ltree *
lca_inner(ltree **a, int len)
{
int tmp,
num,
i,
reslen;
ltree **ptr;
ltree_level *l1,
*l2;
ltree *res;
if (len <= 0)
return NULL; /* no inputs? */
if ((*a)->numlevel == 0)
return NULL; /* any empty input means NULL result */
/* num is the length of the longest common ancestor so far */
num = (*a)->numlevel - 1;
/* Compare each additional input to *a */
ptr = a + 1;
while (ptr - a < len)
{
if ((*ptr)->numlevel == 0)
return NULL;
else if ((*ptr)->numlevel == 1)
num = 0;
else
{
l1 = LTREE_FIRST(*a);
l2 = LTREE_FIRST(*ptr);
tmp = Min(num, (*ptr)->numlevel - 1);
num = 0;
for (i = 0; i < tmp; i++)
{
if (l1->len == l2->len &&
memcmp(l1->name, l2->name, l1->len) == 0)
num = i + 1;
else
break;
l1 = LEVEL_NEXT(l1);
l2 = LEVEL_NEXT(l2);
}
}
ptr++;
}
/* Now compute size of result ... */
reslen = LTREE_HDRSIZE;
l1 = LTREE_FIRST(*a);
for (i = 0; i < num; i++)
{
reslen += MAXALIGN(l1->len + LEVEL_HDRSIZE);
l1 = LEVEL_NEXT(l1);
}
/* ... and construct it by copying from *a */
res = (ltree *) palloc0(reslen);
SET_VARSIZE(res, reslen);
res->numlevel = num;
l1 = LTREE_FIRST(*a);
l2 = LTREE_FIRST(res);
for (i = 0; i < num; i++)
{
memcpy(l2, l1, MAXALIGN(l1->len + LEVEL_HDRSIZE));
l1 = LEVEL_NEXT(l1);
l2 = LEVEL_NEXT(l2);
}
return res;
}
Datum
lca(PG_FUNCTION_ARGS)
{
int i;
ltree **a,
*res;
a = (ltree **) palloc(sizeof(ltree *) * fcinfo->nargs);
for (i = 0; i < fcinfo->nargs; i++)
a[i] = PG_GETARG_LTREE_P(i);
res = lca_inner(a, (int) fcinfo->nargs);
for (i = 0; i < fcinfo->nargs; i++)
PG_FREE_IF_COPY(a[i], i);
pfree(a);
if (res)
PG_RETURN_POINTER(res);
else
PG_RETURN_NULL();
}
Datum
text2ltree(PG_FUNCTION_ARGS)
{
text *in = PG_GETARG_TEXT_PP(0);
char *s;
ltree *out;
s = text_to_cstring(in);
out = (ltree *) DatumGetPointer(DirectFunctionCall1(ltree_in,
PointerGetDatum(s)));
pfree(s);
PG_FREE_IF_COPY(in, 0);
PG_RETURN_POINTER(out);
}
Datum
ltree2text(PG_FUNCTION_ARGS)
{
ltree *in = PG_GETARG_LTREE_P(0);
char *ptr;
int i;
ltree_level *curlevel;
text *out;
out = (text *) palloc(VARSIZE(in) + VARHDRSZ);
ptr = VARDATA(out);
curlevel = LTREE_FIRST(in);
for (i = 0; i < in->numlevel; i++)
{
if (i != 0)
{
*ptr = '.';
ptr++;
}
memcpy(ptr, curlevel->name, curlevel->len);
ptr += curlevel->len;
curlevel = LEVEL_NEXT(curlevel);
}
SET_VARSIZE(out, ptr - ((char *) out));
PG_FREE_IF_COPY(in, 0);
PG_RETURN_POINTER(out);
}
/*
* ltreeparentsel - Selectivity of parent relationship for ltree data types.
*
* This function is not used anymore, if the ltree extension has been
* updated to 1.2 or later.
*/
Datum
ltreeparentsel(PG_FUNCTION_ARGS)
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
double selec;
/* Use generic restriction selectivity logic, with default 0.001. */
selec = generic_restriction_selectivity(root, operator, InvalidOid,
args, varRelid,
0.001);
PG_RETURN_FLOAT8((float8) selec);
}
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