postgresql/contrib/ltree/ltree_op.c
2002-09-04 20:31:48 +00:00

434 lines
7.9 KiB
C

/*
* op function for ltree
* Teodor Sigaev <teodor@stack.net>
*/
#include "ltree.h"
#include <ctype.h>
/* 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(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_addltree);
PG_FUNCTION_INFO_V1(ltree_addtext);
PG_FUNCTION_INFO_V1(ltree_textadd);
PG_FUNCTION_INFO_V1(lca);
Datum ltree_cmp(PG_FUNCTION_ARGS);
Datum ltree_lt(PG_FUNCTION_ARGS);
Datum ltree_le(PG_FUNCTION_ARGS);
Datum ltree_eq(PG_FUNCTION_ARGS);
Datum ltree_ne(PG_FUNCTION_ARGS);
Datum ltree_ge(PG_FUNCTION_ARGS);
Datum ltree_gt(PG_FUNCTION_ARGS);
Datum nlevel(PG_FUNCTION_ARGS);
Datum subltree(PG_FUNCTION_ARGS);
Datum subpath(PG_FUNCTION_ARGS);
Datum ltree_addltree(PG_FUNCTION_ARGS);
Datum ltree_addtext(PG_FUNCTION_ARGS);
Datum ltree_textadd(PG_FUNCTION_ARGS);
Datum lca(PG_FUNCTION_ARGS);
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;
int res = 0;
while (an > 0 && bn > 0)
{
if ((res = strncmp(al->name, bl->name, min(al->len, bl->len))) == 0)
{
if (al->len != bl->len)
return (al->len - bl->len) * 10 * (an + 1);
}
else
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(0); \
ltree *b = PG_GETARG_LTREE(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) ? true : false);
}
Datum
ltree_le(PG_FUNCTION_ARGS)
{
RUNCMP
PG_RETURN_BOOL((res <= 0) ? true : false);
}
Datum
ltree_eq(PG_FUNCTION_ARGS)
{
RUNCMP
PG_RETURN_BOOL((res == 0) ? true : false);
}
Datum
ltree_ge(PG_FUNCTION_ARGS)
{
RUNCMP
PG_RETURN_BOOL((res >= 0) ? true : false);
}
Datum
ltree_gt(PG_FUNCTION_ARGS)
{
RUNCMP
PG_RETURN_BOOL((res > 0) ? true : false);
}
Datum
ltree_ne(PG_FUNCTION_ARGS)
{
RUNCMP
PG_RETURN_BOOL((res != 0) ? true : false);
}
Datum
nlevel(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE(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 (strncmp(cl->name, pl->name, cl->len))
return false;
pn--;
cl = LEVEL_NEXT(cl);
pl = LEVEL_NEXT(pl);
}
return true;
}
Datum
ltree_isparent(PG_FUNCTION_ARGS)
{
ltree *c = PG_GETARG_LTREE(1);
ltree *p = PG_GETARG_LTREE(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(0);
ltree *p = PG_GETARG_LTREE(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, int4 startpos, int4 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)
elog(ERROR, "Wrong positions");
if (endpos > t->numlevel)
endpos = t->numlevel;
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 *) palloc(LTREE_HDRSIZE + (end - start));
res->len = 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(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(0);
int4 start = PG_GETARG_INT32(1);
int4 len = (fcinfo->nargs == 3) ? PG_GETARG_INT32(2) : 0;
int4 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 = 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;
r = (ltree *) palloc(a->len + b->len - LTREE_HDRSIZE);
r->len = a->len + b->len - LTREE_HDRSIZE;
r->numlevel = a->numlevel + b->numlevel;
memcpy(LTREE_FIRST(r), LTREE_FIRST(a), a->len - LTREE_HDRSIZE);
memcpy(((char *) LTREE_FIRST(r)) + a->len - LTREE_HDRSIZE, LTREE_FIRST(b), b->len -
LTREE_HDRSIZE);
return r;
}
Datum
ltree_addltree(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE(0);
ltree *b = PG_GETARG_LTREE(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(0);
text *b = PG_GETARG_TEXT_P(1);
char *s;
ltree *r,
*tmp;
s = (char *) palloc(VARSIZE(b) - VARHDRSZ + 1);
memcpy(s, VARDATA(b), VARSIZE(b) - VARHDRSZ);
s[VARSIZE(b) - VARHDRSZ] = '\0';
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_textadd(PG_FUNCTION_ARGS)
{
ltree *a = PG_GETARG_LTREE(1);
text *b = PG_GETARG_TEXT_P(0);
char *s;
ltree *r,
*tmp;
s = (char *) palloc(VARSIZE(b) - VARHDRSZ + 1);
memcpy(s, VARDATA(b), VARSIZE(b) - VARHDRSZ);
s[VARSIZE(b) - VARHDRSZ] = '\0';
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);
}
ltree *
lca_inner(ltree ** a, int len)
{
int tmp,
num = ((*a)->numlevel) ? (*a)->numlevel - 1 : 0;
ltree **ptr = a + 1;
int i,
reslen = LTREE_HDRSIZE;
ltree_level *l1,
*l2;
ltree *res;
if ((*a)->numlevel == 0)
return NULL;
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 = num;
num = 0;
for (i = 0; i < min(tmp, (*ptr)->numlevel - 1); i++)
{
if (l1->len == l2->len && strncmp(l1->name, l2->name, l1->len) == 0)
num = i + 1;
else
break;
l1 = LEVEL_NEXT(l1);
l2 = LEVEL_NEXT(l2);
}
}
ptr++;
}
l1 = LTREE_FIRST(*a);
for (i = 0; i < num; i++)
{
reslen += MAXALIGN(l1->len + LEVEL_HDRSIZE);
l1 = LEVEL_NEXT(l1);
}
res = (ltree *) palloc(reslen);
res->len = 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(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();
}