postgresql/contrib/intarray/_int_tool.c
Bruce Momjian c155f654b4 intarray: return empty zero-dimensional array for an empty array
Previously a one-dimensional empty array was returned, but its text
representation matched a zero-dimensional array, and there is no way to
dump/reload a one-dimensional empty array.

BACKWARD INCOMPATIBILITY

Per report from elein
2013-09-07 11:44:33 -04:00

411 lines
6.4 KiB
C

/*
* contrib/intarray/_int_tool.c
*/
#include "postgres.h"
#include "catalog/pg_type.h"
#include "_int.h"
/* arguments are assumed sorted & unique-ified */
bool
inner_int_contains(ArrayType *a, ArrayType *b)
{
int na,
nb;
int i,
j,
n;
int *da,
*db;
na = ARRNELEMS(a);
nb = ARRNELEMS(b);
da = ARRPTR(a);
db = ARRPTR(b);
i = j = n = 0;
while (i < na && j < nb)
{
if (da[i] < db[j])
i++;
else if (da[i] == db[j])
{
n++;
i++;
j++;
}
else
break; /* db[j] is not in da */
}
return (n == nb) ? TRUE : FALSE;
}
/* arguments are assumed sorted */
bool
inner_int_overlap(ArrayType *a, ArrayType *b)
{
int na,
nb;
int i,
j;
int *da,
*db;
na = ARRNELEMS(a);
nb = ARRNELEMS(b);
da = ARRPTR(a);
db = ARRPTR(b);
i = j = 0;
while (i < na && j < nb)
{
if (da[i] < db[j])
i++;
else if (da[i] == db[j])
return TRUE;
else
j++;
}
return FALSE;
}
ArrayType *
inner_int_union(ArrayType *a, ArrayType *b)
{
ArrayType *r = NULL;
CHECKARRVALID(a);
CHECKARRVALID(b);
if (ARRISEMPTY(a) && ARRISEMPTY(b))
return new_intArrayType(0);
if (ARRISEMPTY(a))
r = copy_intArrayType(b);
if (ARRISEMPTY(b))
r = copy_intArrayType(a);
if (!r)
{
int na = ARRNELEMS(a),
nb = ARRNELEMS(b);
int *da = ARRPTR(a),
*db = ARRPTR(b);
int i,
j,
*dr;
r = new_intArrayType(na + nb);
dr = ARRPTR(r);
/* union */
i = j = 0;
while (i < na && j < nb)
{
if (da[i] == db[j])
{
*dr++ = da[i++];
j++;
}
else if (da[i] < db[j])
*dr++ = da[i++];
else
*dr++ = db[j++];
}
while (i < na)
*dr++ = da[i++];
while (j < nb)
*dr++ = db[j++];
r = resize_intArrayType(r, dr - ARRPTR(r));
}
if (ARRNELEMS(r) > 1)
r = _int_unique(r);
return r;
}
ArrayType *
inner_int_inter(ArrayType *a, ArrayType *b)
{
ArrayType *r;
int na,
nb;
int *da,
*db,
*dr;
int i,
j,
k;
if (ARRISEMPTY(a) || ARRISEMPTY(b))
return new_intArrayType(0);
na = ARRNELEMS(a);
nb = ARRNELEMS(b);
da = ARRPTR(a);
db = ARRPTR(b);
r = new_intArrayType(Min(na, nb));
dr = ARRPTR(r);
i = j = k = 0;
while (i < na && j < nb)
{
if (da[i] < db[j])
i++;
else if (da[i] == db[j])
{
if (k == 0 || dr[k - 1] != db[j])
dr[k++] = db[j];
i++;
j++;
}
else
j++;
}
if (k == 0)
{
pfree(r);
return new_intArrayType(0);
}
else
return resize_intArrayType(r, k);
}
void
rt__int_size(ArrayType *a, float *size)
{
*size = (float) ARRNELEMS(a);
}
/* Sort the given data (len >= 2). Return true if any duplicates found */
bool
isort(int32 *a, int len)
{
int32 cur,
prev;
int32 *pcur,
*pprev,
*end;
bool r = FALSE;
/*
* We use a simple insertion sort. While this is O(N^2) in the worst
* case, it's quite fast if the input is already sorted or nearly so.
* Also, for not-too-large inputs it's faster than more complex methods
* anyhow.
*/
end = a + len;
for (pcur = a + 1; pcur < end; pcur++)
{
cur = *pcur;
for (pprev = pcur - 1; pprev >= a; pprev--)
{
prev = *pprev;
if (prev <= cur)
{
if (prev == cur)
r = TRUE;
break;
}
pprev[1] = prev;
}
pprev[1] = cur;
}
return r;
}
/* Create a new int array with room for "num" elements */
ArrayType *
new_intArrayType(int num)
{
ArrayType *r;
int nbytes = ARR_OVERHEAD_NONULLS(1) + sizeof(int) * num;
r = (ArrayType *) palloc0(nbytes);
SET_VARSIZE(r, nbytes);
ARR_NDIM(r) = 1;
r->dataoffset = 0; /* marker for no null bitmap */
ARR_ELEMTYPE(r) = INT4OID;
ARR_DIMS(r)[0] = num;
ARR_LBOUND(r)[0] = 1;
return r;
}
ArrayType *
resize_intArrayType(ArrayType *a, int num)
{
int nbytes = ARR_DATA_OFFSET(a) + sizeof(int) * num;
int i;
/* if no elements, return a zero-dimensional array */
if (num == 0)
{
ARR_NDIM(a) = 0;
return a;
}
if (num == ARRNELEMS(a))
return a;
a = (ArrayType *) repalloc(a, nbytes);
SET_VARSIZE(a, nbytes);
/* usually the array should be 1-D already, but just in case ... */
for (i = 0; i < ARR_NDIM(a); i++)
{
ARR_DIMS(a)[i] = num;
num = 1;
}
return a;
}
ArrayType *
copy_intArrayType(ArrayType *a)
{
ArrayType *r;
int n = ARRNELEMS(a);
r = new_intArrayType(n);
memcpy(ARRPTR(r), ARRPTR(a), n * sizeof(int32));
return r;
}
/* num for compressed key */
int
internal_size(int *a, int len)
{
int i,
size = 0;
for (i = 0; i < len; i += 2)
{
if (!i || a[i] != a[i - 1]) /* do not count repeated range */
size += a[i + 1] - a[i] + 1;
}
return size;
}
/* unique-ify elements of r in-place ... r must be sorted already */
ArrayType *
_int_unique(ArrayType *r)
{
int *tmp,
*dr,
*data;
int num = ARRNELEMS(r);
if (num < 2)
return r;
data = tmp = dr = ARRPTR(r);
while (tmp - data < num)
{
if (*tmp != *dr)
*(++dr) = *tmp++;
else
tmp++;
}
return resize_intArrayType(r, dr + 1 - ARRPTR(r));
}
void
gensign(BITVEC sign, int *a, int len)
{
int i;
/* we assume that the sign vector is previously zeroed */
for (i = 0; i < len; i++)
{
HASH(sign, *a);
a++;
}
}
int32
intarray_match_first(ArrayType *a, int32 elem)
{
int32 *aa,
c,
i;
CHECKARRVALID(a);
c = ARRNELEMS(a);
aa = ARRPTR(a);
for (i = 0; i < c; i++)
if (aa[i] == elem)
return (i + 1);
return 0;
}
ArrayType *
intarray_add_elem(ArrayType *a, int32 elem)
{
ArrayType *result;
int32 *r;
int32 c;
CHECKARRVALID(a);
c = ARRNELEMS(a);
result = new_intArrayType(c + 1);
r = ARRPTR(result);
if (c > 0)
memcpy(r, ARRPTR(a), c * sizeof(int32));
r[c] = elem;
return result;
}
ArrayType *
intarray_concat_arrays(ArrayType *a, ArrayType *b)
{
ArrayType *result;
int32 ac = ARRNELEMS(a);
int32 bc = ARRNELEMS(b);
CHECKARRVALID(a);
CHECKARRVALID(b);
result = new_intArrayType(ac + bc);
if (ac)
memcpy(ARRPTR(result), ARRPTR(a), ac * sizeof(int32));
if (bc)
memcpy(ARRPTR(result) + ac, ARRPTR(b), bc * sizeof(int32));
return result;
}
ArrayType *
int_to_intset(int32 n)
{
ArrayType *result;
int32 *aa;
result = new_intArrayType(1);
aa = ARRPTR(result);
aa[0] = n;
return result;
}
int
compASC(const void *a, const void *b)
{
if (*(const int32 *) a == *(const int32 *) b)
return 0;
return (*(const int32 *) a > *(const int32 *) b) ? 1 : -1;
}
int
compDESC(const void *a, const void *b)
{
if (*(const int32 *) a == *(const int32 *) b)
return 0;
return (*(const int32 *) a < *(const int32 *) b) ? 1 : -1;
}