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postgresql/contrib/intarray/_int_tool.c
Tom Lane 8d1f239003 Replace insertion sort in contrib/intarray with qsort().
It's all very well to claim that a simplistic sort is fast in easy
cases, but O(N^2) in the worst case is not good ... especially if the
worst case is as easy to hit as "descending order input".  Replace that
bit with our standard qsort.

Per bug  from Maksym Boguk.  Back-patch to all active branches.
2015-03-15 23:22:03 -04:00

405 lines
6.3 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);
}
/* qsort_arg comparison function for isort() */
static int
isort_cmp(const void *a, const void *b, void *arg)
{
int32 aval = *((const int32 *) a);
int32 bval = *((const int32 *) b);
if (aval < bval)
return -1;
if (aval > bval)
return 1;
/*
* Report if we have any duplicates. If there are equal keys, qsort must
* compare them at some point, else it wouldn't know whether one should go
* before or after the other.
*/
*((bool *) arg) = true;
return 0;
}
/* Sort the given data (len >= 2). Return true if any duplicates found */
bool
isort(int32 *a, int len)
{
bool r = false;
qsort_arg(a, len, sizeof(int32), isort_cmp, (void *) &r);
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;
}