Age Owner TLA Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * qunique.h
4 : * inline array unique functions
5 : * Portions Copyright (c) 2019-2023, PostgreSQL Global Development Group
6 : *
7 : * IDENTIFICATION
8 : * src/include/lib/qunique.h
9 : *-------------------------------------------------------------------------
10 : */
11 :
12 : #ifndef QUNIQUE_H
13 : #define QUNIQUE_H
14 :
15 : /*
16 : * Remove duplicates from a pre-sorted array, according to a user-supplied
17 : * comparator. Usually the array should have been sorted with qsort() using
18 : * the same arguments. Return the new size.
19 : */
20 : static inline size_t
1249 tmunro 21 CBC 180787 : qunique(void *array, size_t elements, size_t width,
22 : int (*compare) (const void *, const void *))
23 : {
24 180787 : char *bytes = (char *) array;
25 : size_t i,
26 : j;
27 :
28 180787 : if (elements <= 1)
29 5095 : return elements;
30 :
31 4210521 : for (i = 1, j = 0; i < elements; ++i)
32 : {
1191 noah 33 4034829 : if (compare(bytes + i * width, bytes + j * width) != 0 &&
34 : ++j != i)
35 1974596 : memcpy(bytes + j * width, bytes + i * width, width);
36 : }
37 :
1249 tmunro 38 175692 : return j + 1;
39 : }
40 :
41 : /*
42 : * Like qunique(), but takes a comparator with an extra user data argument
43 : * which is passed through, for compatibility with qsort_arg().
44 : */
45 : static inline size_t
46 1628755 : qunique_arg(void *array, size_t elements, size_t width,
47 : int (*compare) (const void *, const void *, void *),
48 : void *arg)
49 : {
50 1628755 : char *bytes = (char *) array;
51 : size_t i,
52 : j;
53 :
54 1628755 : if (elements <= 1)
1249 tmunro 55 UBC 0 : return elements;
56 :
1249 tmunro 57 CBC 29828406 : for (i = 1, j = 0; i < elements; ++i)
58 : {
1191 noah 59 28199651 : if (compare(bytes + i * width, bytes + j * width, arg) != 0 &&
60 : ++j != i)
61 1845107 : memcpy(bytes + j * width, bytes + i * width, width);
62 : }
63 :
1249 tmunro 64 1628755 : return j + 1;
65 : }
66 :
67 : #endif /* QUNIQUE_H */
|
