| /*------------------------------------------------------------------------- | |
| * | |
| * qunique.h | |
| * inline array unique functions | |
| * Portions Copyright (c) 2019-2024, PostgreSQL Global Development Group | |
| * | |
| * IDENTIFICATION | |
| * src/include/lib/qunique.h | |
| *------------------------------------------------------------------------- | |
| */ | |
| /* | |
| * Remove duplicates from a pre-sorted array, according to a user-supplied | |
| * comparator. Usually the array should have been sorted with qsort() using | |
| * the same arguments. Return the new size. | |
| */ | |
| static inline size_t | |
| qunique(void *array, size_t elements, size_t width, | |
| int (*compare) (const void *, const void *)) | |
| { | |
| char *bytes = (char *) array; | |
| size_t i, | |
| j; | |
| if (elements <= 1) | |
| return elements; | |
| for (i = 1, j = 0; i < elements; ++i) | |
| { | |
| if (compare(bytes + i * width, bytes + j * width) != 0 && | |
| ++j != i) | |
| memcpy(bytes + j * width, bytes + i * width, width); | |
| } | |
| return j + 1; | |
| } | |
| /* | |
| * Like qunique(), but takes a comparator with an extra user data argument | |
| * which is passed through, for compatibility with qsort_arg(). | |
| */ | |
| static inline size_t | |
| qunique_arg(void *array, size_t elements, size_t width, | |
| int (*compare) (const void *, const void *, void *), | |
| void *arg) | |
| { | |
| char *bytes = (char *) array; | |
| size_t i, | |
| j; | |
| if (elements <= 1) | |
| return elements; | |
| for (i = 1, j = 0; i < elements; ++i) | |
| { | |
| if (compare(bytes + i * width, bytes + j * width, arg) != 0 && | |
| ++j != i) | |
| memcpy(bytes + j * width, bytes + i * width, width); | |
| } | |
| return j + 1; | |
| } | |