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author | vvvv <vvvv@yandex-team.com> | 2024-11-07 12:29:36 +0300 |
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committer | vvvv <vvvv@yandex-team.com> | 2024-11-07 13:49:47 +0300 |
commit | d4c258e9431675bab6745c8638df6e3dfd4dca6b (patch) | |
tree | b5efcfa11351152a4c872fccaea35749141c0b11 /yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h | |
parent | 13a4f274caef5cfdaf0263b24e4d6bdd5521472b (diff) | |
download | ydb-d4c258e9431675bab6745c8638df6e3dfd4dca6b.tar.gz |
Moved other yql/essentials libs YQL-19206
init
commit_hash:7d4c435602078407bbf20dd3c32f9c90d2bbcbc0
Diffstat (limited to 'yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h')
-rw-r--r-- | yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h b/yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h new file mode 100644 index 00000000000..30b67c794f6 --- /dev/null +++ b/yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h @@ -0,0 +1,67 @@ +/*------------------------------------------------------------------------- + * + * qunique.h + * inline array unique functions + * Portions Copyright (c) 2019-2023, PostgreSQL Global Development Group + * + * IDENTIFICATION + * src/include/lib/qunique.h + *------------------------------------------------------------------------- + */ + +#ifndef QUNIQUE_H +#define 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; +} + +#endif /* QUNIQUE_H */ |