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authorvvvv <vvvv@yandex-team.com>2024-11-07 12:29:36 +0300
committervvvv <vvvv@yandex-team.com>2024-11-07 13:49:47 +0300
commitd4c258e9431675bab6745c8638df6e3dfd4dca6b (patch)
treeb5efcfa11351152a4c872fccaea35749141c0b11 /yql/essentials/parser/pg_wrapper/postgresql/src/include/lib/qunique.h
parent13a4f274caef5cfdaf0263b24e4d6bdd5521472b (diff)
downloadydb-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.h67
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
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index 00000000000..30b67c794f6
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+++ 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 */