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-rw-r--r--gl/lib/gl_anyhash2.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/gl/lib/gl_anyhash2.h b/gl/lib/gl_anyhash2.h
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+/* Hash table for sequential list, set, and map data type.
+ Copyright (C) 2006, 2009-2022 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2006.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Common code of
+ gl_linkedhash_list.c, gl_avltreehash_list.c, gl_rbtreehash_list.c,
+ gl_linkedhash_set.c, gl_hash_set.c,
+ gl_linkedhash_map.c, gl_hash_map.c. */
+
+#include "gl_anyhash_primes.h"
+
+/* Resizes the hash table with a new estimated size. */
+static void
+hash_resize (CONTAINER_T container, size_t estimate)
+{
+ size_t new_size = next_prime (estimate);
+
+ if (new_size > container->table_size)
+ {
+ gl_hash_entry_t *old_table = container->table;
+ /* Allocate the new table. */
+ gl_hash_entry_t *new_table;
+ size_t i;
+
+ if (size_overflow_p (xtimes (new_size, sizeof (gl_hash_entry_t))))
+ goto fail;
+ new_table =
+ (gl_hash_entry_t *) calloc (new_size, sizeof (gl_hash_entry_t));
+ if (new_table == NULL)
+ goto fail;
+
+ /* Iterate through the entries of the old table. */
+ for (i = container->table_size; i > 0; )
+ {
+ gl_hash_entry_t node = old_table[--i];
+
+ while (node != NULL)
+ {
+ gl_hash_entry_t next = node->hash_next;
+ /* Add the entry to the new table. */
+ size_t bucket = node->hashcode % new_size;
+ node->hash_next = new_table[bucket];
+ new_table[bucket] = node;
+
+ node = next;
+ }
+ }
+
+ container->table = new_table;
+ container->table_size = new_size;
+ free (old_table);
+ }
+ return;
+
+ fail:
+ /* Just continue without resizing the table. */
+ return;
+}
+
+/* Resizes the hash table if needed, after CONTAINER_COUNT (container) was
+ incremented. */
+static void
+hash_resize_after_add (CONTAINER_T container)
+{
+ size_t count = CONTAINER_COUNT (container);
+ size_t estimate = xsum (count, count / 2); /* 1.5 * count */
+ if (estimate > container->table_size)
+ hash_resize (container, estimate);
+}