1 files changed, 103 insertions, 0 deletions
diff --git a/gl/lib/hash.h b/gl/lib/hash.h
new file mode 100644
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--- /dev/null
+++ b/gl/lib/hash.h
@@ -0,0 +1,103 @@
+/* hash - hashing table processing.
+   Copyright (C) 1998-1999, 2001, 2003, 2009-2019 Free Software Foundation,
+   Inc.
+   Written by Jim Meyering <meyering@ascend.com>, 1998.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* A generic hash table package.  */
+
+/* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use
+   obstacks instead of malloc, and recompile 'hash.c' with same setting.  */
+
+#ifndef HASH_H_
+# define HASH_H_
+
+# include <stdio.h>
+# include <stdbool.h>
+
+/* The __attribute__ feature is available in gcc versions 2.5 and later.
+   The warn_unused_result attribute appeared first in gcc-3.4.0.  */
+# if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+#  define _GL_ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__))
+# else
+#  define _GL_ATTRIBUTE_WUR /* empty */
+# endif
+
+# ifndef _GL_ATTRIBUTE_DEPRECATED
+/* The __attribute__((__deprecated__)) feature
+   is available in gcc versions 3.1 and newer.  */
+#  if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 1)
+#   define _GL_ATTRIBUTE_DEPRECATED /* empty */
+#  else
+#   define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
+#  endif
+# endif
+
+typedef size_t (*Hash_hasher) (const void *, size_t);
+typedef bool (*Hash_comparator) (const void *, const void *);
+typedef void (*Hash_data_freer) (void *);
+typedef bool (*Hash_processor) (void *, void *);
+
+struct hash_tuning
+  {
+    /* This structure is mainly used for 'hash_initialize', see the block
+       documentation of 'hash_reset_tuning' for more complete comments.  */
+
+    float shrink_threshold;     /* ratio of used buckets to trigger a shrink */
+    float shrink_factor;        /* ratio of new smaller size to original size */
+    float growth_threshold;     /* ratio of used buckets to trigger a growth */
+    float growth_factor;        /* ratio of new bigger size to original size */
+    bool is_n_buckets;          /* if CANDIDATE really means table size */
+  };
+
+typedef struct hash_tuning Hash_tuning;
+
+struct hash_table;
+
+typedef struct hash_table Hash_table;
+
+/* Information and lookup.  */
+size_t hash_get_n_buckets (const Hash_table *) _GL_ATTRIBUTE_PURE;
+size_t hash_get_n_buckets_used (const Hash_table *) _GL_ATTRIBUTE_PURE;
+size_t hash_get_n_entries (const Hash_table *) _GL_ATTRIBUTE_PURE;
+size_t hash_get_max_bucket_length (const Hash_table *) _GL_ATTRIBUTE_PURE;
+bool hash_table_ok (const Hash_table *) _GL_ATTRIBUTE_PURE;
+void hash_print_statistics (const Hash_table *, FILE *);
+void *hash_lookup (const Hash_table *, const void *);
+
+/* Walking.  */
+void *hash_get_first (const Hash_table *) _GL_ATTRIBUTE_PURE;
+void *hash_get_next (const Hash_table *, const void *);
+size_t hash_get_entries (const Hash_table *, void **, size_t);
+size_t hash_do_for_each (const Hash_table *, Hash_processor, void *);
+
+/* Allocation and clean-up.  */
+size_t hash_string (const char *, size_t) _GL_ATTRIBUTE_PURE;
+void hash_reset_tuning (Hash_tuning *);
+Hash_table *hash_initialize (size_t, const Hash_tuning *,
+                             Hash_hasher, Hash_comparator,
+                             Hash_data_freer) _GL_ATTRIBUTE_WUR;
+void hash_clear (Hash_table *);
+void hash_free (Hash_table *);
+
+/* Insertion and deletion.  */
+bool hash_rehash (Hash_table *, size_t) _GL_ATTRIBUTE_WUR;
+void *hash_insert (Hash_table *, const void *) _GL_ATTRIBUTE_WUR;
+
+int hash_insert_if_absent (Hash_table *table, const void *entry,
+                           const void **matched_ent);
+void *hash_delete (Hash_table *, const void *);
+
+#endif