--- a/ChangeLog	Fri Dec 14 23:07:43 2018 +0100
+++ b/ChangeLog	Fri Dec 14 23:07:49 2018 +0100
@@ -1,5 +1,12 @@
 2018-12-14  Bruno Haible  <bruno@clisp.org>
 
+	linkedhash-map: New module.
+	* lib/gl_linkedhash_map.h: New file.
+	* lib/gl_linkedhash_map.c: New file.
+	* lib/gl_anyhash1.h: Update comments.
+	* lib/gl_anyhash2.h: Likewise.
+	* modules/linkedhash-map: New file.
+
 	array-map: New module.
 	* lib/gl_array_map.h: New file.
 	* lib/gl_array_map.c: New file.

--- a/lib/gl_anyhash1.h	Fri Dec 14 23:07:43 2018 +0100
+++ b/lib/gl_anyhash1.h	Fri Dec 14 23:07:49 2018 +0100
@@ -17,7 +17,8 @@
 
 /* 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_set.c, gl_hash_set.c,
+   gl_linkedhash_map.c, gl_hash_map.c.  */
 
 /* Hash table entry.  */
 struct gl_hash_entry

--- a/lib/gl_anyhash2.h	Fri Dec 14 23:07:43 2018 +0100
+++ b/lib/gl_anyhash2.h	Fri Dec 14 23:07:49 2018 +0100
@@ -17,7 +17,8 @@
 
 /* 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_set.c, gl_hash_set.c,
+   gl_linkedhash_map.c, gl_hash_map.c.  */
 
 #include "gl_anyhash_primes.h"
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/gl_linkedhash_map.c	Fri Dec 14 23:07:49 2018 +0100
@@ -0,0 +1,334 @@
+/* Map data type implemented by a hash table with a linked list.
+   Copyright (C) 2006, 2008-2018 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2018.
+
+   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/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "gl_linkedhash_map.h"
+
+#include <stdint.h> /* for SIZE_MAX */
+#include <stdlib.h>
+
+#include "xsize.h"
+
+#ifndef uintptr_t
+# define uintptr_t unsigned long
+#endif
+
+/* --------------------------- gl_map_t Data Type --------------------------- */
+
+#include "gl_anyhash1.h"
+
+/* Concrete list node implementation, valid for this file only.  */
+struct gl_list_node_impl
+{
+  struct gl_hash_entry h;           /* hash table entry fields; must be first */
+  struct gl_list_node_impl *next;
+  struct gl_list_node_impl *prev;
+  const void *key;
+  const void *value;
+};
+typedef struct gl_list_node_impl * gl_list_node_t;
+
+/* Concrete gl_map_impl type, valid for this file only.  */
+struct gl_map_impl
+{
+  struct gl_map_impl_base base;
+  gl_mapkey_hashcode_fn hashcode_fn;
+  /* A hash table: managed as an array of collision lists.  */
+  struct gl_hash_entry **table;
+  size_t table_size;
+  /* A circular list anchored at root.
+     The first node is = root.next, the last node is = root.prev.
+     The root's value is unused.  */
+  struct gl_list_node_impl root;
+  /* Number of list nodes, excluding the root.  */
+  size_t count;
+};
+
+#define CONTAINER_T gl_map_t
+#define CONTAINER_COUNT(map) (map)->count
+#include "gl_anyhash2.h"
+
+/* If the symbol SIGNAL_SAFE_MAP is defined, the code is compiled in such
+   a way that a gl_map_t data structure may be used from within a signal
+   handler.  The operations allowed in the signal handler are:
+     gl_map_iterator, gl_map_iterator_next, gl_map_iterator_free.
+   The map and node fields that are therefore accessed from the signal handler
+   are:
+     map->root, node->next, node->value.
+   We are careful to make modifications to these fields only in an order
+   that maintains the consistency of the list data structure at any moment,
+   and we use 'volatile' assignments to prevent the compiler from reordering
+   such assignments.  */
+#ifdef SIGNAL_SAFE_MAP
+# define ASYNCSAFE(type) *(type volatile *)&
+#else
+# define ASYNCSAFE(type)
+#endif
+
+/* --------------------------- gl_map_t Data Type --------------------------- */
+
+static gl_map_t
+gl_linkedhash_nx_create_empty (gl_map_implementation_t implementation,
+                               gl_mapkey_equals_fn equals_fn,
+                               gl_mapkey_hashcode_fn hashcode_fn,
+                               gl_mapkey_dispose_fn kdispose_fn,
+                               gl_mapvalue_dispose_fn vdispose_fn)
+{
+  struct gl_map_impl *map =
+    (struct gl_map_impl *) malloc (sizeof (struct gl_map_impl));
+
+  if (map == NULL)
+    return NULL;
+
+  map->base.vtable = implementation;
+  map->base.equals_fn = equals_fn;
+  map->base.kdispose_fn = kdispose_fn;
+  map->base.vdispose_fn = vdispose_fn;
+  map->hashcode_fn = hashcode_fn;
+  map->table_size = 11;
+  map->table =
+    (gl_hash_entry_t *) calloc (map->table_size, sizeof (gl_hash_entry_t));
+  if (map->table == NULL)
+    goto fail;
+  map->root.next = &map->root;
+  map->root.prev = &map->root;
+  map->count = 0;
+
+  return map;
+
+ fail:
+  free (map);
+  return NULL;
+}
+
+static size_t _GL_ATTRIBUTE_PURE
+gl_linkedhash_size (gl_map_t map)
+{
+  return map->count;
+}
+
+static bool _GL_ATTRIBUTE_PURE
+gl_linkedhash_search (gl_map_t map, const void *key, const void **valuep)
+{
+  size_t hashcode =
+    (map->hashcode_fn != NULL
+     ? map->hashcode_fn (key)
+     : (size_t)(uintptr_t) key);
+  size_t bucket = hashcode % map->table_size;
+  gl_mapkey_equals_fn equals = map->base.equals_fn;
+
+  /* Look for a match in the hash bucket.  */
+  gl_list_node_t node;
+
+  for (node = (gl_list_node_t) map->table[bucket];
+       node != NULL;
+       node = (gl_list_node_t) node->h.hash_next)
+    if (node->h.hashcode == hashcode
+        && (equals != NULL
+            ? equals (key, node->key)
+            : key == node->key))
+      {
+        *valuep = node->value;
+        return true;
+      }
+  return false;
+}
+
+static int
+gl_linkedhash_nx_getput (gl_map_t map, const void *key, const void *value,
+                         const void **oldvaluep)
+{
+  size_t hashcode =
+    (map->hashcode_fn != NULL
+     ? map->hashcode_fn (key)
+     : (size_t)(uintptr_t) key);
+  size_t bucket = hashcode % map->table_size;
+  gl_mapkey_equals_fn equals = map->base.equals_fn;
+
+  /* Look for a match in the hash bucket.  */
+  {
+    gl_list_node_t node;
+
+    for (node = (gl_list_node_t) map->table[bucket];
+         node != NULL;
+         node = (gl_list_node_t) node->h.hash_next)
+      if (node->h.hashcode == hashcode
+          && (equals != NULL
+              ? equals (key, node->key)
+              : key == node->key))
+        {
+          *oldvaluep = node->value;
+          node->value = value;
+          return 0;
+        }
+  }
+
+  /* Allocate a new node.  */
+  gl_list_node_t node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+
+  if (node == NULL)
+    return -1;
+
+  ASYNCSAFE(const void *) node->key = key;
+  ASYNCSAFE(const void *) node->value = value;
+  node->h.hashcode = hashcode;
+
+  /* Add node to the hash table.  */
+  node->h.hash_next = map->table[bucket];
+  map->table[bucket] = &node->h;
+
+  /* Add node to the map.  */
+  ASYNCSAFE(gl_list_node_t) node->next = &map->root;
+  node->prev = map->root.prev;
+  ASYNCSAFE(gl_list_node_t) node->prev->next = node;
+  map->root.prev = node;
+  map->count++;
+
+  hash_resize_after_add (map);
+
+  return 1;
+}
+
+static bool
+gl_linkedhash_getremove (gl_map_t map, const void *key, const void **oldvaluep)
+{
+  size_t hashcode =
+    (map->hashcode_fn != NULL
+     ? map->hashcode_fn (key)
+     : (size_t)(uintptr_t) key);
+  size_t bucket = hashcode % map->table_size;
+  gl_mapkey_equals_fn equals = map->base.equals_fn;
+
+  /* Look for the first match in the hash bucket.  */
+  gl_list_node_t *nodep;
+
+  for (nodep = (gl_list_node_t *) &map->table[bucket];
+       *nodep != NULL;
+       nodep = (gl_list_node_t *) &(*nodep)->h.hash_next)
+    {
+      gl_list_node_t node = *nodep;
+      if (node->h.hashcode == hashcode
+          && (equals != NULL
+              ? equals (key, node->key)
+              : key == node->key))
+        {
+          *oldvaluep = node->value;
+
+          /* Remove node from the hash table.  */
+          *nodep = (gl_list_node_t) node->h.hash_next;
+
+          /* Remove node from the list.  */
+          {
+            gl_list_node_t prev = node->prev;
+            gl_list_node_t next = node->next;
+
+            ASYNCSAFE(gl_list_node_t) prev->next = next;
+            next->prev = prev;
+          }
+          map->count--;
+
+          if (map->base.kdispose_fn != NULL)
+            map->base.kdispose_fn (node->key);
+          free (node);
+          return true;
+        }
+    }
+
+  return false;
+}
+
+static void
+gl_linkedhash_free (gl_map_t map)
+{
+  gl_mapkey_dispose_fn kdispose = map->base.kdispose_fn;
+  gl_mapvalue_dispose_fn vdispose = map->base.vdispose_fn;
+  gl_list_node_t node;
+
+  for (node = map->root.next; node != &map->root; )
+    {
+      gl_list_node_t next = node->next;
+      if (vdispose != NULL)
+        vdispose (node->value);
+      if (kdispose != NULL)
+        kdispose (node->key);
+      free (node);
+      node = next;
+    }
+  free (map->table);
+  free (map);
+}
+
+/* ---------------------- gl_map_iterator_t Data Type ---------------------- */
+
+/* Iterate through the list, not through the hash buckets, so that the order
+   in which the pairs are returned is predictable.  */
+
+static gl_map_iterator_t
+gl_linkedhash_iterator (gl_map_t map)
+{
+  gl_map_iterator_t result;
+
+  result.vtable = map->base.vtable;
+  result.map = map;
+  result.p = map->root.next;
+  result.q = &map->root;
+#if defined GCC_LINT || defined lint
+  result.i = 0;
+  result.j = 0;
+  result.count = 0;
+#endif
+
+  return result;
+}
+
+static bool
+gl_linkedhash_iterator_next (gl_map_iterator_t *iterator,
+                             const void **keyp, const void **valuep)
+{
+  if (iterator->p != iterator->q)
+    {
+      gl_list_node_t node = (gl_list_node_t) iterator->p;
+      *keyp = node->key;
+      *valuep = node->value;
+      iterator->p = node->next;
+      return true;
+    }
+  else
+    return false;
+}
+
+static void
+gl_linkedhash_iterator_free (gl_map_iterator_t *iterator)
+{
+}
+
+
+const struct gl_map_implementation gl_linkedhash_map_implementation =
+  {
+    gl_linkedhash_nx_create_empty,
+    gl_linkedhash_size,
+    gl_linkedhash_search,
+    gl_linkedhash_nx_getput,
+    gl_linkedhash_getremove,
+    gl_linkedhash_free,
+    gl_linkedhash_iterator,
+    gl_linkedhash_iterator_next,
+    gl_linkedhash_iterator_free
+  };

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/gl_linkedhash_map.h	Fri Dec 14 23:07:49 2018 +0100
@@ -0,0 +1,34 @@
+/* Map data type implemented by a hash table with a linked list.
+   Copyright (C) 2006, 2009-2018 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2018.
+
+   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/>.  */
+
+#ifndef _GL_LINKEDHASH_MAP_H
+#define _GL_LINKEDHASH_MAP_H
+
+#include "gl_map.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const struct gl_map_implementation gl_linkedhash_map_implementation;
+#define GL_LINKEDHASH_MAP &gl_linkedhash_map_implementation
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _GL_LINKEDHASH_MAP_H */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/linkedhash-map	Fri Dec 14 23:07:49 2018 +0100
@@ -0,0 +1,28 @@
+Description:
+Set data type implemented by a hash table with a linked list.
+
+Files:
+lib/gl_linkedhash_map.h
+lib/gl_linkedhash_map.c
+lib/gl_anyhash1.h
+lib/gl_anyhash2.h
+lib/gl_anyhash_primes.h
+
+Depends-on:
+map
+stdint
+xsize
+
+configure.ac:
+
+Makefile.am:
+lib_SOURCES += gl_linkedhash_map.h gl_linkedhash_map.c gl_anyhash1.h gl_anyhash2.h gl_anyhash_primes.h
+
+Include:
+"gl_linkedhash_map.h"
+
+License:
+GPL
+
+Maintainer:
+all