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+/* Abstract map data type.
+ Copyright (C) 2006-2007, 2009-2022 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_MAP_H
+#define _GL_MAP_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#ifndef _GL_INLINE_HEADER_BEGIN
+ #error "Please include config.h first."
+#endif
+_GL_INLINE_HEADER_BEGIN
+#ifndef GL_MAP_INLINE
+# define GL_MAP_INLINE _GL_INLINE
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* gl_map is an abstract map data type. It can contain any number of
+ (key, value) pairs, where
+ - keys and values are objects ('void *' or 'const void *' pointers),
+ - There are no (key, value1) and (key, value2) pairs with the same key
+ (in the sense of a given comparator function).
+
+ There are several implementations of this map datatype, optimized for
+ different operations or for memory. You can start using the simplest map
+ implementation, GL_ARRAY_MAP, and switch to a different implementation
+ later, when you realize which operations are performed the most frequently.
+ The API of the different implementations is exactly the same; when switching
+ to a different implementation, you only have to change the gl_map_create
+ call.
+
+ The implementations are:
+ GL_ARRAY_MAP a growable array
+ GL_LINKEDHASH_MAP a hash table with a linked list
+ GL_HASH_MAP a hash table
+
+ The memory consumption is asymptotically the same: O(1) for every pair
+ in the map. When looking more closely at the average memory consumed
+ for an object, GL_ARRAY_MAP is the most compact representation, then comes
+ GL_HASH_MAP, and GL_LINKEDHASH_MAP needs the most memory.
+
+ The guaranteed average performance of the operations is, for a map of
+ n pairs:
+
+ Operation ARRAY LINKEDHASH
+ HASH
+
+ gl_map_size O(1) O(1)
+ gl_map_get O(n) O(1)
+ gl_map_put O(n) O(1)
+ gl_map_remove O(n) O(1)
+ gl_map_search O(n) O(1)
+ gl_map_iterator O(1) O(1)
+ gl_map_iterator_next O(1) O(1)
+ */
+
+/* --------------------------- gl_map_t Data Type --------------------------- */
+
+/* Type of function used to compare two keys.
+ NULL denotes pointer comparison. */
+typedef bool (*gl_mapkey_equals_fn) (const void *key1, const void *key2);
+
+/* Type of function used to compute a hash code.
+ NULL denotes a function that depends only on the pointer itself. */
+typedef size_t (*gl_mapkey_hashcode_fn) (const void *key);
+
+#ifndef _GL_MAP_DISPOSE_FNS_DEFINED
+
+/* Type of function used to dispose a key once a (key, value) pair is removed
+ from a map. NULL denotes a no-op. */
+typedef void (*gl_mapkey_dispose_fn) (const void *key);
+
+/* Type of function used to dispose a value once a (key, value) pair is removed
+ from a map. NULL denotes a no-op. */
+typedef void (*gl_mapvalue_dispose_fn) (const void *value);
+
+# define _GL_MAP_DISPOSE_FNS_DEFINED 1
+#endif
+
+struct gl_map_impl;
+/* Type representing an entire map. */
+typedef struct gl_map_impl * gl_map_t;
+
+struct gl_map_implementation;
+/* Type representing a map datatype implementation. */
+typedef const struct gl_map_implementation * gl_map_implementation_t;
+
+#if 0 /* Unless otherwise specified, these are defined inline below. */
+
+/* Creates an empty map.
+ IMPLEMENTATION is one of GL_ARRAY_MAP, GL_LINKEDHASH_MAP, GL_HASH_MAP.
+ EQUALS_FN is a key comparison function or NULL.
+ HASHCODE_FN is a key hash code function or NULL.
+ KDISPOSE_FN is a key disposal function or NULL.
+ VDISPOSE_FN is a value disposal function or NULL. */
+/* declared in gl_xmap.h */
+extern gl_map_t gl_map_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)
+ /*_GL_ATTRIBUTE_DEALLOC (gl_map_free, 1)*/
+ _GL_ATTRIBUTE_RETURNS_NONNULL;
+/* Likewise. Returns NULL upon out-of-memory. */
+extern gl_map_t gl_map_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)
+ /*_GL_ATTRIBUTE_DEALLOC (gl_map_free, 1)*/;
+
+/* Returns the current number of pairs in a map. */
+extern size_t gl_map_size (gl_map_t map);
+
+/* Searches whether a pair with the given key is already in the map.
+ Returns the value if found, or NULL if not present in the map. */
+extern const void * gl_map_get (gl_map_t map, const void *key);
+
+/* Searches whether a pair with the given key is already in the map.
+ Returns true and sets *VALUEP to the value if found.
+ Returns false if not present in the map. */
+extern bool gl_map_search (gl_map_t map, const void *key, const void **valuep);
+
+/* Adds a pair to a map.
+ Returns true if a pair with the given key was not already in the map and so
+ this pair was added.
+ Returns false if a pair with the given key was already in the map and only
+ its value was replaced. */
+/* declared in gl_xmap.h */
+extern bool gl_map_put (gl_map_t map, const void *key, const void *value);
+/* Likewise. Returns -1 upon out-of-memory. */
+_GL_ATTRIBUTE_NODISCARD
+extern int gl_map_nx_put (gl_map_t map, const void *key, const void *value);
+
+/* Adds a pair to a map and retrieves the previous value.
+ Returns true if a pair with the given key was not already in the map and so
+ this pair was added.
+ Returns false and sets *OLDVALUEP to the previous value, if a pair with the
+ given key was already in the map and only its value was replaced. */
+/* declared in gl_xmap.h */
+extern bool gl_map_getput (gl_map_t map, const void *key, const void *value,
+ const void **oldvaluep);
+/* Likewise. Returns -1 upon out-of-memory. */
+_GL_ATTRIBUTE_NODISCARD
+extern int gl_map_nx_getput (gl_map_t map, const void *key, const void *value,
+ const void **oldvaluep);
+
+/* Removes a pair from a map.
+ Returns true if the key was found and its pair removed.
+ Returns false otherwise. */
+extern bool gl_map_remove (gl_map_t map, const void *key);
+
+/* Removes a pair from a map and retrieves the previous value.
+ Returns true and sets *OLDVALUEP to the previous value, if the key was found
+ and its pair removed.
+ Returns false otherwise. */
+extern bool gl_map_getremove (gl_map_t map, const void *key,
+ const void **oldvaluep);
+
+/* Frees an entire map.
+ (But this call does not free the keys and values of the pairs in the map.
+ It only invokes the KDISPOSE_FN on each key and the VDISPOSE_FN on each value
+ of the pairs in the map.) */
+extern void gl_map_free (gl_map_t map);
+
+#endif /* End of inline and gl_xmap.h-defined functions. */
+
+/* ---------------------- gl_map_iterator_t Data Type ---------------------- */
+
+/* Functions for iterating through a map.
+ Note: Iterating through a map of type GL_HASH_MAP returns the pairs in an
+ unpredictable order. If you need a predictable order, use GL_LINKEDHASH_MAP
+ instead of GL_HASH_MAP. */
+
+/* Type of an iterator that traverses a map.
+ This is a fixed-size struct, so that creation of an iterator doesn't need
+ memory allocation on the heap. */
+typedef struct
+{
+ /* For fast dispatch of gl_map_iterator_next. */
+ const struct gl_map_implementation *vtable;
+ /* For detecting whether the last returned pair was removed. */
+ gl_map_t map;
+ size_t count;
+ /* Other, implementation-private fields. */
+ void *p; void *q;
+ size_t i; size_t j;
+} gl_map_iterator_t;
+
+#if 0 /* These are defined inline below. */
+
+/* Creates an iterator traversing a map.
+ The map's contents must not be modified while the iterator is in use,
+ except for modifying the value of the last returned key or removing the
+ last returned pair. */
+extern gl_map_iterator_t gl_map_iterator (gl_map_t map);
+
+/* If there is a next pair, stores the next pair in *KEYP and *VALUEP, advances
+ the iterator, and returns true. Otherwise, returns false. */
+extern bool gl_map_iterator_next (gl_map_iterator_t *iterator,
+ const void **keyp, const void **valuep);
+
+/* Frees an iterator. */
+extern void gl_map_iterator_free (gl_map_iterator_t *iterator);
+
+#endif /* End of inline functions. */
+
+/* ------------------------- Implementation Details ------------------------- */
+
+struct gl_map_implementation
+{
+ /* gl_map_t functions. */
+ gl_map_t (*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);
+ size_t (*size) (gl_map_t map);
+ bool (*search) (gl_map_t map, const void *key, const void **valuep);
+ int (*nx_getput) (gl_map_t map, const void *key, const void *value,
+ const void **oldvaluep);
+ bool (*getremove) (gl_map_t map, const void *key, const void **oldvaluep);
+ void (*map_free) (gl_map_t map);
+ /* gl_map_iterator_t functions. */
+ gl_map_iterator_t (*iterator) (gl_map_t map);
+ bool (*iterator_next) (gl_map_iterator_t *iterator,
+ const void **keyp, const void **valuep);
+ void (*iterator_free) (gl_map_iterator_t *iterator);
+};
+
+struct gl_map_impl_base
+{
+ const struct gl_map_implementation *vtable;
+ gl_mapkey_equals_fn equals_fn;
+ gl_mapkey_dispose_fn kdispose_fn;
+ gl_mapvalue_dispose_fn vdispose_fn;
+};
+
+/* Define most functions of this file as accesses to the
+ struct gl_map_implementation. */
+
+GL_MAP_INLINE
+/*_GL_ATTRIBUTE_DEALLOC (gl_map_free, 1)*/
+gl_map_t
+gl_map_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)
+{
+ return implementation->nx_create_empty (implementation,
+ equals_fn, hashcode_fn,
+ kdispose_fn, vdispose_fn);
+}
+
+GL_MAP_INLINE size_t
+gl_map_size (gl_map_t map)
+{
+ return ((const struct gl_map_impl_base *) map)->vtable->size (map);
+}
+
+GL_MAP_INLINE bool
+gl_map_search (gl_map_t map, const void *key, const void **valuep)
+{
+ return ((const struct gl_map_impl_base *) map)->vtable
+ ->search (map, key, valuep);
+}
+
+_GL_ATTRIBUTE_NODISCARD GL_MAP_INLINE int
+gl_map_nx_getput (gl_map_t map, const void *key, const void *value,
+ const void **oldvaluep)
+{
+ return ((const struct gl_map_impl_base *) map)->vtable
+ ->nx_getput (map, key, value, oldvaluep);
+}
+
+GL_MAP_INLINE bool
+gl_map_getremove (gl_map_t map, const void *key, const void **oldvaluep)
+{
+ return ((const struct gl_map_impl_base *) map)->vtable
+ ->getremove (map, key, oldvaluep);
+}
+
+GL_MAP_INLINE void
+gl_map_free (gl_map_t map)
+{
+ ((const struct gl_map_impl_base *) map)->vtable->map_free (map);
+}
+
+GL_MAP_INLINE gl_map_iterator_t
+gl_map_iterator (gl_map_t map)
+{
+ return ((const struct gl_map_impl_base *) map)->vtable->iterator (map);
+}
+
+GL_MAP_INLINE bool
+gl_map_iterator_next (gl_map_iterator_t *iterator,
+ const void **keyp, const void **valuep)
+{
+ return iterator->vtable->iterator_next (iterator, keyp, valuep);
+}
+
+GL_MAP_INLINE void
+gl_map_iterator_free (gl_map_iterator_t *iterator)
+{
+ iterator->vtable->iterator_free (iterator);
+}
+
+/* Define the convenience functions, that is, the functions that are independent
+ of the implementation. */
+
+GL_MAP_INLINE const void *
+gl_map_get (gl_map_t map, const void *key)
+{
+ const void *value = NULL;
+ gl_map_search (map, key, &value);
+ return value;
+}
+
+_GL_ATTRIBUTE_NODISCARD GL_MAP_INLINE int
+gl_map_nx_put (gl_map_t map, const void *key, const void *value)
+{
+ const void *oldvalue;
+ int result = gl_map_nx_getput (map, key, value, &oldvalue);
+ if (result == 0)
+ {
+ gl_mapvalue_dispose_fn vdispose_fn =
+ ((const struct gl_map_impl_base *) map)->vdispose_fn;
+ if (vdispose_fn != NULL)
+ vdispose_fn (oldvalue);
+ }
+ return result;
+}
+
+GL_MAP_INLINE bool
+gl_map_remove (gl_map_t map, const void *key)
+{
+ const void *oldvalue;
+ bool result = gl_map_getremove (map, key, &oldvalue);
+ if (result)
+ {
+ gl_mapvalue_dispose_fn vdispose_fn =
+ ((const struct gl_map_impl_base *) map)->vdispose_fn;
+ if (vdispose_fn != NULL)
+ vdispose_fn (oldvalue);
+ }
+ return result;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+_GL_INLINE_HEADER_END
+
+#endif /* _GL_MAP_H */