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1/* SPDX-License-Identifier: GPL-2.0-or-later */2/* Generic associative array implementation.3 *4 * See Documentation/core-api/assoc_array.rst for information.5 *6 * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.7 * Written by David Howells (dhowells@redhat.com)8 */9 10#ifndef _LINUX_ASSOC_ARRAY_H11#define _LINUX_ASSOC_ARRAY_H12 13#ifdef CONFIG_ASSOCIATIVE_ARRAY14 15#include <linux/types.h>16 17#define ASSOC_ARRAY_KEY_CHUNK_SIZE BITS_PER_LONG /* Key data retrieved in chunks of this size */18 19/*20 * Generic associative array.21 */22struct assoc_array {23 struct assoc_array_ptr *root; /* The node at the root of the tree */24 unsigned long nr_leaves_on_tree;25};26 27/*28 * Operations on objects and index keys for use by array manipulation routines.29 */30struct assoc_array_ops {31 /* Method to get a chunk of an index key from caller-supplied data */32 unsigned long (*get_key_chunk)(const void *index_key, int level);33 34 /* Method to get a piece of an object's index key */35 unsigned long (*get_object_key_chunk)(const void *object, int level);36 37 /* Is this the object we're looking for? */38 bool (*compare_object)(const void *object, const void *index_key);39 40 /* How different is an object from an index key, to a bit position in41 * their keys? (or -1 if they're the same)42 */43 int (*diff_objects)(const void *object, const void *index_key);44 45 /* Method to free an object. */46 void (*free_object)(void *object);47};48 49/*50 * Access and manipulation functions.51 */52struct assoc_array_edit;53 54static inline void assoc_array_init(struct assoc_array *array)55{56 array->root = NULL;57 array->nr_leaves_on_tree = 0;58}59 60extern int assoc_array_iterate(const struct assoc_array *array,61 int (*iterator)(const void *object,62 void *iterator_data),63 void *iterator_data);64extern void *assoc_array_find(const struct assoc_array *array,65 const struct assoc_array_ops *ops,66 const void *index_key);67extern void assoc_array_destroy(struct assoc_array *array,68 const struct assoc_array_ops *ops);69extern struct assoc_array_edit *assoc_array_insert(struct assoc_array *array,70 const struct assoc_array_ops *ops,71 const void *index_key,72 void *object);73extern void assoc_array_insert_set_object(struct assoc_array_edit *edit,74 void *object);75extern struct assoc_array_edit *assoc_array_delete(struct assoc_array *array,76 const struct assoc_array_ops *ops,77 const void *index_key);78extern struct assoc_array_edit *assoc_array_clear(struct assoc_array *array,79 const struct assoc_array_ops *ops);80extern void assoc_array_apply_edit(struct assoc_array_edit *edit);81extern void assoc_array_cancel_edit(struct assoc_array_edit *edit);82extern int assoc_array_gc(struct assoc_array *array,83 const struct assoc_array_ops *ops,84 bool (*iterator)(void *object, void *iterator_data),85 void *iterator_data);86 87#endif /* CONFIG_ASSOCIATIVE_ARRAY */88#endif /* _LINUX_ASSOC_ARRAY_H */89