/* Generic associative array implementation. * * See Documentation/assoc_array.txt for information. * * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #ifndef _LINUX_ASSOC_ARRAY_H #define _LINUX_ASSOC_ARRAY_H #ifdef CONFIG_ASSOCIATIVE_ARRAY #include <linux/types.h> #define ASSOC_ARRAY_KEY_CHUNK_SIZE BITS_PER_LONG /* Key data retrieved in chunks of this size */ /* * Generic associative array. */ struct assoc_array { struct assoc_array_ptr *root; /* The node at the root of the tree */ unsigned long nr_leaves_on_tree; }; /* * Operations on objects and index keys for use by array manipulation routines. */ struct assoc_array_ops { /* Method to get a chunk of an index key from caller-supplied data */ unsigned long (*get_key_chunk)(const void *index_key, int level); /* Method to get a piece of an object's index key */ unsigned long (*get_object_key_chunk)(const void *object, int level); /* Is this the object we're looking for? */ bool (*compare_object)(const void *object, const void *index_key); /* How different is an object from an index key, to a bit position in * their keys? (or -1 if they're the same) */ int (*diff_objects)(const void *object, const void *index_key); /* Method to free an object. */ void (*free_object)(void *object); }; /* * Access and manipulation functions. */ struct assoc_array_edit; static inline void assoc_array_init(struct assoc_array *array) { array->root = NULL; array->nr_leaves_on_tree = 0; } extern int assoc_array_iterate(const struct assoc_array *array, int (*iterator)(const void *object, void *iterator_data), void *iterator_data); extern void *assoc_array_find(const struct assoc_array *array, const struct assoc_array_ops *ops, const void *index_key); extern void assoc_array_destroy(struct assoc_array *array, const struct assoc_array_ops *ops); extern struct assoc_array_edit *assoc_array_insert(struct assoc_array *array, const struct assoc_array_ops *ops, const void *index_key, void *object); extern void assoc_array_insert_set_object(struct assoc_array_edit *edit, void *object); extern struct assoc_array_edit *assoc_array_delete(struct assoc_array *array, const struct assoc_array_ops *ops, const void *index_key); extern struct assoc_array_edit *assoc_array_clear(struct assoc_array *array, const struct assoc_array_ops *ops); extern void assoc_array_apply_edit(struct assoc_array_edit *edit); extern void assoc_array_cancel_edit(struct assoc_array_edit *edit); extern int assoc_array_gc(struct assoc_array *array, const struct assoc_array_ops *ops, bool (*iterator)(void *object, void *iterator_data), void *iterator_data); #endif /* CONFIG_ASSOCIATIVE_ARRAY */ #endif /* _LINUX_ASSOC_ARRAY_H */