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Diffstat (limited to 'lib/gl_oset.h')
| -rw-r--r-- | lib/gl_oset.h | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/lib/gl_oset.h b/lib/gl_oset.h new file mode 100644 index 0000000..5134065 --- /dev/null +++ b/lib/gl_oset.h @@ -0,0 +1,293 @@ +/* Abstract ordered set data type. + Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2006. + + 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 <http://www.gnu.org/licenses/>. */ + +#ifndef _GL_OSET_H +#define _GL_OSET_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_OSET_INLINE +# define GL_OSET_INLINE _GL_INLINE +#endif + +#ifdef __cplusplus +extern "C" { +#endif + + +/* gl_oset is an abstract ordered set data type. It can contain any number + of objects ('void *' or 'const void *' pointers) in the order of a given + comparator function. Duplicates (in the sense of the comparator) are + forbidden. + + There are several implementations of this ordered set datatype, optimized + for different operations or for memory. You can start using the simplest + ordered set implementation, GL_ARRAY_OSET, 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_oset_create call. + + The implementations are: + GL_ARRAY_OSET a growable array + GL_AVLTREE_OSET a binary tree (AVL tree) + GL_RBTREE_OSET a binary tree (red-black tree) + + The memory consumption is asymptotically the same: O(1) for every object + in the set. When looking more closely at the average memory consumed + for an object, GL_ARRAY_OSET is the most compact representation, and + GL_AVLTREE_OSET, GL_RBTREE_OSET need more memory. + + The guaranteed average performance of the operations is, for a set of + n elements: + + Operation ARRAY TREE + + gl_oset_size O(1) O(1) + gl_oset_add O(n) O(log n) + gl_oset_remove O(n) O(log n) + gl_oset_search O(log n) O(log n) + gl_oset_search_atleast O(log n) O(log n) + gl_oset_iterator O(1) O(log n) + gl_oset_iterator_next O(1) O(log n) + */ + +/* -------------------------- gl_oset_t Data Type -------------------------- */ + +/* Type of function used to compare two elements. Same as for qsort(). + NULL denotes pointer comparison. */ +typedef int (*gl_setelement_compar_fn) (const void *elt1, const void *elt2); + +/* Type of function used to dispose an element once it's removed from a set. + NULL denotes a no-op. */ +typedef void (*gl_setelement_dispose_fn) (const void *elt); + +/* Type of function used to compare an element with a threshold. + Return true if the element is greater or equal than the threshold. */ +typedef bool (*gl_setelement_threshold_fn) (const void *elt, const void *threshold); + +struct gl_oset_impl; +/* Type representing an entire ordered set. */ +typedef struct gl_oset_impl * gl_oset_t; + +struct gl_oset_implementation; +/* Type representing a ordered set datatype implementation. */ +typedef const struct gl_oset_implementation * gl_oset_implementation_t; + +#if 0 /* Unless otherwise specified, these are defined inline below. */ + +/* Create an empty set. + IMPLEMENTATION is one of GL_ARRAY_OSET, GL_AVLTREE_OSET, GL_RBTREE_OSET. + COMPAR_FN is an element comparison function or NULL. + DISPOSE_FN is an element disposal function or NULL. */ +/* declared in gl_xoset.h */ +extern gl_oset_t gl_oset_create_empty (gl_oset_implementation_t implementation, + gl_setelement_compar_fn compar_fn, + gl_setelement_dispose_fn dispose_fn); +/* Likewise. Return NULL upon out-of-memory. */ +extern gl_oset_t gl_oset_nx_create_empty (gl_oset_implementation_t implementation, + gl_setelement_compar_fn compar_fn, + gl_setelement_dispose_fn dispose_fn); + +/* Return the current number of elements in an ordered set. */ +extern size_t gl_oset_size (gl_oset_t set); + +/* Search whether an element is already in the ordered set. + Return true if found, or false if not present in the set. */ +extern bool gl_oset_search (gl_oset_t set, const void *elt); + +/* Search the least element in the ordered set that compares greater or equal + to the given THRESHOLD. The representation of the THRESHOLD is defined + by the THRESHOLD_FN. + Return true and store the found element in *ELTP if found, otherwise return + false. */ +extern bool gl_oset_search_atleast (gl_oset_t set, + gl_setelement_threshold_fn threshold_fn, + const void *threshold, + const void **eltp); + +/* Add an element to an ordered set. + Return true if it was not already in the set and added, false otherwise. */ +/* declared in gl_xoset.h */ +extern bool gl_oset_add (gl_oset_t set, const void *elt); +/* Likewise. Return -1 upon out-of-memory. */ +extern int gl_oset_nx_add (gl_oset_t set, const void *elt) +#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) + __attribute__ ((__warn_unused_result__)) +#endif + ; + +/* Remove an element from an ordered set. + Return true if it was found and removed. */ +extern bool gl_oset_remove (gl_oset_t set, const void *elt); + +/* Free an entire ordered set. + (But this call does not free the elements of the set.) */ +extern void gl_oset_free (gl_oset_t set); + +#endif /* End of inline and gl_xlist.h-defined functions. */ + +/* --------------------- gl_oset_iterator_t Data Type --------------------- */ + +/* Functions for iterating through an ordered set. */ + +/* Type of an iterator that traverses an ordered set. + 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_oset_iterator_next. */ + const struct gl_oset_implementation *vtable; + /* For detecting whether the last returned element was removed. */ + gl_oset_t set; + size_t count; + /* Other, implementation-private fields. */ + void *p; void *q; + size_t i; size_t j; +} gl_oset_iterator_t; + +#if 0 /* These are defined inline below. */ + +/* Create an iterator traversing an ordered set. + The set's contents must not be modified while the iterator is in use, + except for removing the last returned element. */ +extern gl_oset_iterator_t gl_oset_iterator (gl_oset_t set); + +/* If there is a next element, store the next element in *ELTP, advance the + iterator and return true. Otherwise, return false. */ +extern bool gl_oset_iterator_next (gl_oset_iterator_t *iterator, + const void **eltp); + +/* Free an iterator. */ +extern void gl_oset_iterator_free (gl_oset_iterator_t *iterator); + +#endif /* End of inline functions. */ + +/* ------------------------ Implementation Details ------------------------ */ + +struct gl_oset_implementation +{ + /* gl_oset_t functions. */ + gl_oset_t (*nx_create_empty) (gl_oset_implementation_t implementation, + gl_setelement_compar_fn compar_fn, + gl_setelement_dispose_fn dispose_fn); + size_t (*size) (gl_oset_t set); + bool (*search) (gl_oset_t set, const void *elt); + bool (*search_atleast) (gl_oset_t set, + gl_setelement_threshold_fn threshold_fn, + const void *threshold, const void **eltp); + int (*nx_add) (gl_oset_t set, const void *elt); + bool (*remove_elt) (gl_oset_t set, const void *elt); + void (*oset_free) (gl_oset_t set); + /* gl_oset_iterator_t functions. */ + gl_oset_iterator_t (*iterator) (gl_oset_t set); + bool (*iterator_next) (gl_oset_iterator_t *iterator, const void **eltp); + void (*iterator_free) (gl_oset_iterator_t *iterator); +}; + +struct gl_oset_impl_base +{ + const struct gl_oset_implementation *vtable; + gl_setelement_compar_fn compar_fn; + gl_setelement_dispose_fn dispose_fn; +}; + +/* Define all functions of this file as accesses to the + struct gl_oset_implementation. */ + +GL_OSET_INLINE gl_oset_t +gl_oset_nx_create_empty (gl_oset_implementation_t implementation, + gl_setelement_compar_fn compar_fn, + gl_setelement_dispose_fn dispose_fn) +{ + return implementation->nx_create_empty (implementation, compar_fn, + dispose_fn); +} + +GL_OSET_INLINE size_t +gl_oset_size (gl_oset_t set) +{ + return ((const struct gl_oset_impl_base *) set)->vtable->size (set); +} + +GL_OSET_INLINE bool +gl_oset_search (gl_oset_t set, const void *elt) +{ + return ((const struct gl_oset_impl_base *) set)->vtable->search (set, elt); +} + +GL_OSET_INLINE bool +gl_oset_search_atleast (gl_oset_t set, + gl_setelement_threshold_fn threshold_fn, + const void *threshold, const void **eltp) +{ + return ((const struct gl_oset_impl_base *) set)->vtable + ->search_atleast (set, threshold_fn, threshold, eltp); +} + +GL_OSET_INLINE int +#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) + __attribute__ ((__warn_unused_result__)) +#endif +gl_oset_nx_add (gl_oset_t set, const void *elt) +{ + return ((const struct gl_oset_impl_base *) set)->vtable->nx_add (set, elt); +} + +GL_OSET_INLINE bool +gl_oset_remove (gl_oset_t set, const void *elt) +{ + return ((const struct gl_oset_impl_base *) set)->vtable + ->remove_elt (set, elt); +} + +GL_OSET_INLINE void +gl_oset_free (gl_oset_t set) +{ + ((const struct gl_oset_impl_base *) set)->vtable->oset_free (set); +} + +GL_OSET_INLINE gl_oset_iterator_t +gl_oset_iterator (gl_oset_t set) +{ + return ((const struct gl_oset_impl_base *) set)->vtable->iterator (set); +} + +GL_OSET_INLINE bool +gl_oset_iterator_next (gl_oset_iterator_t *iterator, const void **eltp) +{ + return iterator->vtable->iterator_next (iterator, eltp); +} + +GL_OSET_INLINE void +gl_oset_iterator_free (gl_oset_iterator_t *iterator) +{ + iterator->vtable->iterator_free (iterator); +} + +#ifdef __cplusplus +} +#endif + +_GL_INLINE_HEADER_END + +#endif /* _GL_OSET_H */ |