2 This file is part of GNUnet.
3 (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file include/gnunet_container_lib.h
23 * @brief container classes for GNUnet
25 * @author Christian Grothoff
29 #ifndef GNUNET_CONTAINER_LIB_H
30 #define GNUNET_CONTAINER_LIB_H
32 /* add error and config prototypes */
33 #include "gnunet_crypto_lib.h"
34 #include <extractor.h>
36 #ifndef EXTRACTOR_METATYPE_GNUNET_ORIGINAL_FILENAME
37 /* hack for LE < 0.6.3 */
38 #define EXTRACTOR_METATYPE_GNUNET_ORIGINAL_FILENAME 180
44 #if 0 /* keep Emacsens' auto-indent happy */
50 /* ******************* bloomfilter ***************** */
53 * @brief bloomfilter representation (opaque)
55 struct GNUNET_CONTAINER_BloomFilter;
58 * Iterator over HashCodes.
61 * @param next set to the next hash code
62 * @return GNUNET_YES if next was updated
63 * GNUNET_NO if there are no more entries
65 typedef int (*GNUNET_HashCodeIterator) (void *cls, GNUNET_HashCode * next);
69 * Load a bloom-filter from a file.
71 * @param filename the name of the file (or the prefix)
72 * @param size the size of the bloom-filter (number of
73 * bytes of storage space to use)
74 * @param k the number of GNUNET_CRYPTO_hash-functions to apply per
75 * element (number of bits set per element in the set)
76 * @return the bloomfilter
78 struct GNUNET_CONTAINER_BloomFilter *
79 GNUNET_CONTAINER_bloomfilter_load (const char *filename, size_t size,
84 * Create a bloom filter from raw bits.
86 * @param data the raw bits in memory (maybe NULL,
87 * in which case all bits should be considered
89 * @param size the size of the bloom-filter (number of
90 * bytes of storage space to use); also size of data
91 * -- unless data is NULL. Must be a power of 2.
92 * @param k the number of GNUNET_CRYPTO_hash-functions to apply per
93 * element (number of bits set per element in the set)
94 * @return the bloomfilter
96 struct GNUNET_CONTAINER_BloomFilter *
97 GNUNET_CONTAINER_bloomfilter_init (const char *data, size_t size,
102 * Copy the raw data of this bloomfilter into
103 * the given data array.
105 * @param data where to write the data
106 * @param size the size of the given data array
107 * @return GNUNET_SYSERR if the data array of the wrong size
110 GNUNET_CONTAINER_bloomfilter_get_raw_data (const struct
111 GNUNET_CONTAINER_BloomFilter *bf,
112 char *data, size_t size);
116 * Test if an element is in the filter.
117 * @param e the element
118 * @param bf the filter
119 * @return GNUNET_YES if the element is in the filter, GNUNET_NO if not
122 GNUNET_CONTAINER_bloomfilter_test (const struct GNUNET_CONTAINER_BloomFilter
123 *bf, const GNUNET_HashCode * e);
127 * Add an element to the filter
128 * @param bf the filter
129 * @param e the element
132 GNUNET_CONTAINER_bloomfilter_add (struct GNUNET_CONTAINER_BloomFilter *bf,
133 const GNUNET_HashCode * e);
137 * Remove an element from the filter.
138 * @param bf the filter
139 * @param e the element to remove
142 GNUNET_CONTAINER_bloomfilter_remove (struct GNUNET_CONTAINER_BloomFilter *bf,
143 const GNUNET_HashCode * e);
147 * Create a copy of a bloomfilter.
149 * @param bf the filter
152 struct GNUNET_CONTAINER_BloomFilter *
153 GNUNET_CONTAINER_bloomfilter_copy (const struct GNUNET_CONTAINER_BloomFilter
159 * Free the space associcated with a filter
160 * in memory, flush to drive if needed (do not
161 * free the space on the drive)
162 * @param bf the filter
165 GNUNET_CONTAINER_bloomfilter_free (struct GNUNET_CONTAINER_BloomFilter *bf);
169 * Get size of the bloom filter.
171 * @param bf the filter
172 * @return number of bytes used for the data of the bloom filter
175 GNUNET_CONTAINER_bloomfilter_get_size (const struct GNUNET_CONTAINER_BloomFilter
180 * Reset a bloom filter to empty.
181 * @param bf the filter
184 GNUNET_CONTAINER_bloomfilter_clear (struct GNUNET_CONTAINER_BloomFilter *bf);
187 * Or the entries of the given raw data array with the
188 * data of the given bloom filter. Assumes that
189 * the size of the data array and the current filter
192 * @param bf the filter
193 * @param data data to OR-in
194 * @param size size of data
195 * @return GNUNET_OK on success
198 GNUNET_CONTAINER_bloomfilter_or (struct GNUNET_CONTAINER_BloomFilter *bf,
199 const char *data, size_t size);
202 * Or the entries of the given raw data array with the
203 * data of the given bloom filter. Assumes that
204 * the size of the data array and the current filter
207 * @param bf the filter
208 * @param to_or the bloomfilter to or-in
209 * @param size number of bytes in data
212 GNUNET_CONTAINER_bloomfilter_or2 (struct GNUNET_CONTAINER_BloomFilter *bf,
213 const struct GNUNET_CONTAINER_BloomFilter
214 *to_or, size_t size);
217 * Resize a bloom filter. Note that this operation
218 * is pretty costly. Essentially, the bloom filter
219 * needs to be completely re-build.
221 * @param bf the filter
222 * @param iterator an iterator over all elements stored in the BF
223 * @param iterator_cls closure for iterator
224 * @param size the new size for the filter
225 * @param k the new number of GNUNET_CRYPTO_hash-function to apply per element
228 GNUNET_CONTAINER_bloomfilter_resize (struct GNUNET_CONTAINER_BloomFilter *bf,
229 GNUNET_HashCodeIterator iterator,
230 void *iterator_cls, size_t size,
233 /* ****************** metadata ******************* */
236 * Meta data to associate with a file, directory or namespace.
238 struct GNUNET_CONTAINER_MetaData;
241 * Create a fresh MetaData token.
243 * @return empty meta-data container
245 struct GNUNET_CONTAINER_MetaData *
246 GNUNET_CONTAINER_meta_data_create (void);
249 * Duplicate a MetaData token.
251 * @param md what to duplicate
252 * @return duplicate meta-data container
254 struct GNUNET_CONTAINER_MetaData *
255 GNUNET_CONTAINER_meta_data_duplicate (const struct GNUNET_CONTAINER_MetaData
261 * @param md what to free
264 GNUNET_CONTAINER_meta_data_destroy (struct GNUNET_CONTAINER_MetaData *md);
267 * Test if two MDs are equal. We consider them equal if
268 * the meta types, formats and content match (we do not
269 * include the mime types and plugins names in this
272 * @param md1 first value to check
273 * @param md2 other value to check
274 * @return GNUNET_YES if they are equal
277 GNUNET_CONTAINER_meta_data_test_equal (const struct GNUNET_CONTAINER_MetaData
279 const struct GNUNET_CONTAINER_MetaData
286 * @param md metadata to extend
287 * @param plugin_name name of the plugin that produced this value;
288 * special values can be used (i.e. '<zlib>' for zlib being
289 * used in the main libextractor library and yielding
291 * @param type libextractor-type describing the meta data
292 * @param format basic format information about data
293 * @param data_mime_type mime-type of data (not of the original file);
294 * can be NULL (if mime-type is not known)
295 * @param data actual meta-data found
296 * @param data_len number of bytes in data
297 * @return GNUNET_OK on success, GNUNET_SYSERR if this entry already exists
298 * data_mime_type and plugin_name are not considered for "exists" checks
301 GNUNET_CONTAINER_meta_data_insert (struct GNUNET_CONTAINER_MetaData *md,
302 const char *plugin_name,
303 enum EXTRACTOR_MetaType type,
304 enum EXTRACTOR_MetaFormat format,
305 const char *data_mime_type, const char *data,
310 * Extend metadata. Merges the meta data from the second argument
311 * into the first, discarding duplicate key-value pairs.
313 * @param md metadata to extend
314 * @param in metadata to merge
317 GNUNET_CONTAINER_meta_data_merge (struct GNUNET_CONTAINER_MetaData *md,
318 const struct GNUNET_CONTAINER_MetaData *in);
324 * @param md metadata to manipulate
325 * @param type type of the item to remove
326 * @param data specific value to remove, NULL to remove all
327 * entries of the given type
328 * @param data_len number of bytes in data
329 * @return GNUNET_OK on success, GNUNET_SYSERR if the item does not exist in md
332 GNUNET_CONTAINER_meta_data_delete (struct GNUNET_CONTAINER_MetaData *md,
333 enum EXTRACTOR_MetaType type,
334 const char *data, size_t data_len);
338 * Remove all items in the container.
340 * @param md metadata to manipulate
343 GNUNET_CONTAINER_meta_data_clear (struct GNUNET_CONTAINER_MetaData *md);
347 * Add the current time as the publication date
350 * @param md metadata to modify
353 GNUNET_CONTAINER_meta_data_add_publication_date (struct
354 GNUNET_CONTAINER_MetaData *md);
358 * Iterate over MD entries.
360 * @param md metadata to inspect
361 * @param iter function to call on each entry
362 * @param iter_cls closure for iterator
363 * @return number of entries
366 GNUNET_CONTAINER_meta_data_iterate (const struct GNUNET_CONTAINER_MetaData *md,
367 EXTRACTOR_MetaDataProcessor iter,
371 * Get the first MD entry of the given type. Caller
372 * is responsible for freeing the return value.
373 * Also, only meta data items that are strings (0-terminated)
374 * are returned by this function.
376 * @param md metadata to inspect
377 * @param type type to look for
378 * @return NULL if no entry was found
381 GNUNET_CONTAINER_meta_data_get_by_type (const struct GNUNET_CONTAINER_MetaData
382 *md, enum EXTRACTOR_MetaType type);
386 * Get the first matching MD entry of the given types. Caller is
387 * responsible for freeing the return value. Also, only meta data
388 * items that are strings (0-terminated) are returned by this
391 * @param md metadata to inspect
392 * @param ... -1-terminated list of types
393 * @return NULL if we do not have any such entry,
394 * otherwise client is responsible for freeing the value!
397 GNUNET_CONTAINER_meta_data_get_first_by_types (const struct
398 GNUNET_CONTAINER_MetaData *md,
402 * Get a thumbnail from the meta-data (if present). Only matches meta
403 * data with mime type "image" and binary format.
405 * @param md metadata to inspect
406 * @param thumb will be set to the thumbnail data. Must be
407 * freed by the caller!
408 * @return number of bytes in thumbnail, 0 if not available
411 GNUNET_CONTAINER_meta_data_get_thumbnail (const struct GNUNET_CONTAINER_MetaData
412 *md, unsigned char **thumb);
417 * Options for metadata serialization.
419 enum GNUNET_CONTAINER_MetaDataSerializationOptions
422 * Serialize all of the data.
424 GNUNET_CONTAINER_META_DATA_SERIALIZE_FULL = 0,
427 * If not enough space is available, it is acceptable
428 * to only serialize some of the metadata.
430 GNUNET_CONTAINER_META_DATA_SERIALIZE_PART = 1,
433 * Speed is of the essence, do not allow compression.
435 GNUNET_CONTAINER_META_DATA_SERIALIZE_NO_COMPRESS = 2
440 * Serialize meta-data to target.
442 * @param md metadata to serialize
443 * @param target where to write the serialized metadata;
444 * *target can be NULL, in which case memory is allocated
445 * @param max maximum number of bytes available
446 * @param opt is it ok to just write SOME of the
447 * meta-data to match the size constraint,
448 * possibly discarding some data?
449 * @return number of bytes written on success,
450 * -1 on error (typically: not enough
454 GNUNET_CONTAINER_meta_data_serialize (const struct GNUNET_CONTAINER_MetaData
455 *md, char **target, size_t max,
457 GNUNET_CONTAINER_MetaDataSerializationOptions
462 * Get the size of the full meta-data in serialized form.
464 * @param md metadata to inspect
465 * @return number of bytes needed for serialization, -1 on error
468 GNUNET_CONTAINER_meta_data_get_serialized_size (const struct
469 GNUNET_CONTAINER_MetaData *md);
473 * Deserialize meta-data. Initializes md.
475 * @param input serialized meta-data.
476 * @param size number of bytes available
477 * @return MD on success, NULL on error (i.e.
480 struct GNUNET_CONTAINER_MetaData *
481 GNUNET_CONTAINER_meta_data_deserialize (const char *input, size_t size);
484 /* ******************************* HashMap **************************** */
487 * Opaque handle for a HashMap.
489 struct GNUNET_CONTAINER_MultiHashMap;
492 * Options for storing values in the HashMap.
494 enum GNUNET_CONTAINER_MultiHashMapOption
498 * If a value with the given key exists, replace it. Note that the
499 * old value would NOT be freed by replace (the application has to
500 * make sure that this happens if required).
502 GNUNET_CONTAINER_MULTIHASHMAPOPTION_REPLACE,
505 * Allow multiple values with the same key.
507 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE,
510 * There must only be one value per key; storing a value should fail
511 * if a value under the same key already exists.
513 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY,
516 * There must only be one value per key, but don't bother checking
517 * if a value already exists (faster than UNIQUE_ONLY; implemented
518 * just like MULTIPLE but this option documents better what is
519 * intended if UNIQUE is what is desired).
521 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST
526 * Iterator over hash map entries.
529 * @param key current key code
530 * @param value value in the hash map
531 * @return GNUNET_YES if we should continue to
535 typedef int (*GNUNET_CONTAINER_HashMapIterator) (void *cls,
536 const GNUNET_HashCode * key,
541 * Create a multi hash map.
543 * @param len initial size (map will grow as needed)
544 * @return NULL on error
546 struct GNUNET_CONTAINER_MultiHashMap *
547 GNUNET_CONTAINER_multihashmap_create (unsigned int len);
551 * Destroy a hash map. Will not free any values
552 * stored in the hash map!
557 GNUNET_CONTAINER_multihashmap_destroy (struct GNUNET_CONTAINER_MultiHashMap
562 * Given a key find a value in the map matching the key.
565 * @param key what to look for
566 * @return NULL if no value was found; note that
567 * this is indistinguishable from values that just
568 * happen to be NULL; use "contains" to test for
569 * key-value pairs with value NULL
572 GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap
573 *map, const GNUNET_HashCode * key);
577 * Remove the given key-value pair from the map. Note that if the
578 * key-value pair is in the map multiple times, only one of the pairs
582 * @param key key of the key-value pair
583 * @param value value of the key-value pair
584 * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
588 GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap *map,
589 const GNUNET_HashCode * key, void *value);
592 * Remove all entries for the given key from the map.
593 * Note that the values would not be "freed".
596 * @param key identifies values to be removed
597 * @return number of values removed
600 GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
601 *map, const GNUNET_HashCode * key);
605 * Check if the map contains any value under the given
606 * key (including values that are NULL).
609 * @param key the key to test if a value exists for it
610 * @return GNUNET_YES if such a value exists,
614 GNUNET_CONTAINER_multihashmap_contains (const struct
615 GNUNET_CONTAINER_MultiHashMap *map,
616 const GNUNET_HashCode * key);
620 * Check if the map contains the given value under the given
624 * @param key the key to test if a value exists for it
625 * @param value value to test for
626 * @return GNUNET_YES if such a value exists,
630 GNUNET_CONTAINER_multihashmap_contains_value (const struct
631 GNUNET_CONTAINER_MultiHashMap
632 *map, const GNUNET_HashCode * key,
637 * Store a key-value pair in the map.
640 * @param key key to use
641 * @param value value to use
642 * @param opt options for put
643 * @return GNUNET_OK on success,
644 * GNUNET_NO if a value was replaced (with REPLACE)
645 * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
646 * value already exists
649 GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
650 const GNUNET_HashCode * key, void *value,
651 enum GNUNET_CONTAINER_MultiHashMapOption
655 * Get the number of key-value pairs in the map.
658 * @return the number of key value pairs
661 GNUNET_CONTAINER_multihashmap_size (const struct GNUNET_CONTAINER_MultiHashMap
666 * Iterate over all entries in the map.
669 * @param it function to call on each entry
670 * @param it_cls extra argument to it
671 * @return the number of key value pairs processed,
672 * GNUNET_SYSERR if it aborted iteration
675 GNUNET_CONTAINER_multihashmap_iterate (const struct
676 GNUNET_CONTAINER_MultiHashMap *map,
677 GNUNET_CONTAINER_HashMapIterator it,
682 * Iterate over all entries in the map that match a particular key.
685 * @param key key that the entries must correspond to
686 * @param it function to call on each entry
687 * @param it_cls extra argument to it
688 * @return the number of key value pairs processed,
689 * GNUNET_SYSERR if it aborted iteration
692 GNUNET_CONTAINER_multihashmap_get_multiple (const struct
693 GNUNET_CONTAINER_MultiHashMap *map,
694 const GNUNET_HashCode * key,
695 GNUNET_CONTAINER_HashMapIterator it,
699 /* ******************** doubly-linked list *************** */
700 /* To avoid mistakes: head->prev == tail->next == NULL */
703 * Insert an element at the head of a DLL. Assumes that head, tail and
704 * element are structs with prev and next fields.
706 * @param head pointer to the head of the DLL
707 * @param tail pointer to the tail of the DLL
708 * @param element element to insert
710 #define GNUNET_CONTAINER_DLL_insert(head,tail,element) do { \
711 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
712 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
713 (element)->next = (head); \
714 (element)->prev = NULL; \
715 if ((tail) == NULL) \
718 (head)->prev = element; \
719 (head) = (element); } while (0)
723 * Insert an element at the tail of a DLL. Assumes that head, tail and
724 * element are structs with prev and next fields.
726 * @param head pointer to the head of the DLL
727 * @param tail pointer to the tail of the DLL
728 * @param element element to insert
730 #define GNUNET_CONTAINER_DLL_insert_tail(head,tail,element) do { \
731 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
732 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
733 (element)->prev = (tail); \
734 (element)->next = NULL; \
735 if ((head) == NULL) \
738 (tail)->next = element; \
739 (tail) = (element); } while (0)
743 * Insert an element into a DLL after the given other element. Insert
744 * at the head if the other element is NULL.
746 * @param head pointer to the head of the DLL
747 * @param tail pointer to the tail of the DLL
748 * @param other prior element, NULL for insertion at head of DLL
749 * @param element element to insert
751 #define GNUNET_CONTAINER_DLL_insert_after(head,tail,other,element) do { \
752 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
753 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
754 (element)->prev = (other); \
757 (element)->next = (head); \
758 (head) = (element); \
762 (element)->next = (other)->next; \
763 (other)->next = (element); \
765 if (NULL == (element)->next) \
766 (tail) = (element); \
768 (element)->next->prev = (element); } while (0)
772 * Insert an element into a DLL before the given other element. Insert
773 * at the tail if the other element is NULL.
775 * @param head pointer to the head of the DLL
776 * @param tail pointer to the tail of the DLL
777 * @param other prior element, NULL for insertion at head of DLL
778 * @param element element to insert
780 #define GNUNET_CONTAINER_DLL_insert_before(head,tail,other,element) do { \
781 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
782 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
783 (element)->next = (other); \
786 (element)->prev = (tail); \
787 (tail) = (element); \
791 (element)->prev = (other)->prev; \
792 (other)->prev = (element); \
794 if (NULL == (element)->prev) \
795 (head) = (element); \
797 (element)->prev->next = (element); } while (0)
801 * Remove an element from a DLL. Assumes
802 * that head, tail and element are structs
803 * with prev and next fields.
805 * @param head pointer to the head of the DLL
806 * @param tail pointer to the tail of the DLL
807 * @param element element to remove
809 #define GNUNET_CONTAINER_DLL_remove(head,tail,element) do { \
810 GNUNET_assert ( ( (element)->prev != NULL) || ((head) == (element))); \
811 GNUNET_assert ( ( (element)->next != NULL) || ((tail) == (element))); \
812 if ((element)->prev == NULL) \
813 (head) = (element)->next; \
815 (element)->prev->next = (element)->next; \
816 if ((element)->next == NULL) \
817 (tail) = (element)->prev; \
819 (element)->next->prev = (element)->prev; \
820 (element)->next = NULL; \
821 (element)->prev = NULL; } while (0)
825 /* ******************** Heap *************** */
829 * Cost by which elements in a heap can be ordered.
831 typedef uint64_t GNUNET_CONTAINER_HeapCostType;
835 * Heap type, either max or min. Hopefully makes the
836 * implementation more useful.
838 enum GNUNET_CONTAINER_HeapOrder
841 * Heap with the maximum cost at the root.
843 GNUNET_CONTAINER_HEAP_ORDER_MAX,
846 * Heap with the minimum cost at the root.
848 GNUNET_CONTAINER_HEAP_ORDER_MIN
855 struct GNUNET_CONTAINER_Heap;
860 * Handle to a node in a heap.
862 struct GNUNET_CONTAINER_HeapNode;
868 * @param order how should the heap be sorted?
869 * @return handle to the heap
871 struct GNUNET_CONTAINER_Heap *
872 GNUNET_CONTAINER_heap_create (enum GNUNET_CONTAINER_HeapOrder order);
876 * Destroys the heap. Only call on a heap that
879 * @param heap heap to destroy
882 GNUNET_CONTAINER_heap_destroy (struct GNUNET_CONTAINER_Heap *heap);
886 * Get element stored at root of heap.
888 * @param heap heap to inspect
889 * @return NULL if heap is empty
892 GNUNET_CONTAINER_heap_peek (const struct GNUNET_CONTAINER_Heap *heap);
896 * Get the current size of the heap
898 * @param heap the heap to get the size of
899 * @return number of elements stored
902 GNUNET_CONTAINER_heap_get_size (const struct GNUNET_CONTAINER_Heap *heap);
906 * Get the current cost of the node
908 * @param node the node to get the cost of
909 * @return cost of the node
911 GNUNET_CONTAINER_HeapCostType
912 GNUNET_CONTAINER_heap_node_get_cost (const struct GNUNET_CONTAINER_HeapNode
919 * @param node internal node of the heap
920 * @param element value stored at the node
921 * @param cost cost associated with the node
922 * @return GNUNET_YES if we should continue to iterate,
925 typedef int (*GNUNET_CONTAINER_HeapIterator) (void *cls,
926 struct GNUNET_CONTAINER_HeapNode *
928 GNUNET_CONTAINER_HeapCostType
933 * Iterate over all entries in the heap.
935 * @param heap the heap
936 * @param iterator function to call on each entry
937 * @param iterator_cls closure for iterator
940 GNUNET_CONTAINER_heap_iterate (const struct GNUNET_CONTAINER_Heap *heap,
941 GNUNET_CONTAINER_HeapIterator iterator,
946 * Return a *uniform* random element from the heap. Choose a random
947 * number between 0 and heap size and then walk directly to it.
948 * This cost can be between 0 and n, amortized cost of logN.
950 * @param heap heap to choose random element from
951 * @param max how many nodes from the heap to choose from
953 * @return data stored at the chosen random node,
954 * NULL if the heap is empty.
958 GNUNET_CONTAINER_heap_get_random (struct GNUNET_CONTAINER_Heap *heap,
963 * Perform a random walk of the tree. The walk is biased
964 * towards elements closer to the root of the tree (since
965 * each walk starts at the root and ends at a random leaf).
966 * The heap internally tracks the current position of the
969 * @param heap heap to walk
970 * @return data stored at the next random node in the walk;
971 * NULL if the tree is empty.
974 GNUNET_CONTAINER_heap_walk_get_next (struct GNUNET_CONTAINER_Heap *heap);
978 * Inserts a new element into the heap.
980 * @param heap heap to modify
981 * @param element element to insert
982 * @param cost cost for the element
983 * @return node for the new element
985 struct GNUNET_CONTAINER_HeapNode *
986 GNUNET_CONTAINER_heap_insert (struct GNUNET_CONTAINER_Heap *heap, void *element,
987 GNUNET_CONTAINER_HeapCostType cost);
991 * Remove root of the heap.
993 * @param heap heap to modify
994 * @return element data stored at the root node
997 GNUNET_CONTAINER_heap_remove_root (struct GNUNET_CONTAINER_Heap *heap);
1001 * Removes a node from the heap.
1003 * @param node node to remove
1004 * @return element data stored at the node, NULL if heap is empty
1007 GNUNET_CONTAINER_heap_remove_node (struct GNUNET_CONTAINER_HeapNode *node);
1011 * Updates the cost of any node in the tree
1013 * @param heap heap to modify
1014 * @param node node for which the cost is to be changed
1015 * @param new_cost new cost for the node
1018 GNUNET_CONTAINER_heap_update_cost (struct GNUNET_CONTAINER_Heap *heap,
1019 struct GNUNET_CONTAINER_HeapNode *node,
1020 GNUNET_CONTAINER_HeapCostType new_cost);
1023 /* ******************** Singly linked list *************** */
1026 * Possible ways for how data stored in the linked list
1027 * might be allocated.
1029 enum GNUNET_CONTAINER_SListDisposition
1032 * Single-linked list must copy the buffer.
1034 GNUNET_CONTAINER_SLIST_DISPOSITION_TRANSIENT = 0,
1037 * Data is static, no need to copy or free.
1039 GNUNET_CONTAINER_SLIST_DISPOSITION_STATIC = 2,
1042 * Data is dynamic, do not copy but free when done.
1044 GNUNET_CONTAINER_SLIST_DISPOSITION_DYNAMIC = 4
1050 * Handle to a singly linked list
1052 struct GNUNET_CONTAINER_SList;
1055 * Handle to a singly linked list iterator
1057 struct GNUNET_CONTAINER_SList_Iterator
1060 * Linked list that we are iterating over.
1062 struct GNUNET_CONTAINER_SList *list;
1065 * Last element accessed.
1067 struct GNUNET_CONTAINER_SList_Elem *last;
1070 * Current list element.
1072 struct GNUNET_CONTAINER_SList_Elem *elem;
1078 * Add a new element to the list
1080 * @param disp memory disposition
1081 * @param buf payload buffer
1082 * @param len length of the buffer
1085 GNUNET_CONTAINER_slist_add (struct GNUNET_CONTAINER_SList *l,
1086 enum GNUNET_CONTAINER_SListDisposition disp,
1087 const void *buf, size_t len);
1091 * Add a new element to the end of the list
1093 * @param disp memory disposition
1094 * @param buf payload buffer
1095 * @param len length of the buffer
1098 GNUNET_CONTAINER_slist_add_end (struct GNUNET_CONTAINER_SList *l,
1099 enum GNUNET_CONTAINER_SListDisposition disp,
1100 const void *buf, size_t len);
1104 * Append a singly linked list to another
1105 * @param dst list to append to
1109 GNUNET_CONTAINER_slist_append (struct GNUNET_CONTAINER_SList *dst,
1110 struct GNUNET_CONTAINER_SList *src);
1114 * Create a new singly linked list
1115 * @return the new list
1117 struct GNUNET_CONTAINER_SList *
1118 GNUNET_CONTAINER_slist_create (void);
1122 * Destroy a singly linked list
1123 * @param l the list to be destroyed
1126 GNUNET_CONTAINER_slist_destroy (struct GNUNET_CONTAINER_SList *l);
1130 * Return the beginning of a list
1133 * @return iterator pointing to the beginning (by value! Either allocate the
1134 * structure on the stack, or use GNUNET_malloc() yourself! All other
1135 * functions do take pointer to this struct though)
1137 struct GNUNET_CONTAINER_SList_Iterator
1138 GNUNET_CONTAINER_slist_begin (struct GNUNET_CONTAINER_SList *l);
1147 GNUNET_CONTAINER_slist_clear (struct GNUNET_CONTAINER_SList *l);
1151 * Check if a list contains a certain element
1153 * @param buf payload buffer to find
1154 * @param len length of the payload (number of bytes in buf)
1157 GNUNET_CONTAINER_slist_contains (const struct GNUNET_CONTAINER_SList *l,
1158 const void *buf, size_t len);
1162 * Count the elements of a list
1164 * @return number of elements in the list
1167 GNUNET_CONTAINER_slist_count (const struct GNUNET_CONTAINER_SList *l);
1171 * Remove an element from the list
1172 * @param i iterator that points to the element to be removed
1175 GNUNET_CONTAINER_slist_erase (struct GNUNET_CONTAINER_SList_Iterator *i);
1179 * Insert an element into a list at a specific position
1180 * @param before where to insert the new element
1181 * @param disp memory disposition
1182 * @param buf payload buffer
1183 * @param len length of the payload
1186 GNUNET_CONTAINER_slist_insert (struct GNUNET_CONTAINER_SList_Iterator *before,
1187 enum GNUNET_CONTAINER_SListDisposition disp,
1188 const void *buf, size_t len);
1192 * Advance an iterator to the next element
1194 * @return GNUNET_YES on success, GNUNET_NO if the end has been reached
1197 GNUNET_CONTAINER_slist_next (struct GNUNET_CONTAINER_SList_Iterator *i);
1201 * Check if an iterator points beyond the end of a list
1203 * @return GNUNET_YES if the end has been reached, GNUNET_NO if the iterator
1204 * points to a valid element
1207 GNUNET_CONTAINER_slist_end (struct GNUNET_CONTAINER_SList_Iterator *i);
1211 * Retrieve the element at a specific position in a list
1214 * @param len set to the payload length
1218 GNUNET_CONTAINER_slist_get (const struct GNUNET_CONTAINER_SList_Iterator *i,
1223 * Release an iterator
1227 GNUNET_CONTAINER_slist_iter_destroy (struct GNUNET_CONTAINER_SList_Iterator *i);
1230 #if 0 /* keep Emacsens' auto-indent happy */
1238 /* ifndef GNUNET_CONTAINER_LIB_H */
1240 /* end of gnunet_container_lib.h */