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
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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 *GNUNET_CONTAINER_bloomfilter_load (const
88 * Create a bloom filter from raw bits.
90 * @param data the raw bits in memory (maybe NULL,
91 * in which case all bits should be considered
93 * @param size the size of the bloom-filter (number of
94 * bytes of storage space to use); also size of data
95 * -- unless data is NULL. Must be a power of 2.
96 * @param k the number of GNUNET_CRYPTO_hash-functions to apply per
97 * element (number of bits set per element in the set)
98 * @return the bloomfilter
100 struct GNUNET_CONTAINER_BloomFilter *GNUNET_CONTAINER_bloomfilter_init (const
110 * Copy the raw data of this bloomfilter into
111 * the given data array.
113 * @param data where to write the data
114 * @param size the size of the given data array
115 * @return GNUNET_SYSERR if the data array of the wrong size
117 int GNUNET_CONTAINER_bloomfilter_get_raw_data (const struct
118 GNUNET_CONTAINER_BloomFilter *bf,
119 char *data, size_t size);
123 * Test if an element is in the filter.
124 * @param e the element
125 * @param bf the filter
126 * @return GNUNET_YES if the element is in the filter, GNUNET_NO if not
128 int GNUNET_CONTAINER_bloomfilter_test (const struct GNUNET_CONTAINER_BloomFilter
129 *bf, const GNUNET_HashCode * e);
133 * Add an element to the filter
134 * @param bf the filter
135 * @param e the element
137 void GNUNET_CONTAINER_bloomfilter_add (struct GNUNET_CONTAINER_BloomFilter *bf,
138 const GNUNET_HashCode * e);
142 * Remove an element from the filter.
143 * @param bf the filter
144 * @param e the element to remove
146 void GNUNET_CONTAINER_bloomfilter_remove (struct GNUNET_CONTAINER_BloomFilter
147 *bf, const GNUNET_HashCode * e);
151 * Create a copy of a bloomfilter.
153 * @param bf the filter
156 struct GNUNET_CONTAINER_BloomFilter *GNUNET_CONTAINER_bloomfilter_copy (const
158 GNUNET_CONTAINER_BloomFilter
164 * Free the space associcated with a filter
165 * in memory, flush to drive if needed (do not
166 * free the space on the drive)
167 * @param bf the filter
169 void GNUNET_CONTAINER_bloomfilter_free (struct GNUNET_CONTAINER_BloomFilter
174 * Get size of the bloom filter.
176 * @param bf the filter
177 * @return number of bytes used for the data of the bloom filter
179 size_t GNUNET_CONTAINER_bloomfilter_get_size (const struct
180 GNUNET_CONTAINER_BloomFilter
185 * Reset a bloom filter to empty.
186 * @param bf the filter
188 void GNUNET_CONTAINER_bloomfilter_clear (struct GNUNET_CONTAINER_BloomFilter
192 * Or the entries of the given raw data array with the
193 * data of the given bloom filter. Assumes that
194 * the size of the data array and the current filter
197 * @param bf the filter
198 * @param data data to OR-in
199 * @param size size of data
200 * @return GNUNET_OK on success
202 int GNUNET_CONTAINER_bloomfilter_or (struct GNUNET_CONTAINER_BloomFilter *bf,
203 const char *data, size_t size);
206 * Or the entries of the given raw data array with the
207 * data of the given bloom filter. Assumes that
208 * the size of the data array and the current filter
211 * @param bf the filter
212 * @param to_or the bloomfilter to or-in
213 * @param size number of bytes in data
215 int GNUNET_CONTAINER_bloomfilter_or2 (struct GNUNET_CONTAINER_BloomFilter *bf,
216 const struct GNUNET_CONTAINER_BloomFilter
217 *to_or, size_t size);
220 * Resize a bloom filter. Note that this operation
221 * is pretty costly. Essentially, the bloom filter
222 * needs to be completely re-build.
224 * @param bf the filter
225 * @param iterator an iterator over all elements stored in the BF
226 * @param iterator_cls closure for iterator
227 * @param size the new size for the filter
228 * @param k the new number of GNUNET_CRYPTO_hash-function to apply per element
230 void GNUNET_CONTAINER_bloomfilter_resize (struct GNUNET_CONTAINER_BloomFilter
231 *bf, GNUNET_HashCodeIterator iterator,
232 void *iterator_cls, size_t size,
235 /* ****************** metadata ******************* */
238 * Meta data to associate with a file, directory or namespace.
240 struct GNUNET_CONTAINER_MetaData;
243 * Create a fresh MetaData token.
245 * @return empty meta-data container
247 struct GNUNET_CONTAINER_MetaData *GNUNET_CONTAINER_meta_data_create (void);
250 * Duplicate a MetaData token.
252 * @param md what to duplicate
253 * @return duplicate meta-data container
255 struct GNUNET_CONTAINER_MetaData *GNUNET_CONTAINER_meta_data_duplicate (const
257 GNUNET_CONTAINER_MetaData
263 * @param md what to free
265 void GNUNET_CONTAINER_meta_data_destroy (struct GNUNET_CONTAINER_MetaData *md);
268 * Test if two MDs are equal. We consider them equal if
269 * the meta types, formats and content match (we do not
270 * include the mime types and plugins names in this
273 * @param md1 first value to check
274 * @param md2 other value to check
275 * @return GNUNET_YES if they are equal
277 int GNUNET_CONTAINER_meta_data_test_equal (const struct
278 GNUNET_CONTAINER_MetaData *md1,
280 GNUNET_CONTAINER_MetaData *md2);
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
300 int GNUNET_CONTAINER_meta_data_insert (struct GNUNET_CONTAINER_MetaData *md,
301 const char *plugin_name,
302 enum EXTRACTOR_MetaType type,
303 enum EXTRACTOR_MetaFormat format,
304 const char *data_mime_type,
305 const char *data, size_t data_len);
309 * Extend metadata. Merges the meta data from the second argument
310 * into the first, discarding duplicate key-value pairs.
312 * @param md metadata to extend
313 * @param in metadata to merge
315 void GNUNET_CONTAINER_meta_data_merge (struct GNUNET_CONTAINER_MetaData *md,
316 const struct GNUNET_CONTAINER_MetaData
323 * @param md metadata to manipulate
324 * @param type type of the item to remove
325 * @param data specific value to remove, NULL to remove all
326 * entries of the given type
327 * @param data_len number of bytes in data
328 * @return GNUNET_OK on success, GNUNET_SYSERR if the item does not exist in md
330 int GNUNET_CONTAINER_meta_data_delete (struct GNUNET_CONTAINER_MetaData *md,
331 enum EXTRACTOR_MetaType type,
332 const char *data, size_t data_len);
336 * Remove all items in the container.
338 * @param md metadata to manipulate
340 void GNUNET_CONTAINER_meta_data_clear (struct GNUNET_CONTAINER_MetaData *md);
344 * Add the current time as the publication date
347 * @param md metadata to modify
349 void GNUNET_CONTAINER_meta_data_add_publication_date (struct
350 GNUNET_CONTAINER_MetaData
355 * Iterate over MD entries.
357 * @param md metadata to inspect
358 * @param iter function to call on each entry
359 * @param iter_cls closure for iterator
360 * @return number of entries
362 int GNUNET_CONTAINER_meta_data_iterate (const struct GNUNET_CONTAINER_MetaData
363 *md, EXTRACTOR_MetaDataProcessor iter,
367 * Get the first MD entry of the given type. Caller
368 * is responsible for freeing the return value.
369 * Also, only meta data items that are strings (0-terminated)
370 * are returned by this function.
372 * @param md metadata to inspect
373 * @param type type to look for
374 * @return NULL if no entry was found
376 char *GNUNET_CONTAINER_meta_data_get_by_type (const struct
377 GNUNET_CONTAINER_MetaData *md,
378 enum EXTRACTOR_MetaType type);
382 * Get the first matching MD entry of the given types. Caller is
383 * responsible for freeing the return value. Also, only meta data
384 * items that are strings (0-terminated) are returned by this
387 * @param md metadata to inspect
388 * @param ... -1-terminated list of types
389 * @return NULL if we do not have any such entry,
390 * otherwise client is responsible for freeing the value!
392 char *GNUNET_CONTAINER_meta_data_get_first_by_types (const struct
393 GNUNET_CONTAINER_MetaData
397 * Get a thumbnail from the meta-data (if present). Only matches meta
398 * data with mime type "image" and binary format.
400 * @param md metadata to inspect
401 * @param thumb will be set to the thumbnail data. Must be
402 * freed by the caller!
403 * @return number of bytes in thumbnail, 0 if not available
405 size_t GNUNET_CONTAINER_meta_data_get_thumbnail (const struct
406 GNUNET_CONTAINER_MetaData *md,
407 unsigned char **thumb);
412 * Options for metadata serialization.
414 enum GNUNET_CONTAINER_MetaDataSerializationOptions
417 * Serialize all of the data.
419 GNUNET_CONTAINER_META_DATA_SERIALIZE_FULL = 0,
422 * If not enough space is available, it is acceptable
423 * to only serialize some of the metadata.
425 GNUNET_CONTAINER_META_DATA_SERIALIZE_PART = 1,
428 * Speed is of the essence, do not allow compression.
430 GNUNET_CONTAINER_META_DATA_SERIALIZE_NO_COMPRESS = 2
435 * Serialize meta-data to target.
437 * @param md metadata to serialize
438 * @param target where to write the serialized metadata;
439 * *target can be NULL, in which case memory is allocated
440 * @param max maximum number of bytes available
441 * @param opt is it ok to just write SOME of the
442 * meta-data to match the size constraint,
443 * possibly discarding some data?
444 * @return number of bytes written on success,
445 * -1 on error (typically: not enough
449 GNUNET_CONTAINER_meta_data_serialize (const struct GNUNET_CONTAINER_MetaData
450 *md, char **target, size_t max,
452 GNUNET_CONTAINER_MetaDataSerializationOptions
457 * Get the size of the full meta-data in serialized form.
459 * @param md metadata to inspect
460 * @return number of bytes needed for serialization, -1 on error
463 GNUNET_CONTAINER_meta_data_get_serialized_size (const struct
464 GNUNET_CONTAINER_MetaData *md);
468 * Deserialize meta-data. Initializes md.
470 * @param input serialized meta-data.
471 * @param size number of bytes available
472 * @return MD on success, NULL on error (i.e.
475 struct GNUNET_CONTAINER_MetaData *GNUNET_CONTAINER_meta_data_deserialize (const
482 /* ******************************* HashMap **************************** */
485 * Opaque handle for a HashMap.
487 struct GNUNET_CONTAINER_MultiHashMap;
490 * Options for storing values in the HashMap.
492 enum GNUNET_CONTAINER_MultiHashMapOption
496 * If a value with the given key exists, replace it. Note that the
497 * old value would NOT be freed by replace (the application has to
498 * make sure that this happens if required).
500 GNUNET_CONTAINER_MULTIHASHMAPOPTION_REPLACE,
503 * Allow multiple values with the same key.
505 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE,
508 * There must only be one value per key; storing a value should fail
509 * if a value under the same key already exists.
511 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY,
514 * There must only be one value per key, but don't bother checking
515 * if a value already exists (faster than UNIQUE_ONLY; implemented
516 * just like MULTIPLE but this option documents better what is
517 * intended if UNIQUE is what is desired).
519 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST
524 * Iterator over hash map entries.
527 * @param key current key code
528 * @param value value in the hash map
529 * @return GNUNET_YES if we should continue to
533 typedef int (*GNUNET_CONTAINER_HashMapIterator) (void *cls,
534 const GNUNET_HashCode * key,
539 * Create a multi hash map.
541 * @param len initial size (map will grow as needed)
542 * @return NULL on error
544 struct GNUNET_CONTAINER_MultiHashMap
545 *GNUNET_CONTAINER_multihashmap_create (unsigned int len);
549 * Destroy a hash map. Will not free any values
550 * stored in the hash map!
554 void GNUNET_CONTAINER_multihashmap_destroy (struct GNUNET_CONTAINER_MultiHashMap
559 * Given a key find a value in the map matching the key.
562 * @param key what to look for
563 * @return NULL if no value was found; note that
564 * this is indistinguishable from values that just
565 * happen to be NULL; use "contains" to test for
566 * key-value pairs with value NULL
568 void *GNUNET_CONTAINER_multihashmap_get (const struct
569 GNUNET_CONTAINER_MultiHashMap *map,
570 const GNUNET_HashCode * key);
574 * Remove the given key-value pair from the map. Note that if the
575 * key-value pair is in the map multiple times, only one of the pairs
579 * @param key key of the key-value pair
580 * @param value value of the key-value pair
581 * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
584 int GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap
585 *map, const GNUNET_HashCode * key,
589 * Remove all entries for the given key from the map.
590 * Note that the values would not be "freed".
593 * @param key identifies values to be removed
594 * @return number of values removed
596 int GNUNET_CONTAINER_multihashmap_remove_all (struct
597 GNUNET_CONTAINER_MultiHashMap
599 const GNUNET_HashCode * key);
603 * Check if the map contains any value under the given
604 * key (including values that are NULL).
607 * @param key the key to test if a value exists for it
608 * @return GNUNET_YES if such a value exists,
611 int GNUNET_CONTAINER_multihashmap_contains (const struct
612 GNUNET_CONTAINER_MultiHashMap *map,
613 const GNUNET_HashCode * key);
617 * Check if the map contains the given value under the given
621 * @param key the key to test if a value exists for it
622 * @param value value to test for
623 * @return GNUNET_YES if such a value exists,
626 int GNUNET_CONTAINER_multihashmap_contains_value (const struct
627 GNUNET_CONTAINER_MultiHashMap
629 const GNUNET_HashCode * key,
634 * Store a key-value pair in the map.
637 * @param key key to use
638 * @param value value to use
639 * @param opt options for put
640 * @return GNUNET_OK on success,
641 * GNUNET_NO if a value was replaced (with REPLACE)
642 * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
643 * value already exists
645 int GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap
646 *map, const GNUNET_HashCode * key,
648 enum GNUNET_CONTAINER_MultiHashMapOption
652 * Get the number of key-value pairs in the map.
655 * @return the number of key value pairs
657 unsigned int GNUNET_CONTAINER_multihashmap_size (const struct
658 GNUNET_CONTAINER_MultiHashMap
663 * Iterate over all entries in the map.
666 * @param it function to call on each entry
667 * @param it_cls extra argument to it
668 * @return the number of key value pairs processed,
669 * GNUNET_SYSERR if it aborted iteration
671 int GNUNET_CONTAINER_multihashmap_iterate (const struct
672 GNUNET_CONTAINER_MultiHashMap *map,
673 GNUNET_CONTAINER_HashMapIterator it,
678 * Iterate over all entries in the map that match a particular key.
681 * @param key key that the entries must correspond to
682 * @param it function to call on each entry
683 * @param it_cls extra argument to it
684 * @return the number of key value pairs processed,
685 * GNUNET_SYSERR if it aborted iteration
687 int GNUNET_CONTAINER_multihashmap_get_multiple (const struct
688 GNUNET_CONTAINER_MultiHashMap
690 const GNUNET_HashCode * key,
691 GNUNET_CONTAINER_HashMapIterator
695 /* ******************** doubly-linked list *************** */
696 /* To avoid mistakes: head->prev == tail->next == NULL */
699 * Insert an element at the head of a DLL. Assumes that head, tail and
700 * element are structs with prev and next fields.
702 * @param head pointer to the head of the DLL
703 * @param tail pointer to the tail of the DLL
704 * @param element element to insert
706 #define GNUNET_CONTAINER_DLL_insert(head,tail,element) do { \
707 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
708 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
709 (element)->next = (head); \
710 (element)->prev = NULL; \
711 if ((tail) == NULL) \
714 (head)->prev = element; \
715 (head) = (element); } while (0)
719 * Insert an element at the tail of a DLL. Assumes that head, tail and
720 * element are structs with prev and next fields.
722 * @param head pointer to the head of the DLL
723 * @param tail pointer to the tail of the DLL
724 * @param element element to insert
726 #define GNUNET_CONTAINER_DLL_insert_tail(head,tail,element) do { \
727 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
728 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
729 (element)->prev = (tail); \
730 (element)->next = NULL; \
731 if ((head) == NULL) \
734 (tail)->next = element; \
735 (tail) = (element); } while (0)
739 * Insert an element into a DLL after the given other element. Insert
740 * at the head if the other element is NULL.
742 * @param head pointer to the head of the DLL
743 * @param tail pointer to the tail of the DLL
744 * @param other prior element, NULL for insertion at head of DLL
745 * @param element element to insert
747 #define GNUNET_CONTAINER_DLL_insert_after(head,tail,other,element) do { \
748 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
749 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
750 (element)->prev = (other); \
753 (element)->next = (head); \
754 (head) = (element); \
758 (element)->next = (other)->next; \
759 (other)->next = (element); \
761 if (NULL == (element)->next) \
762 (tail) = (element); \
764 (element)->next->prev = (element); } while (0)
768 * Insert an element into a DLL before the given other element. Insert
769 * at the tail if the other element is NULL.
771 * @param head pointer to the head of the DLL
772 * @param tail pointer to the tail of the DLL
773 * @param other prior element, NULL for insertion at head of DLL
774 * @param element element to insert
776 #define GNUNET_CONTAINER_DLL_insert_before(head,tail,other,element) do { \
777 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
778 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
779 (element)->next = (other); \
782 (element)->prev = (tail); \
783 (tail) = (element); \
787 (element)->prev = (other)->prev; \
788 (other)->prev = (element); \
790 if (NULL == (element)->prev) \
791 (head) = (element); \
793 (element)->prev->next = (element); } while (0)
797 * Remove an element from a DLL. Assumes
798 * that head, tail and element are structs
799 * with prev and next fields.
801 * @param head pointer to the head of the DLL
802 * @param tail pointer to the tail of the DLL
803 * @param element element to remove
805 #define GNUNET_CONTAINER_DLL_remove(head,tail,element) do { \
806 GNUNET_assert ( ( (element)->prev != NULL) || ((head) == (element))); \
807 GNUNET_assert ( ( (element)->next != NULL) || ((tail) == (element))); \
808 if ((element)->prev == NULL) \
809 (head) = (element)->next; \
811 (element)->prev->next = (element)->next; \
812 if ((element)->next == NULL) \
813 (tail) = (element)->prev; \
815 (element)->next->prev = (element)->prev; \
816 (element)->next = NULL; \
817 (element)->prev = NULL; } while (0)
821 /* ******************** Heap *************** */
825 * Cost by which elements in a heap can be ordered.
827 typedef uint64_t GNUNET_CONTAINER_HeapCostType;
831 * Heap type, either max or min. Hopefully makes the
832 * implementation more useful.
834 enum GNUNET_CONTAINER_HeapOrder
837 * Heap with the maximum cost at the root.
839 GNUNET_CONTAINER_HEAP_ORDER_MAX,
842 * Heap with the minimum cost at the root.
844 GNUNET_CONTAINER_HEAP_ORDER_MIN
851 struct GNUNET_CONTAINER_Heap;
856 * Handle to a node in a heap.
858 struct GNUNET_CONTAINER_HeapNode;
864 * @param order how should the heap be sorted?
865 * @return handle to the heap
867 struct GNUNET_CONTAINER_Heap *GNUNET_CONTAINER_heap_create (enum
868 GNUNET_CONTAINER_HeapOrder
873 * Destroys the heap. Only call on a heap that
876 * @param heap heap to destroy
878 void GNUNET_CONTAINER_heap_destroy (struct GNUNET_CONTAINER_Heap *heap);
882 * Get element stored at root of heap.
884 * @param heap heap to inspect
885 * @return NULL if heap is empty
887 void *GNUNET_CONTAINER_heap_peek (const struct GNUNET_CONTAINER_Heap *heap);
891 * Get the current size of the heap
893 * @param heap the heap to get the size of
894 * @return number of elements stored
896 unsigned int GNUNET_CONTAINER_heap_get_size (const struct GNUNET_CONTAINER_Heap
901 * Get the current cost of the node
903 * @param node the node to get the cost of
904 * @return cost of the node
906 GNUNET_CONTAINER_HeapCostType GNUNET_CONTAINER_heap_node_get_cost (const struct
907 GNUNET_CONTAINER_HeapNode
914 * @param node internal node of the heap
915 * @param element value stored at the node
916 * @param cost cost associated with the node
917 * @return GNUNET_YES if we should continue to iterate,
920 typedef int (*GNUNET_CONTAINER_HeapIterator) (void *cls,
921 struct GNUNET_CONTAINER_HeapNode *
923 GNUNET_CONTAINER_HeapCostType
928 * Iterate over all entries in the heap.
930 * @param heap the heap
931 * @param iterator function to call on each entry
932 * @param iterator_cls closure for iterator
934 void GNUNET_CONTAINER_heap_iterate (const struct GNUNET_CONTAINER_Heap *heap,
935 GNUNET_CONTAINER_HeapIterator iterator,
940 * Return a *uniform* random element from the heap. Choose a random
941 * number between 0 and heap size and then walk directly to it.
942 * This cost can be between 0 and n, amortized cost of logN.
944 * @param heap heap to choose random element from
945 * @param max how many nodes from the heap to choose from
947 * @return data stored at the chosen random node,
948 * NULL if the heap is empty.
951 void *GNUNET_CONTAINER_heap_get_random (struct GNUNET_CONTAINER_Heap *heap,
956 * Perform a random walk of the tree. The walk is biased
957 * towards elements closer to the root of the tree (since
958 * each walk starts at the root and ends at a random leaf).
959 * The heap internally tracks the current position of the
962 * @param heap heap to walk
963 * @return data stored at the next random node in the walk;
964 * NULL if the tree is empty.
966 void *GNUNET_CONTAINER_heap_walk_get_next (struct GNUNET_CONTAINER_Heap *heap);
970 * Inserts a new element into the heap.
972 * @param heap heap to modify
973 * @param element element to insert
974 * @param cost cost for the element
975 * @return node for the new element
977 struct GNUNET_CONTAINER_HeapNode *GNUNET_CONTAINER_heap_insert (struct
978 GNUNET_CONTAINER_Heap
981 GNUNET_CONTAINER_HeapCostType
986 * Remove root of the heap.
988 * @param heap heap to modify
989 * @return element data stored at the root node
991 void *GNUNET_CONTAINER_heap_remove_root (struct GNUNET_CONTAINER_Heap *heap);
995 * Removes a node from the heap.
997 * @param node node to remove
998 * @return element data stored at the node, NULL if heap is empty
1000 void *GNUNET_CONTAINER_heap_remove_node (struct GNUNET_CONTAINER_HeapNode
1005 * Updates the cost of any node in the tree
1007 * @param heap heap to modify
1008 * @param node node for which the cost is to be changed
1009 * @param new_cost new cost for the node
1011 void GNUNET_CONTAINER_heap_update_cost (struct GNUNET_CONTAINER_Heap *heap,
1012 struct GNUNET_CONTAINER_HeapNode *node,
1013 GNUNET_CONTAINER_HeapCostType new_cost);
1016 /* ******************** Singly linked list *************** */
1019 * Possible ways for how data stored in the linked list
1020 * might be allocated.
1022 enum GNUNET_CONTAINER_SListDisposition
1025 * Single-linked list must copy the buffer.
1027 GNUNET_CONTAINER_SLIST_DISPOSITION_TRANSIENT = 0,
1030 * Data is static, no need to copy or free.
1032 GNUNET_CONTAINER_SLIST_DISPOSITION_STATIC = 2,
1035 * Data is dynamic, do not copy but free when done.
1037 GNUNET_CONTAINER_SLIST_DISPOSITION_DYNAMIC = 4
1043 * Handle to a singly linked list
1045 struct GNUNET_CONTAINER_SList;
1048 * Handle to a singly linked list iterator
1050 struct GNUNET_CONTAINER_SList_Iterator;
1054 * Add a new element to the list
1056 * @param disp memory disposition
1057 * @param buf payload buffer
1058 * @param len length of the buffer
1060 void GNUNET_CONTAINER_slist_add (struct GNUNET_CONTAINER_SList *l,
1061 enum GNUNET_CONTAINER_SListDisposition disp,
1062 const void *buf, size_t len);
1066 * Add a new element to the end of the list
1068 * @param disp memory disposition
1069 * @param buf payload buffer
1070 * @param len length of the buffer
1072 void GNUNET_CONTAINER_slist_add_end (struct GNUNET_CONTAINER_SList *l,
1073 enum GNUNET_CONTAINER_SListDisposition
1074 disp, const void *buf, size_t len);
1078 * Append a singly linked list to another
1079 * @param dst list to append to
1082 void GNUNET_CONTAINER_slist_append (struct GNUNET_CONTAINER_SList *dst,
1083 struct GNUNET_CONTAINER_SList *src);
1087 * Create a new singly linked list
1088 * @return the new list
1090 struct GNUNET_CONTAINER_SList *GNUNET_CONTAINER_slist_create (void);
1094 * Destroy a singly linked list
1095 * @param l the list to be destroyed
1097 void GNUNET_CONTAINER_slist_destroy (struct GNUNET_CONTAINER_SList *l);
1101 * Return the beginning of a list
1104 * @return iterator pointing to the beginning, free using "GNUNET_free"
1106 struct GNUNET_CONTAINER_SList_Iterator *GNUNET_CONTAINER_slist_begin (struct
1107 GNUNET_CONTAINER_SList
1116 void GNUNET_CONTAINER_slist_clear (struct GNUNET_CONTAINER_SList *l);
1120 * Check if a list contains a certain element
1122 * @param buf payload buffer to find
1123 * @param len length of the payload (number of bytes in buf)
1125 int GNUNET_CONTAINER_slist_contains (const struct GNUNET_CONTAINER_SList *l,
1126 const void *buf, size_t len);
1130 * Count the elements of a list
1132 * @return number of elements in the list
1134 int GNUNET_CONTAINER_slist_count (const struct GNUNET_CONTAINER_SList *l);
1138 * Remove an element from the list
1139 * @param i iterator that points to the element to be removed
1141 void GNUNET_CONTAINER_slist_erase (struct GNUNET_CONTAINER_SList_Iterator *i);
1145 * Insert an element into a list at a specific position
1146 * @param before where to insert the new element
1147 * @param disp memory disposition
1148 * @param buf payload buffer
1149 * @param len length of the payload
1151 void GNUNET_CONTAINER_slist_insert (struct GNUNET_CONTAINER_SList_Iterator
1153 enum GNUNET_CONTAINER_SListDisposition disp,
1154 const void *buf, size_t len);
1158 * Advance an iterator to the next element
1160 * @return GNUNET_YES on success, GNUNET_NO if the end has been reached
1162 int GNUNET_CONTAINER_slist_next (struct GNUNET_CONTAINER_SList_Iterator *i);
1166 * Check if an iterator points beyond the end of a list
1168 * @return GNUNET_YES if the end has been reached, GNUNET_NO if the iterator
1169 * points to a valid element
1171 int GNUNET_CONTAINER_slist_end (struct GNUNET_CONTAINER_SList_Iterator *i);
1175 * Retrieve the element at a specific position in a list
1178 * @param len set to the payload length
1181 void *GNUNET_CONTAINER_slist_get (const struct GNUNET_CONTAINER_SList_Iterator
1186 * Release an iterator
1189 void GNUNET_CONTAINER_slist_iter_destroy (struct GNUNET_CONTAINER_SList_Iterator
1193 #if 0 /* keep Emacsens' auto-indent happy */
1201 /* ifndef GNUNET_CONTAINER_LIB_H */
1203 /* end of gnunet_container_lib.h */