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); will be rounded up
75 * @param k the number of GNUNET_CRYPTO_hash-functions to apply per
76 * element (number of bits set per element in the set)
77 * @return the bloomfilter
79 struct GNUNET_CONTAINER_BloomFilter *
80 GNUNET_CONTAINER_bloomfilter_load (const char *filename, size_t size,
85 * Create a bloom filter from raw bits.
87 * @param data the raw bits in memory (maybe NULL,
88 * in which case all bits should be considered
90 * @param size the size of the bloom-filter (number of
91 * bytes of storage space to use); also size of data
92 * -- unless data is NULL. Must be a power of 2.
93 * @param k the number of GNUNET_CRYPTO_hash-functions to apply per
94 * element (number of bits set per element in the set)
95 * @return the bloomfilter
97 struct GNUNET_CONTAINER_BloomFilter *
98 GNUNET_CONTAINER_bloomfilter_init (const char *data, size_t size,
103 * Copy the raw data of this bloomfilter into
104 * the given data array.
106 * @param data where to write the data
107 * @param size the size of the given data array
108 * @return GNUNET_SYSERR if the data array of the wrong size
111 GNUNET_CONTAINER_bloomfilter_get_raw_data (const struct
112 GNUNET_CONTAINER_BloomFilter *bf,
113 char *data, size_t size);
117 * Test if an element is in the filter.
118 * @param e the element
119 * @param bf the filter
120 * @return GNUNET_YES if the element is in the filter, GNUNET_NO if not
123 GNUNET_CONTAINER_bloomfilter_test (const struct GNUNET_CONTAINER_BloomFilter
124 *bf, const GNUNET_HashCode * e);
128 * Add an element to the filter
129 * @param bf the filter
130 * @param e the element
133 GNUNET_CONTAINER_bloomfilter_add (struct GNUNET_CONTAINER_BloomFilter *bf,
134 const GNUNET_HashCode * e);
138 * Remove an element from the filter.
139 * @param bf the filter
140 * @param e the element to remove
143 GNUNET_CONTAINER_bloomfilter_remove (struct GNUNET_CONTAINER_BloomFilter *bf,
144 const GNUNET_HashCode * e);
148 * Create a copy of a bloomfilter.
150 * @param bf the filter
153 struct GNUNET_CONTAINER_BloomFilter *
154 GNUNET_CONTAINER_bloomfilter_copy (const struct GNUNET_CONTAINER_BloomFilter
160 * Free the space associcated with a filter
161 * in memory, flush to drive if needed (do not
162 * free the space on the drive)
163 * @param bf the filter
166 GNUNET_CONTAINER_bloomfilter_free (struct GNUNET_CONTAINER_BloomFilter *bf);
170 * Get size of the bloom filter.
172 * @param bf the filter
173 * @return number of bytes used for the data of the bloom filter
176 GNUNET_CONTAINER_bloomfilter_get_size (const struct GNUNET_CONTAINER_BloomFilter
181 * Reset a bloom filter to empty.
182 * @param bf the filter
185 GNUNET_CONTAINER_bloomfilter_clear (struct GNUNET_CONTAINER_BloomFilter *bf);
188 * Or the entries of the given raw data array with the
189 * data of the given bloom filter. Assumes that
190 * the size of the data array and the current filter
193 * @param bf the filter
194 * @param data data to OR-in
195 * @param size size of data
196 * @return GNUNET_OK on success
199 GNUNET_CONTAINER_bloomfilter_or (struct GNUNET_CONTAINER_BloomFilter *bf,
200 const char *data, size_t size);
203 * Or the entries of the given raw data array with the
204 * data of the given bloom filter. Assumes that
205 * the size of the data array and the current filter
208 * @param bf the filter
209 * @param to_or the bloomfilter to or-in
210 * @param size number of bytes in data
213 GNUNET_CONTAINER_bloomfilter_or2 (struct GNUNET_CONTAINER_BloomFilter *bf,
214 const struct GNUNET_CONTAINER_BloomFilter
215 *to_or, size_t size);
218 * Resize a bloom filter. Note that this operation
219 * is pretty costly. Essentially, the bloom filter
220 * needs to be completely re-build.
222 * @param bf the filter
223 * @param iterator an iterator over all elements stored in the BF
224 * @param iterator_cls closure for iterator
225 * @param size the new size for the filter
226 * @param k the new number of GNUNET_CRYPTO_hash-function to apply per element
229 GNUNET_CONTAINER_bloomfilter_resize (struct GNUNET_CONTAINER_BloomFilter *bf,
230 GNUNET_HashCodeIterator iterator,
231 void *iterator_cls, size_t size,
234 /* ****************** metadata ******************* */
237 * Meta data to associate with a file, directory or namespace.
239 struct GNUNET_CONTAINER_MetaData;
242 * Create a fresh MetaData token.
244 * @return empty meta-data container
246 struct GNUNET_CONTAINER_MetaData *
247 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 *
256 GNUNET_CONTAINER_meta_data_duplicate (const struct GNUNET_CONTAINER_MetaData
262 * @param md what to free
265 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
278 GNUNET_CONTAINER_meta_data_test_equal (const struct GNUNET_CONTAINER_MetaData
280 const struct GNUNET_CONTAINER_MetaData
287 * @param md metadata to extend
288 * @param plugin_name name of the plugin that produced this value;
289 * special values can be used (i.e. '<zlib>' for zlib being
290 * used in the main libextractor library and yielding
292 * @param type libextractor-type describing the meta data
293 * @param format basic format information about data
294 * @param data_mime_type mime-type of data (not of the original file);
295 * can be NULL (if mime-type is not known)
296 * @param data actual meta-data found
297 * @param data_len number of bytes in data
298 * @return GNUNET_OK on success, GNUNET_SYSERR if this entry already exists
299 * data_mime_type and plugin_name are not considered for "exists" checks
302 GNUNET_CONTAINER_meta_data_insert (struct GNUNET_CONTAINER_MetaData *md,
303 const char *plugin_name,
304 enum EXTRACTOR_MetaType type,
305 enum EXTRACTOR_MetaFormat format,
306 const char *data_mime_type, const char *data,
311 * Extend metadata. Merges the meta data from the second argument
312 * into the first, discarding duplicate key-value pairs.
314 * @param md metadata to extend
315 * @param in metadata to merge
318 GNUNET_CONTAINER_meta_data_merge (struct GNUNET_CONTAINER_MetaData *md,
319 const struct GNUNET_CONTAINER_MetaData *in);
325 * @param md metadata to manipulate
326 * @param type type of the item to remove
327 * @param data specific value to remove, NULL to remove all
328 * entries of the given type
329 * @param data_len number of bytes in data
330 * @return GNUNET_OK on success, GNUNET_SYSERR if the item does not exist in md
333 GNUNET_CONTAINER_meta_data_delete (struct GNUNET_CONTAINER_MetaData *md,
334 enum EXTRACTOR_MetaType type,
335 const char *data, size_t data_len);
339 * Remove all items in the container.
341 * @param md metadata to manipulate
344 GNUNET_CONTAINER_meta_data_clear (struct GNUNET_CONTAINER_MetaData *md);
348 * Add the current time as the publication date
351 * @param md metadata to modify
354 GNUNET_CONTAINER_meta_data_add_publication_date (struct
355 GNUNET_CONTAINER_MetaData *md);
359 * Iterate over MD entries.
361 * @param md metadata to inspect
362 * @param iter function to call on each entry
363 * @param iter_cls closure for iterator
364 * @return number of entries
367 GNUNET_CONTAINER_meta_data_iterate (const struct GNUNET_CONTAINER_MetaData *md,
368 EXTRACTOR_MetaDataProcessor iter,
372 * Get the first MD entry of the given type. Caller
373 * is responsible for freeing the return value.
374 * Also, only meta data items that are strings (0-terminated)
375 * are returned by this function.
377 * @param md metadata to inspect
378 * @param type type to look for
379 * @return NULL if no entry was found
382 GNUNET_CONTAINER_meta_data_get_by_type (const struct GNUNET_CONTAINER_MetaData
383 *md, enum EXTRACTOR_MetaType type);
387 * Get the first matching MD entry of the given types. Caller is
388 * responsible for freeing the return value. Also, only meta data
389 * items that are strings (0-terminated) are returned by this
392 * @param md metadata to inspect
393 * @param ... -1-terminated list of types
394 * @return NULL if we do not have any such entry,
395 * otherwise client is responsible for freeing the value!
398 GNUNET_CONTAINER_meta_data_get_first_by_types (const struct
399 GNUNET_CONTAINER_MetaData *md,
403 * Get a thumbnail from the meta-data (if present). Only matches meta
404 * data with mime type "image" and binary format.
406 * @param md metadata to inspect
407 * @param thumb will be set to the thumbnail data. Must be
408 * freed by the caller!
409 * @return number of bytes in thumbnail, 0 if not available
412 GNUNET_CONTAINER_meta_data_get_thumbnail (const struct GNUNET_CONTAINER_MetaData
413 *md, unsigned char **thumb);
418 * Options for metadata serialization.
420 enum GNUNET_CONTAINER_MetaDataSerializationOptions
423 * Serialize all of the data.
425 GNUNET_CONTAINER_META_DATA_SERIALIZE_FULL = 0,
428 * If not enough space is available, it is acceptable
429 * to only serialize some of the metadata.
431 GNUNET_CONTAINER_META_DATA_SERIALIZE_PART = 1,
434 * Speed is of the essence, do not allow compression.
436 GNUNET_CONTAINER_META_DATA_SERIALIZE_NO_COMPRESS = 2
441 * Serialize meta-data to target.
443 * @param md metadata to serialize
444 * @param target where to write the serialized metadata;
445 * *target can be NULL, in which case memory is allocated
446 * @param max maximum number of bytes available
447 * @param opt is it ok to just write SOME of the
448 * meta-data to match the size constraint,
449 * possibly discarding some data?
450 * @return number of bytes written on success,
451 * -1 on error (typically: not enough
455 GNUNET_CONTAINER_meta_data_serialize (const struct GNUNET_CONTAINER_MetaData
456 *md, char **target, size_t max,
458 GNUNET_CONTAINER_MetaDataSerializationOptions
463 * Get the size of the full meta-data in serialized form.
465 * @param md metadata to inspect
466 * @return number of bytes needed for serialization, -1 on error
469 GNUNET_CONTAINER_meta_data_get_serialized_size (const struct
470 GNUNET_CONTAINER_MetaData *md);
474 * Deserialize meta-data. Initializes md.
476 * @param input serialized meta-data.
477 * @param size number of bytes available
478 * @return MD on success, NULL on error (i.e.
481 struct GNUNET_CONTAINER_MetaData *
482 GNUNET_CONTAINER_meta_data_deserialize (const char *input, size_t size);
485 /* ******************************* HashMap **************************** */
488 * Opaque handle for a HashMap.
490 struct GNUNET_CONTAINER_MultiHashMap;
493 * Options for storing values in the HashMap.
495 enum GNUNET_CONTAINER_MultiHashMapOption
499 * If a value with the given key exists, replace it. Note that the
500 * old value would NOT be freed by replace (the application has to
501 * make sure that this happens if required).
503 GNUNET_CONTAINER_MULTIHASHMAPOPTION_REPLACE,
506 * Allow multiple values with the same key.
508 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE,
511 * There must only be one value per key; storing a value should fail
512 * if a value under the same key already exists.
514 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY,
517 * There must only be one value per key, but don't bother checking
518 * if a value already exists (faster than UNIQUE_ONLY; implemented
519 * just like MULTIPLE but this option documents better what is
520 * intended if UNIQUE is what is desired).
522 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST
527 * Iterator over hash map entries.
530 * @param key current key code
531 * @param value value in the hash map
532 * @return GNUNET_YES if we should continue to
536 typedef int (*GNUNET_CONTAINER_HashMapIterator) (void *cls,
537 const GNUNET_HashCode * key,
542 * Create a multi hash map.
544 * @param len initial size (map will grow as needed)
545 * @return NULL on error
547 struct GNUNET_CONTAINER_MultiHashMap *
548 GNUNET_CONTAINER_multihashmap_create (unsigned int len);
552 * Destroy a hash map. Will not free any values
553 * stored in the hash map!
558 GNUNET_CONTAINER_multihashmap_destroy (struct GNUNET_CONTAINER_MultiHashMap
563 * Given a key find a value in the map matching the key.
566 * @param key what to look for
567 * @return NULL if no value was found; note that
568 * this is indistinguishable from values that just
569 * happen to be NULL; use "contains" to test for
570 * key-value pairs with value NULL
573 GNUNET_CONTAINER_multihashmap_get (const struct GNUNET_CONTAINER_MultiHashMap
574 *map, const GNUNET_HashCode * key);
578 * Remove the given key-value pair from the map. Note that if the
579 * key-value pair is in the map multiple times, only one of the pairs
583 * @param key key of the key-value pair
584 * @param value value of the key-value pair
585 * @return GNUNET_YES on success, GNUNET_NO if the key-value pair
589 GNUNET_CONTAINER_multihashmap_remove (struct GNUNET_CONTAINER_MultiHashMap *map,
590 const GNUNET_HashCode * key, void *value);
593 * Remove all entries for the given key from the map.
594 * Note that the values would not be "freed".
597 * @param key identifies values to be removed
598 * @return number of values removed
601 GNUNET_CONTAINER_multihashmap_remove_all (struct GNUNET_CONTAINER_MultiHashMap
602 *map, const GNUNET_HashCode * key);
606 * Check if the map contains any value under the given
607 * key (including values that are NULL).
610 * @param key the key to test if a value exists for it
611 * @return GNUNET_YES if such a value exists,
615 GNUNET_CONTAINER_multihashmap_contains (const struct
616 GNUNET_CONTAINER_MultiHashMap *map,
617 const GNUNET_HashCode * key);
621 * Check if the map contains the given value under the given
625 * @param key the key to test if a value exists for it
626 * @param value value to test for
627 * @return GNUNET_YES if such a value exists,
631 GNUNET_CONTAINER_multihashmap_contains_value (const struct
632 GNUNET_CONTAINER_MultiHashMap
633 *map, const GNUNET_HashCode * key,
638 * Store a key-value pair in the map.
641 * @param key key to use
642 * @param value value to use
643 * @param opt options for put
644 * @return GNUNET_OK on success,
645 * GNUNET_NO if a value was replaced (with REPLACE)
646 * GNUNET_SYSERR if UNIQUE_ONLY was the option and the
647 * value already exists
650 GNUNET_CONTAINER_multihashmap_put (struct GNUNET_CONTAINER_MultiHashMap *map,
651 const GNUNET_HashCode * key, void *value,
652 enum GNUNET_CONTAINER_MultiHashMapOption
656 * Get the number of key-value pairs in the map.
659 * @return the number of key value pairs
662 GNUNET_CONTAINER_multihashmap_size (const struct GNUNET_CONTAINER_MultiHashMap
667 * Iterate over all entries in the map.
670 * @param it function to call on each entry
671 * @param it_cls extra argument to it
672 * @return the number of key value pairs processed,
673 * GNUNET_SYSERR if it aborted iteration
676 GNUNET_CONTAINER_multihashmap_iterate (const struct
677 GNUNET_CONTAINER_MultiHashMap *map,
678 GNUNET_CONTAINER_HashMapIterator it,
683 * Iterate over all entries in the map that match a particular key.
686 * @param key key that the entries must correspond to
687 * @param it function to call on each entry
688 * @param it_cls extra argument to it
689 * @return the number of key value pairs processed,
690 * GNUNET_SYSERR if it aborted iteration
693 GNUNET_CONTAINER_multihashmap_get_multiple (const struct
694 GNUNET_CONTAINER_MultiHashMap *map,
695 const GNUNET_HashCode * key,
696 GNUNET_CONTAINER_HashMapIterator it,
700 /* ******************** doubly-linked list *************** */
701 /* To avoid mistakes: head->prev == tail->next == NULL */
704 * Insert an element at the head of a DLL. Assumes that head, tail and
705 * element are structs with prev and next fields.
707 * @param head pointer to the head of the DLL
708 * @param tail pointer to the tail of the DLL
709 * @param element element to insert
711 #define GNUNET_CONTAINER_DLL_insert(head,tail,element) do { \
712 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
713 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
714 (element)->next = (head); \
715 (element)->prev = NULL; \
716 if ((tail) == NULL) \
719 (head)->prev = element; \
720 (head) = (element); } while (0)
724 * Insert an element at the tail of a DLL. Assumes that head, tail and
725 * element are structs with prev and next fields.
727 * @param head pointer to the head of the DLL
728 * @param tail pointer to the tail of the DLL
729 * @param element element to insert
731 #define GNUNET_CONTAINER_DLL_insert_tail(head,tail,element) do { \
732 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
733 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
734 (element)->prev = (tail); \
735 (element)->next = NULL; \
736 if ((head) == NULL) \
739 (tail)->next = element; \
740 (tail) = (element); } while (0)
744 * Insert an element into a DLL after the given other element. Insert
745 * at the head if the other element is NULL.
747 * @param head pointer to the head of the DLL
748 * @param tail pointer to the tail of the DLL
749 * @param other prior element, NULL for insertion at head of DLL
750 * @param element element to insert
752 #define GNUNET_CONTAINER_DLL_insert_after(head,tail,other,element) do { \
753 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
754 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
755 (element)->prev = (other); \
758 (element)->next = (head); \
759 (head) = (element); \
763 (element)->next = (other)->next; \
764 (other)->next = (element); \
766 if (NULL == (element)->next) \
767 (tail) = (element); \
769 (element)->next->prev = (element); } while (0)
773 * Insert an element into a DLL before the given other element. Insert
774 * at the tail if the other element is NULL.
776 * @param head pointer to the head of the DLL
777 * @param tail pointer to the tail of the DLL
778 * @param other prior element, NULL for insertion at head of DLL
779 * @param element element to insert
781 #define GNUNET_CONTAINER_DLL_insert_before(head,tail,other,element) do { \
782 GNUNET_assert ( ( (element)->prev == NULL) && ((head) != (element))); \
783 GNUNET_assert ( ( (element)->next == NULL) && ((tail) != (element))); \
784 (element)->next = (other); \
787 (element)->prev = (tail); \
788 (tail) = (element); \
792 (element)->prev = (other)->prev; \
793 (other)->prev = (element); \
795 if (NULL == (element)->prev) \
796 (head) = (element); \
798 (element)->prev->next = (element); } while (0)
802 * Remove an element from a DLL. Assumes
803 * that head, tail and element are structs
804 * with prev and next fields.
806 * @param head pointer to the head of the DLL
807 * @param tail pointer to the tail of the DLL
808 * @param element element to remove
810 #define GNUNET_CONTAINER_DLL_remove(head,tail,element) do { \
811 GNUNET_assert ( ( (element)->prev != NULL) || ((head) == (element))); \
812 GNUNET_assert ( ( (element)->next != NULL) || ((tail) == (element))); \
813 if ((element)->prev == NULL) \
814 (head) = (element)->next; \
816 (element)->prev->next = (element)->next; \
817 if ((element)->next == NULL) \
818 (tail) = (element)->prev; \
820 (element)->next->prev = (element)->prev; \
821 (element)->next = NULL; \
822 (element)->prev = NULL; } while (0)
826 /* ******************** Heap *************** */
830 * Cost by which elements in a heap can be ordered.
832 typedef uint64_t GNUNET_CONTAINER_HeapCostType;
836 * Heap type, either max or min. Hopefully makes the
837 * implementation more useful.
839 enum GNUNET_CONTAINER_HeapOrder
842 * Heap with the maximum cost at the root.
844 GNUNET_CONTAINER_HEAP_ORDER_MAX,
847 * Heap with the minimum cost at the root.
849 GNUNET_CONTAINER_HEAP_ORDER_MIN
856 struct GNUNET_CONTAINER_Heap;
861 * Handle to a node in a heap.
863 struct GNUNET_CONTAINER_HeapNode;
869 * @param order how should the heap be sorted?
870 * @return handle to the heap
872 struct GNUNET_CONTAINER_Heap *
873 GNUNET_CONTAINER_heap_create (enum GNUNET_CONTAINER_HeapOrder order);
877 * Destroys the heap. Only call on a heap that
880 * @param heap heap to destroy
883 GNUNET_CONTAINER_heap_destroy (struct GNUNET_CONTAINER_Heap *heap);
887 * Get element stored at root of heap.
889 * @param heap heap to inspect
890 * @return NULL if heap is empty
893 GNUNET_CONTAINER_heap_peek (const struct GNUNET_CONTAINER_Heap *heap);
897 * Get the current size of the heap
899 * @param heap the heap to get the size of
900 * @return number of elements stored
903 GNUNET_CONTAINER_heap_get_size (const struct GNUNET_CONTAINER_Heap *heap);
907 * Get the current cost of the node
909 * @param node the node to get the cost of
910 * @return cost of the node
912 GNUNET_CONTAINER_HeapCostType
913 GNUNET_CONTAINER_heap_node_get_cost (const struct GNUNET_CONTAINER_HeapNode
920 * @param node internal node of the heap
921 * @param element value stored at the node
922 * @param cost cost associated with the node
923 * @return GNUNET_YES if we should continue to iterate,
926 typedef int (*GNUNET_CONTAINER_HeapIterator) (void *cls,
927 struct GNUNET_CONTAINER_HeapNode *
929 GNUNET_CONTAINER_HeapCostType
934 * Iterate over all entries in the heap.
936 * @param heap the heap
937 * @param iterator function to call on each entry
938 * @param iterator_cls closure for iterator
941 GNUNET_CONTAINER_heap_iterate (const struct GNUNET_CONTAINER_Heap *heap,
942 GNUNET_CONTAINER_HeapIterator iterator,
947 * Return a *uniform* random element from the heap. Choose a random
948 * number between 0 and heap size and then walk directly to it.
949 * This cost can be between 0 and n, amortized cost of logN.
951 * @param heap heap to choose random element from
952 * @param max how many nodes from the heap to choose from
954 * @return data stored at the chosen random node,
955 * NULL if the heap is empty.
959 GNUNET_CONTAINER_heap_get_random (struct GNUNET_CONTAINER_Heap *heap,
964 * Perform a random walk of the tree. The walk is biased
965 * towards elements closer to the root of the tree (since
966 * each walk starts at the root and ends at a random leaf).
967 * The heap internally tracks the current position of the
970 * @param heap heap to walk
971 * @return data stored at the next random node in the walk;
972 * NULL if the tree is empty.
975 GNUNET_CONTAINER_heap_walk_get_next (struct GNUNET_CONTAINER_Heap *heap);
979 * Inserts a new element into the heap.
981 * @param heap heap to modify
982 * @param element element to insert
983 * @param cost cost for the element
984 * @return node for the new element
986 struct GNUNET_CONTAINER_HeapNode *
987 GNUNET_CONTAINER_heap_insert (struct GNUNET_CONTAINER_Heap *heap, void *element,
988 GNUNET_CONTAINER_HeapCostType cost);
992 * Remove root of the heap.
994 * @param heap heap to modify
995 * @return element data stored at the root node
998 GNUNET_CONTAINER_heap_remove_root (struct GNUNET_CONTAINER_Heap *heap);
1002 * Removes a node from the heap.
1004 * @param node node to remove
1005 * @return element data stored at the node, NULL if heap is empty
1008 GNUNET_CONTAINER_heap_remove_node (struct GNUNET_CONTAINER_HeapNode *node);
1012 * Updates the cost of any node in the tree
1014 * @param heap heap to modify
1015 * @param node node for which the cost is to be changed
1016 * @param new_cost new cost for the node
1019 GNUNET_CONTAINER_heap_update_cost (struct GNUNET_CONTAINER_Heap *heap,
1020 struct GNUNET_CONTAINER_HeapNode *node,
1021 GNUNET_CONTAINER_HeapCostType new_cost);
1024 /* ******************** Singly linked list *************** */
1027 * Possible ways for how data stored in the linked list
1028 * might be allocated.
1030 enum GNUNET_CONTAINER_SListDisposition
1033 * Single-linked list must copy the buffer.
1035 GNUNET_CONTAINER_SLIST_DISPOSITION_TRANSIENT = 0,
1038 * Data is static, no need to copy or free.
1040 GNUNET_CONTAINER_SLIST_DISPOSITION_STATIC = 2,
1043 * Data is dynamic, do not copy but free when done.
1045 GNUNET_CONTAINER_SLIST_DISPOSITION_DYNAMIC = 4
1051 * Handle to a singly linked list
1053 struct GNUNET_CONTAINER_SList;
1056 * Handle to a singly linked list iterator
1058 struct GNUNET_CONTAINER_SList_Iterator
1061 * Linked list that we are iterating over.
1063 struct GNUNET_CONTAINER_SList *list;
1066 * Last element accessed.
1068 struct GNUNET_CONTAINER_SList_Elem *last;
1071 * Current list element.
1073 struct GNUNET_CONTAINER_SList_Elem *elem;
1079 * Add a new element to the list
1081 * @param disp memory disposition
1082 * @param buf payload buffer
1083 * @param len length of the buffer
1086 GNUNET_CONTAINER_slist_add (struct GNUNET_CONTAINER_SList *l,
1087 enum GNUNET_CONTAINER_SListDisposition disp,
1088 const void *buf, size_t len);
1092 * Add a new element to the end of the list
1094 * @param disp memory disposition
1095 * @param buf payload buffer
1096 * @param len length of the buffer
1099 GNUNET_CONTAINER_slist_add_end (struct GNUNET_CONTAINER_SList *l,
1100 enum GNUNET_CONTAINER_SListDisposition disp,
1101 const void *buf, size_t len);
1105 * Append a singly linked list to another
1106 * @param dst list to append to
1110 GNUNET_CONTAINER_slist_append (struct GNUNET_CONTAINER_SList *dst,
1111 struct GNUNET_CONTAINER_SList *src);
1115 * Create a new singly linked list
1116 * @return the new list
1118 struct GNUNET_CONTAINER_SList *
1119 GNUNET_CONTAINER_slist_create (void);
1123 * Destroy a singly linked list
1124 * @param l the list to be destroyed
1127 GNUNET_CONTAINER_slist_destroy (struct GNUNET_CONTAINER_SList *l);
1131 * Return the beginning of a list
1134 * @return iterator pointing to the beginning (by value! Either allocate the
1135 * structure on the stack, or use GNUNET_malloc() yourself! All other
1136 * functions do take pointer to this struct though)
1138 struct GNUNET_CONTAINER_SList_Iterator
1139 GNUNET_CONTAINER_slist_begin (struct GNUNET_CONTAINER_SList *l);
1148 GNUNET_CONTAINER_slist_clear (struct GNUNET_CONTAINER_SList *l);
1152 * Check if a list contains a certain element
1154 * @param buf payload buffer to find
1155 * @param len length of the payload (number of bytes in buf)
1157 * @return GNUNET_YES if found, GNUNET_NO otherwise
1160 GNUNET_CONTAINER_slist_contains (const struct GNUNET_CONTAINER_SList *l,
1161 const void *buf, size_t len);
1164 * Check if a list contains a certain element using 'compare' function
1167 * @param buf payload buffer to find
1168 * @param len length of the payload (number of bytes in buf)
1169 * @param compare comparison function
1171 * @return NULL if the 'buf' could not be found, pointer to the
1172 * list element, if found
1175 GNUNET_CONTAINER_slist_contains2 (const struct GNUNET_CONTAINER_SList *l,
1176 const void *buf, size_t len,
1177 int (*compare)(const void *, const size_t, const void *, const size_t));
1179 * Count the elements of a list
1181 * @return number of elements in the list
1184 GNUNET_CONTAINER_slist_count (const struct GNUNET_CONTAINER_SList *l);
1188 * Remove an element from the list
1189 * @param i iterator that points to the element to be removed
1192 GNUNET_CONTAINER_slist_erase (struct GNUNET_CONTAINER_SList_Iterator *i);
1196 * Insert an element into a list at a specific position
1197 * @param before where to insert the new element
1198 * @param disp memory disposition
1199 * @param buf payload buffer
1200 * @param len length of the payload
1203 GNUNET_CONTAINER_slist_insert (struct GNUNET_CONTAINER_SList_Iterator *before,
1204 enum GNUNET_CONTAINER_SListDisposition disp,
1205 const void *buf, size_t len);
1209 * Advance an iterator to the next element
1211 * @return GNUNET_YES on success, GNUNET_NO if the end has been reached
1214 GNUNET_CONTAINER_slist_next (struct GNUNET_CONTAINER_SList_Iterator *i);
1218 * Check if an iterator points beyond the end of a list
1220 * @return GNUNET_YES if the end has been reached, GNUNET_NO if the iterator
1221 * points to a valid element
1224 GNUNET_CONTAINER_slist_end (struct GNUNET_CONTAINER_SList_Iterator *i);
1228 * Retrieve the element at a specific position in a list
1231 * @param len set to the payload length
1235 GNUNET_CONTAINER_slist_get (const struct GNUNET_CONTAINER_SList_Iterator *i,
1240 * Release an iterator
1244 GNUNET_CONTAINER_slist_iter_destroy (struct GNUNET_CONTAINER_SList_Iterator *i);
1247 #if 0 /* keep Emacsens' auto-indent happy */
1255 /* ifndef GNUNET_CONTAINER_LIB_H */
1257 /* end of gnunet_container_lib.h */