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3 Copyright (C) 2010 GNUnet e.V.
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20 * @author Christian Grothoff
23 * Library for data block manipulation
25 * @defgroup block Block library
26 * Library for data block manipulation
29 #ifndef GNUNET_BLOCK_LIB_H
30 #define GNUNET_BLOCK_LIB_H
32 #include "gnunet_util_lib.h"
36 #if 0 /* keep Emacsens' auto-indent happy */
43 * Blocks in the datastore and the datacache must have a unique type.
45 enum GNUNET_BLOCK_Type
48 * Any type of block, used as a wildcard when searching. Should
49 * never be attached to a specific block.
51 GNUNET_BLOCK_TYPE_ANY = 0,
54 * Data block (leaf) in the CHK tree.
56 GNUNET_BLOCK_TYPE_FS_DBLOCK = 1,
59 * Inner block in the CHK tree.
61 GNUNET_BLOCK_TYPE_FS_IBLOCK = 2,
64 * Legacy type, no longer in use.
66 GNUNET_BLOCK_TYPE_FS_KBLOCK = 3,
69 * Legacy type, no longer in use.
71 GNUNET_BLOCK_TYPE_FS_SBLOCK = 4,
74 * Legacy type, no longer in use.
76 GNUNET_BLOCK_TYPE_FS_NBLOCK = 5,
79 * Type of a block representing a block to be encoded on demand from disk.
80 * Should never appear on the network directly.
82 GNUNET_BLOCK_TYPE_FS_ONDEMAND = 6,
85 * Type of a block that contains a HELLO for a peer (for
86 * DHT and CADET find-peer operations).
88 GNUNET_BLOCK_TYPE_DHT_HELLO = 7,
93 GNUNET_BLOCK_TYPE_TEST = 8,
96 * Type of a block representing any type of search result
97 * (universal). Implemented in the context of #2564, replaces
98 * SBLOCKS, KBLOCKS and NBLOCKS.
100 GNUNET_BLOCK_TYPE_FS_UBLOCK = 9,
103 * Block for storing DNS exit service advertisements.
105 GNUNET_BLOCK_TYPE_DNS = 10,
108 * Block for storing record data
110 GNUNET_BLOCK_TYPE_GNS_NAMERECORD = 11,
113 * Block type for a revocation message by which a key is revoked.
115 GNUNET_BLOCK_TYPE_REVOCATION = 12,
118 * Block to store a cadet regex state
120 GNUNET_BLOCK_TYPE_REGEX = 22,
123 * Block to store a cadet regex accepting state
125 GNUNET_BLOCK_TYPE_REGEX_ACCEPT = 23,
128 * Block for testing set/consensus. If first byte of the block
129 * is non-zero, the block is considered invalid.
131 GNUNET_BLOCK_TYPE_SET_TEST = 24,
134 * Block type for consensus elements.
135 * Contains either special marker elements or a nested block.
137 GNUNET_BLOCK_TYPE_CONSENSUS_ELEMENT = 25,
142 * Flags that can be set to control the evaluation.
144 enum GNUNET_BLOCK_EvaluationOptions
150 GNUNET_BLOCK_EO_NONE = 0,
153 * The block is obtained from the local database, skip cryptographic
156 GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO = 1
161 * Possible ways for how a block may relate to a query.
163 enum GNUNET_BLOCK_EvaluationResult
166 * Valid result, and there may be more.
168 GNUNET_BLOCK_EVALUATION_OK_MORE = 0,
171 * Last possible valid result.
173 GNUNET_BLOCK_EVALUATION_OK_LAST = 1,
176 * Valid result, but suppressed because it is a duplicate.
178 GNUNET_BLOCK_EVALUATION_OK_DUPLICATE = 2,
181 * Block does not match query (invalid result)
183 GNUNET_BLOCK_EVALUATION_RESULT_INVALID = 3,
186 * Block does not match xquery (valid result, not relevant for the request)
188 GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT = 4,
191 * Query is valid, no reply given.
193 GNUNET_BLOCK_EVALUATION_REQUEST_VALID = 10,
196 * Query format does not match block type (invalid query). For
197 * example, xquery not given or xquery_size not appropriate for
200 GNUNET_BLOCK_EVALUATION_REQUEST_INVALID = 11,
203 * Specified block type not supported by this plugin.
205 GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED = 20
210 * Handle to an initialized block library.
212 struct GNUNET_BLOCK_Context;
216 * Mingle hash with the mingle_number to produce different bits.
218 * @param in original hash code
219 * @param mingle_number number for hash permutation
220 * @param hc where to store the result.
223 GNUNET_BLOCK_mingle_hash (const struct GNUNET_HashCode *in,
224 uint32_t mingle_number,
225 struct GNUNET_HashCode *hc);
229 * Create a block context. Loads the block plugins.
231 * @param cfg configuration to use
232 * @return NULL on error
234 struct GNUNET_BLOCK_Context *
235 GNUNET_BLOCK_context_create (const struct GNUNET_CONFIGURATION_Handle *cfg);
239 * Destroy the block context.
241 * @param ctx context to destroy
244 GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx);
248 * Handle for a group of elements that will be evaluated together.
249 * They must all be of the same type. A block group allows the
250 * plugin to keep some state across individual evaluations.
252 struct GNUNET_BLOCK_Group;
256 * Create a new block group.
258 * @param ctx block context in which the block group is created
259 * @param type type of the block for which we are creating the group
260 * @param nonce random value used to seed the group creation
261 * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
262 * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
263 * @param ... type-specific additional data, can be empty
264 * @return block group handle, NULL if block groups are not supported
265 * by this @a type of block (this is not an error)
267 struct GNUNET_BLOCK_Group *
268 GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
269 enum GNUNET_BLOCK_Type type,
271 const void *raw_data,
272 size_t raw_data_size,
277 * Serialize state of a block group.
279 * @param bg group to serialize
280 * @param[out] nonce set to the nonce of the @a bg
281 * @param[out] raw_data set to the serialized state
282 * @param[out] raw_data_size set to the number of bytes in @a raw_data
283 * @return #GNUNET_OK on success, #GNUNET_NO if serialization is not
284 * supported, #GNUNET_SYSERR on error
287 GNUNET_BLOCK_group_serialize (struct GNUNET_BLOCK_Group *bg,
290 size_t *raw_data_size);
294 * Destroy resources used by a block group.
296 * @param bg group to destroy, NULL is allowed
299 GNUNET_BLOCK_group_destroy (struct GNUNET_BLOCK_Group *bg);
303 * Function called to validate a reply or a request. For
304 * request evaluation, simply pass "NULL" for the @a reply_block.
305 * Note that it is assumed that the reply has already been
306 * matched to the key (and signatures checked) as it would
307 * be done with the #GNUNET_BLOCK_get_key() function.
309 * @param ctx block contxt
310 * @param type block type
311 * @param group block group to use for evaluation
312 * @param eo evaluation options to control evaluation
313 * @param query original query (hash)
314 * @param xquery extrended query data (can be NULL, depending on type)
315 * @param xquery_size number of bytes in @a xquery
316 * @param reply_block response to validate
317 * @param reply_block_size number of bytes in @a reply_block
318 * @return characterization of result
320 enum GNUNET_BLOCK_EvaluationResult
321 GNUNET_BLOCK_evaluate (struct GNUNET_BLOCK_Context *ctx,
322 enum GNUNET_BLOCK_Type type,
323 struct GNUNET_BLOCK_Group *group,
324 enum GNUNET_BLOCK_EvaluationOptions eo,
325 const struct GNUNET_HashCode *query,
328 const void *reply_block,
329 size_t reply_block_size);
333 * Function called to obtain the key for a block.
335 * @param ctx block context
336 * @param type block type
337 * @param block block to get the key for
338 * @param block_size number of bytes in @a block
339 * @param key set to the key (query) for the given block
340 * @return #GNUNET_YES on success,
341 * #GNUNET_NO if the block is malformed
342 * #GNUNET_SYSERR if type not supported
343 * (or if extracting a key from a block of this type does not work)
346 GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
347 enum GNUNET_BLOCK_Type type,
350 struct GNUNET_HashCode *key);
354 * Update block group to filter out the given results. Note that the
355 * use of a hash for seen results implies that the caller magically
356 * knows how the specific block engine hashes for filtering
357 * duplicates, so this API may not always apply.
359 * @param bf_mutator mutation value to use
360 * @param seen_results results already seen
361 * @param seen_results_count number of entries in @a seen_results
362 * @return #GNUNET_SYSERR if not supported, #GNUNET_OK on success
365 GNUNET_BLOCK_group_set_seen (struct GNUNET_BLOCK_Group *bg,
366 const struct GNUNET_HashCode *seen_results,
367 unsigned int seen_results_count);
371 * Try merging two block groups. Afterwards, @a bg1 should remain
372 * valid and contain the rules from both @a bg1 and @bg2, and
373 * @a bg2 should be destroyed (as part of this call). The latter
374 * should happen even if merging is not supported.
376 * @param[in,out] bg1 first group to merge, is updated
377 * @param bg2 second group to merge, is destroyed
378 * @return #GNUNET_OK on success,
379 * #GNUNET_NO if merge failed due to different nonce
380 * #GNUNET_SYSERR if merging is not supported
383 GNUNET_BLOCK_group_merge (struct GNUNET_BLOCK_Group *bg1,
384 struct GNUNET_BLOCK_Group *bg2);
387 #if 0 /* keep Emacsens' auto-indent happy */
394 /* ifndef GNUNET_BLOCK_LIB_H */
397 /** @} */ /* end of group */
399 /* end of gnunet_block_lib.h */