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21 * @file set/gnunet-service-set.h
22 * @brief common components for the implementation the different set operations
23 * @author Florian Dold
24 * @author Christian Grothoff
26 #ifndef GNUNET_SERVICE_SET_H_PRIVATE
27 #define GNUNET_SERVICE_SET_H_PRIVATE
30 #include "gnunet_util_lib.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet_applications.h"
33 #include "gnunet_core_service.h"
34 #include "gnunet_cadet_service.h"
35 #include "gnunet_set_service.h"
40 * Implementation-specific set state. Used as opaque pointer, and
41 * specified further in the respective implementation.
46 * Implementation-specific set operation. Used as opaque pointer, and
47 * specified further in the respective implementation.
49 struct OperationState;
52 * A set that supports a specific operation with other peers.
57 * Information about an element element in the set. All elements are
58 * stored in a hash-table from their hash-code to their 'struct
59 * Element', so that the remove and add operations are reasonably
65 * Operation context used to execute a set operation.
71 * Signature of functions that create the implementation-specific
72 * state for a set supporting a specific operation.
74 * @return a set state specific to the supported operation, NULL on error
76 typedef struct SetState *
77 (*SetCreateImpl) (void);
81 * Signature of functions that implement the add/remove functionality
82 * for a set supporting a specific operation.
84 * @param set implementation-specific set state
85 * @param ee element message from the client
88 (*SetAddRemoveImpl) (struct SetState *state,
89 struct ElementEntry *ee);
93 * Make a copy of a set's internal state.
95 * @param state set state to copy
96 * @return copy of the internal state
98 typedef struct SetState *
99 (*SetCopyStateImpl) (struct SetState *state);
103 * Signature of functions that implement the destruction of the
104 * implementation-specific set state.
106 * @param state the set state, contains implementation-specific data
109 (*SetDestroyImpl) (struct SetState *state);
113 * Signature of functions that implement accepting a set operation.
115 * @param op operation that is created by accepting the operation,
116 * should be initialized by the implementation
117 * @return operation-specific state to keep in @a op
119 typedef struct OperationState *
120 (*OpAcceptImpl) (struct Operation *op);
124 * Signature of functions that implement starting the evaluation of
127 * @param op operation that is created, should be initialized to
128 * begin the evaluation
129 * @param opaque_context message to be transmitted to the listener
130 * to convince it to accept, may be NULL
131 * @return operation-specific state to keep in @a op
133 typedef struct OperationState *
134 (*OpEvaluateImpl) (struct Operation *op,
135 const struct GNUNET_MessageHeader *opaque_context);
138 * Signature of functions that implement operation cancelation.
139 * This includes notifying the client about the operation's final
142 * @param op operation state
145 (*OpCancelImpl) (struct Operation *op);
149 * Signature of functions called when the CADET channel died.
151 * @param op operation state
154 (*OpChannelDeathImpl) (struct Operation *op);
158 * Dispatch table for a specific set operation. Every set operation
159 * has to implement the callback in this struct.
164 * Callback for the set creation.
166 SetCreateImpl create;
169 * Callback for element insertion
171 SetAddRemoveImpl add;
174 * Callback for element removal.
176 SetAddRemoveImpl remove;
179 * Callback for making a copy of a set's internal state.
181 SetCopyStateImpl copy_state;
184 * Callback for destruction of the set state.
186 SetDestroyImpl destroy_set;
189 * Callback for accepting a set operation request
194 * Callback for starting evaluation with a remote peer.
196 OpEvaluateImpl evaluate;
199 * Callback for canceling an operation.
204 * Callback called in case the CADET channel died.
206 OpChannelDeathImpl channel_death;
211 * MutationEvent gives information about changes
212 * to an element (removal / addition) in a set content.
217 * First generation affected by this mutation event.
219 * If @a generation is 0, this mutation event is a list
222 unsigned int generation;
225 * If @a added is #GNUNET_YES, then this is a
226 * `remove` event, otherwise it is an `add` event.
233 * Information about an element element in the set. All elements are
234 * stored in a hash-table from their hash-code to their `struct
235 * Element`, so that the remove and add operations are reasonably
241 * The actual element. The data for the element
242 * should be allocated at the end of this struct.
244 struct GNUNET_SET_Element element;
247 * Hash of the element. For set union: Will be used to derive the
248 * different IBF keys for different salts.
250 struct GNUNET_HashCode element_hash;
253 * If @a mutations is not NULL, it contains
254 * a list of mutations, ordered by increasing generation.
255 * The list is terminated by a sentinel event with `generation`
258 * If @a mutations is NULL, then this element exists in all generations
259 * of the respective set content this element belongs to.
261 struct MutationEvent *mutations;
264 * Number of elements in the array @a mutations.
266 unsigned int mutations_size;
269 * #GNUNET_YES if the element is a remote element, and does not belong
270 * to the operation's set.
277 * A listener is inhabited by a client, and waits for evaluation
278 * requests from remote peers.
284 * State we keep per client.
289 * Set, if associated with the client, otherwise NULL.
294 * Listener, if associated with the client, otherwise NULL.
296 struct Listener *listener;
301 struct GNUNET_SERVICE_Client *client;
306 struct GNUNET_MQ_Handle *mq;
311 * Operation context used to execute a set operation.
316 * Kept in a DLL of the listener, if @e listener is non-NULL.
318 struct Operation *next;
321 * Kept in a DLL of the listener, if @e listener is non-NULL.
323 struct Operation *prev;
326 * Channel to the peer.
328 struct GNUNET_CADET_Channel *channel;
331 * Port this operation runs on.
333 struct Listener *listener;
336 * Message queue for the channel.
338 struct GNUNET_MQ_Handle *mq;
341 * Context message, may be NULL.
343 struct GNUNET_MessageHeader *context_msg;
346 * Set associated with the operation, NULL until the spec has been
347 * associated with a set.
352 * Operation-specific operation state. Note that the exact
353 * type depends on this being a union or intersection operation
354 * (and thus on @e vt).
356 struct OperationState *state;
359 * The identity of the requesting peer. Needs to
360 * be stored here as the op spec might not have been created yet.
362 struct GNUNET_PeerIdentity peer;
365 * Timeout task, if the incoming peer has not been accepted
366 * after the timeout, it will be disconnected.
368 struct GNUNET_SCHEDULER_Task *timeout_task;
371 * Salt to use for the operation.
376 * Remote peers element count
378 uint32_t remote_element_count;
381 * ID used to identify an operation between service and client
383 uint32_t client_request_id;
386 * When are elements sent to the client, and which elements are sent?
388 enum GNUNET_SET_ResultMode result_mode;
391 * Always use delta operation instead of sending full sets,
392 * even it it's less efficient.
397 * Always send full sets, even if delta operations would
403 * #GNUNET_YES to fail operations where Byzantine faults
409 * Lower bound for the set size, used only when
410 * byzantine mode is enabled.
412 int byzantine_lower_bound;
415 * Unique request id for the request from a remote peer, sent to the
416 * client, which will accept or reject the request. Set to '0' iff
417 * the request has not been suggested yet.
422 * Generation in which the operation handle
425 unsigned int generation_created;
430 * SetContent stores the actual set elements, which may be shared by
431 * multiple generations derived from one set.
436 * Maps `struct GNUNET_HashCode *` to `struct ElementEntry *`.
438 struct GNUNET_CONTAINER_MultiHashMap *elements;
441 * Mutations requested by the client that we're
442 * unable to execute right now because we're iterating
443 * over the underlying hash map of elements.
445 struct PendingMutation *pending_mutations_head;
448 * Mutations requested by the client that we're
449 * unable to execute right now because we're iterating
450 * over the underlying hash map of elements.
452 struct PendingMutation *pending_mutations_tail;
455 * Number of references to the content.
457 unsigned int refcount;
462 unsigned int latest_generation;
465 * Number of concurrently active iterators.
471 struct GenerationRange
474 * First generation that is excluded.
479 * Generation after the last excluded generation.
486 * Information about a mutation to apply to a set.
488 struct PendingMutation
491 * Mutations are kept in a DLL.
493 struct PendingMutation *prev;
496 * Mutations are kept in a DLL.
498 struct PendingMutation *next;
501 * Set this mutation is about.
506 * Message that describes the desired mutation.
507 * May only be a #GNUNET_MESSAGE_TYPE_SET_ADD or
508 * #GNUNET_MESSAGE_TYPE_SET_REMOVE.
510 struct GNUNET_SET_ElementMessage *msg;
515 * A set that supports a specific operation with other peers.
520 * Sets are held in a doubly linked list (in `sets_head` and `sets_tail`).
525 * Sets are held in a doubly linked list.
530 * Client that owns the set. Only one client may own a set,
531 * and there can only be one set per client.
533 struct ClientState *cs;
536 * Content, possibly shared by multiple sets,
537 * and thus reference counted.
539 struct SetContent *content;
542 * Virtual table for this set. Determined by the operation type of
545 * Used only for Add/remove of elements and when receiving an incoming
546 * operation from a remote peer.
548 const struct SetVT *vt;
551 * Implementation-specific state.
553 struct SetState *state;
556 * Current state of iterating elements for the client.
557 * NULL if we are not currently iterating.
559 struct GNUNET_CONTAINER_MultiHashMapIterator *iter;
562 * Evaluate operations are held in a linked list.
564 struct Operation *ops_head;
567 * Evaluate operations are held in a linked list.
569 struct Operation *ops_tail;
572 * List of generations we have to exclude, due to lazy copies.
574 struct GenerationRange *excluded_generations;
577 * Current generation, that is, number of previously executed
578 * operations and lazy copies on the underlying set content.
580 unsigned int current_generation;
583 * Number of elements in array @a excluded_generations.
585 unsigned int excluded_generations_size;
588 * Type of operation supported for this set
590 enum GNUNET_SET_OperationType operation;
593 * Generation we're currently iteration over.
595 unsigned int iter_generation;
598 * Each @e iter is assigned a unique number, so that the client
599 * can distinguish iterations.
601 uint16_t iteration_id;
605 extern struct GNUNET_STATISTICS_Handle *_GSS_statistics;
609 * Destroy the given operation. Used for any operation where both
610 * peers were known and that thus actually had a vt and channel. Must
611 * not be used for operations where 'listener' is still set and we do
612 * not know the other peer.
614 * Call the implementation-specific cancel function of the operation.
615 * Disconnects from the remote peer. Does not disconnect the client,
616 * as there may be multiple operations per set.
618 * @param op operation to destroy
619 * @param gc #GNUNET_YES to perform garbage collection on the set
622 _GSS_operation_destroy (struct Operation *op,
627 * This function probably should not exist
628 * and be replaced by inlining more specific
629 * logic in the various places where it is called.
632 _GSS_operation_destroy2 (struct Operation *op);
636 * Get the table with implementing functions for set union.
638 * @return the operation specific VTable
641 _GSS_union_vt (void);
645 * Get the table with implementing functions for set intersection.
647 * @return the operation specific VTable
650 _GSS_intersection_vt (void);
654 * Is element @a ee part of the set used by @a op?
656 * @param ee element to test
657 * @param op operation the defines the set and its generation
658 * @return #GNUNET_YES if the element is in the set, #GNUNET_NO if not
661 _GSS_is_element_of_operation (struct ElementEntry *ee,
662 struct Operation *op);