* State from which this transition origins.
*/
struct GNUNET_REGEX_State *from_state;
-
- /**
- * Mark this transition. For example when reversing the automaton.
- */
- int mark;
};
*/
unsigned int id;
+ /**
+ * Unique state id that is used for traversing the automaton. It is guaranteed
+ * to be > 0 and < state_count.
+ */
+ unsigned int traversal_id;
+
/**
* If this is an accepting state or not.
*/
/**
* Marking the state as contained. This is used for checking, if the state is
- * contained in a set in constant time
+ * contained in a set in constant time.
*/
int contained;
struct GNUNET_HashCode hash;
/**
- * State ID for proof creation.
+ * Linear state ID accquired by depth-first-search. This ID should be used for
+ * storing information about the state in an array, because the 'id' of the
+ * state is not guaranteed to be linear. The 'dfs_id' is guaranteed to be > 0
+ * and < 'state_count'.
*/
- unsigned int proof_id;
+ unsigned int dfs_id;
/**
* Proof for this state.
*/
struct GNUNET_REGEX_Transition *transitions_tail;
+ /**
+ * Number of incoming transitions. Used for compressing DFA paths.
+ */
+ unsigned int incoming_transition_count;
+
/**
* Set of states on which this state is based on. Used when creating a DFA out
* of several NFA states.
* Canonical regex (result of RX->NFA->DFA->RX)
*/
char *canonical_regex;
+
+ /**
+ * GNUNET_YES, if multi strides have been added to the Automaton.
+ */
+ int is_multistrided;
};
+/**
+ * Function that get's passed to automaton traversal and is called before each
+ * next traversal from state 's' using transition 't' to check if traversal
+ * should proceed. Return GNUNET_NO to stop traversal or GNUNET_YES to continue.
+ *
+ * @param cls closure for the check.
+ * @param s current state in the traversal.
+ * @param t current transition from state 's' that will be used for the next
+ * step.
+ *
+ * @return GNUNET_YES to proceed traversal, GNUNET_NO to stop.
+ */
+typedef int (*GNUNET_REGEX_traverse_check) (void *cls,
+ struct GNUNET_REGEX_State * s,
+ struct GNUNET_REGEX_Transition * t);
+
+
/**
* Function that is called with each state, when traversing an automaton.
*
* @param count current count of the state, from 0 to a->state_count -1.
* @param s state.
*/
-typedef void (*GNUNET_REGEX_traverse_action) (void *cls, unsigned int count,
+typedef void (*GNUNET_REGEX_traverse_action) (void *cls,
+ const unsigned int count,
struct GNUNET_REGEX_State * s);
/**
- * Traverses the given automaton from it's start state, visiting all reachable
- * states and calling 'action' on each one of them.
+ * Traverses the given automaton using depth-first-search (DFS) from it's start
+ * state, visiting all reachable states and calling 'action' on each one of
+ * them.
*
- * @param a automaton.
+ * @param a automaton to be traversed.
+ * @param start start state, pass a->start or NULL to traverse the whole automaton.
+ * @param check function that is checked before advancing on each transition
+ * in the DFS.
+ * @param check_cls closure for check.
* @param action action to be performed on each state.
* @param action_cls closure for action
*/
void
-GNUNET_REGEX_automaton_traverse (struct GNUNET_REGEX_Automaton *a,
+GNUNET_REGEX_automaton_traverse (const struct GNUNET_REGEX_Automaton *a,
+ struct GNUNET_REGEX_State *start,
+ GNUNET_REGEX_traverse_check check,
+ void *check_cls,
GNUNET_REGEX_traverse_action action,
void *action_cls);
-
/**
* Get the canonical regex of the given automaton.
* When constructing the automaton a proof is computed for each state,
*
* @param a automaton for which the canonical regex should be returned.
*
- * @return
+ * @return canonical regex string.
*/
const char *
GNUNET_REGEX_get_canonical_regex (struct GNUNET_REGEX_Automaton *a);
+/**
+ * Get the number of transitions that are contained in the given automaton.
+ *
+ * @param a automaton for which the number of transitions should be returned.
+ *
+ * @return number of transitions in the given automaton.
+ */
+unsigned int
+GNUNET_REGEX_get_transition_count (struct GNUNET_REGEX_Automaton *a);
+
+
+/**
+ * Context that contains an id counter for states and transitions as well as a
+ * DLL of automatons used as a stack for NFA construction.
+ */
+struct GNUNET_REGEX_Context
+{
+ /**
+ * Unique state id.
+ */
+ unsigned int state_id;
+
+ /**
+ * Unique transition id.
+ */
+ unsigned int transition_id;
+
+ /**
+ * DLL of GNUNET_REGEX_Automaton's used as a stack.
+ */
+ struct GNUNET_REGEX_Automaton *stack_head;
+
+ /**
+ * DLL of GNUNET_REGEX_Automaton's used as a stack.
+ */
+ struct GNUNET_REGEX_Automaton *stack_tail;
+};
+
+
+/**
+ * Adds multi-strided transitions to the given 'dfa'.
+ *
+ * @param regex_ctx regex context needed to add transitions to the automaton.
+ * @param dfa DFA to which the multi strided transitions should be added.
+ * @param stride_len length of the strides.
+ */
+void
+GNUNET_REGEX_dfa_add_multi_strides (struct GNUNET_REGEX_Context *regex_ctx,
+ struct GNUNET_REGEX_Automaton *dfa,
+ const unsigned int stride_len);
+
+
/**
* Generate a (pseudo) random regular expression of length 'rx_length', as well
* as a (optional) string that will be matched by the generated regex. The
char *
GNUNET_REGEX_generate_random_string (size_t max_len);
+
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
projects / oweals / gnunet.git / blobdiff