*/
struct Transition *transitions_tail;
- /**
- * Number of incoming transitions.
- */
- unsigned int incoming_transition_count;
-
- /**
- * Set of incoming transitions.
- */
- struct Transition **incoming_transitions;
-
/**
* Set of states on which this state is based on. Used when creating a DFA out
* of several NFA states.
* State from which this transition origins.
*/
struct GNUNET_REGEX_State *from_state;
+
+ /**
+ * Mark this transition. For example when reversing the automaton.
+ */
+ int mark;
};
/**
return (*s1)->id - (*s2)->id;
}
-/**
- * Create a proof for the given state. Intended to be used as a parameter for
- * automaton_traverse() function.
- *
- * @param cls closure
- * @param s state
- */
-void
-state_create_proof (void *cls, struct GNUNET_REGEX_State *s)
-{
- struct Transition *inc_t;
- int i;
- char *proof = NULL;
- char *stars = NULL;
- char *tmp = NULL;
-
- for (i = 0; i < s->incoming_transition_count; i++)
- {
- inc_t = s->incoming_transitions[i];
-
- if (NULL == inc_t)
- continue;
-
- GNUNET_assert (inc_t->label != 0 && inc_t->from_state != NULL);
-
- if (inc_t->from_state == inc_t->to_state)
- GNUNET_asprintf (&stars, "%c*", inc_t->label);
- else
- {
- if (NULL != inc_t->from_state->proof)
- GNUNET_asprintf (&tmp, "%s%c", inc_t->from_state->proof, inc_t->label);
- else
- GNUNET_asprintf (&tmp, "%c", inc_t->label);
- }
-
- if (i > 0 && NULL != tmp && NULL != proof)
- GNUNET_asprintf (&proof, "%s|%s", proof, tmp);
- else if (NULL != tmp)
- proof = GNUNET_strdup (tmp);
-
- if (NULL != tmp)
- {
- GNUNET_free (tmp);
- tmp = NULL;
- }
- }
-
- if (NULL != s->proof)
- GNUNET_free (s->proof);
-
- if (s->incoming_transition_count > 1)
- {
- if (NULL != stars)
- {
- GNUNET_asprintf (&s->proof, "(%s)%s", proof, stars);
- GNUNET_free (stars);
- }
- else if (NULL != proof)
- GNUNET_asprintf (&s->proof, "(%s)", proof);
-
- if (NULL != proof)
- GNUNET_free (proof);
- }
- else
- s->proof = proof;
-}
-
/**
* Get all edges leaving state 's'.
*
if (NULL != s->name)
GNUNET_free (s->name);
+ if (NULL != s->proof)
+ GNUNET_free (s->proof);
+
for (t = s->transitions_head; NULL != t; t = next_t)
{
next_t = t->next;
GNUNET_free (t);
}
- if (s->incoming_transition_count > 0 && NULL != s->incoming_transitions)
- {
- GNUNET_free (s->incoming_transitions);
- }
-
state_set_clear (s->nfa_set);
GNUNET_free (s);
struct GNUNET_REGEX_State *s_check;
struct Transition *t_check;
char *new_name;
- int i;
- struct Transition *inc_t;
GNUNET_assert (NULL != ctx && NULL != a && NULL != s1 && NULL != s2);
}
}
- // 2. Remove all transitions coming from s2
- for (s_check = a->states_head; NULL != s_check; s_check = s_check->next)
- {
- for (i = 0; i < s_check->incoming_transition_count; i++)
- {
- inc_t = s_check->incoming_transitions[i];
-
- if (inc_t != 0 && inc_t->from_state == s2)
- {
- s_check->incoming_transitions[i] = NULL;
- }
- }
- }
-
- // 3. Add all transitions from s2 to sX to s1
+ // 2. Add all transitions from s2 to sX to s1
for (t_check = s2->transitions_head; NULL != t_check; t_check = t_check->next)
{
if (t_check->to_state != s1)
state_add_transition (ctx, s1, t_check->label, t_check->to_state);
}
- // 4. Rename s1 to {s1,s2}
+ // 3. Rename s1 to {s1,s2}
new_name = GNUNET_strdup (s1->name);
if (NULL != s1->name)
{
GNUNET_REGEX_traverse_action action)
{
struct Transition *t;
- int i;
if (GNUNET_NO == s->marked)
{
s->marked = GNUNET_YES;
- // First make sure all incoming states have been traversed
- for (i = 0; i < s->incoming_transition_count; i++)
- {
- if (NULL != s->incoming_transitions[i])
- automaton_state_traverse (cls, s->incoming_transitions[i]->from_state,
- action);
- }
-
if (action > 0)
action (cls, s);
automaton_state_traverse (cls, a->start, action);
}
+/**
+ * Reverses all transitions of the given automaton.
+ *
+ * @param a automaton.
+ */
+static void
+automaton_reverse (struct GNUNET_REGEX_Automaton *a)
+{
+ struct GNUNET_REGEX_State *s;
+ struct Transition *t;
+ struct Transition *t_next;
+ struct GNUNET_REGEX_State *s_swp;
+
+ for (s = a->states_head; NULL != s; s = s->next)
+ for (t = s->transitions_head; NULL != t; t = t->next)
+ t->mark = GNUNET_NO;
+
+ for (s = a->states_head; NULL != s; s = s->next)
+ {
+ for (t = s->transitions_head; NULL != t; t = t_next)
+ {
+ t_next = t->next;
+
+ if (GNUNET_YES == t->mark || t->from_state == t->to_state)
+ continue;
+
+ t->mark = GNUNET_YES;
+
+ GNUNET_CONTAINER_DLL_remove (t->from_state->transitions_head,
+ t->from_state->transitions_tail, t);
+ t->from_state->transition_count--;
+ GNUNET_CONTAINER_DLL_insert (t->to_state->transitions_head,
+ t->to_state->transitions_tail, t);
+ t->to_state->transition_count++;
+
+ s_swp = t->from_state;
+ t->from_state = t->to_state;
+ t->to_state = s_swp;
+ }
+ }
+}
+
+/**
+ * Create proof for the given state.
+ *
+ * @param cls closure.
+ * @param s state.
+ */
+static void
+automaton_create_proofs_step (void *cls, struct GNUNET_REGEX_State *s)
+{
+ struct Transition *t;
+ int i;
+ char *tmp;
+
+ for (i = 0, t = s->transitions_head; NULL != t; t = t->next, i++)
+ {
+ if (t->to_state == s)
+ GNUNET_asprintf (&tmp, "%c*", t->label);
+ else if (i != s->transition_count - 1)
+ GNUNET_asprintf (&tmp, "%c|", t->label);
+ else
+ GNUNET_asprintf (&tmp, "%c", t->label);
+
+ if (NULL != s->proof)
+ s->proof =
+ GNUNET_realloc (s->proof, strlen (s->proof) + strlen (tmp) + 1);
+ else
+ s->proof = GNUNET_malloc (strlen (tmp) + 1);
+ strcat (s->proof, tmp);
+ GNUNET_free (tmp);
+ }
+}
+
+/**
+ * Create proofs for all states in the given automaton.
+ *
+ * @param a automaton.
+ */
+static void
+automaton_create_proofs (struct GNUNET_REGEX_Automaton *a)
+{
+ struct GNUNET_REGEX_State *s;
+
+ automaton_reverse (a);
+
+ for (s = a->states_head; NULL != s; s = s->next)
+ automaton_create_proofs_step (NULL, s);
+
+ automaton_reverse (a);
+}
+
/**
* Creates a new DFA state based on a set of NFA states. Needs to be freed using
* automaton_destroy_state.
if (NULL == state_contains)
{
automaton_add_state (dfa, new_dfa_state);
- construct_dfa_states (ctx, nfa, dfa, new_dfa_state);
ctran->to_state = new_dfa_state;
+ construct_dfa_states (ctx, nfa, dfa, new_dfa_state);
}
else
{
ctran->to_state = state_contains;
automaton_destroy_state (new_dfa_state);
}
-
- GNUNET_array_append (ctran->to_state->incoming_transitions,
- ctran->to_state->incoming_transition_count, ctran);
}
}
scc_tarjan (&ctx, dfa);
// Create proofs for all states
- automaton_traverse (NULL, dfa, &state_create_proof);
+ automaton_create_proofs (dfa);
return dfa;
}
projects / oweals / gnunet.git / commitdiff