- WiP

[oweals/gnunet.git] / src / regex / regex_internal.h

diff --git a/src/regex/regex_internal.h b/src/regex/regex_internal.h
index f96d51fb09b8207075b075d2869f701a49e4a9cc..3e4d0ca0ed0be9e19052d12b5fa52fa2359dddb3 100644 (file)
--- a/src/regex/regex_internal.h
+++ b/src/regex/regex_internal.h
@@ -120,7 +120,7 @@ struct GNUNET_REGEX_State
 
   /**
    * 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;
 
@@ -180,6 +180,11 @@ struct GNUNET_REGEX_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.
@@ -253,9 +258,31 @@ struct GNUNET_REGEX_Automaton
    * 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.
  *
@@ -275,16 +302,20 @@ typedef void (*GNUNET_REGEX_traverse_action) (void *cls,
  *
  * @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 (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,
@@ -294,12 +325,64 @@ GNUNET_REGEX_automaton_traverse (const struct GNUNET_REGEX_Automaton *a,
  *
  * @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