#endif
#endif
+
+/**
+ * Constant for how many bytes the initial string regex should have.
+ */
+#define GNUNET_REGEX_INITIAL_BYTES 24
+
+
+/**
+ * Maximum regex string length for use with GNUNET_REGEX_ipv4toregex
+ */
+#define GNUNET_REGEX_IPV4_REGEXLEN 32 + 6
+
+
/**
- * NFA representation
+ * Maximum regex string length for use with GNUNET_REGEX_ipv6toregex
+ */
+#define GNUNET_REGEX_IPV6_REGEXLEN 128 + 6
+
+
+/**
+ * Automaton (NFA/DFA) representation.
*/
struct GNUNET_REGEX_Automaton;
+
/**
- * Construct an NFA by parsing the regex string of length 'len'.
+ * Edge representation.
+ */
+struct GNUNET_REGEX_Edge
+{
+ /**
+ * Label of the edge. FIXME: might want to not consume exactly multiples of 8 bits, need length?
+ */
+ const char *label;
+
+ /**
+ * Destionation of the edge.
+ */
+ struct GNUNET_HashCode destination;
+};
+
+
+/**
+ * Construct DFA for the given 'regex' of length 'len'.
*
- * @param regex regular expression string
- * @param len length of the string
+ * Path compression means, that for example a DFA o -> a -> b -> c -> o will be
+ * compressed to o -> abc -> o. Note that this parameter influences the
+ * non-determinism of states of the resulting NFA in the DHT (number of outgoing
+ * edges with the same label). For example for an application that stores IPv4
+ * addresses as bitstrings it could make sense to limit the path compression to
+ * 4 or 8.
*
- * @return NFA.Needs to be freed using GNUNET_REGEX_destroy_automaton
+ * @param regex regular expression string.
+ * @param len length of the regular expression.
+ * @param max_path_len limit the path compression length to the
+ * given value. If set to 1, no path compression is applied. Set to 0 for
+ * maximal possible path compression (generally not desireable).
+ * @return DFA, needs to be freed using GNUNET_REGEX_automaton_destroy.
*/
struct GNUNET_REGEX_Automaton *
-GNUNET_REGEX_construct_nfa(const char *regex, const size_t len);
+GNUNET_REGEX_construct_dfa (const char *regex, const size_t len,
+ int max_path_len);
+
/**
- * Construct DFA for the given 'regex' of lenght 'len'
+ * Free the memory allocated by constructing the GNUNET_REGEX_Automaton.
+ * data structure.
*
- * @param regex regular expression string
- * @param len length of the regular expression
+ * @param a automaton to be destroyed.
+ */
+void
+GNUNET_REGEX_automaton_destroy (struct GNUNET_REGEX_Automaton *a);
+
+
+/**
+ * Options for graph creation function
+ * GNUNET_REGEX_automaton_save_graph.
+ */
+enum GNUNET_REGEX_GraphSavingOptions
+{
+ /**
+ * Default. Do nothing special.
+ */
+ GNUNET_REGEX_GRAPH_DEFAULT = 0,
+
+ /**
+ * The generated graph will include extra information such as the NFA states
+ * that were used to generate the DFA state.
+ */
+ GNUNET_REGEX_GRAPH_VERBOSE = 1,
+
+ /**
+ * Enable graph coloring. Will color each SCC in a different color.
+ */
+ GNUNET_REGEX_GRAPH_COLORING = 2
+};
+
+
+/**
+ * Save the given automaton as a GraphViz dot file.
*
- * @return DFA. Needs to be freed using GNUNET_REGEX_destroy_automaton
+ * @param a the automaton to be saved.
+ * @param filename where to save the file.
+ * @param options options for graph generation that include coloring or verbose
+ * mode
*/
-struct GNUNET_REGEX_Automaton *
-GNUNET_REGEX_construct_dfa (const char *regex, const size_t len);
+void
+GNUNET_REGEX_automaton_save_graph (struct GNUNET_REGEX_Automaton *a,
+ const char *filename,
+ enum GNUNET_REGEX_GraphSavingOptions options);
+
/**
- * Free the memory allocated by constructing the GNUNET_REGEX_Automaton
- * data structure.
+ * Evaluates the given 'string' against the given compiled regex.
+ *
+ * @param a automaton.
+ * @param string string to check.
+ *
+ * @return 0 if string matches, non 0 otherwise.
+ */
+int
+GNUNET_REGEX_eval (struct GNUNET_REGEX_Automaton *a,
+ const char *string);
+
+
+/**
+ * Get the first key for the given 'input_string'. This hashes
+ * the first x bits of the 'input_string'.
+ *
+ * @param input_string string.
+ * @param string_len length of the 'input_string'.
+ * @param key pointer to where to write the hash code.
+ *
+ * @return number of bits of 'input_string' that have been consumed
+ * to construct the key
+ */
+size_t
+GNUNET_REGEX_get_first_key (const char *input_string, size_t string_len,
+ struct GNUNET_HashCode * key);
+
+
+/**
+ * Check if the given 'proof' matches the given 'key'.
+ *
+ * @param proof partial regex of a state.
+ * @param key hash of a state.
+ *
+ * @return GNUNET_OK if the proof is valid for the given key.
+ */
+int
+GNUNET_REGEX_check_proof (const char *proof,
+ const struct GNUNET_HashCode *key);
+
+
+/**
+ * Iterator callback function.
+ *
+ * @param cls closure.
+ * @param key hash for current state.
+ * @param proof proof for current state.
+ * @param accepting GNUNET_YES if this is an accepting state, GNUNET_NO if not.
+ * @param num_edges number of edges leaving current state.
+ * @param edges edges leaving current state.
+ */
+typedef void (*GNUNET_REGEX_KeyIterator)(void *cls,
+ const struct GNUNET_HashCode *key,
+ const char *proof,
+ int accepting,
+ unsigned int num_edges,
+ const struct GNUNET_REGEX_Edge *edges);
+
+
+/**
+ * Iterate over all edges starting from start state of automaton 'a'. Calling
+ * iterator for each edge.
*
- * @param a automaton to be destroyed
+ * @param a automaton.
+ * @param iterator iterator called for each edge.
+ * @param iterator_cls closure.
*/
void
-GNUNET_REGEX_automaton_destroy(struct GNUNET_REGEX_Automaton *a);
+GNUNET_REGEX_iterate_all_edges (struct GNUNET_REGEX_Automaton *a,
+ GNUNET_REGEX_KeyIterator iterator,
+ void *iterator_cls);
+
+
+/**
+ * Create a regex in 'rxstr' from the given 'ip' and 'netmask'.
+ *
+ * @param ip IPv4 representation.
+ * @param netmask netmask for the ip.
+ * @param rxstr generated regex, must be at least GNUNET_REGEX_IPV4_REGEXLEN
+ * bytes long.
+ */
+void
+GNUNET_REGEX_ipv4toregex (const struct in_addr *ip, const char *netmask,
+ char *rxstr);
+
/**
- * Save the given automaton as a GraphViz dot file
+ * Create a regex in 'rxstr' from the given 'ipv6' and 'prefixlen'.
*
- * @param a the automaton to be saved
- * @param filename where to save the file
+ * @param ipv6 IPv6 representation.
+ * @param prefixlen length of the ipv6 prefix.
+ * @param rxstr generated regex, must be at least GNUNET_REGEX_IPV6_REGEXLEN
+ * bytes long.
*/
void
-GNUNET_REGEX_automaton_save_graph(struct GNUNET_REGEX_Automaton *a,
- const char *filename);
+GNUNET_REGEX_ipv6toregex (const struct in6_addr *ipv6,
+ unsigned int prefixlen, char *rxstr);
+
#if 0 /* keep Emacsens' auto-indent happy */
{