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21 * @file include/gnunet_regex_lib.h
22 * @brief library to parse regular expressions into dfa
23 * @author Maximilian Szengel
27 #ifndef GNUNET_REGEX_LIB_H
28 #define GNUNET_REGEX_LIB_H
30 #include "gnunet_util_lib.h"
35 #if 0 /* keep Emacsens' auto-indent happy */
41 * Automaton (NFA/DFA) representation.
43 struct GNUNET_REGEX_Automaton;
46 * Edge representation.
48 struct GNUNET_REGEX_Edge
51 * Label of the edge. FIXME: might want to not consume exactly multiples of 8 bits, need length?
56 * Destionation of the edge.
58 struct GNUNET_HashCode destination;
62 * Construct an NFA by parsing the regex string of length 'len'.
64 * @param regex regular expression string.
65 * @param len length of the string.
67 * @return NFA, needs to be freed using GNUNET_REGEX_destroy_automaton.
69 struct GNUNET_REGEX_Automaton *
70 GNUNET_REGEX_construct_nfa (const char *regex, const size_t len);
73 * Construct DFA for the given 'regex' of length 'len'.
75 * @param regex regular expression string.
76 * @param len length of the regular expression.
78 * @return DFA, needs to be freed using GNUNET_REGEX_destroy_automaton.
80 struct GNUNET_REGEX_Automaton *
81 GNUNET_REGEX_construct_dfa (const char *regex, const size_t len);
84 * Free the memory allocated by constructing the GNUNET_REGEX_Automaton.
87 * @param a automaton to be destroyed.
90 GNUNET_REGEX_automaton_destroy (struct GNUNET_REGEX_Automaton *a);
93 * Save the given automaton as a GraphViz dot file.
95 * @param a the automaton to be saved.
96 * @param filename where to save the file.
99 GNUNET_REGEX_automaton_save_graph (struct GNUNET_REGEX_Automaton *a,
100 const char *filename);
103 * Evaluates the given 'string' against the given compiled regex.
105 * @param a automaton.
106 * @param string string to check.
108 * @return 0 if string matches, non 0 otherwise.
111 GNUNET_REGEX_eval (struct GNUNET_REGEX_Automaton *a,
115 * Get the canonical regex of the given automaton.
116 * When constructing the automaton a proof is computed for each state,
117 * consisting of the regular expression leading to this state. A complete
118 * regex for the automaton can be computed by combining these proofs.
119 * As of now this function is only useful for testing.
121 * @param a automaton for which the canonical regex should be returned.
126 GNUNET_REGEX_get_canonical_regex (struct GNUNET_REGEX_Automaton *a);
129 * Get the first key for the given 'input_string'. This hashes
130 * the first x bits of the 'input_strings'.
132 * @param input_string string.
133 * @param string_len length of the 'input_string'.
134 * @param key pointer to where to write the hash code.
136 * @return number of bits of 'input_string' that have been consumed
137 * to construct the key
139 unsigned int /* FIXME: size_t */
140 GNUNET_REGEX_get_first_key (const char *input_string, /* FIXME: size_t */ unsigned int string_len,
141 struct GNUNET_HashCode * key);
144 * Check if the given 'proof' matches the given 'key'.
146 * @param proof partial regex
149 * @return GNUNET_OK if the proof is valid for the given key
152 GNUNET_REGEX_check_proof (const char *proof,
153 const struct GNUNET_HashCode *key);
156 * Iterator callback function.
158 * @param cls closure.
159 * @param key hash for current state.
160 * @param proof proof for current state.
161 * @param accepting GNUNET_YES if this is an accepting state, GNUNET_NO if not.
162 * @param num_edges number of edges leaving current state.
163 * @param edges edges leaving current state.
165 typedef void (*GNUNET_REGEX_KeyIterator)(void *cls,
166 const struct GNUNET_HashCode *key,
169 unsigned int num_edges,
170 const struct GNUNET_REGEX_Edge *edges);
173 * Iterate over all edges starting from start state of automaton 'a'. Calling
174 * iterator for each edge.
176 * @param a automaton.
177 * @param iterator iterator called for each edge.
178 * @param iterator_cls closure.
181 GNUNET_REGEX_iterate_all_edges (struct GNUNET_REGEX_Automaton *a,
182 GNUNET_REGEX_KeyIterator iterator,
185 #if 0 /* keep Emacsens' auto-indent happy */
192 /* end of gnunet_regex_lib.h */