1 files changed, 180 insertions, 0 deletions
diff --git a/src/include/gnunet_regex_lib.h b/src/include/gnunet_regex_lib.h
new file mode 100644
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+++ b/src/include/gnunet_regex_lib.h
@@ -0,0 +1,180 @@
+/*
+     This file is part of GNUnet
+     (C) 2012 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file include/gnunet_regex_lib.h
+ * @brief library to parse regular expressions into dfa
+ * @author Maximilian Szengel
+ *
+ */
+
+#ifndef GNUNET_REGEX_LIB_H
+#define GNUNET_REGEX_LIB_H
+
+#include "gnunet_util_lib.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#if 0                           /* keep Emacsens' auto-indent happy */
+}
+#endif
+#endif
+
+/**
+ * Automaton (NFA/DFA) representation.
+ */
+struct GNUNET_REGEX_Automaton;
+
+/**
+ * Edge representation.
+ */
+struct GNUNET_REGEX_Edge
+{
+  /**
+   * Label of the edge.
+   */
+  const char *label;
+
+  /**
+   * Destionation of the edge.
+   */
+  GNUNET_HashCode destination;
+};
+
+/**
+ * Construct an NFA by parsing the regex string of length 'len'.
+ *
+ * @param regex regular expression string.
+ * @param len length of the string.
+ *
+ * @return NFA, needs to be freed using GNUNET_REGEX_destroy_automaton.
+ */
+struct GNUNET_REGEX_Automaton *
+GNUNET_REGEX_construct_nfa (const char *regex, const size_t len);
+
+/**
+ * Construct DFA for the given 'regex' of length 'len'.
+ *
+ * @param regex regular expression string.
+ * @param len length of the regular expression.
+ *
+ * @return DFA, needs to be freed using GNUNET_REGEX_destroy_automaton.
+ */
+struct GNUNET_REGEX_Automaton *
+GNUNET_REGEX_construct_dfa (const char *regex, const size_t len);
+
+/**
+ * Free the memory allocated by constructing the GNUNET_REGEX_Automaton.
+ * data structure.
+ *
+ * @param a automaton to be destroyed.
+ */
+void
+GNUNET_REGEX_automaton_destroy (struct GNUNET_REGEX_Automaton *a);
+
+/**
+ * Save the given automaton as a GraphViz dot file.
+ *
+ * @param a the automaton to be saved.
+ * @param filename where to save the file.
+ */
+void
+GNUNET_REGEX_automaton_save_graph (struct GNUNET_REGEX_Automaton *a,
+                                   const char *filename);
+
+/**
+ * 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_strings'.
+ *
+ * @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
+ */
+unsigned int
+GNUNET_REGEX_get_first_key (const char *input_string, unsigned int string_len,
+                            GNUNET_HashCode * key);
+
+/**
+ * Check if the given 'proof' matches the given 'key'.
+ *
+ * @param proof partial regex
+ * @param key hash
+ *
+ * @return GNUNET_OK if the proof is valid for the given key
+ */
+int
+GNUNET_REGEX_check_proof (const char *proof,
+                          const 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 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.
+ * @param iterator iterator called for each edge.
+ * @param iterator_cls closure.
+ */
+void
+GNUNET_REGEX_iterate_all_edges (struct GNUNET_REGEX_Automaton *a,
+                                GNUNET_REGEX_KeyIterator iterator,
+                                void *iterator_cls);
+
+#if 0                           /* keep Emacsens' auto-indent happy */
+{
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+/* end of gnunet_regex_lib.h */
+#endif
+