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/*
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.
*/
struct 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 computed regex of the given automaton.
* When constructing the automaton a proof is computed for each state,
* consisting of the regular expression leading to this state. A complete
* regex for the automaton can be computed by combining these proofs.
* As of now this computed regex is only useful for testing.
*/
const char *
GNUNET_REGEX_get_computed_regex (struct GNUNET_REGEX_Automaton *a);
/**
* 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,
struct 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 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.
* @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
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