1 | /* |
2 | * Copyright (c) 2015-2018, Intel Corporation |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions are met: |
6 | * |
7 | * * Redistributions of source code must retain the above copyright notice, |
8 | * this list of conditions and the following disclaimer. |
9 | * * Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * * Neither the name of Intel Corporation nor the names of its contributors |
13 | * may be used to endorse or promote products derived from this software |
14 | * without specific prior written permission. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
17 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
20 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
28 | |
29 | /** \file |
30 | * \brief Stop Alphabet calculation. |
31 | */ |
32 | |
33 | #ifndef NG_STOP_H |
34 | #define NG_STOP_H |
35 | |
36 | #include "ue2common.h" |
37 | #include "som/som.h" |
38 | |
39 | #include <vector> |
40 | |
41 | namespace ue2 { |
42 | |
43 | struct CastleProto; |
44 | class CharReach; |
45 | class NGHolder; |
46 | |
47 | /** Find the set of characters that are not present in the reachability of |
48 | * graph \p g after a certain depth (currently 8). If a character in this set |
49 | * is encountered, it means that the NFA is either dead or has not progressed |
50 | * more than 8 characters from its start states. |
51 | * |
52 | * This is only used to guide merging heuristics, use |
53 | * findLeftOffsetStopAlphabet for real uses. |
54 | */ |
55 | CharReach findStopAlphabet(const NGHolder &g, som_type som); |
56 | |
57 | /** Calculate the stop alphabet for each depth from 0 to MAX_STOP_DEPTH. Then |
58 | * build an eight-bit mask per character C, with each bit representing the |
59 | * depth before the location of character C (if encountered) that the NFA would |
60 | * be in a predictable start state. */ |
61 | std::vector<u8> findLeftOffsetStopAlphabet(const NGHolder &g, som_type som); |
62 | std::vector<u8> findLeftOffsetStopAlphabet(const CastleProto &c, som_type som); |
63 | |
64 | } // namespace ue2 |
65 | |
66 | #endif |
67 | |