1 | /* |
2 | * Copyright (c) 2015, 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 Bounded Repeat implementation for the LimEx NFA. |
31 | */ |
32 | |
33 | #ifndef LIMEX_RING_H |
34 | #define LIMEX_RING_H |
35 | |
36 | #include "ue2common.h" |
37 | #include "repeat.h" |
38 | |
39 | #ifdef __cplusplus |
40 | extern "C" |
41 | { |
42 | #endif |
43 | |
44 | /** \brief Return values from \ref processTugTrigger, used to provide feedback |
45 | * about a bounded repeat to the caller. |
46 | * |
47 | * TRIGGER_FAIL does not get cached as we prefer to use TRIGGER_STALE which |
48 | * allows the exception to squash the cyclic state as well. */ |
49 | enum TriggerResult { |
50 | TRIGGER_FAIL, /**< no valid matches, but history still valid */ |
51 | TRIGGER_SUCCESS, /**< valid match found */ |
52 | TRIGGER_STALE, /**< no valid matches and history is invalid (stale) */ |
53 | TRIGGER_SUCCESS_CACHE /**< valid match found; can cache as the repeat has no |
54 | upper bound. */ |
55 | }; |
56 | |
57 | /** \brief Handle a TUG trigger: given an \p offset, returns whether a repeat |
58 | * matches or not. */ |
59 | static really_inline |
60 | enum TriggerResult processTugTrigger(const struct RepeatInfo *info, |
61 | const union RepeatControl *ctrl, |
62 | const char *state, u64a offset) { |
63 | DEBUG_PRINTF("tug trigger, %s history, repeat={%u,%u}, offset=%llu, " |
64 | "ctrl=%p, state=%p\n" , |
65 | repeatTypeName(info->type), info->repeatMin, info->repeatMax, |
66 | offset, ctrl, state); |
67 | |
68 | assert(ISALIGNED(ctrl)); |
69 | |
70 | enum RepeatMatch rv = repeatHasMatch(info, ctrl, state, offset); |
71 | switch (rv) { |
72 | case REPEAT_NOMATCH: |
73 | return TRIGGER_FAIL; |
74 | case REPEAT_STALE: |
75 | return TRIGGER_STALE; |
76 | case REPEAT_MATCH: |
77 | if (info->repeatMax == REPEAT_INF) { |
78 | // {N,} repeats can be cached. |
79 | return TRIGGER_SUCCESS_CACHE; |
80 | } else { |
81 | return TRIGGER_SUCCESS; |
82 | } |
83 | } |
84 | |
85 | assert(0); // unreachable |
86 | return TRIGGER_FAIL; |
87 | } |
88 | |
89 | /** \brief Handle a POS trigger: stores a top in the repeat. */ |
90 | static really_inline |
91 | void processPosTrigger(const struct RepeatInfo *info, union RepeatControl *ctrl, |
92 | char *state, u64a offset, char is_alive) { |
93 | DEBUG_PRINTF("pos trigger, %s history, repeat={%u,%u}, offset=%llu, " |
94 | "is_alive=%d\n" , repeatTypeName(info->type), |
95 | info->repeatMin, info->repeatMax, offset, is_alive); |
96 | |
97 | assert(ISALIGNED(ctrl)); |
98 | |
99 | repeatStore(info, ctrl, state, offset, is_alive); |
100 | } |
101 | |
102 | #ifdef __cplusplus |
103 | } |
104 | #endif |
105 | |
106 | #endif |
107 | |