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/*
* Copyright (c) 2015, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/** \file
* \brief Bounded Repeat implementation for the LimEx NFA.
*/
#ifndef LIMEX_RING_H
#define LIMEX_RING_H
#include "ue2common.h"
#include "repeat.h"
#ifdef __cplusplus
extern "C"
{
#endif
/** \brief Return values from \ref processTugTrigger, used to provide feedback
* about a bounded repeat to the caller.
*
* TRIGGER_FAIL does not get cached as we prefer to use TRIGGER_STALE which
* allows the exception to squash the cyclic state as well. */
enum TriggerResult {
TRIGGER_FAIL, /**< no valid matches, but history still valid */
TRIGGER_SUCCESS, /**< valid match found */
TRIGGER_STALE, /**< no valid matches and history is invalid (stale) */
TRIGGER_SUCCESS_CACHE /**< valid match found; can cache as the repeat has no
upper bound. */
};
/** \brief Handle a TUG trigger: given an \p offset, returns whether a repeat
* matches or not. */
static really_inline
enum TriggerResult processTugTrigger(const struct RepeatInfo *info,
const union RepeatControl *ctrl,
const char *state, u64a offset) {
DEBUG_PRINTF("tug trigger, %s history, repeat={%u,%u}, offset=%llu, "
"ctrl=%p, state=%p\n",
repeatTypeName(info->type), info->repeatMin, info->repeatMax,
offset, ctrl, state);
assert(ISALIGNED(ctrl));
enum RepeatMatch rv = repeatHasMatch(info, ctrl, state, offset);
switch (rv) {
case REPEAT_NOMATCH:
return TRIGGER_FAIL;
case REPEAT_STALE:
return TRIGGER_STALE;
case REPEAT_MATCH:
if (info->repeatMax == REPEAT_INF) {
// {N,} repeats can be cached.
return TRIGGER_SUCCESS_CACHE;
} else {
return TRIGGER_SUCCESS;
}
}
assert(0); // unreachable
return TRIGGER_FAIL;
}
/** \brief Handle a POS trigger: stores a top in the repeat. */
static really_inline
void processPosTrigger(const struct RepeatInfo *info, union RepeatControl *ctrl,
char *state, u64a offset, char is_alive) {
DEBUG_PRINTF("pos trigger, %s history, repeat={%u,%u}, offset=%llu, "
"is_alive=%d\n", repeatTypeName(info->type),
info->repeatMin, info->repeatMax, offset, is_alive);
assert(ISALIGNED(ctrl));
repeatStore(info, ctrl, state, offset, is_alive);
}
#ifdef __cplusplus
}
#endif
#endif
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