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author | Devtools Arcadia <arcadia-devtools@yandex-team.ru> | 2022-02-07 18:08:42 +0300 |
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committer | Devtools Arcadia <arcadia-devtools@mous.vla.yp-c.yandex.net> | 2022-02-07 18:08:42 +0300 |
commit | 1110808a9d39d4b808aef724c861a2e1a38d2a69 (patch) | |
tree | e26c9fed0de5d9873cce7e00bc214573dc2195b7 /contrib/libs/hyperscan/src/nfagraph/ng_sep.cpp | |
download | ydb-1110808a9d39d4b808aef724c861a2e1a38d2a69.tar.gz |
intermediate changes
ref:cde9a383711a11544ce7e107a78147fb96cc4029
Diffstat (limited to 'contrib/libs/hyperscan/src/nfagraph/ng_sep.cpp')
-rw-r--r-- | contrib/libs/hyperscan/src/nfagraph/ng_sep.cpp | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/contrib/libs/hyperscan/src/nfagraph/ng_sep.cpp b/contrib/libs/hyperscan/src/nfagraph/ng_sep.cpp new file mode 100644 index 0000000000..86528b4a00 --- /dev/null +++ b/contrib/libs/hyperscan/src/nfagraph/ng_sep.cpp @@ -0,0 +1,93 @@ +/* + * 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 Short Exhaustible Passthroughs. + * + * Analysis code for determining whether a graph should be treated specially + * because it is short and contains exhaustible reports; typically we turn + * these into outfixes rather than risk them becoming Rose literals. + * + * For example, the pattern: + * + * /[a-f]/H + * + * ... is far better suited to becoming a small outfix that generates one match + * and goes dead than being split into six one-byte Rose literals that end up + * in the literal matcher. + */ +#include "ng_sep.h" + +#include "grey.h" +#include "ng_holder.h" +#include "ng_reports.h" +#include "ng_util.h" +#include "ue2common.h" +#include "util/graph_range.h" + +using namespace std; + +namespace ue2 { + +static +bool checkFromVertex(const NGHolder &g, NFAVertex start) { + for (auto v : adjacent_vertices_range(start, g)) { + if (v == g.startDs) { + continue; + } + + assert(!is_special(v, g)); /* should not be vacuous */ + + if (!edge(g.startDs, v, g).second) { /* only floating starts */ + return false; + } else if (out_degree(v, g) == 1 + && edge(v, g.accept, g).second) { /* only floating end */ + ; /* possible sep */ + } else { + return false; + } + } + return true; +} + +bool isSEP(const NGHolder &g, const ReportManager &rm, const Grey &grey) { + if (!grey.mergeSEP || !can_exhaust(g, rm)) { + return false; + } + + if (!checkFromVertex(g, g.start) || !checkFromVertex(g, g.startDs)) { + return false; + } + + assert(out_degree(g.start, g) || proper_out_degree(g.startDs, g)); + + DEBUG_PRINTF("graph is an SEP\n"); + return true; +} + +} // namespace ue2 |