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/*
* Copyright (c) 2015-2019, 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 Hamster Wheel Literal Matcher: literal representation at build time.
*/
#include "hwlm_literal.h"
#include "util/bitutils.h" // for CASE_BIT
#include "util/compare.h" // for ourisalpha
#include "util/ue2string.h" // for escapeString
#include <algorithm>
#include <iomanip>
#include <sstream>
using namespace std;
namespace ue2 {
#ifdef DEBUG
static UNUSED
std::string dumpMask(const vector<u8> &v) {
ostringstream oss;
vector<u8>::const_iterator it, ite;
for (it = v.begin(), ite = v.end(); it != ite; ++it) {
oss << setfill('0') << setw(2) << hex << (unsigned int)*it;
}
return oss.str();
}
#endif
bool maskIsConsistent(const std::string &s, bool nocase, const vector<u8> &msk,
const vector<u8> &cmp) {
string::const_reverse_iterator si = s.rbegin();
vector<u8>::const_reverse_iterator mi = msk.rbegin(), ci = cmp.rbegin();
for (; si != s.rend() && mi != msk.rend(); ++si, ++mi, ++ci) {
u8 c = *si, m = *mi, v = *ci;
if (nocase && ourisalpha(c)) {
m &= ~CASE_BIT;
v &= ~CASE_BIT;
}
assert(ci != cmp.rend());
if ((c & m) != v) {
DEBUG_PRINTF("c = %02hhx; *ci = %02hhx m =%02hhx\n", c, *ci, m);
DEBUG_PRINTF("s = %s; dist = %zd\n", s.c_str(), si - s.rbegin());
return false;
}
}
return true;
}
/** \brief Complete constructor, takes group information and msk/cmp.
*
* This constructor takes a msk/cmp pair. Both must be vectors of length <=
* \ref HWLM_MASKLEN. */
hwlmLiteral::hwlmLiteral(const std::string &s_in, bool nocase_in,
bool noruns_in, u32 id_in, hwlm_group_t groups_in,
const vector<u8> &msk_in, const vector<u8> &cmp_in)
: s(s_in), id(id_in), nocase(nocase_in), noruns(noruns_in),
groups(groups_in), msk(msk_in), cmp(cmp_in) {
assert(s.size() <= HWLM_LITERAL_MAX_LEN);
assert(msk.size() <= HWLM_MASKLEN);
assert(msk.size() == cmp.size());
// If we've been handled a nocase literal, all letter characters must be
// upper-case.
if (nocase) {
upperString(s);
}
DEBUG_PRINTF("literal '%s'%s, msk=%s, cmp=%s\n", escapeString(s).c_str(),
nocase ? " (nocase)" : "", dumpMask(msk).c_str(),
dumpMask(cmp).c_str());
// Mask and compare vectors MUST be the same size.
assert(msk.size() == cmp.size());
// We must have been passed a msk/cmp that can be applied to s.
assert(maskIsConsistent(s, nocase, msk, cmp));
// In the name of good hygiene, zap msk/cmp if msk is all zeroes.
if (all_of(begin(msk), end(msk), [](u8 val) { return val == 0; })) {
msk.clear();
cmp.clear();
}
}
} // namespace ue2
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