Nagram/TMessagesProj/jni/voip/webrtc/base/i18n/string_search.cc
2020-09-30 16:48:47 +03:00

112 lines
4.2 KiB
C++

// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdint.h>
#include "base/i18n/string_search.h"
#include "base/logging.h"
#include "third_party/icu/source/i18n/unicode/usearch.h"
namespace base {
namespace i18n {
FixedPatternStringSearch::FixedPatternStringSearch(const string16& find_this,
bool case_sensitive)
: find_this_(find_this) {
// usearch_open requires a valid string argument to be searched, even if we
// want to set it by usearch_setText afterwards. So, supplying a dummy text.
const string16& dummy = find_this_;
UErrorCode status = U_ZERO_ERROR;
search_ = usearch_open(find_this_.data(), find_this_.size(), dummy.data(),
dummy.size(), uloc_getDefault(),
nullptr, // breakiter
&status);
if (U_SUCCESS(status)) {
// http://icu-project.org/apiref/icu4c40/ucol_8h.html#6a967f36248b0a1bc7654f538ee8ba96
// Set comparison level to UCOL_PRIMARY to ignore secondary and tertiary
// differences. Set comparison level to UCOL_TERTIARY to include all
// comparison differences.
// Diacritical differences on the same base letter represent a
// secondary difference.
// Uppercase and lowercase versions of the same character represents a
// tertiary difference.
UCollator* collator = usearch_getCollator(search_);
ucol_setStrength(collator, case_sensitive ? UCOL_TERTIARY : UCOL_PRIMARY);
usearch_reset(search_);
}
}
FixedPatternStringSearch::~FixedPatternStringSearch() {
if (search_)
usearch_close(search_);
}
bool FixedPatternStringSearch::Search(const string16& in_this,
size_t* match_index,
size_t* match_length,
bool forward_search) {
UErrorCode status = U_ZERO_ERROR;
usearch_setText(search_, in_this.data(), in_this.size(), &status);
// Default to basic substring search if usearch fails. According to
// http://icu-project.org/apiref/icu4c/usearch_8h.html, usearch_open will fail
// if either |find_this| or |in_this| are empty. In either case basic
// substring search will give the correct return value.
if (!U_SUCCESS(status)) {
size_t index = in_this.find(find_this_);
if (index == string16::npos)
return false;
if (match_index)
*match_index = index;
if (match_length)
*match_length = find_this_.size();
return true;
}
int32_t index = forward_search ? usearch_first(search_, &status)
: usearch_last(search_, &status);
if (!U_SUCCESS(status) || index == USEARCH_DONE)
return false;
if (match_index)
*match_index = static_cast<size_t>(index);
if (match_length)
*match_length = static_cast<size_t>(usearch_getMatchedLength(search_));
return true;
}
FixedPatternStringSearchIgnoringCaseAndAccents::
FixedPatternStringSearchIgnoringCaseAndAccents(const string16& find_this)
: base_search_(find_this, /*case_sensitive=*/false) {}
bool FixedPatternStringSearchIgnoringCaseAndAccents::Search(
const string16& in_this,
size_t* match_index,
size_t* match_length) {
return base_search_.Search(in_this, match_index, match_length,
/*forward_search=*/true);
}
bool StringSearchIgnoringCaseAndAccents(const string16& find_this,
const string16& in_this,
size_t* match_index,
size_t* match_length) {
return FixedPatternStringSearchIgnoringCaseAndAccents(find_this).Search(
in_this, match_index, match_length);
}
bool StringSearch(const string16& find_this,
const string16& in_this,
size_t* match_index,
size_t* match_length,
bool case_sensitive,
bool forward_search) {
return FixedPatternStringSearch(find_this, case_sensitive)
.Search(in_this, match_index, match_length, forward_search);
}
} // namespace i18n
} // namespace base