stringfilter.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "stdafx.h"
#include "string_func.h"
#include "strings_func.h"
#include "stringfilter_type.h"
#include "gfx_func.h"
 
#include "safeguards.h"
 
static const char32_t STATE_WHITESPACE = ' ';
static const char32_t STATE_WORD = 'w';
static const char32_t STATE_QUOTE1 = '\'';
static const char32_t STATE_QUOTE2 = '"';
 
void StringFilter::SetFilterTerm(std::string_view str)
{
  this->word_index.clear();
  this->word_index.shrink_to_fit();
  this->word_matches = 0;
 
  char32_t state = STATE_WHITESPACE;
  auto pos = str.begin();
  auto word_begin = str.end();
  auto word_end = pos;
 
  /* Helper to prevent duplicating code. */
  auto add_word = [&] () {
    if (word_begin != str.end()) {
      this->word_index.emplace_back(std::string(word_begin, word_end + 1), false);
      word_begin = str.end();
    }
  };
 
  for (size_t len; pos < str.end(); pos += len) {
    char32_t c;
    len = Utf8Decode(&c, pos);
 
    if (state == STATE_WORD && IsWhitespace(c)) {
      /* Finish word */
      add_word();
      state = STATE_WHITESPACE;
      continue;
    }
 
    if (state == STATE_WHITESPACE) {
      /* Skip whitespace */
      if (IsWhitespace(c)) continue;
      state = STATE_WORD;
    }
 
    if (c == STATE_QUOTE1 || c == STATE_QUOTE2) {
      if (state == c) {
        /* Stop quoting */
        state = STATE_WORD;
        continue;
      } else if (state == STATE_WORD) {
        /* Start quoting */
        state = c;
        continue;
      }
    }
 
    /* Add to word */
    if (word_begin == str.end()) {
      word_begin = pos;
    }
    word_end = pos;
  }
 
  /* Add the last word of the string. */
  add_word();
}
 
void StringFilter::ResetState()
{
  this->word_matches = 0;
  for (WordState &ws : this->word_index) {
    ws.match = false;
  }
}
 
void StringFilter::AddLine(const char *str)
{
  if (str == nullptr) return;
 
  bool match_case = this->case_sensitive != nullptr && *this->case_sensitive;
  for (WordState &ws : this->word_index) {
    if (!ws.match) {
      if (this->locale_aware) {
        if (match_case ? StrNaturalContains(str, ws.word) : StrNaturalContainsIgnoreCase(str, ws.word)) {
          ws.match = true;
          this->word_matches++;
        }
      } else {
        if ((match_case ? strstr(str, ws.word.c_str()) : strcasestr(str, ws.word.c_str())) != nullptr) {
          ws.match = true;
          this->word_matches++;
        }
      }
    }
  }
}