/*

 * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "utilities/debug.hpp"

#include "utilities/stringUtils.hpp"

int StringUtils::replace_no_expand(char* string, const char* from, const char* to) {

  int replace_count = 0;

  size_t from_len = strlen(from);

  size_t to_len = strlen(to);

  assert(from_len >= to_len, "must not expand input");

  for (char* dst = string; *dst && (dst = strstr(dst, from)) != NULL;) {

    char* left_over = dst + from_len;

    memmove(dst, to, to_len);                       // does not copy trailing 0 of <to>

    dst += to_len;                                  // skip over the replacement.

    memmove(dst, left_over, strlen(left_over) + 1); // copies the trailing 0 of <left_over>

    ++ replace_count;

  }

  return replace_count;

}

double StringUtils::similarity(const char* str1, size_t len1, const char* str2, size_t len2) {

  assert(str1 != NULL && str2 != NULL, "sanity");

  // filter out zero-length strings else we will underflow on len-1 below

  if (len1 == 0 || len2 == 0) {

    return 0.0;

  }

  size_t total = len1 + len2;

  size_t hit = 0;

  for (size_t i = 0; i < len1 - 1; i++) {

    for (size_t j = 0; j < len2 - 1; j++) {

      if ((str1[i] == str2[j]) && (str1[i+1] == str2[j+1])) {

        ++hit;

        break;

      }

    }

  }

  return 2.0 * (double) hit / (double) total;

}