/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.commons.codec.language.bm;
  
  import org.junit.Test;
  
  public class CacheSubSequencePerformanceTest {
  
      @Test
      public void test() {
          final int times = 10000000;
          System.out.print("Test with String : ");
          test("Angelo", times);
          System.out.print("Test with StringBuilder : ");
          test(new StringBuilder("Angelo"), times);
          System.out.print("Test with cached String : ");
          test(cacheSubSequence("Angelo"), times);
          System.out.print("Test with cached StringBuilder : ");
          test(cacheSubSequence(new StringBuilder("Angelo")), times);
      }
  
      private void test(final CharSequence input, final int times) {
          final long beginTime = System.currentTimeMillis();
          for (int i = 0; i < times; i++) {
              test(input);
          }
          System.out.println(System.currentTimeMillis() - beginTime + " millis");
      }
  
      private void test(final CharSequence input) {
          for (int i = 0; i < input.length(); i++) {
              for (int j = i; j <= input.length(); j++) {
                  input.subSequence(i, j);
              }
          }
      }
  
      private CharSequence cacheSubSequence(final CharSequence cached) {
          final CharSequence[][] cache = new CharSequence[cached.length()][cached.length()];
          return new CharSequence() {
              @Override
              public char charAt(final int index) {
                  return cached.charAt(index);
              }
  
              @Override
              public int length() {
                  return cached.length();
              }
  
              @Override
              public CharSequence subSequence(final int start, final int end) {
                  if (start == end) {
                      return "";
                  }
                  CharSequence res = cache[start][end - 1];
                  if (res == null) {
                      res = cached.subSequence(start, end);
                      cache[start][end - 1] = res;
                  }
                  return res;
              }
          };
      }
  }