/*
 * Copyright 2000-2012 JetBrains s.r.o.
 *
 * Licensed 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 com.intellij.util.text;

import org.jetbrains.annotations.NotNull;

import java.lang.reflect.Constructor;

public class StringFactory {
  private static final Constructor<String> sharingCtr;   // String(char[], boolean)
  private static final Constructor<String> oldSharingCtr; // String(int offset, int count, char value[]) in ancient java 1.6

  static {
    Constructor<String> newC = null;
    Constructor<String> oldC = null;
    try {
      newC = String.class.getDeclaredConstructor(char[].class, boolean.class);
      newC.setAccessible(true);
    }
    catch (NoSuchMethodException e) {
      try {
        oldC = String.class.getDeclaredConstructor(int.class, int.class, char[].class);
        oldC.setAccessible(true);
      }
      catch (NoSuchMethodException ignored) {

      }
    }
    sharingCtr = newC;
    oldSharingCtr = oldC;
  }

  @NotNull
  public static String createShared(@NotNull char[] chars) {
    try {
      if (sharingCtr != null) {
        return sharingCtr.newInstance(chars, true);
      }
      if (oldSharingCtr != null) {
        return oldSharingCtr.newInstance(0, chars.length, chars);
      }
      return new String(chars);
    }
    catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
}

@@ -795,16 +795,17 @@
 gCtr;   
+ 
 // Strin
@@ -826,133 +826,74 @@
 ean)
-%0A  private static final Constructor%3CString%3E oldSharingCtr; // String(int offset, int count, char value%5B%5D) in ancient java 1.6
+. Works since JDK1.7, earlier jdks have too slow reflection anyway
 %0A%0A  
@@ -942,45 +942,8 @@
 ll;%0A
-    Constructor%3CString%3E oldC = null;%0A
     
@@ -1098,25 +1098,31 @@
 ception 
-e
+ignored
 ) %7B%0A    
   try %7B%0A
@@ -1117,260 +1117,211 @@
     
-  try %7B%0A        oldC = String.class.getDeclaredConstructor(int.class, int.class, char%5B%5D.class);%0A        oldC.setAccessible(true);%0A      %7D%0A      catch (NoSuchMethodException ignored) %7B%0A%0A      %7D%0A    %7D%0A    sharingCtr = newC;%0A    oldSharingCtr = oldC;%0A  %7D%0A
+%7D%0A    sharingCtr = newC;%0A  %7D%0A%0A  /**%0A   * @return new instance of String which backed by chars array.%0A   *%0A   * CAUTION. EXTREMELY DANGEROUS.%0A   * DO NOT USE THIS METHOD UNLESS YOU ARE TOO DESPERATE%0A   */
 %0A  @
@@ -1389,28 +1389,16 @@
 hars) %7B%0A
-    try %7B%0A  
     if (
@@ -1411,32 +1411,44 @@
 gCtr != null) %7B%0A
+      try %7B%0A
         return s
@@ -1501,100 +1501,66 @@
     
-if (oldSharingCtr != null) %7B%0A        return oldSharingCtr.newInstance(0, chars.length, chars
+catch (Exception e) %7B%0A        throw new RuntimeException(e
 );%0A 
@@ -1564,24 +1564,28 @@
 ;%0A      %7D%0A  
+  %7D%0A
     return n
@@ -1606,83 +1606,8 @@
 s);%0A
-    %7D%0A    catch (Exception e) %7B%0A      throw new RuntimeException(e);%0A    %7D%0A
   %7D%0A

revert to new String for ancient JDKs (<1.7) since reflection there is too slow