/*
    * 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.myfaces.shared.util;
  
  import java.io.IOException;
  import java.io.Writer;
  
  /**
   * StringWriter cannot be reused without create a new object over and over.
   * This class provide a simple implementation that allows reuse the same buffer
   * in a efficient way.
   *
   * @author Jacob Hookom
   */
  public final class FastWriter extends Writer
  {
  
      private char[] buff;
      private int size;
  
      public FastWriter()
      {
          this(1024);
      }
  
      public FastWriter(int initialSize)
      {
          if (initialSize < 0)
          {
              throw new IllegalArgumentException("Initial Size cannot be less than 0");
          }
          this.buff = new char[initialSize];
      }
  
      public void close() throws IOException
      {
          // do nothing
      }
  
      public void flush() throws IOException
      {
          // do nothing
      }
  
      private final void overflow(int len)
      {
          if (this.size + len > this.buff.length)
          {
              char[] next = new char[(this.size + len) * 2];
              System.arraycopy(this.buff, 0, next, 0, this.size);
              this.buff = next;
          }
      }
  
      public void write(char[] cbuf, int off, int len) throws IOException
      {
          overflow(len);
          System.arraycopy(cbuf, off, this.buff, this.size, len);
          this.size += len;
      }
  
      public void write(char[] cbuf) throws IOException
      {
          this.write(cbuf, 0, cbuf.length);
      }
  
      public void write(int c) throws IOException
      {
          this.overflow(1);
          this.buff[this.size] = (char) c;
          this.size++;
      }
  
      public void write(String str, int off, int len) throws IOException
      {
          overflow(len);
          str.getChars(off, off+len, this.buff, size);
          this.size += len;
      }
  
      public void write(String str) throws IOException
      {
          this.write(str, 0, str.length());
     }
 
     public void reset()
     {
         this.size = 0;
     }
 
     public String toString()
     {
         return new String(this.buff, 0, this.size);
     }
 }