package api;

 import java.io.IOException;

 /**

  *

  * @author Jaroslav Tulach

  */

 final class SimpleBuffer implements Writer.ImplSeq {

     private final Writer out;

     private final StringBuffer sb = new StringBuffer();

     public SimpleBuffer(Writer out) {

         this.out = out;

     }

     public void close() throws IOException {

         flush();

         out.close();

     }

     public void flush() throws IOException {

         if (sb.length() > 0) {

             out.write(sb.toString());

             sb.setLength(0);

             out.flush();

         }

     }

     public void write(CharSequence seq) throws IOException {

         if (shouldBufferAsTheSequenceIsNotTooBig(seq)) {

             sb.append(seq);

         } else {

             flush();

             out.append(seq);

         }

     }

     /** At the end the purpose of BufferedWriter is to buffer writes, this

      * method is here to decide when it is OK to prefer buffering and when 

      * it is better to delegate directly into the underlaying stream.

      * 

      * @param csq the seqence to evaluate

      * @return true if buffering from super class should be used

      */

     private static boolean shouldBufferAsTheSequenceIsNotTooBig(CharSequence csq) {

         if (csq == null) {

             return false;

         }

         // as buffers are usually bigger than 1024, it makes sense to 

         // pay the penalty of converting the sequence to string, but buffering

         // the write

         if (csq.length() < 1024) {

             return true;

         } else {

             // otherwise, just directly write down the char sequence

             return false;

         }

     }

 }