[Design] Buffer design

1. Used multiple chunk to compose a buffer.
   ie:
   public static class Chunk
   {
       public byte[]  mArray;
       public int     mLength;
   
       public Chunk(int length)
       {
           mArray = new byte[length];
           mLength = 0;
       }
   }
   
   class ByteArrayBuilder
   {
       private LinkedList mChunks;
   
       public ByteArrayBuilder()
       {
           mChunks = new LinkedList();
       }
   
       public synchronized void append(byte[] array, int offset, int length)
       {
           while (length > 0)
           {
               Chunk c = null;
               if (mChunks.isEmpty())
               {
                   c = new Chunk(length);
                   mChunks.addLast(c);
               }
               else
               {
                   c = mChunks.getLast();
                   if (c.mLength == c.mArray.length)
                   {
                       c = new Chunk(length);
                       mChunks.addLast(c);
                   }
               }
   
               int amount = Math.min(length, c.mArray.length - c.mLength);
               System.arraycopy(array, offset, c.mArray, c.mLength, amount);
   
               c.mLength += amount;
               length -= amount;
               offset += amount;
           }
       }
   
2. xxx