CompressedWritable bug || feature?

[Ion Badita <io...@mcr.ro>]

Hi,

I think there is a bug CompressedWritable, more exactly in write() 
method, which makes subclasses of CompressedWritable not "reusable". 
More exactly: the data that is written to the DataOutput is always the 
same, because is "cached" in the /compressed/ field.

  public final void write(DataOutput out) throws IOException {
    /if (compressed == null) {/
      ByteArrayOutputStream deflated = new ByteArrayOutputStream();
      Deflater deflater = new Deflater(Deflater.BEST_SPEED);
      DataOutputStream dout =
        new DataOutputStream(new DeflaterOutputStream(deflated, deflater));
      writeCompressed(dout);
      dout.close();
      compressed = deflated.toByteArray();
    }
    out.writeInt(compressed.length);
    out.write(compressed);
  }

(code from hadoop 0.12.1)


This makes subclasses not "reusable", no matter if the fields change, 
data written will be the same.

John