0000069: hessian references break when there are more than 256 refs in one call

Viewing Issue Simple Details [ Jump to Notes ]

[ View Advanced ] [ Issue History ] [ Print ]

Category

Severity

Reproducibility

Date Submitted

Last Update

0000069

[Resin]

minor

always

03-01-05 00:00

05-11-05 00:00

Reporter

user102

View Status

public

Assigned To

Priority

normal

Resolution

fixed

Status

closed

Product Version

Summary

0000069: hessian references break when there are more than 256 refs in one call

Description

RSN-60
When you create a Large hessian Object that has more than 256 references in it,
using HessianOutput.writeObject() can produce unpredictable results.
The reason for this is the implementation of HessianOutput.writeRef() as following:

public void writeRef(int value)
    throws IOException
  {
    os.write('R');
    os.write(value << 24);
    os.write(value << 16);
    os.write(value << 8);
    os.write(value);
  }

the above code does bitshifting to the left and write out the value. This will work as long as
the reference value is smaller than 256 because the shifting will not affect the higher bytes, as
they are zero anyway. but anything bigger than 256 will give strange results, resulting in difficult to debug error messages, because the references will not point to the correct objects.
This can cause ClassCastExceptions and other Exceptions.

The solution i found to this problem is the following code:

/*corrected this function so that reference bigger than 256 can work!! i
    * in hessian, the bits were being shifted to the left instead of right
    * @see com.caucho.hessian.io.AbstractHessianOutput#writeRef(int)
    */
    public void writeRef(int value)
      throws IOException
    {
      os.write('R');
      os.write((value >> 24) & 0xFF);
      os.write((value >> 16) & 0xFF);
      os.write((value >> 8) & 0xFF);
      os.write((value) & 0xFF);
    }

this code correctly shifts the bits to the right and everything works fine.

Additional Information

linux

Attached Files

Relationships

There are no notes attached to this issue.

Issue History
Date Modified	Username	Field	Change
03-01-05 00:00	user102	New Issue
11-30-05 00:00	administrator	Fixed in Version	=> 3.0.13

Mantis 1.0.0rc3[^]

31 total queries executed.
25 unique queries executed.