[Jython-bugs] [ jython-Bugs-511493 ] jreload truncates large class files

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Bugs item #511493, was opened at 2002-01-31 23:21
Message generated for change (Settings changed) made by pedronis
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Category: Library
>Group: Fixed in 2.2a0
Status: Closed
Resolution: Fixed
Priority: 5
Submitted By: Matthew Conway (wr0ngway)
Assigned to: Kevin J. Butler (kevinbutler)
Summary: jreload truncates large class files

Initial Comment:
The jreload Module does not read in the entire class 
file due to incorrect usage of InputStream.read().
The following example will fail unless the attached 
patch is applied.  Edit the value of toolsjar to point 
to the tools.jar from your jdk, or use some other 
large class file from somewhere else.  The patch also 
adds a getResourceAsStream() method for finding 
resources from the loadset.

from jreload import makeLoadSet
from java.lang import System

toolsjar = "/path/to/jdk/lib/tools.jar"
makeLoadSet('myls', [toolsjar])
# Any large class file causes a ClassFormatError
from myls.com.sun.tools.corba.se.idl import Parser
print "Success"




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Comment By: Kevin J. Butler (kevinbutler)
Date: 2003-01-03 00:52

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Replaced the broken code in PathVFSLoader.java and similar
code in SyspathJavaLoader.java and imp.java.

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Comment By: Samuele Pedroni (pedronis)
Date: 2002-03-07 20:02

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I think other code in the codebase may share similar 
problems and benefit from the approach.

[Note to self: role of JVM/library bugs?]

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Comment By: Matthew Conway (wr0ngway)
Date: 2002-03-07 19:37

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Kevin's getBytes() is definately a cleaner/better solution.

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Comment By: Kevin J. Butler (kevinbutler)
Date: 2002-03-07 17:29

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I'm uncomfortable with a couple of aspects of this patch -
the use of a member variable 'buf' makes the class loading
process not thread safe (can ClassLoaders be used in 
multiple threads?). Also, this will retain a buffer as large 
as the largest class loaded in the process.

It would probably be better to have a getBytes method 
something like:

protected byte[] getBytes( InputStream s )
{
  int bufsize=4096;
  byte[] buf = new byte[ bufsize ];
  ByteArrayOutputStream out = new ByteArrayOutputStream( 
bufsize );
  int count;
  while( true )
  {
    count = in.read( buf, 0, bufsize );
    if ( count < 0 )
      break;
    out.write( buf, 0, count );
  }
  return out.getBytes();
}     


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