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https://issues.apache.org/jira/browse/JENA-91?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13081251#comment-13081251
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Simon Helsen commented on JENA-91:
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I obviously misunderstood the code. The lengthBuffer.get reads the 4 bytes as
the value, so the endian-ness is not the problem. The problem is the large
value :-). I'll update the title/description
> byte area for lengths is read in platform endian, but expects big endian
> ------------------------------------------------------------------------
>
> Key: JENA-91
> URL: https://issues.apache.org/jira/browse/JENA-91
> Project: Jena
> Issue Type: Bug
> Components: TDB
> Environment: Windows (and I presume any little endian system)
> Reporter: Simon Helsen
> Priority: Critical
>
> I tried to debug the OME and check why a bytebuffer is causing my native
> memory to explode in almost no time. It all seems to happen in this bit of
> code in com.hp.hpl.jena.tdb.base.objectfile.ObjectFileStorage (lines 243
> onwards)
> // No - it's in the underlying file storage.
> lengthBuffer.clear() ;
> int x = file.read(lengthBuffer, loc) ;
> if ( x != 4 )
> throw new
> FileException("ObjectFile.read("+loc+")["+filesize+"]["+file.size()+"]:
> Failed to read the length : got "+x+" bytes") ;
> int len = lengthBuffer.getInt(0) ;
> ByteBuffer bb = ByteBuffer.allocate(len) ;
> My debugger shows that x==4. It also shows the lengthBuffer has the following
> content: [111, 110, 61, 95], however the value of len=1869495647, which is
> rather a lot :-) Obviously, the next statement (ByteBuffer.allocate) causes
> the OME
> So, looking into it, lengthBuffer.getInt(0)==1869495647, but
> lenghtBuffer.get(0)==111, which seems more correct. Then I noticed that the
> bytebuffer also says bigEndian==true. I am running all of this on Windows 7.
> which is to the best of my knowledge little endian
> I think this can only work correctly if the byteBuffer for lengths (at least)
> have their order explicitly set to that of the platform. So, somewhere in the
> code, you'd need to make sure to set
> lengthBuffer.order(ByteOrder.nativeOrder())
> I think this only affects this particular one because it manages lengths, but
> I don't know the code well enough to know if there are other places that may
> be affected
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