Re: [OpenMap Users] VPF Layers From Physical Memory

From: Don Dietrick <>
Date: Thu, 12 Jul 2007 14:03:23 -0400

Hi Nathan,

On Jul 6, 2007, at 4:49 PM, Nathan Gewecke wrote:

> Hello all,
> I have an issue with what I am trying to do, which is read the VPF
> layers from Physical Memory or the OS Virtual memory after loading
> them into physical memory at initialization of the program,
> specifically WVS. I have set up a way to access the file in memory
> via a "Virtual Directory" which holds all of the binary data in
> bytes in a MappedByteBuffer. I then have set up a Flag in the
> properties file to allow the user to change between using the file
> in memory or the actual files on disk, using this flag I have
> altered the BinaryFile to read from a class,
> MemoryStoredBinaryFile, that mimics the calls from
> FileInputReader. These calls use the MappedByteBuffer readers get
> () realitive methods.
> Heres where my issue is when Openmap reads from the
> MemoryStoredBinaryFile along the way something happens and one of
> the BinaryBufferFiles trys to call about 1,700,000,000 bytes from a
> file that is only 696 bytes long. The file its calling from is a
> CoverageTable typeish file... not entirely sure what it is. But
> the program calls on this file several times before it trys to get
> about 2 billion bytes from it. Subsequently it gives me an error,
> ArrayOutofBoundsException.
> I had an idea to basically just move where I mimic to the
> BinaryFile or BinaryBufferFile level, like if the flag is set to
> read from memory then it would read from something other than a
> BinaryFile. As right now I am using BinaryFile as sort of an
> upward filter. Would this help at all?

Could this be a byte-order problem? What you are trying to do sounds
fine, I'd key into why the BBF is trying to read in so many bytes.


- Don

Don Dietrick,
BBN Technologies, Cambridge, MA

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Received on Thu Jul 12 2007 - 14:04:25 EDT

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