Re: Update on CODA (evio) format

[heddle@pcs.cnu.edu]

evio is very nice -- some of us wanted to use it for Hall B but lost a brutal batlle to the BOS/FPACK proponents. For HALLB there are some minor tweaks to it that would have saved a fair amount of space and the DAQ group was going to do this before we dropped it. It was criticized for use in HallB for (a) being too complicated (balderdash) and (b) not providing a memory manager (true)

dph 

    On Mon, 04 Jun 2001 13:15:42 -0400 Elliott Wolin <wolin@jlab.org> wrote: 

>To all interested in binary formats for Hall D,>
>
>The more I look at coda format (aka evio) the more I like it.  Previously I>
>proposed a binary format using 4-byte headers;  evio includes this, as well as a>
>number of other packing options (8-byte, 4-byte, 2-byte).>
>
>The evio package was written years ago, but few new ideas in the "binary format">
>field have appeared since then.   The JLab DAQ group is willing to update the>
>evio package to meet Hall D needs.>
>
>evio seems well suited for serializing data described via xml.  It encodes a>
>recursively self-similar tree structure.  The existing package is thread-safe,>
>handles byte-swapping, has a command-line and Motif browser, and includes a>
>blocking scheme that allows you to recover data in case of file corruption.>
>
>Currently only a c-based api is available.  A java version would be nice, but I>
>don't know if the DAQ group plans to provide this.  We could easily encapsulate>
>the c api in a C++ class, if needed (I'm not sure this is needed).>
>
>The existing browser programs use a "data dictionary" using a special evio>
>format...I've written a simple perl script that converts an xml data description>
>to evio format (/group/halld/utilities/xml2evio).>
>
>Details of evio can be found in http://coda.jlab.org under the docs for coda>
>version 1.4. Please have a look at this.  If we decide to use evio we could>
>start using it immediately.>
>
>				Sincerely,>
>					Elliott>
> >
>
>
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