SciDAC QDP I/O Features    3/27/2004
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File volume types:

   Single file
   Multifile 

   The latter is for staging, temporary scratch, etc.

File handling modes:

   Serial     (master node does all the writing/reading)
   Parallel   (all nodes write/read their portion of the file)

File opening modes:
 
   Create, Open, Append (to be implemented)

Binary File Format

   Metadata description for the file
   Record 1 physics metadata and binary data
   Record 2 physics metadata and binary data
   etc.

The record may contain one of these:
   1. QDP field
   2. Array of QDP fields
   3. Array of QLA data
   4. Character string  (to be implemented)

   The gauge configuration is an example of an array of QDP fields:
   four color matrices per site.
   
   The QLA data and character string data are treated as global.  For
   example a hadron correlator summed over all sites on each time
   slice.

Metadata is encoded in XML through a separate API.