@file piovdc.F90
@author Yannick Polius ypolius@ucar.edu
@version $Revision$
@date $LastChangedDate$
@brief The piovdc library for writing Vapor Data Collection (VDC) 2 data files
https://wiki.ucar.edu/display/dasg/PIOVDC
@details The piovdc library is used to write VDC2 data files in a
parallel manner using PIO. After the prerequisite library functions are
used, a call to pio_writedarray is made, writing the passed
data to an on disk VDC2 collection.
PRE-REQUISITES:
VDF meta-file must be generated, using either rawtovdf or vdfcreate
if advanced features (wavelet type, compression ratios, or boundary type) are needed
VDF file requires VDC version to be 2, and requires the Waveletname,
WaveletBoundaryMode, CompressionRations, and NumTransforms to be set.
POST-EFFECTS:
After a successful write, VDC2 data will be in a directory located in
the same directory as the vdf file, using the vdf name, appended with _data
(ex. ghost.vdf generates VDC2 data in the dir ghost_data in the vdf dir)
If no compression is enabled, a single, uncompressed file will be
generated using PIO instead of a VDC
| Type | Visibility | Attributes | Name | Initial | |||
|---|---|---|---|---|---|---|---|
| integer(kind=i4), | public | :: | vdc_dims(3) | ||||
| integer(kind=i4), | public | :: | vdc_bsize(3) | ||||
| integer(kind=i4), | public | :: | vdc_ts | ||||
| integer(kind=PIO_OFFSET), | public | :: | vdc_iostart(3) | ||||
| integer(kind=PIO_OFFSET), | public | :: | vdc_iocount(3) |
@brief subroutine checks start/count for out of bounds, adjusts if the start/count is too high,
zeroes start if it is invalid
POST-EFFECTS:
all start/counts are now legal, non-IO tasks have zeroed start counts
@param[in] global_dims int(3) global grid dimensions
@param[in] rank int rank of current MPI task
@param[inout] start int(3) current MPI task global start
@param[inout] count int(3) current MPI task global count
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer(kind=i4), | intent(in), | dimension(:) | :: | global_dims | ||
| integer(kind=PIO_OFFSET), | intent(inout), | dimension(:) | :: | start | ||
| integer(kind=PIO_OFFSET), | intent(inout), | dimension(:) | :: | count | ||
| integer(kind=i4), | intent(in) | :: | rank |
@brief subroutine that, given a global grid, VDC blocksize, and max # of nioprocs, will
automatically create an VDC optimized IO decomposition that uses the most possible IO tasks
POST-EFFECTS:
Each MPI Task is now either and IO task or a computational task. IO tasks have nonzero start/counts
@param[in] rank int rank of the current MPI task
@param[inout] nioprocs int represents the max possible # of IO procs,
@algorithm will try to get as close as possible to this # and return it in nioprocs
@param[in] blockdims int(3) global grid dimensions represented as VDC blocks
@param[out] start int(3) iostart for the current MPI task
@param[out] count int(3) iocount for the current MPI task
@param[in] bsize int(3) VDC block size
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer(kind=i4), | intent(in) | :: | rank | |||
| integer(kind=i4), | intent(inout) | :: | nioprocs | |||
| real(kind=r4), | intent(in), | dimension(:) | :: | block_dims | ||
| integer(kind=PIO_OFFSET), | intent(out) | :: | start(3) | |||
| integer(kind=PIO_OFFSET), | intent(out) | :: | count(3) | |||
| integer(kind=i4), | intent(in), | dimension(:) | :: | bsize | ||
| integer(kind=i4), | intent(in), | dimension(:) | :: | data_dims |
@brief subroutine that prepares the global grid to be split by the auto_start_count routine
POST-EFFECTS:
A valid IO decomposition is created that can be used with PIO
@param[in] rank int rank of the current
@param[in] data_dims int(3) size of the global grid
@param[in] vdc_bsize int(3) VDC block size
@param[out] iostart int(3) IO start for the current MPI task
@param[out] iocount int(3) IO count for the current MPI task
@param[inout] ioprocs int max # of IO procs, gets returned as the actual # used
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer(kind=i4), | intent(in) | :: | rank | |||
| integer(kind=i4), | intent(in), | dimension(:) | :: | data_dims | ||
| integer(kind=i4), | intent(in), | dimension(:) | :: | vdc_bsize | ||
| integer(kind=PIO_OFFSET), | intent(out) | :: | iostart(3) | |||
| integer(kind=PIO_OFFSET), | intent(out) | :: | iocount(3) | |||
| integer(kind=i4), | intent(inout) | :: | ioprocs |