Added -writeChecks <format> option

- writes computed mesh metrics to file in using <format>
- currently supported formats are OpenFOAM dictionary and JSON

- primarily relevant for finite-area meshes, in which case they can be
  considered to be an additional, detailed diagnositic that is
  normally not needed (clutters the file system).

  Writing can be enabled with the `-write-edges` option.

- the very old 'writer' class was fully stateless and always templated
  on an particular output type.

  This is now replaced with a 'coordSetWriter' with similar concepts
  as previously introduced for surface writers (#1206).

  - writers change from being a generic state-less set of routines to
    more properly conforming to the normal notion of a writer.

  - Parallel data is done *outside* of the writers, since they are used
    in a wide variety of contexts and the caller is currently still in
    a better position for deciding how to combine parallel data.

ENH: update sampleSets to sample on per-field basis (#2347)

- sample/write a field in a single step.

- support for 'sampleOnExecute' to obtain values at execution
  intervals without writing.

- support 'sets' input as a dictionary entry (as well as a list),
  which is similar to the changes for sampled-surface and permits use
  of changeDictionary to modify content.

- globalIndex for gather to reduce parallel communication, less code

- qualify the sampleSet results (properties) with the name of the set.
  The sample results were previously without a qualifier, which meant
  that only the last property value was actually saved (previous ones
  overwritten).

  For example,
  ```
    sample1
    {
        scalar
        {
            average(line,T) 349.96521;
            min(line,T)     349.9544281;
            max(line,T)     350;
            average(cells,T) 349.9854619;
            min(cells,T)    349.6589286;
            max(cells,T)    350.4967271;
            average(line,epsilon) 0.04947733869;
            min(line,epsilon) 0.04449639927;
            max(line,epsilon) 0.06452856475;
        }
        label
        {
            size(line,T)    79;
            size(cells,T)   1720;
            size(line,epsilon) 79;
        }
    }
  ```

ENH: update particleTracks application

- use globalIndex to manage original parcel addressing and
  for gathering. Simplify code by introducing a helper class,
  storing intermediate fields in hash tables instead of
  separate lists.

ADDITIONAL NOTES:

- the regionSizeDistribution largely retains separate writers since
  the utility of placing sum/dev/count for all fields into a single file
  is questionable.

- the streamline writing remains a "soft" upgrade, which means that
  scalar and vector fields are still collected a priori and not
  on-the-fly.  This is due to how the streamline infrastructure is
  currently handled (should be upgraded in the future).

Mattijs Janssens authored 4 years ago and Andrew Heather committed 4 years ago

This adds a 'geometry' scheme section to the system/fvSchemes:

geometry
{
    type            highAspectRatio;
}

These 'fvGeometryMethod's are used to calculate
- deltaCoeffs
- nonOrthoCoeffs
etc and can even modify the basic face/cellCentres calculation.

STYLE: use global operator instead of HashSet -= operator

- Favour use of argList methods that are more similar to dictionary
  method names with the aim of reducing the cognitive load.

  * Silently deprecate two-parameter get() method in favour of the
    more familiar getOrDefault.
  * Silently deprecate opt() method in favour of get()

  These may be verbosely deprecated in future versions.

- previously only had 'opt<..>()' for options, but 'get<..>()'
  provides more similarity with dictionary methods.
  The 'opt<..>()' method is retained.

- The writers have changed from being a generic state-less set of
  routines to more properly conforming to the normal notion of a writer.
  These changes allow us to combine output fields (eg, in a single
  VTK/vtp file for each timestep).

  Parallel data reduction and any associated bookkeeping is now part
  of the surface writers.
  This improves their re-usability and avoids unnecessary
  and premature data reduction at the sampling stage.

  It is now possible to have different output formats on a per-surface
  basis.

- A new feature of the surface sampling is the ability to "store" the
  sampled surfaces and fields onto a registry for reuse by other
  function objects.

  Additionally, the "store" can be triggered at the execution phase
  as well

- also replaced a few instances of readIfPresent with opt<> for
  constant values.

General:
    * -roots, -hostRoots, -fileHandler

Specific:
    * -to <coordinateSystem> -from <coordinateSystem>

- Display -help-compat when compatibility or ignored options are available

STYLE: capitalization of options text

- the wordHashSet typedef is always available when HashSet has been
  included.

- use default HashTable key (word) instead of explicitly mentioning it

- use succincter method names that more closely resemble dictionary
  and HashTable method names. This improves method name consistency
  between classes and also requires less typing effort:

    args.found(optName)        vs.  args.optionFound(optName)
    args.readIfPresent(..)     vs.  args.optionReadIfPresent(..)
    ...
    args.opt<scalar>(optName)  vs.  args.optionRead<scalar>(optName)
    args.read<scalar>(index)   vs.  args.argRead<scalar>(index)

- the older method names forms have been retained for code compatibility,
  but are now deprecated

Original commit message:
------------------------

Parallel IO: New collated file format

When an OpenFOAM simulation runs in parallel, the data for decomposed fields and
mesh(es) has historically been stored in multiple files within separate
directories for each processor.  Processor directories are named 'processorN',
where N is the processor number.

This commit introduces an alternative "collated" file format where the data for
each decomposed field (and mesh) is collated into a single file, which is
written and read on the master processor.  The files are stored in a single
directory named 'processors'.

The new format produces significantly fewer files - one per field, instead of N
per field.  For large parallel cases, this avoids the restriction on the number
of open files imposed by the operating system limits.

The file writing can be threaded allowing the simulation to continue running
while the data is being written to file.  NFS (Network File System) is not
needed when using the the collated format and additionally, there is an option
to run without NFS with the original uncollated approach, known as
"masterUncollated".

The controls for the file handling are in the OptimisationSwitches of
etc/controlDict:

OptimisationSwitches
{
    ...

    //- Parallel IO file handler
    //  uncollated (default), collated or masterUncollated
    fileHandler uncollated;

    //- collated: thread buffer size for queued file writes.
    //  If set to 0 or not sufficient for the file size threading is not used.
    //  Default: 2e9
    maxThreadFileBufferSize 2e9;

    //- masterUncollated: non-blocking buffer size.
    //  If the file exceeds this buffer size scheduled transfer is used.
    //  Default: 2e9
    maxMasterFileBufferSize 2e9;
}

When using the collated file handling, memory is allocated for the data in the
thread.  maxThreadFileBufferSize sets the maximum size of memory in bytes that
is allocated.  If the data exceeds this size, the write does not use threading.

When using the masterUncollated file handling, non-blocking MPI communication
requires a sufficiently large memory buffer on the master node.
maxMasterFileBufferSize sets the maximum size in bytes of the buffer.  If the
data exceeds this size, the system uses scheduled communication.

The installation defaults for the fileHandler choice, maxThreadFileBufferSize
and maxMasterFileBufferSize (set in etc/controlDict) can be over-ridden within
the case controlDict file, like other parameters.  Additionally the fileHandler
can be set by:
- the "-fileHandler" command line argument;
- a FOAM_FILEHANDLER environment variable.

A foamFormatConvert utility allows users to convert files between the collated
and uncollated formats, e.g.
    mpirun -np 2 foamFormatConvert -parallel -fileHandler uncollated

An example case demonstrating the file handling methods is provided in:
$FOAM_TUTORIALS/IO/fileHandling

The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.

  - the checking for point-connected multiple-regions now also writes the
    conflicting points to a pointSet
  - with the -writeSets option it now also reconstructs & writes pointSets

In parallel the sets are reconstructed. e.g.

mpirun -np 6 checkMesh -parallel -allGeometry -allTopology -writeSets vtk

will create a postProcessing/ folder with the vtk files of the
(reconstructed) faceSets and cellSets.

Also improved analysis of disconnected regions now also checks for point
connectivity with is useful for detecting if AMI regions have duplicate
points.

Patch contributed by Mattijs Janssens

Patch contributed by Mattijs Janssens
Resolves bug-report http://bugs.openfoam.org/view.php?id=2088

- checkMesh has option to write faceSets or (outside of) cellSets as
sampledSurface format. It automatically reconstructs the set on the master
and writes it to the postProcessing folder (as any sampledSurface). E.g.

    mpirun -np 6 checkMesh -allTopology -allGeometry -writeSets vtk -parallel

- fixed order writing of symmTensor in Ensight writers