- this provides a better typesafe means of locating predefined cell
models than relying on strings. The lookup is now ptr() or ref()
directly. The lookup functions behave like on-demand singletons when
loading "etc/cellModels".
Functionality is now located entirely in cellModel but a forwarding
version of cellModeller is provided for API (but not ABI) compatibility
with older existing user code.
STYLE: use constexpr for cellMatcher constants
old "positions" file form
The change to barycentric-based tracking changed the contents of the
cloud "positions" file to a new format comprising the barycentric
co-ordinates and other cell position-based info. This broke
backwards compatibility, providing no option to restart old cases
(v1706 and earlier), and caused difficulties for dependent code, e.g.
for post-processing utilities that could only infer the contents only
after reading.
The barycentric position info is now written to a file called
"coordinates" with provision to restart old cases for which only the
"positions" file is available. Related utilities, e.g. for parallel
running and data conversion have been updated to be able to support both
file types.
To write the "positions" file by default, use set the following option
in the InfoSwitches section of the controlDict:
writeLagrangianPositions 1;
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.
- previous only checked for clouds at the last instance and only
detected lagrangian fields from the first cloud.
Now check for clouds at all instances and detect all of their fields
as well.
- error::throwExceptions(bool) returning the previous state makes it
easier to set and restore states.
- throwing() method to query the current handling (if required).
- the normal error::throwExceptions() and error::dontThrowExceptions()
also return the previous state, to make it easier to restore later.
- use allocator class to wrap the stream pointers instead of passing
them into ISstream, OSstream and using a dynamic cast to delete
then. This is especially important if we will have a bidirectional
stream (can't delete twice!).
STYLE:
- file stream constructors with std::string (C++11)
- for rewind, explicit about in|out direction. This is not currently
important, but avoids surprises with any future bidirectional access.
- combined string streams in StringStream.H header.
Similar to <sstream> include that has both input and output string
streams.
- added an explicit print, but only report profiling to the log
file from master process.
We don't wish to overwrite any profiling that was conducted during
the simulation. Besides which, we don't have a proper Time object
for handling the write nicely either.
- erroneous double logic for subset meshes.
The underlying vtk::vtuCells uses a cellMap to map into a global
field, which also allows handling of decomposed polyhedral cells.
If a mesh subset is involved (eg, cellSet, cellZone), then the
set/zone cellMap can be used to ensure that the original number is
properly adjusted. For foamToVTK, the meshSubsetHelper already
does the subsetting and is used when loading fields.
Does not affect ParaView reader module since there we work on the
full field and do the subsetting manually (using the cellMap).
- disable automatically upgrading copyrights in files since changes to
not automatically imply a change in copyright. Eg, fixing a typo in
comments, or changing a variable from 'loopI' to 'loopi' etc.
- This provides a mechanism for moving mesh patches based on external
input (eg, from an external structures solver). The patch points are
influenced by the position and rotation of the lumped points.
BC: lumpedPointDisplacementPointPatchVectorField
Controlling mechanisms:
- externalCoupler
for coordinating the master/slave
- lumpedPointMovement
manages the patch-points motion, but also for extracting forces/moments
- lumpedPointState
represents the positions/rotations of the controlling points
Utils:
- lumpedPointZones
diagnostic for visualizing the correspondence between controlling
points and patch faces
- lumpedPointMovement
Test that the patch motion is as desired without invoking moveMesh.
With the -slave option, return items from a precalculated table
for the lumpedPointDisplacementPointPatchVectorField BC.
- with the xml append format it is possible to write raw binary
(instead of base64), but the writer becomes more complicated.
Either needs two passes to create, or need to allocate a block
of space for the header information (like VTK itself does) and
write later.
* internalWriter
* patchWriter
* surfaceMeshWriter
* lagrangianWriter
Also these special purpose ones:
* foamVtkWriteSurfFields
- this shifts responsibility away from caller to the individual writers
for knowing which file formats are supported and which file ending is
appropriate. When the writer receives the output format request,
it can elect to downgrade or otherwise adjust it to what it can
actually manage (eg, legacy vs xml vs xml-append).
But currently still just with legacy format backends.
- The reader module allows two levels of caching.
The OpenFOAM fvMesh can be cached in memory, for faster loading of
fields. Additionally, the translated VTK geometries are held in a
local cache. The cached VTK geometries should incur no additional
overhead since they use the VTK reference counting for their storage
management.
- this allows filling in the VTK structures without intermediate data
and without sequencial insertion. Should be faster and smaller
than the previous cell-wise insertion methods.
Most importantly, it improves code reuse.
- has the selected values directly and use these lookup names to store
directly into a hash. This replaces several parallel lists of
decomp information etc and makes it easier.
- Use on/off vs longer compressed/uncompressed.
For consistency, replaced yes/no with on/off.
- Avoid the combination of binary/compressed,
which is disallowed and provokes a warning anyhow
