0.8.0 Release Highlights

(adapted from Conduit's Changelog)

Added

General

• Added setup.py for building and installing Conduit and its Python module via pip
• Added DataAccessor class that helps write generic algorithms that consume data arrays using expected types.
• Added support to register custom memory allocators and a custom data movement handler. This allows conduit to move trees of data between heterogenous memory spaces (e.g. CPU and GPU memory). See conduit_utils.hpp for API details.

Blueprint

• Added conduit::blueprint::{mpi}::partition function that provides a general N-to-M partition capability for Blueprint Meshes. This helps with load balancing and other use cases, including fusing multi-domain data to simplifying post processing. This capability supports several options, see (https://llnl-conduit.readthedocs.io/en/latest/blueprint_mesh_partition.html) for more details.
• Added a Table blueprint used to represent tables of numeric data. See (https://llnl-conduit.readthedocs.io/en/latest/blueprint_table.html) more details.
• Added conduit::blueprint::{mpi}::flatten which transforms Blueprint Meshes into Blueprint Tables. This transforms Mesh Blueprint data into a form that is more easily digestible in machine learning applications.
• Added conduit::blueprint::mpi::generate_partition_field, which uses Parmetis to create a field that identifies how to load balance an input mesh elements. This field can be used as a Field selection input to conduit::blueprint::mpi::partition function.
• Added theblueprint::mesh::examples::polychain example. It is an example of a polyhedral mesh. See Mesh Blueprint Examples docs (https://llnl-conduit.readthedocs.io/en/latest/blueprint_mesh.html#polychain) for more details.
• Added a new function signature for blueprint::mesh::topology::unstructured::generate_sides, which performs the same task as the original and also takes fields from the original topology and maps them onto the new topology.
• Added blueprint::mpi::mesh::to_polygonal, which provides a MPI aware conversion Blueprint Structured AMR meshes to a Blueprint Polyhedral meshes.
• Added a host of conduit::blueprint::mpi::mesh::generate_* methods, which are the MPI parallel equivalents of the conduit::blueprint::mesh::topology::unstructured::generate_* functions.
• Added the conduit::blueprint::mpi::mesh::find_delegate_domain function, which returns a single delegate domain for the given mesh across MPI ranks (useful when all ranks need mesh information and some ranks can have empty meshes).
• Added check and transform functions for the newly-designated pairwise and maxshare variants of adjsets. For more information, see the conduit::blueprint::mesh::adjset namespace.
• Added mesh::topology::unstructured::to_polytopal as an alias to mesh::topology::unstructured::to_polygonal, to reflect that both polygonal and polyhedral are supported.
• Added conduit::blueprint::mpi::mesh::to_polytopal as an alias to conduit::blueprint::mpi::mesh::to_polygonal and conduit::blueprint::mpi::mesh::to_polyhedral.

Relay

• Added conduit::relay::io::hdf5_identifier_report methods, which create conduit nodes that describes active hdf5 resource handles.

Changed

General

• Updated CMake logic to provide more robust Python detection and better support for HDF5 installs that were built with CMake.
• Improved Node::diff and Node::diff_compatible to show string values when strings differ.
• conduit::Node::print() and in Python Node repr and str now use to_summary_string(). This reduces the output for large Nodes. Full output is still supported via to_string(), to_yaml(), etc methods.

Blueprint

• The blueprint::mesh::examples::polytess function now takes a new argument, called nz, which allows it to be extended into 3 dimensions. See Mesh Blueprint Examples docs (https://llnl-conduit.readthedocs.io/en/latest/blueprint_mesh.html#polytess) for more details.
• Added support for both const and non-const inputs to the conduit::blueprint::mesh::domains function.
• Improved mesh blueprint index generation logic (local and MPI) to support domains with different topos, fields, etc.
• Deprecated accepting npts_z !=0 for 2D shape types in conduit::blueprint::mesh::examples::{braid,basic,grid}. They issue a CONDUIT_INFO message when this detected and future versions will issue a CONDUIT_ERROR.
• An empty Conduit Node is now considered a valid multi-domain mesh. This change was made to make serial uses cases better match sparse MPI multi-domain use cases. Existing code that relied mesh::verify to exclude empty Nodes will now need an extra check to see if an input mesh has data.
• Added MPI communicator argument to conduit::blueprint::mpi::mesh::to_polygonal and conduit::blueprint::mpi::mesh::to_polyhedral.

Relay

• Added CMake option (ENABLE_RELAY_WEBSERVER, default = ON) to control if Conduit's Relay Web Server support is built. Down stream codes can check for support via header ifdef CONDUIT_RELAY_WEBSERVER_ENABLED or at runtime in conduit::relay::about.
• Added support to compile against HDF5 1.12.

Fixed

General

• Avoid compile issue with using _Pragma() with Python 3.8 on Windows
• conduit_node and conduit_datatype in the C API are no longer aliases to void so that callers cannot pass just any pointer to the APIs.
• Fixed memory over read issue with Fortran API due to int vs bool binding error. Fortran API still provides logical returns for methods like conduit_node_has_path() however the binding implementation now properly translates C_INT return codes into logical values.
• Fixed a subtle bug with Node fetch and Object role initialization.

Blueprint

• Fixed a bug that was causing the conduit::blueprint::mesh::topology::unstructured::generate_* functions to produce bad results for polyhedral input topologies with heterogeneous elements (e.g. tets and hexs).
• Fixed a bug with conduit::relay::io::blueprint::write_mesh that undermined truncate=true option for root-only style output.
• Fixed options parsing bugs and improved error messages for the conduit_blueprint_verify exe.

Relay

• Changed HDF5 offset support to use 64-bit unsigned integers for offsets, strides, and sizes.
• Fixed a bug with conduit::relay::mpi::io::blueprint::save_mesh where file_style=root_only could crash or truncate output files.
• Fixed a bug with inconsistent HDF5 handles being used in some cases when converting existing HDF5 Datasets from fixed to extendable.