Add hostname attribute to Series

Author: franzpoeschel

include/openPMD/Series.hpp

@@ -66,6 +66,11 @@ namespace internal
  */
 class SeriesData : public AttributableData
 {
+    // friend class openPMD::SeriesImpl;
+    // friend class openPMD::Iteration;
+    // friend class openPMD::Series;
+    // friend class SeriesInternal;
+
 public:
     explicit SeriesData() = default;
 
@@ -96,6 +101,12 @@ class SeriesData : public AttributableData
      */
     StepStatus m_stepStatus = StepStatus::NoStep;
     bool m_parseLazily = false;
+#if openPMD_HAVE_MPI
+    /*
+     * @todo find a better place to put MPI-specific members
+     */
+    MPI_Comm m_communicator;
+#endif
 }; // SeriesData
 
 class SeriesInternal;
@@ -167,6 +178,32 @@ class SeriesImpl : public AttributableImpl
      */
     SeriesImpl& setMeshesPath(std::string const& meshesPath);
 
+    /**
+     * @throw   no_such_attribute_error If optional attribute is not present.
+     * @return  Vector with a String per (writing) MPI rank, indicating user-
+     *          defined meta information per rank. Example: host name.
+     */
+    chunk_assignment::RankMeta
+    mpiRanksMetaInfo() const;
+
+    /**
+     * @brief Set the Mpi Ranks Meta Info attribute, i.e. a Vector with
+     *        a String per (writing) MPI rank, indicating user-
+     *        defined meta information per rank. Example: host name.
+     *
+     * @return Reference to modified series.
+     */
+    SeriesImpl & setMpiRanksMetaInfo( chunk_assignment::RankMeta );
+
+    /**
+     * @brief Set the Mpi Ranks Meta Info attribute, i.e. a Vector with
+     *        a String per (writing) MPI rank, indicating user-
+     *        defined meta information per rank. Example: host name.
+     *
+     * @return Reference to modified series.
+     */
+    SeriesImpl & setMpiRanksMetaInfo( std::string const & myRankInfo );
+
     /**
      * @throw   no_such_attribute_error If optional attribute is not present.
      * @return  String representing the path to particle species, relative(!) to <CODE>basePath</CODE>.

src/Series.cpp

@@ -21,6 +21,7 @@
 #include "openPMD/auxiliary/Date.hpp"
 #include "openPMD/auxiliary/Filesystem.hpp"
 #include "openPMD/auxiliary/JSON.hpp"
+#include "openPMD/auxiliary/MPI.hpp"
 #include "openPMD/auxiliary/StringManip.hpp"
 #include "openPMD/IO/AbstractIOHandler.hpp"
 #include "openPMD/IO/AbstractIOHandlerHelper.hpp"
@@ -162,6 +163,91 @@ SeriesImpl::setMeshesPath(std::string const& mp)
     return *this;
 }
 
+chunk_assignment::RankMeta
+SeriesImpl::mpiRanksMetaInfo() const
+{
+    std::vector< std::string > asContiguousVector;
+    try
+    {
+        asContiguousVector =
+            getAttribute( "rankMetaInfo" ).get< std::vector< std::string > >();
+    }
+    catch( std::runtime_error const & )
+    {
+        // workaround: if vector has length 1, some backends may report a
+        // single value instead of a vector
+        asContiguousVector = {
+            getAttribute( "rankMetaInfo" ).get< std::string >()
+        };
+    }
+    chunk_assignment::RankMeta res;
+    for( size_t i = 0; i < asContiguousVector.size(); ++i )
+    {
+        res[ i ] = std::move( asContiguousVector[ i ] );
+    }
+    return res;
+}
+
+SeriesImpl &
+SeriesImpl::setMpiRanksMetaInfo( chunk_assignment::RankMeta rankMeta )
+{
+    std::vector< std::string > asContiguousVector;
+    asContiguousVector.reserve( rankMeta.size() );
+    try
+    {
+        for( auto & hostname : rankMeta )
+        {
+            asContiguousVector.emplace_back( std::move( hostname.second ) );
+        }
+    }
+    catch( std::out_of_range const & )
+    {
+        throw std::runtime_error( "[setMpiRanksMetaInfo] Can only set meta "
+                                  "info for contiguous ranks 0 to n." );
+    }
+
+    setAttribute( "rankMetaInfo", std::move( asContiguousVector ) );
+    return *this;
+}
+
+SeriesImpl &
+SeriesImpl::setMpiRanksMetaInfo( std::string const & myRankInfo )
+{
+    if( auxiliary::starts_with( myRankInfo, '@' ) )
+    {
+        // read from file
+        std::string fileName = auxiliary::replace_first( myRankInfo, "@", "" );
+        std::vector< std::string > rankMeta;
+        try
+        {
+            rankMeta = auxiliary::read_file_by_lines( fileName );
+        }
+        catch( auxiliary::no_such_file_error const & )
+        {
+            std::cerr << "Not setting rank meta information, because file has "
+                         "not been found: "
+                      << fileName << std::endl;
+            return *this;
+        }
+        setAttribute( "rankMetaInfo", rankMeta );
+        return *this;
+    }
+#if openPMD_HAVE_MPI
+    auto & series = get();
+    int rank;
+    MPI_Comm_rank( series.m_communicator, &rank );
+    std::vector< std::string > rankMeta =
+        auxiliary::collectStringsTo( series.m_communicator, 0, myRankInfo );
+    if( rank == 0 )
+    {
+        setAttribute( "rankMetaInfo", std::move( rankMeta ) );
+    }
+#else
+    setAttribute( "rankMetaInfo", std::vector< std::string >{ myRankInfo } );
+#endif
+    return *this;
+}
+
 std::string
 SeriesImpl::particlesPath() const
 {
@@ -1403,6 +1489,7 @@ SeriesInternal::SeriesInternal(
 {
     nlohmann::json optionsJson = auxiliary::parseOptions( options, comm );
     parseJsonOptions( *this, optionsJson );
+    m_communicator = comm;
     auto input = parseInput( filepath );
     auto handler = createIOHandler(
         input->path, at, input->format, comm, std::move( optionsJson ) );