Add vector variants of meshes/particlesPath

include/openPMD/Series.hpp

@@ -424,6 +424,7 @@ class Series : public Attributable
      * <CODE>basePath</CODE>.
      */
     std::string meshesPath() const;
+    std::vector<std::string> meshesPaths() const;
     /** Set the path to <A
      * HREF="https://github.com/openPMD/openPMD-standard/blob/latest/STANDARD.md#mesh-based-records">mesh
      * records</A>, relative(!) to <CODE>basePath</CODE>.
@@ -434,6 +435,7 @@ class Series : public Attributable
      * @return  Reference to modified series.
      */
     Series &setMeshesPath(std::string const &meshesPath);
+    Series &setMeshesPath(std::vector<std::string> const &meshesPath);
 
     /**
      * @throw   no_such_attribute_error If optional attribute is not present.
@@ -467,6 +469,7 @@ class Series : public Attributable
      * <CODE>basePath</CODE>.
      */
     std::string particlesPath() const;
+    std::vector<std::string> particlesPaths() const;
     /** Set the path to groups for each <A
      * HREF="https://github.com/openPMD/openPMD-standard/blob/latest/STANDARD.md#particle-records">particle
      * species</A>, relative(!) to <CODE>basePath</CODE>.
@@ -477,6 +480,7 @@ class Series : public Attributable
      * @return  Reference to modified series.
      */
     Series &setParticlesPath(std::string const &particlesPath);
+    Series &setParticlesPath(std::vector<std::string> const &particlesPath);
 
     /**
      * @throw   no_such_attribute_error If optional attribute is not present.
@@ -877,8 +881,6 @@ OPENPMD_private
         iterations_iterator end,
         internal::FlushParams const &flushParams,
         bool flushIOHandler = true);
-    void flushMeshesPath();
-    void flushParticlesPath();
     void flushRankTable();
     /* Parameter `read_only_this_single_iteration` used for reopening an
      * Iteration after closing it.

include/openPMD/backend/Attribute.hpp

@@ -292,6 +292,25 @@ namespace detail
                 }
             }
         }
+        // conversion cast: turn a 1-element vector into a single value
+        else if constexpr (auxiliary::IsVector_v<T>)
+        {
+            if constexpr (std::is_convertible_v<typename T::value_type, U>)
+            {
+                if (pv->size() != 1)
+                {
+                    return {std::runtime_error(
+                        "getCast: vector to scalar conversion requires "
+                        "single-element vectors")};
+                }
+                return {U(*pv->begin())};
+            }
+            else
+            {
+                return {std::runtime_error(
+                    "getCast: no vector to scalar conversion possible.")};
+            }
+        }
         else
         {
             return {std::runtime_error("getCast: no cast possible.")};

src/Iteration.cpp

@@ -358,7 +358,6 @@ void Iteration::flushIteration(internal::FlushParams const &flushParams)
             if (!s.containsAttribute("meshesPath"))
             {
                 s.setMeshesPath("meshes/");
-                s.flushMeshesPath();
             }
             meshes.flush(s.meshesPath(), flushParams);
             for (auto &m : meshes)
@@ -374,7 +373,6 @@ void Iteration::flushIteration(internal::FlushParams const &flushParams)
             if (!s.containsAttribute("particlesPath"))
             {
                 s.setParticlesPath("particles/");
-                s.flushParticlesPath();
             }
             particles.flush(s.particlesPath(), flushParams);
             for (auto &species : particles)

src/Series.cpp

@@ -189,7 +189,27 @@ Series &Series::setBasePath(std::string const &bp)
 
 std::string Series::meshesPath() const
 {
-    return getAttribute("meshesPath").get<std::string>();
+    auto res = meshesPaths();
+    if (res.empty())
+    {
+        throw no_such_attribute_error("meshesPath");
+    }
+    /*
+     * @todo: Verify that meshesPath has canonical form
+     */
+    return res.at(0);
+}
+
+std::vector<std::string> Series::meshesPaths() const
+{
+    if (containsAttribute("meshesPath"))
+    {
+        return getAttribute("meshesPath").get<std::vector<std::string>>();
+    }
+    else
+    {
+        return {};
+    }
 }
 
 Series &Series::setMeshesPath(std::string const &mp)
@@ -212,6 +232,23 @@ Series &Series::setMeshesPath(std::string const &mp)
     setDirty(true);
     return *this;
 }
+Series &Series::setMeshesPath(std::vector<std::string> const &mp)
+{
+    // @todo if already written, then append
+    switch (mp.size())
+    {
+    case 0:
+        return *this;
+    case 1:
+        setAttribute("meshesPath", *mp.begin());
+        break;
+    default:
+        setAttribute("meshesPath", mp);
+        break;
+    }
+    dirty() = true;
+    return *this;
+}
 
 #if openPMD_HAVE_MPI
 chunk_assignment::RankMeta Series::rankTable(bool collective)
@@ -479,7 +516,27 @@ void Series::flushRankTable()
 
 std::string Series::particlesPath() const
 {
-    return getAttribute("particlesPath").get<std::string>();
+    auto res = particlesPaths();
+    if (res.empty())
+    {
+        throw no_such_attribute_error("particlesPath");
+    }
+    /*
+     * @todo: Verify that particlesPath has canonical form
+     */
+    return res.at(0);
+}
+
+std::vector<std::string> Series::particlesPaths() const
+{
+    if (containsAttribute("particlesPath"))
+    {
+        return getAttribute("particlesPath").get<std::vector<std::string>>();
+    }
+    else
+    {
+        return {};
+    }
 }
 
 Series &Series::setParticlesPath(std::string const &pp)
@@ -502,6 +559,23 @@ Series &Series::setParticlesPath(std::string const &pp)
     setDirty(true);
     return *this;
 }
+Series &Series::setParticlesPath(std::vector<std::string> const &pp)
+{
+    // @todo if already written, then append
+    switch (pp.size())
+    {
+    case 0:
+        return *this;
+    case 1:
+        setAttribute("particlesPath", *pp.begin());
+        break;
+    default:
+        setAttribute("particlesPath", pp);
+        break;
+    }
+    dirty() = true;
+    return *this;
+}
 
 std::string Series::author() const
 {
@@ -1547,26 +1621,6 @@ void Series::flushGorVBased(
     }
 }
 
-void Series::flushMeshesPath()
-{
-    Parameter<Operation::WRITE_ATT> aWrite;
-    aWrite.name = "meshesPath";
-    Attribute a = getAttribute("meshesPath");
-    aWrite.resource = a.getResource();
-    aWrite.dtype = a.dtype;
-    IOHandler()->enqueue(IOTask(this, aWrite));
-}
-
-void Series::flushParticlesPath()
-{
-    Parameter<Operation::WRITE_ATT> aWrite;
-    aWrite.name = "particlesPath";
-    Attribute a = getAttribute("particlesPath");
-    aWrite.resource = a.getResource();
-    aWrite.dtype = a.dtype;
-    IOHandler()->enqueue(IOTask(this, aWrite));
-}
-
 void Series::readFileBased(
     std::optional<IterationIndex_t> read_only_this_single_iteration)
 {
@@ -2287,7 +2341,8 @@ void Series::readBase()
         aRead.name = "meshesPath";
         IOHandler()->enqueue(IOTask(this, aRead));
         IOHandler()->flush(internal::defaultFlushParams);
-        if (auto val = Attribute(*aRead.resource).getOptional<std::string>();
+        if (auto val = Attribute(*aRead.resource)
+                           .getOptional<std::vector<std::string>>();
             val.has_value())
         {
             /* allow setting the meshes path after completed IO */
@@ -2325,7 +2380,8 @@ void Series::readBase()
         aRead.name = "particlesPath";
         IOHandler()->enqueue(IOTask(this, aRead));
         IOHandler()->flush(internal::defaultFlushParams);
-        if (auto val = Attribute(*aRead.resource).getOptional<std::string>();
+        if (auto val = Attribute(*aRead.resource)
+                           .getOptional<std::vector<std::string>>();
             val.has_value())
         {
             /* allow setting the meshes path after completed IO */