Overlink IO: Write Padding Dimensions for Structured Meshes (#1204)

src/libs/relay/conduit_relay_io_silo.cpp

@@ -4542,6 +4542,51 @@ write_multimats(DBfile *dbfile,
     }
 }
 
+//-----------------------------------------------------------------------------
+// only for overlink
+void
+write_pad_dims(DBfile *dbfile,
+               const std::string &opts_mesh_name,
+               const Node &root)
+{
+    // TODO_PADDIMS add tests for this
+
+    const Node &n_mesh = root["blueprint_index"][opts_mesh_name];
+    // this only applies to structured topos 
+    // (quadmeshes, so rectilinear, uniform, and structured)
+    // we can grab the "first" topo because we know there is only one.
+    const std::string topo_type = n_mesh["topologies"][0]["type"].as_string();
+    if (topo_type == "structured" ||
+        topo_type == "rectilinear" ||
+        topo_type == "uniform")
+    {
+        char const *elemname = "paddims";
+        const int elemlength = 6;
+        const int nelems = 1;
+        const int nvalues = 6;
+
+        // we do not have a way to record ghost nodes in blueprint
+        // so we just write out all zeroes to make overlink happy
+        std::vector<int> paddim_vals;
+        paddim_vals.push_back(0);
+        paddim_vals.push_back(0);
+        paddim_vals.push_back(0);
+        paddim_vals.push_back(0);
+        paddim_vals.push_back(0);
+        paddim_vals.push_back(0);
+
+        DBPutCompoundarray(dbfile, // dbfile
+                           "PAD_DIMS", // name
+                           &elemname, // elemnames
+                           &elemlength, // elemlengths
+                           nelems, // nelems
+                           static_cast<void *>(paddim_vals.data()), // values
+                           nvalues, // nvalues
+                           DB_INT, // datatype
+                           NULL); // optlist
+    }
+}
+
 //-----------------------------------------------------------------------------
 // only for overlink
 void
@@ -6009,6 +6054,10 @@ void CONDUIT_RELAY_API write_mesh(const Node &mesh,
             write_var_attributes(dbfile.getSiloObject(),
                                  opts_out_mesh_name,
                                  root);
+
+            write_pad_dims(dbfile.getSiloObject(), 
+                           opts_out_mesh_name, 
+                           root);
         }
     }
 

src/tests/relay/t_relay_io_silo.cpp

@@ -1271,7 +1271,7 @@ TEST(conduit_relay_io_silo, round_trip_save_option_overlink1)
 }
 
 //-----------------------------------------------------------------------------
-// this tests var attributes
+// this tests var attributes and padding dimensions
 TEST(conduit_relay_io_silo, round_trip_save_option_overlink2)
 {
     const std::string basename = "silo_save_option_overlink_basic";
@@ -1304,6 +1304,73 @@ TEST(conduit_relay_io_silo, round_trip_save_option_overlink2)
     EXPECT_EQ(load_mesh[0].number_of_children(), save_mesh.number_of_children());
 
     EXPECT_FALSE(load_mesh[0].diff(save_mesh, info));
+
+    // open silo file and do some checks
+
+    DBfile *dbfile = DBOpen(filename.c_str(), DB_UNKNOWN, DB_READ);
+    EXPECT_TRUE(DBInqVarExists(dbfile, "VAR_ATTRIBUTES"));
+    EXPECT_TRUE(DBInqVarType(dbfile, "VAR_ATTRIBUTES") == DB_ARRAY);
+
+    DBcompoundarray *var_attr = DBGetCompoundarray(dbfile, "VAR_ATTRIBUTES");
+
+    // fetch pointers to elements inside the compound array
+    char **elemnames = var_attr->elemnames;
+    int *elemlengths = var_attr->elemlengths;
+    int nelems       = var_attr->nelems;
+    int *values      = static_cast<int *>(var_attr->values);
+    int nvalues      = var_attr->nvalues;
+    int datatype     = var_attr->datatype;
+
+    EXPECT_EQ(std::string(elemnames[0]), "field");
+    EXPECT_EQ(std::string(elemnames[1]), "field2");
+    EXPECT_EQ(elemlengths[0], 5);
+    EXPECT_EQ(elemlengths[1], 5);
+    EXPECT_EQ(nelems, 2);
+    // for first var
+    EXPECT_EQ(values[0], 1);
+    EXPECT_EQ(values[1], 0);
+    EXPECT_EQ(values[2], 1);
+    EXPECT_EQ(values[3], 0);
+    EXPECT_EQ(values[4], 1);
+    // for second var
+    EXPECT_EQ(values[5], 1);
+    EXPECT_EQ(values[6], 1);
+    EXPECT_EQ(values[7], 1);
+    EXPECT_EQ(values[8], 0);
+    EXPECT_EQ(values[9], 1);
+    EXPECT_EQ(nvalues, 10);
+    EXPECT_EQ(datatype, DB_INT);
+
+    DBFreeCompoundarray(var_attr);
+
+    EXPECT_TRUE(DBInqVarExists(dbfile, "PAD_DIMS"));
+    EXPECT_TRUE(DBInqVarType(dbfile, "PAD_DIMS") == DB_ARRAY);
+
+    DBcompoundarray *pad_dims = DBGetCompoundarray(dbfile, "PAD_DIMS");
+
+    // fetch pointers to elements inside the compound array
+    elemnames   = pad_dims->elemnames;
+    elemlengths = pad_dims->elemlengths;
+    nelems      = pad_dims->nelems;
+    values      = static_cast<int *>(pad_dims->values);
+    nvalues     = pad_dims->nvalues;
+    datatype    = pad_dims->datatype;
+
+    EXPECT_EQ(std::string(elemnames[0]), "paddims");
+    EXPECT_EQ(elemlengths[0], 6);
+    EXPECT_EQ(nelems, 1);
+    EXPECT_EQ(values[0], 0);
+    EXPECT_EQ(values[1], 0);
+    EXPECT_EQ(values[2], 0);
+    EXPECT_EQ(values[3], 0);
+    EXPECT_EQ(values[4], 0);
+    EXPECT_EQ(values[5], 0);
+    EXPECT_EQ(nvalues, 6);
+    EXPECT_EQ(datatype, DB_INT);
+
+    DBFreeCompoundarray(pad_dims);
+
+    DBClose(dbfile);
 }
 
 //-----------------------------------------------------------------------------
@@ -1588,6 +1655,6 @@ TEST(conduit_relay_io_silo, read_overlink_directly)
 //  - units once they are supported
 //  - etc.
 
-// TODO what are those bonus tar files doing in the overlink data dir?
+// TODO add tetra8 and c36_m5 to all the overlink i/o tests
 
 // TODO somewhere I need to error on overlink when there are different var or mesh types across domains