GDALWriter: Write features directly if they have no array columns

isciences · Jan 8, 2024 · b476a40 · b476a40
1 parent 3f67a2c
commit b476a40
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Showing 3 changed files with 20 additions and 7 deletions.
diff --git a/src/deferred_gdal_writer.cpp b/src/deferred_gdal_writer.cpp
@@ -37,7 +37,13 @@ DeferredGDALWriter::finish()
     for (const auto& feature : m_features) {
         for (const auto& [field_name, _] : feature.map()) {
             if (ogr_fields.find(field_name) == ogr_fields.end()) {
-                OGRFieldType field_type = ogr_type(feature.field_type(field_name), m_unnest);
+                const auto& typ = feature.field_type(field_name);
+
+                if (typ == typeid(Feature::DoubleArray) || typ == typeid(Feature::IntegerArray) || typ == typeid(Feature::Integer64Array)) {
+                    m_contains_nested_fields = true;
+                }
+
+                OGRFieldType field_type = ogr_type(typ, m_unnest_if_needed);
                 ogr_fields[field_name] = OGR_Fld_Create(field_name.c_str(), field_type);
             }
         }
@@ -59,7 +65,7 @@ DeferredGDALWriter::finish()
 
     OGRFeatureDefnH defn = OGR_L_GetLayerDefn(m_layer);
     for (const auto& feature : m_features) {
-        if (m_unnest) {
+        if (m_unnest_if_needed && m_contains_nested_fields) {
             GDALFeatureUnnester unnester(feature, defn);
             unnester.unnest();
 

diff --git a/src/gdal_writer.cpp b/src/gdal_writer.cpp
@@ -30,7 +30,7 @@
 namespace exactextract {
 GDALWriter::
   GDALWriter(const std::string& filename, bool unnest)
-  : m_unnest(unnest)
+  : m_unnest_if_needed(unnest)
 {
     auto driver_name = get_driver_name(filename);
     auto driver = OGRGetDriverByName(driver_name.c_str());
@@ -62,7 +62,7 @@ std::unique_ptr<Feature>
 GDALWriter::create_feature()
 {
     auto defn = OGR_L_GetLayerDefn(m_layer);
-    if (m_unnest) {
+    if (m_unnest_if_needed && m_contains_nested_fields) {
         return std::make_unique<MapFeature>();
     }
     return std::make_unique<GDALFeature>(OGR_F_Create(defn));
@@ -101,7 +101,13 @@ GDALWriter::add_operation(const Operation& op)
     op.set_empty_result(mf);
 
     for (const auto& field_name : op.field_names()) {
-        OGRFieldType ogr_typ = ogr_type(mf.field_type(field_name), m_unnest);
+        const auto& typ = mf.field_type(field_name);
+
+        if (typ == typeid(Feature::DoubleArray) || typ == typeid(Feature::IntegerArray) || typ == typeid(Feature::Integer64Array)) {
+            m_contains_nested_fields = true;
+        }
+
+        OGRFieldType ogr_typ = ogr_type(typ, m_unnest_if_needed);
 
         auto def = OGR_Fld_Create(field_name.c_str(), ogr_typ);
         OGR_L_CreateField(m_layer, def, true);
@@ -112,7 +118,7 @@ GDALWriter::add_operation(const Operation& op)
 void
 GDALWriter::write(const Feature& f)
 {
-    if (m_unnest) {
+    if (m_unnest_if_needed && m_contains_nested_fields) {
         auto defn = OGR_L_GetLayerDefn(m_layer);
 
         GDALFeatureUnnester unnester(f, defn);

diff --git a/src/gdal_writer.h b/src/gdal_writer.h
@@ -44,7 +44,8 @@ class GDALWriter : public OutputWriter
     GDALDatasetH m_dataset;
     OGRLayerH m_layer;
 
-    bool m_unnest = true;
+    bool m_unnest_if_needed = true;
+    bool m_contains_nested_fields = false;
 };
 
 }