Merge #273

273: MDArray r=jdroenner a=ChristianBeilschmidt

- [X] I agree to follow the project's [code of conduct](https://github.com/georust/gdal/blob/master/CODE_OF_CONDUCT.md).
- [x] I added an entry to `CHANGES.md` if knowledge of this change could be valuable to users.
---

I rebased and extended the following PR since it seems to be inactive:
#233

I tried to solve my own suggestions. However, please take a look at everything.

Moreover, I ran the tests with
`RUSTFLAGS="-Z sanitizer=leak" cargo +nightly-2022-04-12-x86_64-unknown-linux-gnu test --all-features -- raster::mdarray::tests`
to check for memory leaks.

All new NetCDF files are taken from GDAL's repo at OSGeo.

Co-authored-by: Leonardo Hardtke <[email protected]>
Co-authored-by: Christian Beilschmidt <[email protected]>

Author: 3 people

CHANGES.md

@@ -31,6 +31,10 @@
 
   - <https://github.com/georust/gdal/pull/246>
 
+- Add support for MDArray API
+
+  - <https://github.com/georust/gdal/pull/273>
+
 ## 0.12
 
 - Bump Rust edition to 2021

fixtures/alldatatypes.nc

@@ -17,12 +17,16 @@ use crate::{
     gdal_major_object::MajorObject, raster::RasterBand, spatial_ref::SpatialRef, vector::Layer,
     Driver, Metadata,
 };
+
 use gdal_sys::OGRGeometryH;
 use gdal_sys::{
     self, CPLErr, GDALAccess, GDALDatasetH, GDALMajorObjectH, OGRErr, OGRLayerH, OGRwkbGeometryType,
 };
 use libc::{c_double, c_int, c_uint};
 
+#[cfg(all(major_ge_3, minor_ge_1))]
+use crate::raster::Group;
+
 use bitflags::bitflags;
 
 /// A 2-D affine transform mapping pixel coordiates to world
@@ -415,6 +419,23 @@ impl Dataset {
         }
     }
 
+    /// Opens the root group of a multi-dim GDAL raster
+    ///
+    /// # Note
+    /// You must have opened the dataset with the `GdalOpenFlags::GDAL_OF_MULTIDIM_RASTER`
+    /// flag in order for it to work.
+    ///
+    #[cfg(all(major_ge_3, minor_ge_1))]
+    pub fn root_group(&self) -> Result<Group> {
+        unsafe {
+            let c_group = gdal_sys::GDALDatasetGetRootGroup(self.c_dataset());
+            if c_group.is_null() {
+                return Err(_last_null_pointer_err("GDALDatasetGetRootGroup"));
+            }
+            Ok(Group::from_c_group(self, c_group))
+        }
+    }
+
     /// Builds overviews for the current `Dataset`. See [`GDALBuildOverviews`].
     ///
     /// # Arguments