netcdf: add convenience methods for indexing a NetCDF file

Cargo.toml

@@ -39,6 +39,7 @@ rayon = "1.6"
 ndarray = { version = "0.15", features = [ "rayon" ] }
 pyo3 = { version = "0.17.3", optional = true, features = ["anyhow", "auto-initialize", "abi3-py38"] }
 numpy = { version = "0.17.2", optional = true }
+netcdf = { version = "^0.8", optional = true }
 
 [dependencies.serde]
 features = ["derive"]
@@ -64,9 +65,10 @@ codegen-units = 1
 debug = true
 
 [features]
-default = ["static", "fast-index"]
-static = ["hdf5-sys/static", "hdf5-sys/zlib"]
+default = ["static", "fast-index", "netcdf"]
+static = ["hdf5-sys/static", "hdf5-sys/zlib", "netcdf?/static"]
 fast-index = []
 python = ["pyo3", "numpy"]
 extension-module = ["python", "pyo3/extension-module"]
+netcdf = [ "dep:netcdf" ]
 

src/idx/index.rs

@@ -34,6 +34,17 @@ impl TryFrom<&hdf5::File> for Index<'_> {
     }
 }
 
+#[cfg(feature = "netcdf")]
+impl TryFrom<&netcdf::File> for Index<'_> {
+    type Error = anyhow::Error;
+
+    fn try_from(f: &netcdf::File) -> Result<Index<'static>, anyhow::Error> {
+        let path = PathBuf::from(&f.path()?);
+
+        Index::index(path)
+    }
+}
+
 impl Index<'_> {
     /// Open an existing HDF5 file and index all variables.
     #[allow(clippy::self_named_constructors)]
@@ -137,6 +148,21 @@ mod tests {
         r.values::<f32>(None, None).unwrap();
     }
 
+    #[test]
+    #[cfg(feature = "netcdf")]
+    fn index_from_netcdf() {
+        use std::convert::TryInto;
+
+        let f = netcdf::open("tests/data/coads_climatology.nc4").unwrap();
+        let i: Index = (&f).try_into().unwrap();
+        let mut r = i.reader("SST").unwrap();
+        let iv = r.values::<f32>(None, None).unwrap();
+
+        let nv = f.variable("SST").unwrap().values::<f32, _>(..).unwrap();
+
+        assert_eq!(iv, nv);
+    }
+
     #[test]
     fn index_from_path() {
         use std::convert::TryInto;

src/idx/mod.rs

@@ -44,6 +44,15 @@ impl IntoIndex for hdf5::Dataset {
     }
 }
 
+#[cfg(feature = "netcdf")]
+impl IntoIndex for netcdf::File {
+    type Indexed = Index<'static>;
+
+    fn index(&self) -> anyhow::Result<Self::Indexed> {
+        self.try_into()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -55,6 +64,14 @@ mod test {
         println!("index: {:#?}", i);
     }
 
+    #[test]
+    #[cfg(feature = "netcdf")]
+    fn into_idx_netcdf() {
+        let hf = netcdf::open("tests/data/coads_climatology.nc4").unwrap();
+        let i = hf.index().unwrap();
+        println!("index: {:#?}", i);
+    }
+
     #[test]
     fn into_idx_dataset() {
         let hf = hdf5::File::open("tests/data/coads_climatology.nc4").unwrap();

src/lib.rs

@@ -32,6 +32,42 @@
 //! or convert a [hdf5::File] or [hdf5::Dataset] into an index by using
 //! [`try_from`](std::convert::TryFrom) or the [`index`](idx::IntoIndex) method.
 //!
+//! or use the [IntoIndex](idx::IntoIndex) trait:
+//!
+//! ```
+//! use hidefix::prelude::*;
+//!
+//! let i = hdf5::File::open("tests/data/coads_climatology.nc4").unwrap().index().unwrap();
+//! let iv = i.reader("SST").unwrap().values::<f32>(None, None).unwrap();
+//! ```
+//!
+//! ## NetCDF4 files
+//!
+//! NetCDF4 uses HDF5 as their underlying data-format. Hidefix can be used to read the NetCDF
+//! variables, though there might be extra decoding necessary. The hidefix-`xarray` does that for
+//! you in the python bindings.
+//!
+//! ```
+//! use std::convert::TryInto;
+//! use hidefix::prelude::*;
+//!
+//! let f = netcdf::open("tests/data/coads_climatology.nc4").unwrap();
+//! let nv = f.variable("SST").unwrap().values::<f32, _>(..).unwrap();
+//!
+//! let i: Index = (&f).try_into().unwrap();
+//! let iv = i.reader("SST").unwrap().values::<f32>(None, None).unwrap();
+//!
+//! assert_eq!(iv, nv);
+//! ```
+//!
+//! or use the [IntoIndex](idx::IntoIndex) trait:
+//!
+//! ```
+//! use hidefix::prelude::*;
+//!
+//! let i = netcdf::open("tests/data/coads_climatology.nc4").unwrap().index().unwrap();
+//! let iv = i.reader("SST").unwrap().values::<f32>(None, None).unwrap();
+//! ```
 //!
 //! It is also possible to [stream](reader::stream::StreamReader) the values. The streamer is
 //! currently optimized for streaming bytes.