Merge pull request #136 from mulimoen/feature/sync

Add sync call

netcdf/src/file.rs

@@ -19,12 +19,18 @@ pub(crate) struct RawFile {
     ncid: nc_type,
 }
 
+impl RawFile {
+    fn close(self) -> error::Result<()> {
+        let Self { ncid } = self;
+        error::checked(super::with_lock(|| unsafe { nc_close(ncid) }))
+    }
+}
+
 impl Drop for RawFile {
     fn drop(&mut self) {
-        unsafe {
-            // Can't really do much with an error here
-            let _err = error::checked(super::with_lock(|| nc_close(self.ncid)));
-        }
+        // Can't really do much with an error here
+        let ncid = self.ncid;
+        let _err = error::checked(super::with_lock(|| unsafe { nc_close(ncid) }));
     }
 }
 
@@ -245,6 +251,15 @@ impl File {
     pub fn types(&self) -> error::Result<impl Iterator<Item = super::types::VariableType>> {
         super::types::all_at_location(self.ncid()).map(|x| x.map(Result::unwrap))
     }
+
+    /// Close the file
+    ///
+    /// Note: This is called automatically by `Drop`, but can be useful
+    /// if flushing data or closing the file would result in an error.
+    pub fn close(self) -> error::Result<()> {
+        let Self(file) = self;
+        file.close()
+    }
 }
 
 /// Mutable access to file.
@@ -423,6 +438,26 @@ impl FileMut {
         let (ncid, name) = super::group::get_parent_ncid_and_stem(self.ncid(), name)?;
         super::variable::add_variable_from_identifiers(ncid, name, dims, T::NCTYPE)
     }
+
+    /// Flush pending buffers to disk to minimise data loss in case of termination.
+    ///
+    /// Note: When writing and reading from the same file from multiple processes
+    /// it is recommended to instead open the file in both the reader and
+    /// writer process with the [`Options::SHARE`] flag.
+    pub fn sync(&self) -> error::Result<()> {
+        error::checked(super::with_lock(|| unsafe {
+            netcdf_sys::nc_sync(self.ncid())
+        }))
+    }
+
+    /// Close the file
+    ///
+    /// Note: This is called automatically by `Drop`, but can be useful
+    /// if flushing data or closing the file would result in an error.
+    pub fn close(self) -> error::Result<()> {
+        let Self(File(file)) = self;
+        file.close()
+    }
 }
 
 #[cfg(feature = "has-mmap")]

netcdf/tests/lib.rs

@@ -1743,3 +1743,28 @@ fn ndarray_get_into() {
         .unwrap();
     assert_eq!(values, outarray.slice(s![0, .., .., ..]));
 }
+
+#[test]
+fn sync_file() {
+    let d = tempfile::tempdir().unwrap();
+    let path = d.path().join("sync_file.nc");
+
+    let mut f = netcdf::create(path).unwrap();
+
+    f.add_unlimited_dimension("t").unwrap();
+    f.sync().unwrap();
+}
+
+#[test]
+fn close_file() {
+    let d = tempfile::tempdir().unwrap();
+    let path = d.path().join("close_file.nc");
+
+    let mut f = netcdf::create(&path).unwrap();
+
+    f.add_unlimited_dimension("t").unwrap();
+    f.close().unwrap();
+
+    let f = netcdf::open(path).unwrap();
+    f.close().unwrap();
+}