From 00a092239367ed5d5906c3d195784343cd6b07d9 Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <magnus@ulimoen.dev>
Date: Thu, 28 Mar 2024 15:09:08 +0100
Subject: [PATCH 1/2] Add sync call

---
 netcdf/src/file.rs  | 11 +++++++++++
 netcdf/tests/lib.rs | 11 +++++++++++
 2 files changed, 22 insertions(+)

diff --git a/netcdf/src/file.rs b/netcdf/src/file.rs
index 17a8029..4a9d20f 100644
--- a/netcdf/src/file.rs
+++ b/netcdf/src/file.rs
@@ -423,6 +423,17 @@ 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())
+        }))
+    }
 }
 
 #[cfg(feature = "has-mmap")]
diff --git a/netcdf/tests/lib.rs b/netcdf/tests/lib.rs
index 8913db7..b0ca837 100644
--- a/netcdf/tests/lib.rs
+++ b/netcdf/tests/lib.rs
@@ -1743,3 +1743,14 @@ 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();
+}

From c868e4515625fe6300373f619eb3511ff129d152 Mon Sep 17 00:00:00 2001
From: Magnus Ulimoen <magnus@ulimoen.dev>
Date: Thu, 28 Mar 2024 15:52:59 +0100
Subject: [PATCH 2/2] Add close call to catch IO errors

---
 netcdf/src/file.rs  | 32 ++++++++++++++++++++++++++++----
 netcdf/tests/lib.rs | 14 ++++++++++++++
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/netcdf/src/file.rs b/netcdf/src/file.rs
index 4a9d20f..0443594 100644
--- a/netcdf/src/file.rs
+++ b/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.
@@ -434,6 +449,15 @@ impl FileMut {
             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")]
diff --git a/netcdf/tests/lib.rs b/netcdf/tests/lib.rs
index b0ca837..e714983 100644
--- a/netcdf/tests/lib.rs
+++ b/netcdf/tests/lib.rs
@@ -1754,3 +1754,17 @@ fn sync_file() {
     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();
+}