1 files changed, 51 insertions, 0 deletions
diff --git a/vendor/gix-index/src/file/write.rs b/vendor/gix-index/src/file/write.rs
new file mode 100644
index 000000000..1e8afc07d
--- /dev/null
+++ b/vendor/gix-index/src/file/write.rs
@@ -0,0 +1,51 @@
+use gix_features::hash;
+
+use crate::{write, File, Version};
+
+/// The error produced by [`File::write()`].
+#[derive(Debug, thiserror::Error)]
+#[allow(missing_docs)]
+pub enum Error {
+    #[error(transparent)]
+    Io(#[from] std::io::Error),
+    #[error("Could not acquire lock for index file")]
+    AcquireLock(#[from] gix_lock::acquire::Error),
+    #[error("Could not commit lock for index file")]
+    CommitLock(#[from] gix_lock::commit::Error<gix_lock::File>),
+}
+
+impl File {
+    /// Write the index to `out` with `options`, to be readable by [`File::at()`], returning the version that was actually written
+    /// to retain all information of this index.
+    pub fn write_to(
+        &self,
+        mut out: impl std::io::Write,
+        options: write::Options,
+    ) -> std::io::Result<(Version, gix_hash::ObjectId)> {
+        let mut hasher = hash::Write::new(&mut out, self.state.object_hash);
+        let version = self.state.write_to(&mut hasher, options)?;
+
+        let hash = hasher.hash.digest();
+        out.write_all(&hash)?;
+        Ok((version, gix_hash::ObjectId::from(hash)))
+    }
+
+    /// Write ourselves to the path we were read from after acquiring a lock, using `options`.
+    ///
+    /// Note that the hash produced will be stored which is why we need to be mutable.
+    pub fn write(&mut self, options: write::Options) -> Result<(), Error> {
+        let mut lock = std::io::BufWriter::new(gix_lock::File::acquire_to_update_resource(
+            &self.path,
+            gix_lock::acquire::Fail::Immediately,
+            None,
+        )?);
+        let (version, digest) = self.write_to(&mut lock, options)?;
+        match lock.into_inner() {
+            Ok(lock) => lock.commit()?,
+            Err(err) => return Err(err.into_error().into()),
+        };
+        self.state.version = version;
+        self.checksum = Some(digest);
+        Ok(())
+    }
+}