[PATCH v5 proxmox-backup 03/16] datastore: add TempTestDir that is automatically deleted on drop

[Robert Obkircher <r.obkircher@proxmox.com>]

This will be used to test the FixedIndexWriter and chunk store
creation.

Signed-off-by: Robert Obkircher <r.obkircher@proxmox.com>
---
 pbs-datastore/src/lib.rs           |  4 ++++
 pbs-datastore/src/temp_test_dir.rs | 33 ++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 pbs-datastore/src/temp_test_dir.rs

diff --git a/pbs-datastore/src/lib.rs b/pbs-datastore/src/lib.rs
index 1f7c54ae..b48ec93c 100644
--- a/pbs-datastore/src/lib.rs
+++ b/pbs-datastore/src/lib.rs
@@ -233,3 +233,7 @@ pub use local_chunk_reader::LocalChunkReader;
 
 mod local_datastore_lru_cache;
 pub use local_datastore_lru_cache::LocalDatastoreLruCache;
+
+#[cfg(test)]
+mod temp_test_dir;
+
diff --git a/pbs-datastore/src/temp_test_dir.rs b/pbs-datastore/src/temp_test_dir.rs
new file mode 100644
index 00000000..13e16c91
--- /dev/null
+++ b/pbs-datastore/src/temp_test_dir.rs
@@ -0,0 +1,33 @@
+use std::convert::From;
+use std::env;
+use std::path::{Path, PathBuf};
+
+/// A temporary directory for tests that is removed on drop.
+/// Deletion is best-effort and errors are silently ignored.
+pub struct TempTestDir(PathBuf);
+
+impl TempTestDir {
+    /// Create an empty directory.
+    pub fn new() -> Self {
+        Self(proxmox_sys::fs::make_tmp_dir(env::temp_dir(), None).unwrap())
+    }
+}
+
+impl std::ops::Deref for TempTestDir {
+    type Target = Path;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Drop for TempTestDir {
+    fn drop(&mut self) {
+        let _ = std::fs::remove_dir_all(&self.0);
+    }
+}
+
+impl<'a> From<&'a TempTestDir> for PathBuf {
+    fn from(temp: &'a TempTestDir) -> Self {
+        temp.0.clone()
+    }
+}
-- 
2.47.3