fix: Add warning about unsorted files and sort where neccessary

crates/core/src/backend/decrypt.rs

@@ -133,6 +133,8 @@ pub trait DecryptReadBackend: ReadBackend + Clone + 'static {
 
     /// Streams all files.
     ///
+    /// Note: The result comes in arbitrary order!
+    ///
     /// # Arguments
     ///
     /// * `p` - The progress bar.
@@ -145,11 +147,13 @@ pub trait DecryptReadBackend: ReadBackend + Clone + 'static {
         p: &impl Progress,
     ) -> RusticResult<Receiver<RusticResult<(Id, F)>>> {
         let list = self.list(F::TYPE).map_err(RusticErrorKind::Backend)?;
-        self.stream_list(list, p)
+        self.stream_list(&list, p)
     }
 
     /// Streams a list of files.
     ///
+    /// Note: The result comes in arbitrary order!
+    ///
     /// # Arguments
     ///
     /// * `list` - The list of files to stream.
@@ -160,15 +164,15 @@ pub trait DecryptReadBackend: ReadBackend + Clone + 'static {
     /// If the files could not be read.
     fn stream_list<F: RepoFile>(
         &self,
-        list: Vec<Id>,
+        list: &[Id],
         p: &impl Progress,
     ) -> RusticResult<Receiver<RusticResult<(Id, F)>>> {
         p.set_length(list.len() as u64);
         let (tx, rx) = unbounded();
 
         list.into_par_iter()
             .for_each_with((self, p, tx), |(be, p, tx), id| {
-                let file = be.get_file::<F>(&id).map(|file| (id, file));
+                let file = be.get_file::<F>(id).map(|file| (*id, file));
                 p.inc(1);
                 tx.send(file).unwrap();
             });

crates/core/src/commands/prune.rs

@@ -1460,14 +1460,14 @@ fn find_used_blobs(
     let ignore_snaps: BTreeSet<_> = ignore_snaps.iter().collect();
 
     let p = pb.progress_counter("reading snapshots...");
-    let list = be
+    let list: Vec<_> = be
         .list(FileType::Snapshot)
         .map_err(RusticErrorKind::Backend)?
         .into_iter()
         .filter(|id| !ignore_snaps.contains(id))
         .collect();
     let snap_trees: Vec<_> = be
-        .stream_list::<SnapshotFile>(list, &p)?
+        .stream_list::<SnapshotFile>(&list, &p)?
         .into_iter()
         .map_ok(|(_, snap)| snap.tree)
         .try_collect()?;

crates/core/src/repofile/snapshotfile.rs

@@ -1,5 +1,6 @@
 use std::{
     cmp::Ordering,
+    collections::BTreeMap,
     fmt::{self, Display},
     path::{Path, PathBuf},
     str::FromStr,
@@ -550,10 +551,14 @@
         p: &impl Progress,
     ) -> RusticResult<Vec<Self>> {
         let ids = be.find_ids(FileType::Snapshot, ids)?;
-        be.stream_list::<Self>(ids, p)?
+        let mut list: BTreeMap<_, _> =
+            be.stream_list::<Self>(&ids, p)?.into_iter().try_collect()?;
+        // sort back to original order
+        Ok(ids
             .into_iter()
-            .map_ok(Self::set_id)
-            .try_collect()
+            .filter_map(|id| list.remove_entry(&id))
+            .map(Self::set_id)
+            .collect())
     }
 
     /// Compare two [`SnapshotFile`]s by criteria from [`SnapshotGroupCriterion`].

crates/core/src/repository.rs

@@ -947,6 +947,9 @@ impl<P: ProgressBars, S: Open> Repository<P, S> {
     ///
     /// # Errors
     ///
+    /// # Note
+    ///  The result is not sorted and may come in random order!
+    ///
     // TODO: Document errors
     pub fn get_matching_snapshots(
         &self,
@@ -1223,6 +1226,9 @@ impl<P: ProgressBars, S: Open> Repository<P, S> {
     ///
     /// # Returns
     ///
+    /// # Note
+    ///  The result is not sorted and may come in random order!
+    ///
     /// An iterator over all files of the given type
     pub fn stream_files<F: RepoFile>(
         &self,

crates/core/tests/integration.rs

@@ -248,6 +248,18 @@ fn test_backup_with_tar_gz_passes(
     // pack files should be unchanged
     let packs2: Vec<_> = repo.list(rustic_core::FileType::Pack)?.collect();
     assert_eq!(packs1, packs2);
+
+    // Check if snapshots can be retrieved
+    let mut ids: Vec<_> = all_snapshots.iter().map(|sn| sn.id.to_string()).collect();
+    let snaps = repo.get_snapshots(&ids)?;
+    assert_eq!(snaps, all_snapshots);
+
+    // reverse order
+    all_snapshots.reverse();
+    ids.reverse();
+    let snaps = repo.get_snapshots(&ids)?;
+    assert_eq!(snaps, all_snapshots);
+
     Ok(())
 }