[pbs-devel] [PATCH v3 proxmox-backup 15/58] client: pxar: switch to stack based encoder state

[Christian Ebner]

In preparation for look-ahead caching where a passing around of
different encoder instances with internal references would not be
feasible to use.

Previously, for each directory level a new encoder instance has been
generated, reducing possible implementation errors. These encoder
instances have been internally linked by references to keep track of
the state changes in a parent child relationship.

This is however not feasible when the encoder has to be passed by
mutable reference, as is the case for the look-ahead cache
implementation. The encoder has therefore been adapted to use a'
single object implementation with an internal stack keeping track of
the state.

Depends on the pxar library version.

Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
---
changes since version 2:
- pass optional parameter to constructor for encoder/decoder/accessor
- finalize encoder via close method call

 pbs-client/src/pxar/create.rs             | 8 +++++---
 src/api2/admin/datastore.rs               | 2 +-
 src/api2/tape/restore.rs                  | 4 ++--
 src/tape/file_formats/snapshot_archive.rs | 3 ++-
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/pbs-client/src/pxar/create.rs b/pbs-client/src/pxar/create.rs
index 60efb0ce5..c9bf6df85 100644
--- a/pbs-client/src/pxar/create.rs
+++ b/pbs-client/src/pxar/create.rs
@@ -170,7 +170,7 @@ where
         set.insert(stat.st_dev);
     }
 
-    let mut encoder = Encoder::new(&mut writer, &metadata).await?;
+    let mut encoder = Encoder::new(&mut writer, &metadata, None).await?;
 
     let mut patterns = options.patterns;
 
@@ -203,6 +203,8 @@ where
         .archive_dir_contents(&mut encoder, source_dir, true)
         .await?;
     encoder.finish().await?;
+    encoder.close().await?;
+
     Ok(())
 }
 
@@ -663,7 +665,7 @@ impl Archiver {
     ) -> Result<(), Error> {
         let dir_name = OsStr::from_bytes(dir_name.to_bytes());
 
-        let mut encoder = encoder.create_directory(dir_name, metadata).await?;
+        encoder.create_directory(dir_name, metadata).await?;
 
         let old_fs_magic = self.fs_magic;
         let old_fs_feature_flags = self.fs_feature_flags;
@@ -686,7 +688,7 @@ impl Archiver {
             log::info!("skipping mount point: {:?}", self.path);
             Ok(())
         } else {
-            self.archive_dir_contents(&mut encoder, dir, false).await
+            self.archive_dir_contents(encoder, dir, false).await
         };
 
         self.fs_magic = old_fs_magic;
diff --git a/src/api2/admin/datastore.rs b/src/api2/admin/datastore.rs
index f7164b877..10e3185b6 100644
--- a/src/api2/admin/datastore.rs
+++ b/src/api2/admin/datastore.rs
@@ -1713,7 +1713,7 @@ pub fn pxar_file_download(
         let archive_size = reader.archive_size();
         let reader = LocalDynamicReadAt::new(reader);
 
-        let decoder = Accessor::new(reader, archive_size).await?;
+        let decoder = Accessor::new(reader, archive_size, None).await?;
         let root = decoder.open_root().await?;
         let path = OsStr::from_bytes(file_path).to_os_string();
         let file = root
diff --git a/src/api2/tape/restore.rs b/src/api2/tape/restore.rs
index 8273c867a..50ea8da1c 100644
--- a/src/api2/tape/restore.rs
+++ b/src/api2/tape/restore.rs
@@ -1066,7 +1066,7 @@ fn restore_snapshots_to_tmpdir(
                     "File {file_num}: snapshot archive {source_datastore}:{snapshot}",
                 );
 
-                let mut decoder = pxar::decoder::sync::Decoder::from_std(reader)?;
+                let mut decoder = pxar::decoder::sync::Decoder::from_std(reader, None)?;
 
                 let target_datastore = match store_map.target_store(&source_datastore) {
                     Some(datastore) => datastore,
@@ -1677,7 +1677,7 @@ fn restore_snapshot_archive<'a>(
     reader: Box<dyn 'a + TapeRead>,
     snapshot_path: &Path,
 ) -> Result<bool, Error> {
-    let mut decoder = pxar::decoder::sync::Decoder::from_std(reader)?;
+    let mut decoder = pxar::decoder::sync::Decoder::from_std(reader, None)?;
     match try_restore_snapshot_archive(worker, &mut decoder, snapshot_path) {
         Ok(_) => Ok(true),
         Err(err) => {
diff --git a/src/tape/file_formats/snapshot_archive.rs b/src/tape/file_formats/snapshot_archive.rs
index 252384b50..43d1cf9c3 100644
--- a/src/tape/file_formats/snapshot_archive.rs
+++ b/src/tape/file_formats/snapshot_archive.rs
@@ -59,7 +59,7 @@ pub fn tape_write_snapshot_archive<'a>(
         }
 
         let mut encoder =
-            pxar::encoder::sync::Encoder::new(PxarTapeWriter::new(writer), &root_metadata)?;
+            pxar::encoder::sync::Encoder::new(PxarTapeWriter::new(writer), &root_metadata, None)?;
 
         for filename in file_list.iter() {
             let mut file = snapshot_reader.open_file(filename).map_err(|err| {
@@ -89,6 +89,7 @@ pub fn tape_write_snapshot_archive<'a>(
             }
         }
         encoder.finish()?;
+        encoder.close()?;
         Ok(())
     });
 
-- 
2.39.2