pxar: Refactor SequentialDecoder to store the callback function within the struct

Reduces the number of arguments for the function calls within the decoder.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>

src/bin/proxmox-backup-client.rs

@@ -649,14 +649,14 @@ fn restore(
     let mut reader = BufferedDynamicReader::new(index, chunk_reader);
 
     let feature_flags = pxar::CA_FORMAT_DEFAULT;
-    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags);
-
-    decoder.restore(Path::new(target), & |path| {
+    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags, |path| {
         if verbose {
             println!("{:?}", path);
         }
         Ok(())
-    })?;
+    });
+
+    decoder.restore(Path::new(target))?;
 
     Ok(Value::Null)
 }

src/bin/pxar.rs

@@ -30,7 +30,7 @@ fn print_filenames(
     let mut feature_flags = pxar::CA_FORMAT_DEFAULT;
     feature_flags ^= pxar::CA_FORMAT_WITH_XATTRS;
     feature_flags ^= pxar::CA_FORMAT_WITH_FCAPS;
-    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags);
+    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags, |_| Ok(()));
 
     let stdout = std::io::stdout();
     let mut out = stdout.lock();
@@ -65,7 +65,7 @@ fn dump_archive(
     if !with_acls {
         feature_flags ^= pxar::CA_FORMAT_WITH_ACL;
     }
-    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags);
+    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags, |_| Ok(()));
 
     let stdout = std::io::stdout();
     let mut out = stdout.lock();
@@ -105,14 +105,14 @@ fn extract_archive(
         feature_flags ^= pxar::CA_FORMAT_WITH_ACL;
     }
 
-    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags);
-
-    decoder.restore(Path::new(target), & |path| {
+    let mut decoder = pxar::SequentialDecoder::new(&mut reader, feature_flags, |path| {
         if verbose {
             println!("{:?}", path);
         }
         Ok(())
-    })?;
+    });
+
+    decoder.restore(Path::new(target))?;
 
     Ok(Value::Null)
 }

src/client/pxar_decode_writer.rs

@@ -31,14 +31,14 @@ impl PxarDecodeWriter {
         
         let child = thread::spawn(move|| {
             let mut reader = unsafe { std::fs::File::from_raw_fd(rx) };
-            let mut decoder = pxar::SequentialDecoder::new(&mut reader, pxar::CA_FORMAT_DEFAULT);
-          
-            if let Err(err) = decoder.restore(&base, & |path| {
+            let mut decoder = pxar::SequentialDecoder::new(&mut reader, pxar::CA_FORMAT_DEFAULT, |path| {
                 if verbose {
                     println!("{:?}", path);
                 }
                 Ok(())
-            }) {
+            });
+
+            if let Err(err) = decoder.restore(&base) {
                 eprintln!("pxar decode failed - {}", err);
             }
         });

src/pxar/decoder.rs

@@ -21,22 +21,22 @@ pub struct CaDirectoryEntry {
 }
 
 // This one needs Read+Seek
-pub struct Decoder<'a, R: Read + Seek> {
-    inner: SequentialDecoder<'a, R>,
+pub struct Decoder<'a, R: Read + Seek, F: Fn(&Path) -> Result<(), Error>> {
+    inner: SequentialDecoder<'a, R, F>,
     root_start: u64,
     root_end: u64,
 }
 
 const HEADER_SIZE: u64 = std::mem::size_of::<CaFormatHeader>() as u64;
 
-impl <'a, R: Read + Seek> Decoder<'a, R> {
+impl <'a, R: Read + Seek, F: Fn(&Path) -> Result<(), Error>> Decoder<'a, R, F> {
 
-    pub fn new(reader: &'a mut R) -> Result<Self, Error> {
+    pub fn new(reader: &'a mut R, callback: F) -> Result<Self, Error> {
 
         let root_end = reader.seek(SeekFrom::End(0))?;
 
         Ok(Self {
-            inner: SequentialDecoder::new(reader, CA_FORMAT_DEFAULT),
+            inner: SequentialDecoder::new(reader, CA_FORMAT_DEFAULT, callback),
             root_start: 0,
             root_end: root_end,
         })
@@ -62,19 +62,16 @@ impl <'a, R: Read + Seek> Decoder<'a, R> {
         Ok(pos)
     }
 
-    pub fn restore<F>(
+    pub fn restore(
         &mut self,
         dir: &CaDirectoryEntry,
         path: &Path,
-        callback: F,
-    ) -> Result<(), Error>
-        where F: Fn(&Path) -> Result<(), Error>
-    {
+    ) -> Result<(), Error> {
         let start = dir.start;
 
         self.seek(SeekFrom::Start(start))?;
 
-        self.inner.restore(path, &callback)?;
+        self.inner.restore(path)?;
 
         Ok(())
     }

src/pxar/sequential_decoder.rs

@@ -29,23 +29,25 @@ use crate::tools::acl;
 use crate::tools::xattr;
 
 // This one need Read, but works without Seek
-pub struct SequentialDecoder<'a, R: Read> {
+pub struct SequentialDecoder<'a, R: Read, F: Fn(&Path) -> Result<(), Error>> {
     reader: &'a mut R,
     feature_flags: u64,
     skip_buffer: Vec<u8>,
+    callback: F,
 }
 
 const HEADER_SIZE: u64 = std::mem::size_of::<CaFormatHeader>() as u64;
 
-impl <'a, R: Read> SequentialDecoder<'a, R> {
+impl <'a, R: Read, F: Fn(&Path) -> Result<(), Error>> SequentialDecoder<'a, R, F> {
 
-    pub fn new(reader: &'a mut R, feature_flags: u64) -> Self {
+    pub fn new(reader: &'a mut R, feature_flags: u64, callback: F) -> Self {
         let skip_buffer = vec::undefined(64*1024);
 
         Self {
             reader,
             feature_flags,
-            skip_buffer
+            skip_buffer,
+            callback,
         }
     }
 
@@ -450,13 +452,7 @@ impl <'a, R: Read> SequentialDecoder<'a, R> {
     /// Restore an archive into the specified directory.
     ///
     /// The directory is created if it does not exist.
-    pub fn restore<F>(
-        &mut self,
-        path: &Path,
-        callback: &F,
-    ) -> Result<(), Error>
-        where F: Fn(&Path) -> Result<(), Error>
-    {
+    pub fn restore(&mut self, path: &Path) -> Result<(), Error> {
 
         let _ = std::fs::create_dir(path);
 
@@ -464,25 +460,22 @@ impl <'a, R: Read> SequentialDecoder<'a, R> {
             .map_err(|err| format_err!("unable to open target directory {:?} - {}", path, err))?;
 
         let mut relative_path = PathBuf::new();
-        self.restore_sequential(path, &mut relative_path, &OsString::new(), &dir, callback)
+        self.restore_sequential(path, &mut relative_path, &OsString::new(), &dir)
     }
 
-    fn restore_sequential<F>(
+    fn restore_sequential(
         &mut self,
         base_path: &Path,
         relative_path: &mut PathBuf,
         filename: &OsStr,  // repeats path last relative_path component
         parent: &nix::dir::Dir,
-        callback: &F,
-    ) -> Result<(), Error>
-        where F: Fn(&Path) -> Result<(), Error>
-    {
+    ) -> Result<(), Error> {
 
         let parent_fd = parent.as_raw_fd();
 
         let full_path = base_path.join(&relative_path);
 
-        (callback)(&full_path)?;
+        (self.callback)(&full_path)?;
 
         let head: CaFormatHeader = self.read_item()?;
 
@@ -519,7 +512,7 @@ impl <'a, R: Read> SequentialDecoder<'a, R> {
             while head.htype == CA_FORMAT_FILENAME {
                 let name = self.read_filename(head.size)?;
                 relative_path.push(&name);
-                self.restore_sequential(base_path, relative_path, &name, &dir, callback)?;
+                self.restore_sequential(base_path, relative_path, &name, &dir)?;
                 relative_path.pop();
 
                 head = self.read_item()?;