Add rename syscall to FilesystemClient

This patch adds a rename syscall to the FilesystemClient that allows
applications to move a file within the same storage location and within
the client namespace.

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added `init_raw` constructor for types generated by the `store!` macro.
 - Added `FilesystemClient::entry_metadata` syscall.
+- Added `FilesystemClient::rename` syscall.
 - Added `Syscall` implementation for `Service`.
 - Added `Syscall::try_into_new_client` service.
 - Added serializable flag to `StorageAttributes` for key agreement.

src/api.rs

@@ -49,6 +49,7 @@ generate_enums! {
     ReadDirFilesNext: 14
     ReadFile: 15
     Metadata: 26
+    Rename: 27
     // ReadCounter: 7
     RandomBytes: 16
     SerializeKey: 17
@@ -255,6 +256,11 @@ pub mod request {
           - location: Location
           - path: PathBuf
 
+        Rename:
+          - location: Location
+          - from: PathBuf
+          - to: PathBuf
+
         RemoveFile:
           - location: Location
           - path: PathBuf
@@ -449,6 +455,8 @@ pub mod reply {
         Metadata:
           - metadata: Option<crate::types::Metadata>
 
+        Rename:
+
         RemoveDir:
 
         RemoveDirAll:

src/client.rs

@@ -666,6 +666,19 @@ pub trait FilesystemClient: PollClient {
         self.request(request::Metadata { location, path })
     }
 
+    /// Rename a file or directory.
+    ///
+    /// If `to` exists, it must be the same type as `from` (i. e., both must be files or both must
+    /// be directories).  If `to` is a directory, it must be empty.
+    fn rename(
+        &mut self,
+        location: Location,
+        from: PathBuf,
+        to: PathBuf,
+    ) -> ClientResult<'_, reply::Rename, Self> {
+        self.request(request::Rename { location, from, to })
+    }
+
     fn locate_file(
         &mut self,
         location: Location,

src/service.rs

@@ -447,6 +447,11 @@ impl<P: Platform> ServiceResources<P> {
                 }))
             }
 
+            Request::Rename(request) => {
+                filestore.rename(&request.from, &request.to, request.location)?;
+                Ok(Reply::Rename(reply::Rename {}))
+            }
+
             Request::RandomBytes(request) => {
                 if request.count <= MAX_MESSAGE_LENGTH {
                     let mut bytes = Message::new();

src/store.rs

@@ -594,6 +594,17 @@ pub fn metadata(
     }
 }
 
+#[inline(never)]
+pub fn rename(store: impl Store, location: Location, from: &Path, to: &Path) -> Result<(), Error> {
+    debug_now!("renaming {} to {}", &from, &to);
+    match location {
+        Location::Internal => store.ifs().rename(from, to),
+        Location::External => store.efs().rename(from, to),
+        Location::Volatile => store.vfs().rename(from, to),
+    }
+    .map_err(|_| Error::FilesystemWriteFailure)
+}
+
 #[inline(never)]
 pub fn remove_dir(store: impl Store, location: Location, path: &Path) -> bool {
     debug_now!("remove_dir'ing {}", &path);

src/store/filestore.rs

@@ -80,6 +80,7 @@ pub trait Filestore {
     fn write(&mut self, path: &Path, location: Location, data: &[u8]) -> Result<()>;
     fn exists(&mut self, path: &Path, location: Location) -> bool;
     fn metadata(&mut self, path: &Path, location: Location) -> Result<Option<Metadata>>;
+    fn rename(&mut self, from: &Path, to: &Path, location: Location) -> Result<()>;
     fn remove_file(&mut self, path: &Path, location: Location) -> Result<()>;
     fn remove_dir(&mut self, path: &Path, location: Location) -> Result<()>;
     fn remove_dir_all(&mut self, path: &Path, location: Location) -> Result<usize>;
@@ -376,6 +377,12 @@ impl<S: Store> Filestore for ClientFilestore<S> {
         store::metadata(self.store, location, &path)
     }
 
+    fn rename(&mut self, from: &Path, to: &Path, location: Location) -> Result<()> {
+        let from = self.actual_path(from)?;
+        let to = self.actual_path(to)?;
+        store::rename(self.store, location, &from, &to)
+    }
+
     fn remove_file(&mut self, path: &Path, location: Location) -> Result<()> {
         let path = self.actual_path(path)?;