remove redundant File::reader fn

hermes/bin/src/hdf5/dir.rs

@@ -263,14 +263,12 @@ mod tests {
         dir.copy_resource_file(&FsResource::new(file_1), file_1_name.into())
             .expect("Failed to copy file to package.");
 
-        let file_1 = dir
+        let mut file_1 = dir
             .get_file(file_1_name.into())
             .expect("Failed to get file.");
 
         let mut data = Vec::new();
         file_1
-            .reader()
-            .expect("Failed to get file reader.")
             .read_to_end(&mut data)
             .expect("Failed to read file's data.");
         assert_eq!(data.as_slice(), file_content);

hermes/bin/src/hdf5/file.rs

@@ -1,7 +1,5 @@
 //! A Hermes HDF5 file abstraction over the HDF5 dataset object.
 
-use std::io::Read;
-
 use super::{compression::enable_compression, Path};
 
 /// Hermes HDF5 file object, wrapper of `hdf5::Dataset`
@@ -39,11 +37,6 @@ impl File {
         Path::from_str(&self.hdf5_ds.name())
     }
 
-    /// Return file reader.
-    pub(crate) fn reader(&self) -> anyhow::Result<impl Read> {
-        Ok(self.hdf5_ds.as_byte_reader()?)
-    }
-
     /// Return file size.
     fn size(&self) -> anyhow::Result<usize> {
         let dataspace = self.hdf5_ds.space()?;
@@ -85,8 +78,44 @@ impl std::io::Read for File {
     }
 }
 
+impl std::io::Seek for File {
+    fn seek(&mut self, pos: std::io::SeekFrom) -> std::io::Result<u64> {
+        let (base_pos, offset) = match pos {
+            std::io::SeekFrom::Start(n) => {
+                self.pos = n.try_into().map_err(map_to_io_error)?;
+                return Ok(n);
+            },
+            std::io::SeekFrom::End(n) => (self.size().map_err(map_to_io_error)?, n),
+            std::io::SeekFrom::Current(n) => (self.pos, n),
+        };
+        let new_pos = if offset.is_negative() {
+            base_pos.checked_sub(offset.wrapping_abs().try_into().map_err(map_to_io_error)?)
+        } else {
+            base_pos.checked_add(offset.try_into().map_err(map_to_io_error)?)
+        };
+        match new_pos {
+            Some(n) => {
+                self.pos = n;
+                Ok(self.pos.try_into().map_err(map_to_io_error)?)
+            },
+            None => {
+                Err(std::io::Error::new(
+                    std::io::ErrorKind::InvalidInput,
+                    "Invalid seek to a negative or overflowing position",
+                ))
+            },
+        }
+    }
+
+    fn stream_position(&mut self) -> std::io::Result<u64> {
+        self.pos.try_into().map_err(map_to_io_error)
+    }
+}
+
 #[cfg(test)]
 mod tests {
+    use std::io::Read;
+
     use temp_dir::TempDir;
 
     use super::*;

hermes/bin/src/packaging/app/mod.rs

@@ -205,7 +205,7 @@ impl ApplicationPackage {
         self.0
             .get_file(Self::METADATA_FILE.into())
             .map_err(|_| MissingPackageFileError(Self::METADATA_FILE.to_string()))
-            .map(|file| Metadata::<Self>::from_reader(file.reader()?))?
+            .map(Metadata::<Self>::from_reader)?
     }
 
     /// Get author `Signature` object from package.
@@ -215,7 +215,7 @@ impl ApplicationPackage {
         self.0
             .get_file(Self::AUTHOR_COSE_FILE.into())
             .ok()
-            .map(|file| Signature::<author_payload::SignaturePayload>::from_reader(file.reader()?))
+            .map(Signature::<author_payload::SignaturePayload>::from_reader)
             .transpose()
     }
 

hermes/bin/src/packaging/package/mod.rs

@@ -50,10 +50,10 @@ impl Package {
     /// Calculates file hash, if present
     pub(crate) fn calculate_file_hash(&self, path: Path) -> anyhow::Result<Option<Blake2b256>> {
         let mut hasher = Blake2b256Hasher::new();
-        let Ok(file) = self.0.get_file(path) else {
+        let Ok(mut file) = self.0.get_file(path) else {
             return Ok(None);
         };
-        calculate_file_hash(&file, &mut hasher)?;
+        calculate_file_hash(&mut file, &mut hasher)?;
         Ok(Some(hasher.finalize()))
     }
 
@@ -75,12 +75,11 @@ const BUFFER_SIZE: usize = 1024 * 1024;
 
 /// Calculates file hash with the provided hasher.
 #[allow(clippy::indexing_slicing)]
-fn calculate_file_hash(file: &File, hasher: &mut Blake2b256Hasher) -> anyhow::Result<()> {
-    let mut reader = file.reader()?;
+fn calculate_file_hash(file: &mut File, hasher: &mut Blake2b256Hasher) -> anyhow::Result<()> {
     let mut buf = vec![0; BUFFER_SIZE];
 
     loop {
-        let len = reader.read(&mut buf)?;
+        let len = file.read(&mut buf)?;
         if len == 0 {
             break;
         }
@@ -105,9 +104,9 @@ fn calculate_dir_hash(dir: &Dir, hasher: &mut Blake2b256Hasher) -> anyhow::Resul
         .into_iter()
         .map(|dir| (dir.path().to_string(), dir))
         .collect();
-    for (path_str, file) in files {
+    for (path_str, mut file) in files {
         hasher.update(path_str.as_bytes());
-        calculate_file_hash(&file, hasher)?;
+        calculate_file_hash(&mut file, hasher)?;
     }
     for (path_str, dir) in dirs {
         hasher.update(path_str.as_bytes());

hermes/bin/src/packaging/wasm_module/mod.rs

@@ -188,23 +188,23 @@ impl WasmModulePackage {
         self.0
             .get_file(Self::METADATA_FILE.into())
             .map_err(|_| MissingPackageFileError(Self::METADATA_FILE.to_string()))
-            .map(|file| Metadata::<Self>::from_reader(file.reader()?))?
+            .map(Metadata::<Self>::from_reader)?
     }
 
     /// Get `wasm::module::Module` object from package.
     pub(crate) fn get_component(&self) -> anyhow::Result<wasm::module::Module> {
         self.0
             .get_file(Self::COMPONENT_FILE.into())
             .map_err(|_| MissingPackageFileError(Self::METADATA_FILE.to_string()))
-            .map(|file| wasm::module::Module::from_reader(file.reader()?))?
+            .map(wasm::module::Module::from_reader)?
     }
 
     /// Get `Signature` object from package.
     pub(crate) fn get_signature(&self) -> anyhow::Result<Option<Signature<SignaturePayload>>> {
         self.0
             .get_file(Self::AUTHOR_COSE_FILE.into())
             .ok()
-            .map(|file| Signature::<SignaturePayload>::from_reader(file.reader()?))
+            .map(Signature::<SignaturePayload>::from_reader)
             .transpose()
     }
 
@@ -213,7 +213,7 @@ impl WasmModulePackage {
         self.0
             .get_file(Self::CONFIG_SCHEMA_FILE.into())
             .ok()
-            .map(|file| ConfigSchema::from_reader(file.reader()?))
+            .map(ConfigSchema::from_reader)
             .transpose()
     }
 
@@ -227,7 +227,7 @@ impl WasmModulePackage {
         };
 
         if let Ok(file) = self.0.get_file(Self::CONFIG_FILE.into()) {
-            let config_file = Config::from_reader(file.reader()?, config_schema.validator())?;
+            let config_file = Config::from_reader(file, config_schema.validator())?;
             Ok((Some(config_file), Some(config_schema)))
         } else {
             Ok((None, Some(config_schema)))
@@ -239,7 +239,7 @@ impl WasmModulePackage {
         self.0
             .get_file(Self::SETTINGS_SCHEMA_FILE.into())
             .ok()
-            .map(|file| SettingsSchema::from_reader(file.reader()?))
+            .map(SettingsSchema::from_reader)
             .transpose()
     }