implement AsyncReadChunk for LocalChunkReader

same as the sync ReadChunk but uses tokio::fs::read instead
of file_get_contents

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/backup/read_chunk.rs

@@ -45,7 +45,7 @@ impl ReadChunk for LocalChunkReader {
     }
 
     fn read_chunk(&mut self, digest: &[u8; 32]) -> Result<Vec<u8>, Error> {
-        let chunk = self.read_raw_chunk(digest)?;
+        let chunk = ReadChunk::read_raw_chunk(self, digest)?;
 
         let raw_data = chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref))?;
 
@@ -68,3 +68,38 @@ pub trait AsyncReadChunk: Send {
         digest: &'a [u8; 32],
     ) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, Error>> + Send + 'a>>;
 }
+
+impl AsyncReadChunk for LocalChunkReader {
+    fn read_raw_chunk<'a>(
+        &'a mut self,
+        digest: &'a [u8; 32],
+    ) -> Pin<Box<dyn Future<Output = Result<DataBlob, Error>> + Send + 'a>> {
+        Box::pin(async move{
+            let digest_str = proxmox::tools::digest_to_hex(digest);
+            println!("READ CHUNK {}", digest_str);
+
+            let (path, _) = self.store.chunk_path(digest);
+
+            let raw_data = tokio::fs::read(&path).await?;
+            let chunk = DataBlob::from_raw(raw_data)?;
+            chunk.verify_crc()?;
+
+            Ok(chunk)
+        })
+    }
+
+    fn read_chunk<'a>(
+        &'a mut self,
+        digest: &'a [u8; 32],
+    ) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, Error>> + Send + 'a>> {
+        Box::pin(async move {
+            let chunk = AsyncReadChunk::read_raw_chunk(self, digest).await?;
+
+            let raw_data = chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref))?;
+
+            // fixme: verify digest?
+
+            Ok(raw_data)
+        })
+    }
+}