src/backup/read_chunk.rs: add read_raw_chunk()

Allow to read chunk data without decoding.

src/backup/read_chunk.rs

@@ -7,6 +7,9 @@ use super::data_blob::*;
 
 /// The ReadChunk trait allows reading backup data chunks (local or remote)
 pub trait ReadChunk {
+    /// Returns the encoded chunk data
+    fn read_raw_chunk(&mut self, digest:&[u8; 32]) -> Result<DataBlob, Error>;
+
     /// Returns the decoded chunk data
     fn read_chunk(&mut self, digest:&[u8; 32]) -> Result<Vec<u8>, Error>;
 }
@@ -25,7 +28,7 @@ impl LocalChunkReader {
 
 impl ReadChunk for LocalChunkReader {
 
-    fn read_chunk(&mut self, digest:&[u8; 32]) -> Result<Vec<u8>, Error> {
+    fn read_raw_chunk(&mut self, digest:&[u8; 32]) -> Result<DataBlob, Error> {
 
         let digest_str = proxmox::tools::digest_to_hex(digest);
         println!("READ CHUNK {}", digest_str);
@@ -35,6 +38,12 @@ impl ReadChunk for LocalChunkReader {
         let chunk = DataBlob::from_raw(raw_data)?;
         chunk.verify_crc()?;
 
+        Ok(chunk)
+    }
+
+    fn read_chunk(&mut self, digest:&[u8; 32]) -> Result<Vec<u8>, Error> {
+        let chunk = self.read_raw_chunk(digest)?;
+
         let raw_data =  chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref))?;
 
         // fixme: verify digest?

src/client/remote_chunk_reader.rs

@@ -31,29 +31,36 @@ impl RemoteChunkReader {
 
 impl ReadChunk for RemoteChunkReader {
 
-    fn read_chunk(&mut self, digest:&[u8; 32]) -> Result<Vec<u8>, Error> {
+    fn read_raw_chunk(&mut self, digest:&[u8; 32]) -> Result<DataBlob, Error> {
 
         let mut chunk_data = Vec::with_capacity(4*1024*1024);
 
-        if let Some(raw_data) = self.cache.get(digest) {
-            return Ok(raw_data.to_vec());
-        }
-
-        let use_cache = self.cache_hint.contains_key(digest);
-
         futures::executor::block_on(self.client.download_chunk(&digest, &mut chunk_data))?;
 
         let chunk = DataBlob::from_raw(chunk_data)?;
         chunk.verify_crc()?;
 
+        Ok(chunk)
+    }
+
+    fn read_chunk(&mut self, digest:&[u8; 32]) -> Result<Vec<u8>, Error> {
+
+        if let Some(raw_data) = self.cache.get(digest) {
+            return Ok(raw_data.to_vec());
+        }
+
+        let chunk = self.read_raw_chunk(digest)?;
+
         let raw_data =  chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref))?;
 
-        // fixme: verify chunk digest
+        // fixme: verify digest?
 
+        let use_cache = self.cache_hint.contains_key(digest);
         if use_cache {
             self.cache.insert(*digest, raw_data.to_vec());
         }
 
         Ok(raw_data)
     }
+
 }