src/client/remote_chunk_reader.rs: implement remote chunk reader

src/client.rs

@@ -9,6 +9,9 @@ mod merge_known_chunks;
 mod http_client;
 pub use  http_client::*;
 
+mod remote_chunk_reader;
+pub use remote_chunk_reader::*;
+
 mod pxar_backup_stream;
 pub use pxar_backup_stream::*;
 

src/client/remote_chunk_reader.rs

@@ -0,0 +1,41 @@
+use failure::*;
+use futures::future::Future;
+use std::sync::Arc;
+
+use super::BackupReader;
+use crate::backup::{ReadChunk, DataChunk, CryptConfig};
+
+/// Read chunks from remote host using ``BackupReader``
+pub struct RemoteChunkReader {
+    client: Arc<BackupReader>,
+    crypt_config: Option<Arc<CryptConfig>>,
+}
+
+impl RemoteChunkReader {
+
+    pub fn new(client: Arc<BackupReader>, crypt_config: Option<Arc<CryptConfig>>) -> Self {
+        Self { client, crypt_config }
+    }
+}
+
+impl ReadChunk for RemoteChunkReader {
+
+    fn read_chunk(&mut self, digest:&[u8; 32]) -> Result<Vec<u8>, Error> {
+
+        let digest_str = proxmox::tools::digest_to_hex(digest);
+
+        let writer = Vec::with_capacity(4*1024*1024);
+
+        let chunk_data = self.client.download_chunk(&digest, writer).wait()?;
+
+        let chunk = DataChunk::from_raw(chunk_data, *digest)?;
+        chunk.verify_crc()?;
+
+        let raw_data = match self.crypt_config {
+            Some(ref crypt_config) => chunk.decode(Some(crypt_config))?,
+            None => chunk.decode(None)?,
+        };
+
+        Ok(raw_data)
+    }
+}