move chunk_stat, read_chunk to pbs-datastore

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

pbs-datastore/src/read_chunk.rs

@@ -0,0 +1,29 @@
+use std::future::Future;
+use std::pin::Pin;
+
+use anyhow::Error;
+
+use crate::data_blob::DataBlob;
+
+/// The ReadChunk trait allows reading backup data chunks (local or remote)
+pub trait ReadChunk {
+    /// Returns the encoded chunk data
+    fn read_raw_chunk(&self, digest: &[u8; 32]) -> Result<DataBlob, Error>;
+
+    /// Returns the decoded chunk data
+    fn read_chunk(&self, digest: &[u8; 32]) -> Result<Vec<u8>, Error>;
+}
+
+pub trait AsyncReadChunk: Send {
+    /// Returns the encoded chunk data
+    fn read_raw_chunk<'a>(
+        &'a self,
+        digest: &'a [u8; 32],
+    ) -> Pin<Box<dyn Future<Output = Result<DataBlob, Error>> + Send + 'a>>;
+
+    /// Returns the decoded chunk data
+    fn read_chunk<'a>(
+        &'a self,
+        digest: &'a [u8; 32],
+    ) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, Error>> + Send + 'a>>;
+}