src/backup.rs - improve doc

src/backup.rs

@@ -1,4 +1,15 @@
-//! This mudule implements the proxmox backup chunked data storage
+//! This module implements the proxmox backup chunked data storage
+//!
+//! A chunk is simply defined as binary blob. We store them inside a
+//! `ChunkStore`, addressed by the SHA256 digest of the binary
+//! blob. This technology is also known as content-addressable
+//! storage.
+//!
+//! We store larger files by splitting them into chunks. The resulting
+//! SHA256 digest list is stored as separate index file. The
+//! `DynamicIndex*` format is able to deal with dynamic chunk sizes,
+//! whereas the `FixedIndex*` format is an optimization to store a
+//! list of equal sized chunks.
 
 pub mod chunker;
 pub mod chunk_store;