doc: added documentation for add_subtree_sync_info

Author: ogabrielides

grovedb/src/replication/state_sync_session.rs

@@ -200,6 +200,35 @@ impl<'db> MultiStateSyncSession<'db> {
         unsafe { Pin::into_inner_unchecked(self) }.transaction
     }
 
+    /// Adds synchronization information for a subtree into the current synchronization session.
+    ///
+    /// This function interacts with a `GroveDb` database to open a Merk tree at the specified path,
+    /// calculate and verify its cryptographic hashes, and update the session state with the relevant
+    /// synchronization information. The function generates and returns the global chunk ID for
+    /// the subtree.
+    ///
+    /// # Parameters
+    /// - `self`: A pinned, boxed instance of the `MultiStateSyncSession`.
+    /// - `db`: A reference to the `GroveDb` instance.
+    /// - `path`: The path to the subtree as a `SubtreePath`.
+    /// - `hash`: The expected cryptographic hash of the subtree.
+    /// - `actual_hash`: An optional actual cryptographic hash to compare against the expected hash.
+    /// - `chunk_prefix`: A 32-byte prefix used for identifying chunks in the synchronization process.
+    /// - `grove_version`: The GroveDB version to use for processing.
+    ///
+    /// # Returns
+    /// - `Ok(Vec<u8>)`: On success, returns the encoded global chunk ID for the subtree.
+    /// - `Err(Error)`: If the Merk tree cannot be opened or synchronization information cannot be added.
+    ///
+    /// # Errors
+    /// This function returns an error if:
+    /// - The Merk tree at the specified path cannot be opened.
+    /// - Any synchronization-related operations fail.
+    /// - Internal errors occur during processing.
+    ///
+    /// # Safety
+    /// - This function uses unsafe code to create a reference to the transaction.
+    ///   Ensure that the transaction is properly managed and the lifetime guarantees are respected.
     pub fn add_subtree_sync_info<'b, B: AsRef<[u8]>>(
         self: &mut Pin<Box<MultiStateSyncSession<'db>>>,
         db: &'db GroveDb,