Address some review issues fmt, errors, comments

src/database/rooms.rs

@@ -35,6 +35,11 @@ use super::admin::AdminCommand;
 /// hashing the entire state.
 pub type StateHashId = IVec;
 
+/// An enum that represents the two valid states when searching
+/// for an events "parent".
+///
+/// An events parent is any event we are aware of that is part of
+/// the events `prev_events` array.
 pub enum ClosestParent {
     Append,
     Insert(u64),
@@ -80,7 +85,7 @@ impl StateStore for Rooms {
             .map_err(StateError::custom)?
             .ok_or_else(|| {
                 StateError::NotFound(format!(
-                    "PDU via room_id and event_id not found in the db.\n{}",
+                    "PDU via room_id and event_id not found in the db: {}",
                     event_id.as_str()
                 ))
             })?;
@@ -258,6 +263,8 @@ impl Rooms {
     }
 
     /// Force the creation of a new StateHash and insert it into the db.
+    ///
+    /// Whatever `state` is supplied to `force_state` __is__ the current room state snapshot.
     pub fn force_state(
         &self,
         room_id: &RoomId,
@@ -403,6 +410,12 @@ impl Rooms {
         }
     }
 
+    /// Recursively search for a PDU from our DB that is also in the
+    /// `prev_events` field of the incoming PDU.
+    ///
+    /// First we check if the last PDU inserted to the given room is a parent
+    /// if not we recursively check older `prev_events` to insert the incoming
+    /// event after.
     pub fn get_closest_parent(
         &self,
         room: &RoomId,

src/database/sending.rs

@@ -2,7 +2,7 @@ use std::{collections::HashMap, convert::TryFrom, time::SystemTime};
 
 use crate::{server_server, utils, Error, PduEvent, Result};
 use federation::transactions::send_transaction_message;
-use log::debug;
+use log::{debug, error};
 use rocket::futures::stream::{FuturesUnordered, StreamExt};
 use ruma::{api::federation, ServerName};
 use sled::IVec;
@@ -115,8 +115,8 @@ impl Sending {
                                     // servercurrentpdus with the prefix should be empty now
                                 }
                             }
-                            Err((_server, _e)) => {
-                                log::error!("server: {}\nerror: {}", _server, _e)
+                            Err((server, e)) => {
+                                error!("server: {}\nerror: {}", server, e)
                                 // TODO: exponential backoff
                             }
                         };