add missing documentation (which, for some reason, didn't trigger a build failure locally)

Author: arik-so

lightning-graph-sync/src/error.rs

@@ -1,9 +1,16 @@
 use lightning::ln::msgs::{DecodeError, LightningError};
 
+/// All-encompassing standard error type that processing can return
 pub enum GraphSyncError {
+	/// IO error wrapper, typically the result of an issue with the file system
 	IOError(std::io::Error),
+	/// Error trying to read the update data, typically due to an erroneous data length indication
+	/// that is greater than the actual amount of data provided
 	DecodeError(DecodeError),
+	/// Error applying the patch to the network graph, usually the result of updates that are too
+	/// old or missing prerequisite data to the application of updates out of order
 	LightningError(LightningError),
+	/// Some other error whose nature is indicated in its descriptor string
 	ProcessingError(String),
 }
 

lightning-graph-sync/src/lib.rs

@@ -8,15 +8,27 @@
 #![deny(unused_variables)]
 #![deny(unused_imports)]
 
+//! This crate exposes functionality to rapidly sync gossip data, aimed primarily at mobile
+//! devices.
+
 use std::fs::File;
 
 use lightning::routing::network_graph;
 
 use crate::error::GraphSyncError;
 
+/// Error types that these functions can return
 pub mod error;
+
+/// Core functionality of this crate
 pub mod processing;
 
+/// Sync gossip data from a file
+///
+/// `network_graph`: The network graph to apply the updates to
+///
+/// `sync_path`: Path to the file where the gossip update data is located
+///
 pub fn sync_network_graph_with_file_path(
 	network_graph: &network_graph::NetworkGraph,
 	sync_path: &str,

lightning-graph-sync/src/processing.rs

@@ -19,6 +19,11 @@ use crate::error::GraphSyncError;
 /// data receipt, as opposed to originally signed value. TODO: TBD
 const TIMESTAMP_RETROGRESSION_DELTA: u32 = 7 * 24 * 3600;
 
+/// Update network graph from binary data
+///
+/// `network_graph`: network graph to be updated
+///
+/// `update_data`: `&[u8]` binary stream that comprises the update data
 pub fn update_network_graph(
 	network_graph: &network_graph::NetworkGraph,
 	update_data: &[u8],