Refactor SyncState (#3297)

* Refactor SyncState

Method sync_error() retrun type was simplified.
update_txhashset_download() was  made type safe, which eliminates a runtime enum variant's  check, added an atomic status update

servers/src/common/adapters.rs

@@ -23,7 +23,9 @@ use std::sync::{Arc, Weak};
 use std::thread;
 use std::time::Instant;
 
-use crate::chain::{self, BlockStatus, ChainAdapter, Options, SyncState, SyncStatus};
+use crate::chain::{
+	self, BlockStatus, ChainAdapter, Options, SyncState, SyncStatus, TxHashsetDownloadStats,
+};
 use crate::common::hooks::{ChainEvents, NetEvents};
 use crate::common::types::{ChainValidationMode, DandelionEpoch, ServerConfig};
 use crate::core::core::hash::{Hash, Hashed};
@@ -399,20 +401,18 @@ impl p2p::ChainAdapter for NetToChainAdapter {
 		total_size: u64,
 	) -> bool {
 		match self.sync_state.status() {
-			SyncStatus::TxHashsetDownload {
-				update_time: old_update_time,
-				downloaded_size: old_downloaded_size,
-				..
-			} => self
-				.sync_state
-				.update_txhashset_download(SyncStatus::TxHashsetDownload {
-					start_time,
-					prev_update_time: old_update_time,
-					update_time: Utc::now(),
-					prev_downloaded_size: old_downloaded_size,
-					downloaded_size,
-					total_size,
-				}),
+			SyncStatus::TxHashsetDownload(prev) => {
+				self.sync_state
+					.update_txhashset_download(TxHashsetDownloadStats {
+						start_time,
+						prev_update_time: prev.update_time,
+						update_time: Utc::now(),
+						prev_downloaded_size: prev.downloaded_size,
+						downloaded_size,
+						total_size,
+					});
+				true
+			}
 			_ => false,
 		}
 	}

servers/src/grin/sync/state_sync.rs

@@ -68,13 +68,9 @@ impl StateSync {
 		let mut sync_need_restart = false;
 
 		// check sync error
-		{
-			let clone = self.sync_state.sync_error();
-			if let Some(ref sync_error) = *clone.read() {
-				error!("state_sync: error = {:?}. restart fast sync", sync_error);
-				sync_need_restart = true;
-			}
-			drop(clone);
+		if let Some(sync_error) = self.sync_state.sync_error() {
+			error!("state_sync: error = {}. restart fast sync", sync_error);
+			sync_need_restart = true;
 		}
 
 		// check peer connection status of this sync
@@ -92,15 +88,16 @@ impl StateSync {
 
 		// if txhashset downloaded and validated successfully, we switch to BodySync state,
 		// and we need call state_sync_reset() to make it ready for next possible state sync.
-		let done = if let SyncStatus::TxHashsetDone = self.sync_state.status() {
-			self.sync_state.update(SyncStatus::BodySync {
+		let done = self.sync_state.update_if(
+			SyncStatus::BodySync {
 				current_height: 0,
 				highest_height: 0,
-			});
-			true
-		} else {
-			false
-		};
+			},
+			|s| match s {
+				SyncStatus::TxHashsetDone => true,
+				_ => false,
+			},
+		);
 
 		if sync_need_restart || done {
 			self.state_sync_reset();
@@ -137,24 +134,19 @@ impl StateSync {
 
 				// to avoid the confusing log,
 				// update the final HeaderSync state mainly for 'current_height'
-				{
-					let status = self.sync_state.status();
-					if let SyncStatus::HeaderSync { .. } = status {
-						self.sync_state.update(SyncStatus::HeaderSync {
-							current_height: header_head.height,
-							highest_height,
-						});
-					}
-				}
+				self.sync_state.update_if(
+					SyncStatus::HeaderSync {
+						current_height: header_head.height,
+						highest_height,
+					},
+					|s| match s {
+						SyncStatus::HeaderSync { .. } => true,
+						_ => false,
+					},
+				);
 
-				self.sync_state.update(SyncStatus::TxHashsetDownload {
-					start_time: Utc::now(),
-					prev_update_time: Utc::now(),
-					update_time: Utc::now(),
-					prev_downloaded_size: 0,
-					downloaded_size: 0,
-					total_size: 0,
-				});
+				self.sync_state
+					.update(SyncStatus::TxHashsetDownload(Default::default()));
 			}
 		}
 		true