[block relayer]is_nearly_synced.

block-relayer/src/block_relayer.rs

@@ -55,9 +55,9 @@ impl BlockRelayer {
         }
     }
 
-    pub fn is_synced(&self) -> bool {
+    pub fn is_nearly_synced(&self) -> bool {
         match self.sync_status.as_ref() {
-            Some(sync_status) => sync_status.is_synced(),
+            Some(sync_status) => sync_status.is_nearly_synced(),
             None => false,
         }
     }
@@ -67,7 +67,7 @@ impl BlockRelayer {
         network: NetworkServiceRef,
         executed_block: Arc<ExecutedBlock>,
     ) {
-        if !self.is_synced() {
+        if !self.is_nearly_synced() {
             debug!("[block-relay] Ignore NewHeadBlock event because the node has not been synchronized yet.");
             return;
         }

types/src/sync_status.rs

@@ -39,6 +39,8 @@ pub struct SyncStatus {
     state: SyncState,
 }
 
+pub const NEARLY_SYNCED_BLOCKS: u64 = 24;
+
 impl SyncStatus {
     pub fn new(chain_status: ChainStatus) -> Self {
         Self {
@@ -78,6 +80,27 @@ impl SyncStatus {
         self.state.is_syncing()
     }
 
+    pub fn is_nearly_synced(&self) -> bool {
+        match &self.state {
+            SyncState::Prepare => false,
+            SyncState::Synchronized => true,
+            SyncState::Synchronizing {
+                target,
+                total_difficulty,
+            } => {
+                if target.number() < self.chain_status.head().number() {
+                    false
+                } else {
+                    target
+                        .number
+                        .saturating_sub(self.chain_status.head().number())
+                        <= NEARLY_SYNCED_BLOCKS
+                        || self.chain_status.total_difficulty() >= *total_difficulty
+                }
+            }
+        }
+    }
+
     pub fn is_synced(&self) -> bool {
         self.state.is_synced()
     }