fix comments

indexer/beacon/forkcache.go

@@ -77,6 +77,7 @@ func (cache *forkCache) addFork(fork *Fork) {
 	cache.forkMap[fork.forkId] = fork
 }
 
+// getForkByLeaf retrieves a fork from the cache by its leaf root.
 func (cache *forkCache) getForkByLeaf(leafRoot phase0.Root) *Fork {
 	cache.cacheMutex.Lock()
 	defer cache.cacheMutex.Unlock()
@@ -90,6 +91,7 @@ func (cache *forkCache) getForkByLeaf(leafRoot phase0.Root) *Fork {
 	return nil
 }
 
+// getForkByBase retrieves forks from the cache by their base root.
 func (cache *forkCache) getForkByBase(baseRoot phase0.Root) []*Fork {
 	cache.cacheMutex.Lock()
 	defer cache.cacheMutex.Unlock()
@@ -112,6 +114,7 @@ func (cache *forkCache) removeFork(forkId ForkKey) {
 	delete(cache.forkMap, forkId)
 }
 
+// getParentForkIds returns the parent fork ids of the given fork.
 func (cache *forkCache) getParentForkIds(forkId ForkKey) []ForkKey {
 	parentForks := []ForkKey{forkId}
 

indexer/beacon/forkdetection.go

@@ -40,8 +40,8 @@ func (cache *forkCache) processBlock(block *Block) error {
 	parentIsProcessed := false
 	parentIsFinalized := false
 
-	parentBlock := cache.indexer.blockCache.getBlockByRoot(*parentRoot)
-	if parentBlock == nil {
+	if parentBlock := cache.indexer.blockCache.getBlockByRoot(*parentRoot); parentBlock == nil {
+		// parent block might already be finalized, check if it's in the database
 		blockHead := db.GetBlockHeadByRoot((*parentRoot)[:])
 		if blockHead != nil {
 			parentForkId = ForkKey(blockHead.ForkId)
@@ -102,9 +102,10 @@ func (cache *forkCache) processBlock(block *Block) error {
 			}
 
 			if !parentIsFinalized && len(otherChildren) == 1 {
-				// parent (a) is not finalized and our new detected fork the first fork based on this parent (c)
+				// parent (a) is not finalized and our new detected fork is the first fork based on this parent (c)
 				// we need to create another fork for the other chain that starts from our fork base (b1, b2, )
 				// and update the blocks building on top of it
+				// we don't need to care about this if there are other forks already based on the parent
 				//   b2
 				//   |
 				//   b1  c