Updates as Per Ian's comments

1. Fix some naming inconsistencies.
2. `GetSyncStatus` returns a bool
3. `Start` handles any `errors` from the `WaitingForSync` function.
4. Add a sleep for the `while` loop.
5. Fix test based on a conditional that would never be met.

statediff/README.md

@@ -81,24 +81,43 @@ This state diffing service runs as an auxiliary service concurrent to the regula
 This service introduces a CLI flag namespace `statediff`
 
 `--statediff` flag is used to turn on the service
+
 `--statediff.writing` is used to tell the service to write state diff objects it produces from synced ChainEvents directly to a configured Postgres database
+
 `--statediff.workers` is used to set the number of concurrent workers to process state diff objects and write them into the database
+
 `--statediff.db.type` is the type of database we write out to (current options: postgres, dump, file)
+
 `--statediff.dump.dst` is the destination to write to when operating in database dump mode (stdout, stderr, discard)
+
 `--statediff.db.driver` is the specific driver to use for the database (current options for postgres: pgx and sqlx)
+
 `--statediff.db.host` is the hostname/ip to dial to connect to the database
+
 `--statediff.db.port` is the port to dial to connect to the database
+
 `--statediff.db.name` is the name of the database to connect to
+
 `--statediff.db.user` is the user to connect to the database as
+
 `--statediff.db.password` is the password to use to connect to the database
+
 `--statediff.db.conntimeout` is the connection timeout (in seconds)
+
 `--statediff.db.maxconns` is the maximum number of database connections
+
 `--statediff.db.minconns` is the minimum number of database connections
+
 `--statediff.db.maxidleconns` is the maximum number of idle connections
+
 `--statediff.db.maxconnidletime` is the maximum lifetime for an idle connection (in seconds)
+
 `--statediff.db.maxconnlifetime` is the maximum lifetime for a connection (in seconds)
+
 `--statediff.db.nodeid` is the node id to use in the Postgres database
+
 `--statediff.db.clientname` is the client name to use in the Postgres database
+
 `--statediff.file.path` full path (including filename) to write statediff data out to when operating in file mode
 
 The service can only operate in full sync mode (`--syncmode=full`), but only the historical RPC endpoints require an archive node (`--gcmode=archive`)

statediff/service.go

@@ -122,7 +122,7 @@ type Service struct {
 	// The publicBackendAPI which provides useful information about the current state
 	BackendAPI ethapi.Backend
 	// Should the statediff service wait for geth to sync to head?
-	WaitforSync bool
+	WaitForSync bool
 	// Whether or not we have any subscribers; only if we do, do we processes state diffs
 	subscribers int32
 	// Interface for publishing statediffs as PG-IPLD objects
@@ -183,7 +183,7 @@ func New(stack *node.Node, ethServ *eth.Ethereum, cfg *ethconfig.Config, params
 		SubscriptionTypes: make(map[common.Hash]Params),
 		BlockCache:        NewBlockCache(workers),
 		BackendAPI:        backend,
-		WaitforSync:       params.WaitForSync,
+		WaitForSync:       params.WaitForSync,
 		indexer:           indexer,
 		enableWriteLoop:   params.EnableWriteLoop,
 		numWorkers:        workers,
@@ -537,19 +537,23 @@ func (sds *Service) Unsubscribe(id rpc.ID) error {
 
 // This function will check the status of geth syncing.
 // It will return false if geth has finished syncing.
-// It will return a non false value if geth is not done syncing.
-func (sds *Service) GetSyncStatus(pubEthAPI *ethapi.PublicEthereumAPI) (interface{}, error) {
+// It will return a true Geth is still syncing.
+func (sds *Service) GetSyncStatus(pubEthAPI *ethapi.PublicEthereumAPI) (bool, error) {
 	syncStatus, err := pubEthAPI.Syncing()
 	if err != nil {
-		return nil, err
+		return true, err
 	}
-	return syncStatus, err
+
+	if syncStatus != false {
+		return true, err
+	}
+	return false, err
 }
 
 // This function calls GetSyncStatus to check if we have caught up to head.
 // It will keep looking and checking if we have caught up to head.
 // It will only complete if we catch up to head, otherwise it will keep looping forever.
-func (sds *Service) WaitForSync() error {
+func (sds *Service) WaitingForSync() error {
 	log.Info("We are going to wait for geth to sync to head!")
 
 	// Has the geth node synced to head?
@@ -560,9 +564,11 @@ func (sds *Service) WaitForSync() error {
 		if err != nil {
 			return err
 		}
-		if syncStatus == false {
+		if !syncStatus {
 			log.Info("Geth has caught up to the head of the chain")
 			Synced = true
+		} else {
+			time.Sleep(1 * time.Second)
 		}
 	}
 	return nil
@@ -572,9 +578,12 @@ func (sds *Service) WaitForSync() error {
 func (sds *Service) Start() error {
 	log.Info("Starting statediff service")
 
-	if sds.WaitforSync {
+	if sds.WaitForSync {
 		log.Info("Statediff service will wait until geth has caught up to the head of the chain.")
-		sds.WaitForSync()
+		err := sds.WaitingForSync()
+		if err != nil {
+			return err
+		}
 		log.Info("Continuing with startdiff start process")
 	}
 	chainEventCh := make(chan core.ChainEvent, chainEventChanSize)

statediff/service_test.go

@@ -328,7 +328,7 @@ func createServiceWithMockBackend(curBlock uint64, highestBlock uint64) (*mocks.
 		SubscriptionTypes: make(map[common.Hash]statediff.Params),
 		BlockCache:        statediff.NewBlockCache(1),
 		BackendAPI:        &backend,
-		WaitforSync:       true,
+		WaitForSync:       true,
 	}
 	return &backend, service
 }
@@ -338,7 +338,7 @@ func createServiceWithMockBackend(curBlock uint64, highestBlock uint64) (*mocks.
 func testWaitForSync(t *testing.T) {
 	t.Log("Starting Sync")
 	_, service := createServiceWithMockBackend(10, 10)
-	err := service.WaitForSync()
+	err := service.WaitingForSync()
 	if err != nil {
 		t.Fatal("Sync Failed")
 	}
@@ -362,7 +362,7 @@ func testGetSyncStatus(t *testing.T) {
 		// Start the sync function which will wait for the sync
 		// Once the sync is complete add a value to the checkSyncComplet channel
 		t.Log("Starting Sync")
-		err := service.WaitForSync()
+		err := service.WaitingForSync()
 		if err != nil {
 			t.Error("Sync Failed")
 			checkSyncComplete <- 1
@@ -400,42 +400,36 @@ func testGetSyncStatus(t *testing.T) {
 		time.Sleep(1 * time.Second)
 
 		// Make sure if syncStatus is false that WaitForSync has completed!
-		if syncStatus == false && len(checkSyncComplete) == 0 {
+		if !syncStatus && len(checkSyncComplete) == 0 {
 			t.Error("Sync is complete but WaitForSync is not")
 		}
 
-		if syncStatus != false && len(checkSyncComplete) == 1 {
+		if syncStatus && len(checkSyncComplete) == 1 {
 			t.Error("Sync is not complete but WaitForSync is")
 		}
 
 		// Make sure sync hasn't completed and that the checkSyncComplete channel is empty
-		if syncStatus != false && len(checkSyncComplete) == 0 {
+		if syncStatus && len(checkSyncComplete) == 0 {
 			continue
 		}
 
 		// This code will only be run if the sync is complete and the WaitForSync function is complete
-		//t.Log("Backend: ", backend)
-		//t.Log("Sync Status: ", syncStatus)
 
 		// If syncstatus is complete, make sure that the blocks match
-		if syncStatus == false && table.currentBlock != table.highestBlock {
+		if !syncStatus && table.currentBlock != table.highestBlock {
 			t.Errorf("syncStatus indicated sync was complete even when current block, %d, and highest block %d aren't equal",
 				table.currentBlock, table.highestBlock)
 		}
 
 		// Make sure that WaitForSync completed once the current block caught up to head!
-		if len(checkSyncComplete) == 1 {
-			checkSyncCompleteVal := <-checkSyncComplete
-			if checkSyncCompleteVal != 0 {
-				t.Errorf("syncStatus indicated sync was complete but the checkSyncComplete has a value of %d",
-					checkSyncCompleteVal)
-			} else {
-				t.Log("Test Passed!")
-			}
-
+		checkSyncCompleteVal := <-checkSyncComplete
+		if checkSyncCompleteVal != 0 {
+			t.Errorf("syncStatus indicated sync was complete but the checkSyncComplete has a value of %d",
+				checkSyncCompleteVal)
 		} else {
-			t.Error("checkSyncComplete is empty: ", len(checkSyncComplete))
+			t.Log("Test Passed!")
 		}
+
 	}
 
 }