add `CheckAndDial` to avoid duplicate code (#13146)

* Don't repeat yourself

* add a log for loadBlocksIntoState

* op-batcher: fix log in batcher/driver.go

* modify log

---------
Co-authored-by: protolambda <proto@protolambda.com>
Co-authored-by: Matthew Slipper <me@matthewslipper.com>

op-batcher/batcher/driver.go

@@ -248,6 +248,12 @@ func (l *BatchSubmitter) loadBlocksIntoState(ctx context.Context, start, end uin
 	if end < start {
 		return fmt.Errorf("start number is > end number %d,%d", start, end)
 	}
+
+	// we don't want to print it in the 1-block case as `loadBlockIntoState` already does
+	if end > start {
+		l.Log.Info("Loading range of multiple blocks into state", "start", start, "end", end)
+	}
+
 	var latestBlock *types.Block
 	// Add all blocks to "state"
 	for i := start; i <= end; i++ {

op-service/client/rpc.go

@@ -152,18 +152,22 @@ func dialRPCClientWithBackoff(ctx context.Context, log log.Logger, addr string,
 		bOff = retry.Fixed(cfg.fixedDialBackoff)
 	}
 	return retry.Do(ctx, cfg.backoffAttempts, bOff, func() (*rpc.Client, error) {
-		if !IsURLAvailable(ctx, addr) {
-			log.Warn("failed to dial address, but may connect later", "addr", addr)
-			return nil, fmt.Errorf("address unavailable (%s)", addr)
-		}
-		client, err := rpc.DialOptions(ctx, addr, cfg.gethRPCOptions...)
-		if err != nil {
-			return nil, fmt.Errorf("failed to dial address (%s): %w", addr, err)
-		}
-		return client, nil
+		return CheckAndDial(ctx, log, addr, cfg.gethRPCOptions...)
 	})
 }
 
+func CheckAndDial(ctx context.Context, log log.Logger, addr string, options ...rpc.ClientOption) (*rpc.Client, error) {
+	if !IsURLAvailable(ctx, addr) {
+		log.Warn("failed to dial address, but may connect later", "addr", addr)
+		return nil, fmt.Errorf("address unavailable (%s)", addr)
+	}
+	client, err := rpc.DialOptions(ctx, addr, options...)
+	if err != nil {
+		return nil, fmt.Errorf("failed to dial address (%s): %w", addr, err)
+	}
+	return client, nil
+}
+
 func IsURLAvailable(ctx context.Context, address string) bool {
 	u, err := url.Parse(address)
 	if err != nil {

op-service/dial/dial.go

@@ -2,7 +2,6 @@ package dial
 
 import (
 	"context"
-	"fmt"
 	"time"
 
 	"github.com/ethereum-optimism/optimism/op-service/client"
@@ -72,13 +71,5 @@ func dialRPCClientWithBackoff(ctx context.Context, log log.Logger, addr string)
 
 // Dials a JSON-RPC endpoint once.
 func dialRPCClient(ctx context.Context, log log.Logger, addr string) (*rpc.Client, error) {
-	if !client.IsURLAvailable(ctx, addr) {
-		log.Warn("failed to dial address, but may connect later", "addr", addr)
-		return nil, fmt.Errorf("address unavailable (%s)", addr)
-	}
-	client, err := rpc.DialOptions(ctx, addr)
-	if err != nil {
-		return nil, fmt.Errorf("failed to dial address (%s): %w", addr, err)
-	}
-	return client, nil
+	return client.CheckAndDial(ctx, log, addr)
 }