Add --batch-size to 'bolt bench'.

This commit adds a --batch-size CLI argument to the 'bolt bench' tool.
This argument will insert into Bolt in smaller batches which is a more
typical use case.

/cc @snormore

cmd/bolt/bench.go

@@ -88,22 +88,41 @@ func benchWrite(db *bolt.DB, options *BenchOptions, results *BenchResults) error
 }
 
 func benchWriteSequential(db *bolt.DB, options *BenchOptions, results *BenchResults) error {
-	results.WriteOps = options.Iterations
+	// Default batch size to iteration count, if not specified.
+	var batchSize, iterations = options.BatchSize, options.Iterations
+	if batchSize == 0 {
+		batchSize = iterations
+	}
 
-	return db.Update(func(tx *bolt.Tx) error {
+	// Insert in batches.
-		b, _ := tx.CreateBucketIfNotExists(benchBucketName)
+	var count int
+	for i := 0; i < (iterations/batchSize)+1; i++ {
+		err := db.Update(func(tx *bolt.Tx) error {
+			b, _ := tx.CreateBucketIfNotExists(benchBucketName)
 
-		for i := 0; i < options.Iterations; i++ {
+			for j := 0; j < batchSize && count < iterations; j++ {
-			var key = make([]byte, options.KeySize)
+				var key = make([]byte, options.KeySize)
-			var value = make([]byte, options.ValueSize)
+				var value = make([]byte, options.ValueSize)
-			binary.BigEndian.PutUint32(key, uint32(i))
+				binary.BigEndian.PutUint32(key, uint32(count))
-			if err := b.Put(key, value); err != nil {
+
-				return err
+				if err := b.Put(key, value); err != nil {
+					return err
+				}
+
+				count++
 			}
-		}
 
-		return nil
+			return nil
-	})
+		})
+		if err != nil {
+			return err
+		}
+	}
+
+	// Update the write op count.
+	results.WriteOps = count
+
+	return nil
 }
 
 // Reads from the database.
@@ -213,6 +232,7 @@ type BenchOptions struct {
 	WriteMode    string
 	ReadMode     string
 	Iterations   int
+	BatchSize    int
 	KeySize      int
 	ValueSize    int
 	CPUProfile   string

cmd/bolt/main.go

@@ -98,6 +98,7 @@ func NewApp() *cli.App {
 				&cli.StringFlag{Name: "write-mode", Value: "seq", Usage: "Write mode"},
 				&cli.StringFlag{Name: "read-mode", Value: "seq", Usage: "Read mode"},
 				&cli.IntFlag{Name: "count", Value: 1000, Usage: "Item count"},
+				&cli.IntFlag{Name: "batch-size", Usage: "Insert batch size"},
 				&cli.IntFlag{Name: "key-size", Value: 8, Usage: "Key size"},
 				&cli.IntFlag{Name: "value-size", Value: 32, Usage: "Value size"},
 				&cli.StringFlag{Name: "cpuprofile", Usage: "CPU profile output path"},
@@ -110,6 +111,7 @@ func NewApp() *cli.App {
 					WriteMode:    c.String("write-mode"),
 					ReadMode:     c.String("read-mode"),
 					Iterations:   c.Int("count"),
+					BatchSize:    c.Int("batch-size"),
 					KeySize:      c.Int("key-size"),
 					ValueSize:    c.Int("value-size"),
 					CPUProfile:   c.String("cpuprofile"),