Refactored option handling

bitcask.go

@@ -2,23 +2,16 @@ package bitcask
 
 import (
 	"errors"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"sort"
-	"strconv"
 	"strings"
 	"time"
 
 	"github.com/gofrs/flock"
 )
 
-const (
-	DefaultMaxDatafileSize = 1 << 20 // 1MB
-)
-
 var (
 	ErrKeyNotFound       = errors.New("error: key not found")
 	ErrCannotAcquireLock = errors.New("error: cannot acquire lock")
@@ -27,6 +20,7 @@ var (
 type Bitcask struct {
 	*flock.Flock
 
+	opts      Options
 	path      string
 	curr      *Datafile
 	keydir    *Keydir
@@ -135,39 +129,6 @@ func (b *Bitcask) setMaxDatafileSize(size int64) error {
 	return nil
 }
 
-func WithMaxDatafileSize(size int64) func(*Bitcask) error {
-	return func(b *Bitcask) error {
-		return b.setMaxDatafileSize(size)
-	}
-}
-
-func getDatafiles(path string) ([]string, error) {
-	fns, err := filepath.Glob(fmt.Sprintf("%s/*.data", path))
-	if err != nil {
-		return nil, err
-	}
-	sort.Strings(fns)
-	return fns, nil
-}
-
-func parseIds(fns []string) ([]int, error) {
-	var ids []int
-	for _, fn := range fns {
-		fn = filepath.Base(fn)
-		ext := filepath.Ext(fn)
-		if ext != ".data" {
-			continue
-		}
-		id, err := strconv.ParseInt(strings.TrimSuffix(fn, ext), 10, 32)
-		if err != nil {
-			return nil, err
-		}
-		ids = append(ids, int(id))
-	}
-	sort.Ints(ids)
-	return ids, nil
-}
-
 func Merge(path string, force bool) error {
 	fns, err := getDatafiles(path)
 	if err != nil {
@@ -353,6 +314,7 @@ func Open(path string, options ...func(*Bitcask) error) (*Bitcask, error) {
 
 	bitcask := &Bitcask{
 		Flock:     flock.New(filepath.Join(path, "lock")),
+		opts:      NewDefaultOptions(),
 		path:      path,
 		curr:      curr,
 		keydir:    keydir,

options.go

@@ -0,0 +1,42 @@
+package bitcask
+
+const (
+	DefaultMaxDatafileSize = 1 << 20 // 1MB
+	DefaultMaxKeySize      = 64      // 64 bytes
+	DefaultMaxValueSize    = 1 << 16 // 65KB
+)
+
+type Options struct {
+	MaxDatafileSize int
+	MaxKeySize      int
+	MaxValueSize    int
+}
+
+func NewDefaultOptions() Options {
+	return Options{
+		MaxDatafileSize: DefaultMaxDatafileSize,
+		MaxKeySize:      DefaultMaxKeySize,
+		MaxValueSize:    DefaultMaxValueSize,
+	}
+}
+
+func WithMaxDatafileSize(size int) func(*Bitcask) error {
+	return func(b *Bitcask) error {
+		b.opts.MaxDatafileSize = size
+		return nil
+	}
+}
+
+func WithMaxKeySize(size int) func(*Bitcask) error {
+	return func(b *Bitcask) error {
+		b.opts.MaxKeySize = size
+		return nil
+	}
+}
+
+func WithMaxValueSize(size int) func(*Bitcask) error {
+	return func(b *Bitcask) error {
+		b.opts.MaxValueSize = size
+		return nil
+	}
+}

utils.go

@@ -0,0 +1,36 @@
+package bitcask
+
+import (
+	"fmt"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+func getDatafiles(path string) ([]string, error) {
+	fns, err := filepath.Glob(fmt.Sprintf("%s/*.data", path))
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(fns)
+	return fns, nil
+}
+
+func parseIds(fns []string) ([]int, error) {
+	var ids []int
+	for _, fn := range fns {
+		fn = filepath.Base(fn)
+		ext := filepath.Ext(fn)
+		if ext != ".data" {
+			continue
+		}
+		id, err := strconv.ParseInt(strings.TrimSuffix(fn, ext), 10, 32)
+		if err != nil {
+			return nil, err
+		}
+		ids = append(ids, int(id))
+	}
+	sort.Ints(ids)
+	return ids, nil
+}