feat: add batch put command

db.go

@@ -302,6 +302,48 @@ func (db *DB) Put(key []byte, value []byte) error {
 	return nil
 }
 
+// BatchPut set multiple keys at one time, it updates the value for the existing key.
+func (db *DB) BatchPut(kvs ...[]byte) error {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	for i := 0; i < len(kvs); i += 2 {
+		key := kvs[i]
+		value := kvs[i+1]
+
+		if len(key) > MaxKeyLength {
+			return errKeyTooLarge
+		}
+		if len(value) > MaxValueLength {
+			return errValueTooLarge
+		}
+		h := db.hash(key)
+		db.metrics.Puts.Add(1)
+
+		segID, offset, err := db.datalog.put(key, value)
+		if err != nil {
+			return err
+		}
+
+		sl := slot{
+			hash:      h,
+			segmentID: segID,
+			keySize:   uint16(len(key)),
+			valueSize: uint32(len(value)),
+			offset:    offset,
+		}
+
+		if err := db.put(sl, key); err != nil {
+			return err
+		}
+	}
+
+	if db.syncWrites {
+		return db.sync()
+	}
+	return nil
+}
+
 func (db *DB) del(h uint32, key []byte, writeWAL bool) error {
 	err := db.index.delete(h, func(sl slot) (b bool, e error) {
 		if uint16(len(key)) != sl.keySize {

db_test.go

@@ -10,6 +10,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -116,6 +117,37 @@ func TestEmpty(t *testing.T) {
 	assert.Nil(t, db.Close())
 }
 
+func TestBatchPut(t *testing.T) {
+	opts := &Options{
+		BackgroundSyncInterval: -1,
+		FileSystem:             testFS,
+		maxSegmentSize:         1024,
+	}
+	db, err := createTestDB(opts)
+	assert.Nil(t, err)
+	defer db.Close()
+
+	count := 1000
+	bucket := 100
+	kvs := [][]byte{}
+	for i := 0; i < count; i++ {
+		key := []byte(strconv.Itoa(i))
+		kvs = append(kvs, key, key)
+		if len(kvs) == bucket {
+			err := db.BatchPut(kvs...)
+			assert.Equal(t, nil, err)
+			kvs = kvs[:0]
+		}
+	}
+
+	for i := 0; i < count; i++ {
+		expected := []byte(strconv.Itoa(i))
+		actual, err := db.Get(expected)
+		assert.Equal(t, nil, err)
+		assert.Equal(t, expected, actual)
+	}
+}
+
 func TestFull(t *testing.T) {
 	opts := &Options{
 		BackgroundSyncInterval: -1,
@@ -414,6 +446,32 @@ func BenchmarkPut(b *testing.B) {
 	assert.Nil(b, db.Close())
 }
 
+func BenchmarkBatchPut(b *testing.B) {
+	db, err := createTestDB(nil)
+	assert.Nil(b, err)
+	b.ResetTimer()
+	k := []byte{1}
+	kvs := [][]byte{}
+	for i := 0; i < b.N; i++ {
+		kvs = append(kvs, k, k)
+		if len(kvs) < 100 {
+			continue
+		}
+
+		if err := db.BatchPut(kvs...); err != nil {
+			b.Fail()
+		}
+		kvs = kvs[:0]
+	}
+
+	if len(kvs) > 0 {
+		if err := db.BatchPut(kvs...); err != nil {
+			b.Fail()
+		}
+	}
+	assert.Nil(b, db.Close())
+}
+
 func BenchmarkGet(b *testing.B) {
 	db, err := createTestDB(nil)
 	assert.Nil(b, err)