refactor(api): restructure bolt package (#1981)

* refactor(api): bolt package refactor

* refactor(api): refactor bolt package

api/bolt/internal/db.go

@@ -0,0 +1,94 @@
+package internal
+
+import (
+	"encoding/binary"
+
+	"github.com/boltdb/bolt"
+	"github.com/portainer/portainer"
+)
+
+// Itob returns an 8-byte big endian representation of v.
+// This function is typically used for encoding integer IDs to byte slices
+// so that they can be used as BoltDB keys.
+func Itob(v int) []byte {
+	b := make([]byte, 8)
+	binary.BigEndian.PutUint64(b, uint64(v))
+	return b
+}
+
+// CreateBucket is a generic function used to create a bucket inside a bolt database.
+func CreateBucket(db *bolt.DB, bucketName string) error {
+	return db.Update(func(tx *bolt.Tx) error {
+		_, err := tx.CreateBucketIfNotExists([]byte(bucketName))
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
+// GetObject is a generic function used to retrieve an unmarshalled object from a bolt database.
+func GetObject(db *bolt.DB, bucketName string, key []byte, object interface{}) error {
+	var data []byte
+
+	err := db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketName))
+
+		value := bucket.Get(key)
+		if value == nil {
+			return portainer.ErrObjectNotFound
+		}
+
+		data = make([]byte, len(value))
+		copy(data, value)
+
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	return UnmarshalObject(data, object)
+}
+
+// UpdateObject is a generic function used to update an object inside a bolt database.
+func UpdateObject(db *bolt.DB, bucketName string, key []byte, object interface{}) error {
+	return db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketName))
+
+		data, err := MarshalObject(object)
+		if err != nil {
+			return err
+		}
+
+		err = bucket.Put(key, data)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
+// DeleteObject is a generic function used to delete an object inside a bolt database.
+func DeleteObject(db *bolt.DB, bucketName string, key []byte) error {
+	return db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketName))
+		return bucket.Delete(key)
+	})
+}
+
+// GetNextIdentifier is a generic function that returns the specified bucket identifier incremented by 1.
+func GetNextIdentifier(db *bolt.DB, bucketName string) int {
+	var identifier int
+
+	db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(bucketName))
+		id := bucket.Sequence()
+		identifier = int(id)
+		return nil
+	})
+
+	identifier++
+	return identifier
+}