add entity metadata

internal/entity/file.go

@@ -10,6 +10,7 @@ import (
 
 // File represent a binary file.
 type File struct {
+	Meta             DocMetadata            `json:"doc,omitempty"`
 	Type             string                 `json:"type,omitempty"`
 	MD5              string                 `json:"md5,omitempty"`
 	SHA1             string                 `json:"sha1,omitempty"`

internal/entity/metadata.go

@@ -0,0 +1,12 @@
+// Copyright 2018 Saferwall. All rights reserved.
+// Use of this source code is governed by Apache v2 license
+// license that can be found in the LICENSE file.
+
+package entity
+
+// DocMetadata stores metadata information for saved documents in the DB.
+type DocMetadata struct {
+	CreatedAt   int64 `json:"created_at,omitempty"`
+	LastUpdated int64 `json:"last_updated,omitempty"`
+	Version     int   `json:"version,omitempty"`
+}

internal/file/service.go

@@ -250,6 +250,7 @@ func (s service) Create(ctx context.Context, req CreateFileRequest) (
 
 		// Create a new file.
 		err = s.repo.Create(ctx, sha256, entity.File{
+			Meta:        entity.DocMetadata{CreatedAt: now, LastUpdated: now, Version: 1},
 			SHA256:      sha256,
 			Type:        "file",
 			FirstSeen:   now,