feat(db): add db factories

Former-commit-id: df8ec1140cc82755e14a739cbb22fb035b3c7d18

cpp/src/db/Factories.cpp

+////////////////////////////////////////////////////////////////////////////////
+// Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
+// Unauthorized copying of this file, via any medium is strictly prohibited.
+// Proprietary and confidential.
+////////////////////////////////////////////////////////////////////////////////
+#include <stdlib.h>
+#include <time.h>
+#include <sstream>
+
+#include "Factories.h"
+
+
+namespace zilliz {
+namespace vecwise {
+namespace engine {
+
+DBMetaOptions DBMetaOptionsFactory::Build(const std::string& path) {
+    auto p = path;
+    if(p == "") {
+        srand(time(nullptr));
+        std::stringstream ss;
+        ss << "/tmp/" << rand();
+        p = ss.str();
+    }
+    DBMetaOptions meta;
+    meta.path = p;
+    return meta;
+}
+
+Options OptionsFactory::Build() {
+    auto meta = DBMetaOptionsFactory::Build();
+    Options options;
+    options.meta = meta;
+    return options;
+}
+
+} // namespace engine
+} // namespace vecwise
+} // namespace zilliz

cpp/src/db/Factories.h

+////////////////////////////////////////////////////////////////////////////////
+// Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
+// Unauthorized copying of this file, via any medium is strictly prohibited.
+// Proprietary and confidential.
+////////////////////////////////////////////////////////////////////////////////
+
+#pragma once
+
+#include <string>
+#include "db/DB.h"
+
+namespace zilliz {
+namespace vecwise {
+namespace engine {
+
+struct DBMetaOptionsFactory {
+    static DBMetaOptions Build(const std::string& path = "");
+};
+
+struct OptionsFactory {
+    static Options Build();
+};
+
+
+} // namespace engine
+} // namespace vecwise
+} // namespace zilliz