feat(db): add serializer

Former-commit-id: ab412bbb430e7711ddee0ad26b34f7b3b6c43582

cpp/src/db/FaissSerializer.cpp

+#include <easylogging++.h>
+#include <faiss/AutoTune.h>
+
+#include "FaissSerializer.h"
+
+namespace zilliz {
+namespace vecwise {
+namespace engine {
+
+const std::string IndexType = "IDMap,Flat";
+
+FaissSerializer::FaissSerializer(uint16_t dimension)
+    : pIndex_(faiss::index_factory(dimension, IndexType.c_str())) {
+}
+
+bool FaissSerializer::AddWithIds(long n, const float *xdata, const long *xids) {
+    pIndex_->add_with_ids(n, xdata, xids);
+    return true;
+}
+
+
+} // namespace engine
+} // namespace vecwise
+} // namespace zilliz

cpp/src/db/FaissSerializer.h

+#pragma once
+
+#include <memory>
+#include <string>
+
+#include "Serializer.h"
+
+namespace faiss {
+    class Index;
+}
+
+namespace zilliz {
+namespace vecwise {
+namespace engine {
+
+class FaissSerializer : public Serializer {
+public:
+    FaissSerializer(uint16_t dimension);
+    virtual bool AddWithIds(long n, const float *xdata, const long *xids) override;
+
+protected:
+    std::shared_ptr<faiss::Index> pIndex_;
+};
+
+
+} // namespace engine
+} // namespace vecwise
+} // namespace zilliz

cpp/src/db/Serializer.cpp

+#include <easylogging++.h>
+#include "Serializer.h"
+
+namespace zilliz {
+namespace vecwise {
+namespace engine {
+
+bool Serializer::AddWithIds(const std::vector<float>& vectors, const std::vector<long>& vector_ids) {
+    long n1 = (long)vectors.size();
+    long n2 = (long)vector_ids.size();
+    if (n1 != n2) {
+        LOG(ERROR) << "vectors size is not equal to the size of vector_ids: " << n1 << "!=" << n2;
+        return false;
+    }
+    return AddWithIds(n1, vectors.data(), vector_ids.data());
+}
+
+
+} // namespace engine
+} // namespace vecwise
+} // namespace zilliz

cpp/src/db/Serializer.h

+#pragma once
+
+#include <vector>
+
+namespace zilliz {
+namespace vecwise {
+namespace engine {
+
+class Serializer {
+public:
+
+    bool AddWithIds(const std::vector<float>& vectors,
+                              const std::vector<long>& vector_ids);
+
+    virtual bool AddWithIds(long n, const float *xdata, const long *xids) = 0;
+
+    virtual ~Serializer() {}
+};
+
+
+} // namespace engine
+} // namespace vecwise
+} // namespace zilliz