Support hnsw (#1131)

* add hnsw

* add config

* format...

* format..

core/src/db/engine/ExecutionEngine.h

@@ -17,12 +17,12 @@
 
 #pragma once
 
-#include "utils/Status.h"
-
 #include <memory>
 #include <string>
 #include <vector>
 
+#include "utils/Status.h"
+
 namespace milvus {
 namespace engine {
 
@@ -39,7 +39,8 @@ enum class EngineType {
     SPTAG_BKT,
     FAISS_BIN_IDMAP,
     FAISS_BIN_IVFFLAT,
-    MAX_VALUE = FAISS_BIN_IVFFLAT,
+    HNSW,
+    MAX_VALUE = HNSW,
 };
 
 enum class MetricType {

core/src/db/engine/ExecutionEngineImpl.cpp

@@ -16,6 +16,11 @@
 // under the License.
 
 #include "db/engine/ExecutionEngineImpl.h"
+
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
 #include "cache/CpuCacheMgr.h"
 #include "cache/GpuCacheMgr.h"
 #include "knowhere/common/Config.h"
@@ -33,10 +38,6 @@
 #include "wrapper/VecImpl.h"
 #include "wrapper/VecIndex.h"
 
-#include <stdexcept>
-#include <utility>
-#include <vector>
-
 //#define ON_SEARCH
 namespace milvus {
 namespace engine {
@@ -196,6 +197,10 @@ ExecutionEngineImpl::CreatetVecIndex(EngineType type) {
             index = GetVecIndexFactory(IndexType::SPTAG_BKT_RNT_CPU);
             break;
         }
+        case EngineType::HNSW: {
+            index = GetVecIndexFactory(IndexType::HNSW);
+            break;
+        }
         case EngineType::FAISS_BIN_IDMAP: {
             index = GetVecIndexFactory(IndexType::FAISS_BIN_IDMAP);
             break;

core/src/index/knowhere/CMakeLists.txt

@@ -37,6 +37,7 @@ set(index_srcs
         knowhere/index/vector_index/IndexBinaryIDMAP.cpp
         knowhere/index/vector_index/helpers/SPTAGParameterMgr.cpp
         knowhere/index/vector_index/IndexNSG.cpp
+        knowhere/index/vector_index/IndexHNSW.cpp
         knowhere/index/vector_index/nsg/NSG.cpp
         knowhere/index/vector_index/nsg/NSGIO.cpp
         knowhere/index/vector_index/nsg/NSGHelper.cpp

core/src/index/knowhere/knowhere/index/vector_index/IndexHNSW.cpp

@@ -0,0 +1,170 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include <algorithm>
+#include <cassert>
+#include <iterator>
+#include <utility>
+#include <vector>
+
+#include "knowhere/adapter/VectorAdapter.h"
+#include "knowhere/common/Exception.h"
+#include "knowhere/index/vector_index/IndexHNSW.h"
+#include "knowhere/index/vector_index/helpers/FaissIO.h"
+
+#include "hnswlib/hnswalg.h"
+#include "hnswlib/space_ip.h"
+#include "hnswlib/space_l2.h"
+
+namespace knowhere {
+
+BinarySet
+IndexHNSW::Serialize() {
+    if (!index_) {
+        KNOWHERE_THROW_MSG("index not initialize or trained");
+    }
+
+    try {
+        MemoryIOWriter writer;
+        index_->saveIndex(writer);
+        auto data = std::make_shared<uint8_t>();
+        data.reset(writer.data_);
+
+        BinarySet res_set;
+        res_set.Append("HNSW", data, writer.total);
+        return res_set;
+    } catch (std::exception& e) {
+        KNOWHERE_THROW_MSG(e.what());
+    }
+}
+
+void
+IndexHNSW::Load(const BinarySet& index_binary) {
+    try {
+        auto binary = index_binary.GetByName("HNSW");
+
+        MemoryIOReader reader;
+        reader.total = binary->size;
+        reader.data_ = binary->data.get();
+
+        hnswlib::SpaceInterface<float>* space;
+        index_ = std::make_shared<hnswlib::HierarchicalNSW<float>>(space);
+        index_->loadIndex(reader);
+    } catch (std::exception& e) {
+        KNOWHERE_THROW_MSG(e.what());
+    }
+}
+
+DatasetPtr
+IndexHNSW::Search(const DatasetPtr& dataset, const Config& config) {
+    auto search_cfg = std::dynamic_pointer_cast<HNSWCfg>(config);
+    if (search_cfg != nullptr) {
+        search_cfg->CheckValid();  // throw exception
+    }
+
+    if (!index_) {
+        KNOWHERE_THROW_MSG("index not initialize or trained");
+    }
+
+    GETTENSOR(dataset)
+    using P = std::pair<float, int64_t>;
+    auto compare = [](P v1, P v2) { return v1.second < v2.second; };
+    std::vector<std::pair<float, int64_t>> ret = index_->searchKnn(p_data, search_cfg->k, compare);
+
+    std::vector<float> dist(ret.size());
+    std::vector<int64_t> ids(ret.size());
+    std::transform(ret.begin(), ret.end(), std::back_inserter(dist),
+                   [](const std::pair<float, int64_t>& e) { return e.first; });
+    std::transform(ret.begin(), ret.end(), std::back_inserter(ids),
+                   [](const std::pair<float, int64_t>& e) { return e.second; });
+
+    auto elems = rows * search_cfg->k;
+    assert(elems == ret.size());
+    size_t p_id_size = sizeof(int64_t) * elems;
+    size_t p_dist_size = sizeof(float) * elems;
+    auto p_id = (int64_t*)malloc(p_id_size);
+    auto p_dist = (float*)malloc(p_dist_size);
+    memcpy(p_dist, dist.data(), dist.size() * sizeof(float));
+    memcpy(p_id, ids.data(), ids.size() * sizeof(int64_t));
+
+    auto ret_ds = std::make_shared<Dataset>();
+    ret_ds->Set(meta::IDS, p_id);
+    ret_ds->Set(meta::DISTANCE, p_dist);
+}
+
+IndexModelPtr
+IndexHNSW::Train(const DatasetPtr& dataset, const Config& config) {
+    auto build_cfg = std::dynamic_pointer_cast<HNSWCfg>(config);
+    if (build_cfg != nullptr) {
+        build_cfg->CheckValid();  // throw exception
+    }
+
+    GETTENSOR(dataset)
+
+    hnswlib::SpaceInterface<float>* space;
+    if (config->metric_type == METRICTYPE::L2) {
+        space = new hnswlib::L2Space(dim);
+    } else if (config->metric_type == METRICTYPE::IP) {
+        space = new hnswlib::InnerProductSpace(dim);
+    }
+    index_ = std::make_shared<hnswlib::HierarchicalNSW<float>>(space, rows, build_cfg->M, build_cfg->ef);
+
+    return nullptr;
+}
+
+void
+IndexHNSW::Add(const DatasetPtr& dataset, const Config& config) {
+    if (!index_) {
+        KNOWHERE_THROW_MSG("index not initialize");
+    }
+
+    std::lock_guard<std::mutex> lk(mutex_);
+
+    GETTENSOR(dataset)
+    auto p_ids = dataset->Get<const int64_t*>(meta::IDS);
+
+    for (int i = 0; i < 1; i++) {
+        index_->addPoint((void*)(p_data + dim * i), p_ids[i]);
+    }
+#pragma omp parallel for
+    for (int i = 1; i < rows; i++) {
+        index_->addPoint((void*)(p_data + dim * i), p_ids[i]);
+    }
+}
+
+void
+IndexHNSW::Seal() {
+    // do nothing
+}
+
+int64_t
+IndexHNSW::Count() {
+    if (!index_) {
+        KNOWHERE_THROW_MSG("index not initialize");
+    }
+    return index_->cur_element_count;
+}
+
+int64_t
+IndexHNSW::Dimension() {
+    if (!index_) {
+        KNOWHERE_THROW_MSG("index not initialize");
+    }
+    return (*(size_t*)index_->dist_func_param_);
+}
+
+}  // namespace knowhere

core/src/index/knowhere/knowhere/index/vector_index/IndexHNSW.h

@@ -0,0 +1,69 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+#include <memory>
+#include <mutex>
+
+#include "hnswlib/hnswlib.h"
+
+#include "knowhere/index/vector_index/VectorIndex.h"
+
+namespace knowhere {
+
+class IndexHNSW : public VectorIndex {
+ public:
+    BinarySet
+    Serialize() override;
+
+    void
+    Load(const BinarySet& index_binary) override;
+
+    DatasetPtr
+    Search(const DatasetPtr& dataset, const Config& config) override;
+
+    //    void
+    //    set_preprocessor(PreprocessorPtr preprocessor) override;
+    //
+    //    void
+    //    set_index_model(IndexModelPtr model) override;
+    //
+    //    PreprocessorPtr
+    //    BuildPreprocessor(const DatasetPtr& dataset, const Config& config) override;
+
+    IndexModelPtr
+    Train(const DatasetPtr& dataset, const Config& config) override;
+
+    void
+    Add(const DatasetPtr& dataset, const Config& config) override;
+
+    void
+    Seal() override;
+
+    int64_t
+    Count() override;
+
+    int64_t
+    Dimension() override;
+
+ private:
+    std::mutex mutex_;
+    std::shared_ptr<hnswlib::HierarchicalNSW<float>> index_;
+};
+
+}  // namespace knowhere

core/src/index/knowhere/knowhere/index/vector_index/helpers/FaissIO.h

@@ -28,6 +28,12 @@ struct MemoryIOWriter : public faiss::IOWriter {
 
     size_t
     operator()(const void* ptr, size_t size, size_t nitems) override;
+
+    template <typename T>
+    size_t
+    write(T* ptr, size_t size, size_t nitems = 1) {
+        operator()((const void*)ptr, size, nitems);
+    }
 };
 
 struct MemoryIOReader : public faiss::IOReader {
@@ -37,6 +43,12 @@ struct MemoryIOReader : public faiss::IOReader {
 
     size_t
     operator()(void* ptr, size_t size, size_t nitems) override;
+
+    template <typename T>
+    size_t
+    read(T* ptr, size_t size, size_t nitems = 1) {
+        operator()((void*)ptr, size, nitems);
+    }
 };
 
 }  // namespace knowhere

core/src/index/knowhere/knowhere/index/vector_index/helpers/IndexParameter.h

@@ -68,6 +68,10 @@ constexpr int64_t DEFAULT_BKTNUMBER = INVALID_VALUE;
 constexpr int64_t DEFAULT_BKTKMEANSK = INVALID_VALUE;
 constexpr int64_t DEFAULT_BKTLEAFSIZE = INVALID_VALUE;
 
+// HNSW Config
+constexpr int64_t DEFAULT_M = INVALID_VALUE;
+constexpr int64_t DEFAULT_EF = INVALID_VALUE;
+
 struct IVFCfg : public Cfg {
     int64_t nlist = DEFAULT_NLIST;
     int64_t nprobe = DEFAULT_NPROBE;
@@ -242,4 +246,12 @@ struct BinIDMAPCfg : public Cfg {
     }
 };
 
+struct HNSWCfg : public Cfg {
+    int64_t M = DEFAULT_M;
+    int64_t ef = DEFAULT_EF;
+
+    HNSWCfg() = default;
+};
+using HNSWConfig = std::shared_ptr<HNSWCfg>;
+
 }  // namespace knowhere

core/src/index/thirdparty/hnswlib/bruteforce.h

@@ -0,0 +1,170 @@
+#pragma once
+#include <unordered_map>
+#include <fstream>
+#include <mutex>
+#include <algorithm>
+
+namespace hnswlib {
+    template<typename dist_t>
+    class BruteforceSearch : public AlgorithmInterface<dist_t> {
+    public:
+        BruteforceSearch(SpaceInterface <dist_t> *s) {
+
+        }
+        BruteforceSearch(SpaceInterface<dist_t> *s, const std::string &location) {
+            loadIndex(location, s);
+        }
+
+        BruteforceSearch(SpaceInterface <dist_t> *s, size_t maxElements) {
+            maxelements_ = maxElements;
+            data_size_ = s->get_data_size();
+            fstdistfunc_ = s->get_dist_func();
+            dist_func_param_ = s->get_dist_func_param();
+            size_per_element_ = data_size_ + sizeof(labeltype);
+            data_ = (char *) malloc(maxElements * size_per_element_);
+            if (data_ == nullptr)
+                std::runtime_error("Not enough memory: BruteforceSearch failed to allocate data");
+            cur_element_count = 0;
+        }
+
+        ~BruteforceSearch() {
+            free(data_);
+        }
+
+        char *data_;
+        size_t maxelements_;
+        size_t cur_element_count;
+        size_t size_per_element_;
+
+        size_t data_size_;
+        DISTFUNC <dist_t> fstdistfunc_;
+        void *dist_func_param_;
+        std::mutex index_lock;
+
+        std::unordered_map<labeltype,size_t > dict_external_to_internal;
+
+        void addPoint(const void *datapoint, labeltype label) {
+
+            int idx;
+            {
+                std::unique_lock<std::mutex> lock(index_lock);
+
+
+
+                auto search=dict_external_to_internal.find(label);
+                if (search != dict_external_to_internal.end()) {
+                    idx=search->second;
+                }
+                else{
+                    if (cur_element_count >= maxelements_) {
+                        throw std::runtime_error("The number of elements exceeds the specified limit\n");
+                    }
+                    idx=cur_element_count;
+                    dict_external_to_internal[label] = idx;
+                    cur_element_count++;
+                }
+            }
+            memcpy(data_ + size_per_element_ * idx + data_size_, &label, sizeof(labeltype));
+            memcpy(data_ + size_per_element_ * idx, datapoint, data_size_);
+
+
+
+
+        };
+
+        void removePoint(labeltype cur_external) {
+            size_t cur_c=dict_external_to_internal[cur_external];
+
+            dict_external_to_internal.erase(cur_external);
+
+            labeltype label=*((labeltype*)(data_ + size_per_element_ * (cur_element_count-1) + data_size_));
+            dict_external_to_internal[label]=cur_c;
+            memcpy(data_ + size_per_element_ * cur_c,
+                   data_ + size_per_element_ * (cur_element_count-1),
+                   data_size_+sizeof(labeltype));
+            cur_element_count--;
+
+        }
+
+
+        std::priority_queue<std::pair<dist_t, labeltype >>
+        searchKnn(const void *query_data, size_t k) const {
+            std::priority_queue<std::pair<dist_t, labeltype >> topResults;
+            if (cur_element_count == 0) return topResults;
+            for (int i = 0; i < k; i++) {
+                dist_t dist = fstdistfunc_(query_data, data_ + size_per_element_ * i, dist_func_param_);
+                topResults.push(std::pair<dist_t, labeltype>(dist, *((labeltype *) (data_ + size_per_element_ * i +
+                                                                                    data_size_))));
+            }
+            dist_t lastdist = topResults.top().first;
+            for (int i = k; i < cur_element_count; i++) {
+                dist_t dist = fstdistfunc_(query_data, data_ + size_per_element_ * i, dist_func_param_);
+                if (dist <= lastdist) {
+                    topResults.push(std::pair<dist_t, labeltype>(dist, *((labeltype *) (data_ + size_per_element_ * i +
+                                                                                        data_size_))));
+                    if (topResults.size() > k)
+                        topResults.pop();
+                    lastdist = topResults.top().first;
+                }
+
+            }
+            return topResults;
+        };
+
+        template <typename Comp>
+        std::vector<std::pair<dist_t, labeltype>>
+        searchKnn(const void* query_data, size_t k, Comp comp) {
+            std::vector<std::pair<dist_t, labeltype>> result;
+            if (cur_element_count == 0) return result;
+
+            auto ret = searchKnn(query_data, k);
+
+            while (!ret.empty()) {
+                result.push_back(ret.top());
+                ret.pop();
+            }
+            
+            std::sort(result.begin(), result.end(), comp);
+
+            return result;
+        }
+
+        void saveIndex(const std::string &location) {
+            std::ofstream output(location, std::ios::binary);
+            std::streampos position;
+
+            writeBinaryPOD(output, maxelements_);
+            writeBinaryPOD(output, size_per_element_);
+            writeBinaryPOD(output, cur_element_count);
+
+            output.write(data_, maxelements_ * size_per_element_);
+
+            output.close();
+        }
+
+        void loadIndex(const std::string &location, SpaceInterface<dist_t> *s) {
+
+
+            std::ifstream input(location, std::ios::binary);
+            std::streampos position;
+
+            readBinaryPOD(input, maxelements_);
+            readBinaryPOD(input, size_per_element_);
+            readBinaryPOD(input, cur_element_count);
+
+            data_size_ = s->get_data_size();
+            fstdistfunc_ = s->get_dist_func();
+            dist_func_param_ = s->get_dist_func_param();
+            size_per_element_ = data_size_ + sizeof(labeltype);
+            data_ = (char *) malloc(maxelements_ * size_per_element_);
+            if (data_ == nullptr)
+                std::runtime_error("Not enough memory: loadIndex failed to allocate data");
+
+            input.read(data_, maxelements_ * size_per_element_);
+
+            input.close();
+
+        }
+
+    };
+}

core/src/index/thirdparty/hnswlib/hnswlib.h

@@ -0,0 +1,98 @@
+#pragma once
+#ifndef NO_MANUAL_VECTORIZATION
+#ifdef __SSE__
+#define USE_SSE
+#ifdef __AVX__
+#define USE_AVX
+#endif
+#endif
+#endif
+
+#if defined(USE_AVX) || defined(USE_SSE)
+#ifdef _MSC_VER
+#include <intrin.h>
+#include <stdexcept>
+#else
+#include <x86intrin.h>
+#endif
+
+#if defined(__GNUC__)
+#define PORTABLE_ALIGN32 __attribute__((aligned(32)))
+#else
+#define PORTABLE_ALIGN32 __declspec(align(32))
+#endif
+#endif
+
+#include <queue>
+#include <vector>
+
+#include <string.h>
+
+namespace hnswlib {
+    typedef int64_t labeltype;
+
+    template <typename T>
+    class pairGreater {
+    public:
+        bool operator()(const T& p1, const T& p2) {
+            return p1.first > p2.first;
+        }
+    };
+
+    template<typename T>
+    static void writeBinaryPOD(std::ostream &out, const T &podRef) {
+        out.write((char *) &podRef, sizeof(T));
+    }
+
+    template<typename T>
+    static void readBinaryPOD(std::istream &in, T &podRef) {
+        in.read((char *) &podRef, sizeof(T));
+    }
+
+    template<typename T, typename W>
+    static void writeBinaryPOD(W &out, const T &podRef) {
+        out.write((char *) &podRef, sizeof(T));
+    }
+
+    template<typename T, typename R>
+    static void readBinaryPOD(R &in, T &podRef) {
+        in.read((char *) &podRef, sizeof(T));
+    }
+
+    template<typename MTYPE>
+    using DISTFUNC = MTYPE(*)(const void *, const void *, const void *);
+
+
+    template<typename MTYPE>
+    class SpaceInterface {
+    public:
+        //virtual void search(void *);
+        virtual size_t get_data_size() = 0;
+
+        virtual DISTFUNC<MTYPE> get_dist_func() = 0;
+
+        virtual void *get_dist_func_param() = 0;
+
+        virtual ~SpaceInterface() {}
+    };
+
+    template<typename dist_t>
+    class AlgorithmInterface {
+    public:
+        virtual void addPoint(const void *datapoint, labeltype label)=0;
+        virtual std::priority_queue<std::pair<dist_t, labeltype >> searchKnn(const void *, size_t) const = 0;
+        template <typename Comp>
+        std::vector<std::pair<dist_t, labeltype>> searchKnn(const void*, size_t, Comp) {
+        }
+        virtual void saveIndex(const std::string &location)=0;
+        virtual ~AlgorithmInterface(){
+        }
+    };
+
+
+}
+
+#include "space_l2.h"
+#include "space_ip.h"
+#include "bruteforce.h"
+#include "hnswalg.h"

core/src/index/thirdparty/hnswlib/space_ip.h

@@ -0,0 +1,248 @@
+#pragma once
+#include "hnswlib.h"
+
+namespace hnswlib {
+
+    static float
+    InnerProduct(const void *pVect1, const void *pVect2, const void *qty_ptr) {
+        size_t qty = *((size_t *) qty_ptr);
+        float res = 0;
+        for (unsigned i = 0; i < qty; i++) {
+            res += ((float *) pVect1)[i] * ((float *) pVect2)[i];
+        }
+        return (1.0f - res);
+
+    }
+
+#if defined(USE_AVX)
+
+// Favor using AVX if available.
+    static float
+    InnerProductSIMD4Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float PORTABLE_ALIGN32 TmpRes[8];
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+
+        size_t qty16 = qty / 16;
+        size_t qty4 = qty / 4;
+
+        const float *pEnd1 = pVect1 + 16 * qty16;
+        const float *pEnd2 = pVect1 + 4 * qty4;
+
+        __m256 sum256 = _mm256_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            //_mm_prefetch((char*)(pVect2 + 16), _MM_HINT_T0);
+
+            __m256 v1 = _mm256_loadu_ps(pVect1);
+            pVect1 += 8;
+            __m256 v2 = _mm256_loadu_ps(pVect2);
+            pVect2 += 8;
+            sum256 = _mm256_add_ps(sum256, _mm256_mul_ps(v1, v2));
+
+            v1 = _mm256_loadu_ps(pVect1);
+            pVect1 += 8;
+            v2 = _mm256_loadu_ps(pVect2);
+            pVect2 += 8;
+            sum256 = _mm256_add_ps(sum256, _mm256_mul_ps(v1, v2));
+        }
+
+        __m128 v1, v2;
+        __m128 sum_prod = _mm_add_ps(_mm256_extractf128_ps(sum256, 0), _mm256_extractf128_ps(sum256, 1));
+
+        while (pVect1 < pEnd2) {
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+        }
+
+        _mm_store_ps(TmpRes, sum_prod);
+        float sum = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3];;
+        return 1.0f - sum;
+}
+
+#elif defined(USE_SSE)
+
+    static float
+    InnerProductSIMD4Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float PORTABLE_ALIGN32 TmpRes[8];
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+
+        size_t qty16 = qty / 16;
+        size_t qty4 = qty / 4;
+
+        const float *pEnd1 = pVect1 + 16 * qty16;
+        const float *pEnd2 = pVect1 + 4 * qty4;
+
+        __m128 v1, v2;
+        __m128 sum_prod = _mm_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+        }
+
+        while (pVect1 < pEnd2) {
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+        }
+
+        _mm_store_ps(TmpRes, sum_prod);
+        float sum = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3];
+
+        return 1.0f - sum;
+    }
+
+#endif
+
+#if defined(USE_AVX)
+
+    static float
+    InnerProductSIMD16Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float PORTABLE_ALIGN32 TmpRes[8];
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+
+        size_t qty16 = qty / 16;
+
+
+        const float *pEnd1 = pVect1 + 16 * qty16;
+
+        __m256 sum256 = _mm256_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            //_mm_prefetch((char*)(pVect2 + 16), _MM_HINT_T0);
+
+            __m256 v1 = _mm256_loadu_ps(pVect1);
+            pVect1 += 8;
+            __m256 v2 = _mm256_loadu_ps(pVect2);
+            pVect2 += 8;
+            sum256 = _mm256_add_ps(sum256, _mm256_mul_ps(v1, v2));
+
+            v1 = _mm256_loadu_ps(pVect1);
+            pVect1 += 8;
+            v2 = _mm256_loadu_ps(pVect2);
+            pVect2 += 8;
+            sum256 = _mm256_add_ps(sum256, _mm256_mul_ps(v1, v2));
+        }
+
+        _mm256_store_ps(TmpRes, sum256);
+        float sum = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3] + TmpRes[4] + TmpRes[5] + TmpRes[6] + TmpRes[7];
+
+        return 1.0f - sum;
+    }
+
+#elif defined(USE_SSE)
+
+      static float
+      InnerProductSIMD16Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float PORTABLE_ALIGN32 TmpRes[8];
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+
+        size_t qty16 = qty / 16;
+
+        const float *pEnd1 = pVect1 + 16 * qty16;
+
+        __m128 v1, v2;
+        __m128 sum_prod = _mm_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            sum_prod = _mm_add_ps(sum_prod, _mm_mul_ps(v1, v2));
+        }
+        _mm_store_ps(TmpRes, sum_prod);
+        float sum = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3];
+
+        return 1.0f - sum;
+    }
+
+#endif
+
+    class InnerProductSpace : public SpaceInterface<float> {
+
+        DISTFUNC<float> fstdistfunc_;
+        size_t data_size_;
+        size_t dim_;
+    public:
+        InnerProductSpace(size_t dim) {
+            fstdistfunc_ = InnerProduct;
+    #if defined(USE_AVX) || defined(USE_SSE)
+            if (dim % 4 == 0)
+                fstdistfunc_ = InnerProductSIMD4Ext;
+            if (dim % 16 == 0)
+                fstdistfunc_ = InnerProductSIMD16Ext;
+#endif
+            dim_ = dim;
+            data_size_ = dim * sizeof(float);
+        }
+
+        size_t get_data_size() {
+            return data_size_;
+        }
+
+        DISTFUNC<float> get_dist_func() {
+            return fstdistfunc_;
+        }
+
+        void *get_dist_func_param() {
+            return &dim_;
+        }
+
+    ~InnerProductSpace() {}
+    };
+
+
+}

core/src/index/thirdparty/hnswlib/space_l2.h

@@ -0,0 +1,244 @@
+#pragma once
+#include "hnswlib.h"
+
+namespace hnswlib {
+
+    static float
+    L2Sqr(const void *pVect1, const void *pVect2, const void *qty_ptr) {
+        //return *((float *)pVect2);
+        size_t qty = *((size_t *) qty_ptr);
+        float res = 0;
+        for (unsigned i = 0; i < qty; i++) {
+            float t = ((float *) pVect1)[i] - ((float *) pVect2)[i];
+            res += t * t;
+        }
+        return (res);
+
+    }
+
+#if defined(USE_AVX)
+
+    // Favor using AVX if available.
+    static float
+    L2SqrSIMD16Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+        float PORTABLE_ALIGN32 TmpRes[8];
+        size_t qty16 = qty >> 4;
+
+        const float *pEnd1 = pVect1 + (qty16 << 4);
+
+        __m256 diff, v1, v2;
+        __m256 sum = _mm256_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            v1 = _mm256_loadu_ps(pVect1);
+            pVect1 += 8;
+            v2 = _mm256_loadu_ps(pVect2);
+            pVect2 += 8;
+            diff = _mm256_sub_ps(v1, v2);
+            sum = _mm256_add_ps(sum, _mm256_mul_ps(diff, diff));
+
+            v1 = _mm256_loadu_ps(pVect1);
+            pVect1 += 8;
+            v2 = _mm256_loadu_ps(pVect2);
+            pVect2 += 8;
+            diff = _mm256_sub_ps(v1, v2);
+            sum = _mm256_add_ps(sum, _mm256_mul_ps(diff, diff));
+        }
+
+        _mm256_store_ps(TmpRes, sum);
+        float res = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3] + TmpRes[4] + TmpRes[5] + TmpRes[6] + TmpRes[7];
+
+        return (res);
+}
+
+#elif defined(USE_SSE)
+
+    static float
+    L2SqrSIMD16Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+        float PORTABLE_ALIGN32 TmpRes[8];
+        // size_t qty4 = qty >> 2;
+        size_t qty16 = qty >> 4;
+
+        const float *pEnd1 = pVect1 + (qty16 << 4);
+        // const float* pEnd2 = pVect1 + (qty4 << 2);
+        // const float* pEnd3 = pVect1 + qty;
+
+        __m128 diff, v1, v2;
+        __m128 sum = _mm_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            //_mm_prefetch((char*)(pVect2 + 16), _MM_HINT_T0);
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            diff = _mm_sub_ps(v1, v2);
+            sum = _mm_add_ps(sum, _mm_mul_ps(diff, diff));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            diff = _mm_sub_ps(v1, v2);
+            sum = _mm_add_ps(sum, _mm_mul_ps(diff, diff));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            diff = _mm_sub_ps(v1, v2);
+            sum = _mm_add_ps(sum, _mm_mul_ps(diff, diff));
+
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            diff = _mm_sub_ps(v1, v2);
+            sum = _mm_add_ps(sum, _mm_mul_ps(diff, diff));
+        }
+        _mm_store_ps(TmpRes, sum);
+        float res = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3];
+
+        return (res);
+    }
+#endif
+
+
+#ifdef USE_SSE
+    static float
+    L2SqrSIMD4Ext(const void *pVect1v, const void *pVect2v, const void *qty_ptr) {
+        float PORTABLE_ALIGN32 TmpRes[8];
+        float *pVect1 = (float *) pVect1v;
+        float *pVect2 = (float *) pVect2v;
+        size_t qty = *((size_t *) qty_ptr);
+
+
+        // size_t qty4 = qty >> 2;
+        size_t qty16 = qty >> 2;
+
+        const float *pEnd1 = pVect1 + (qty16 << 2);
+
+        __m128 diff, v1, v2;
+        __m128 sum = _mm_set1_ps(0);
+
+        while (pVect1 < pEnd1) {
+            v1 = _mm_loadu_ps(pVect1);
+            pVect1 += 4;
+            v2 = _mm_loadu_ps(pVect2);
+            pVect2 += 4;
+            diff = _mm_sub_ps(v1, v2);
+            sum = _mm_add_ps(sum, _mm_mul_ps(diff, diff));
+        }
+        _mm_store_ps(TmpRes, sum);
+        float res = TmpRes[0] + TmpRes[1] + TmpRes[2] + TmpRes[3];
+
+        return (res);
+    }
+#endif
+
+    class L2Space : public SpaceInterface<float> {
+
+        DISTFUNC<float> fstdistfunc_;
+        size_t data_size_;
+        size_t dim_;
+    public:
+        L2Space(size_t dim) {
+            fstdistfunc_ = L2Sqr;
+        #if defined(USE_SSE) || defined(USE_AVX)
+            if (dim % 4 == 0)
+                fstdistfunc_ = L2SqrSIMD4Ext;
+            if (dim % 16 == 0)
+                fstdistfunc_ = L2SqrSIMD16Ext;
+            /*else{
+                throw runtime_error("Data type not supported!");
+            }*/
+        #endif
+            dim_ = dim;
+            data_size_ = dim * sizeof(float);
+        }
+
+        size_t get_data_size() {
+            return data_size_;
+        }
+
+        DISTFUNC<float> get_dist_func() {
+            return fstdistfunc_;
+        }
+
+        void *get_dist_func_param() {
+            return &dim_;
+        }
+
+        ~L2Space() {}
+    };
+
+    static int
+    L2SqrI(const void *__restrict pVect1, const void *__restrict pVect2, const void *__restrict qty_ptr) {
+
+        size_t qty = *((size_t *) qty_ptr);
+        int res = 0;
+        unsigned char *a = (unsigned char *) pVect1;
+        unsigned char *b = (unsigned char *) pVect2;
+        /*for (int i = 0; i < qty; i++) {
+            int t = int((a)[i]) - int((b)[i]);
+            res += t*t;
+        }*/
+
+        qty = qty >> 2;
+        for (size_t i = 0; i < qty; i++) {
+
+            res += ((*a) - (*b)) * ((*a) - (*b));
+            a++;
+            b++;
+            res += ((*a) - (*b)) * ((*a) - (*b));
+            a++;
+            b++;
+            res += ((*a) - (*b)) * ((*a) - (*b));
+            a++;
+            b++;
+            res += ((*a) - (*b)) * ((*a) - (*b));
+            a++;
+            b++;
+
+
+        }
+
+        return (res);
+
+    }
+
+    class L2SpaceI : public SpaceInterface<int> {
+
+        DISTFUNC<int> fstdistfunc_;
+        size_t data_size_;
+        size_t dim_;
+    public:
+        L2SpaceI(size_t dim) {
+            fstdistfunc_ = L2SqrI;
+            dim_ = dim;
+            data_size_ = dim * sizeof(unsigned char);
+        }
+
+        size_t get_data_size() {
+            return data_size_;
+        }
+
+        DISTFUNC<int> get_dist_func() {
+            return fstdistfunc_;
+        }
+
+        void *get_dist_func_param() {
+            return &dim_;
+        }
+
+        ~L2SpaceI() {}
+    };
+
+
+}

core/src/index/thirdparty/hnswlib/visited_list_pool.h

@@ -0,0 +1,78 @@
+#pragma once
+
+#include <mutex>
+#include <string.h>
+
+namespace hnswlib {
+    typedef unsigned short int vl_type;
+
+    class VisitedList {
+    public:
+        vl_type curV;
+        vl_type *mass;
+        unsigned int numelements;
+
+        VisitedList(int numelements1) {
+            curV = -1;
+            numelements = numelements1;
+            mass = new vl_type[numelements];
+        }
+
+        void reset() {
+            curV++;
+            if (curV == 0) {
+                memset(mass, 0, sizeof(vl_type) * numelements);
+                curV++;
+            }
+        };
+
+        ~VisitedList() { delete[] mass; }
+    };
+///////////////////////////////////////////////////////////
+//
+// Class for multi-threaded pool-management of VisitedLists
+//
+/////////////////////////////////////////////////////////
+
+    class VisitedListPool {
+        std::deque<VisitedList *> pool;
+        std::mutex poolguard;
+        int numelements;
+
+    public:
+        VisitedListPool(int initmaxpools, int numelements1) {
+            numelements = numelements1;
+            for (int i = 0; i < initmaxpools; i++)
+                pool.push_front(new VisitedList(numelements));
+        }
+
+        VisitedList *getFreeVisitedList() {
+            VisitedList *rez;
+            {
+                std::unique_lock <std::mutex> lock(poolguard);
+                if (pool.size() > 0) {
+                    rez = pool.front();
+                    pool.pop_front();
+                } else {
+                    rez = new VisitedList(numelements);
+                }
+            }
+            rez->reset();
+            return rez;
+        };
+
+        void releaseVisitedList(VisitedList *vl) {
+            std::unique_lock <std::mutex> lock(poolguard);
+            pool.push_front(vl);
+        };
+
+        ~VisitedListPool() {
+            while (pool.size()) {
+                VisitedList *rez = pool.front();
+                pool.pop_front();
+                delete rez;
+            }
+        };
+    };
+}
+

core/src/wrapper/ConfAdapter.cpp

@@ -16,15 +16,16 @@
 // under the License.
 
 #include "wrapper/ConfAdapter.h"
-#include "WrapperException.h"
-#include "knowhere/index/vector_index/helpers/IndexParameter.h"
-#include "server/Config.h"
-#include "utils/Log.h"
 
 #include <cmath>
 #include <memory>
 #include <vector>
 
+#include "WrapperException.h"
+#include "knowhere/index/vector_index/helpers/IndexParameter.h"
+#include "server/Config.h"
+#include "utils/Log.h"
+
 // TODO(lxj): add conf checker
 
 namespace milvus {
@@ -266,6 +267,17 @@ SPTAGBKTConfAdapter::MatchSearch(const TempMetaConf& metaconf, const IndexType&
     return conf;
 }
 
+knowhere::Config
+HNSWConfAdapter::Match(const TempMetaConf& metaconf) {
+    auto conf = std::make_shared<knowhere::HNSWCfg>();
+    conf->d = metaconf.dim;
+    conf->metric_type = metaconf.metric_type;
+
+    conf->ef = 100;  // ef can be auto-configured by using sample data.
+    conf->M = 16;    // A reasonable range of M is from 5 to 48.
+    return conf;
+}
+
 knowhere::Config
 BinIDMAPConfAdapter::Match(const TempMetaConf& metaconf) {
     auto conf = std::make_shared<knowhere::BinIDMAPCfg>();

core/src/wrapper/ConfAdapter.h

@@ -17,11 +17,11 @@
 
 #pragma once
 
+#include <memory>
+
 #include "VecIndex.h"
 #include "knowhere/common/Config.h"
 
-#include <memory>
-
 namespace milvus {
 namespace engine {
 
@@ -124,5 +124,11 @@ class BinIVFConfAdapter : public IVFConfAdapter {
     Match(const TempMetaConf& metaconf) override;
 };
 
+class HNSWConfAdapter : public ConfAdapter {
+ public:
+    knowhere::Config
+    Match(const TempMetaConf& metaconf) override;
+};
+
 }  // namespace engine
 }  // namespace milvus

core/src/wrapper/ConfAdapterMgr.cpp

@@ -16,6 +16,7 @@
 // under the License.
 
 #include "wrapper/ConfAdapterMgr.h"
+
 #include "utils/Exception.h"
 
 namespace milvus {
@@ -61,6 +62,8 @@ AdapterMgr::RegisterAdapter() {
 
     REGISTER_CONF_ADAPTER(SPTAGKDTConfAdapter, IndexType::SPTAG_KDT_RNT_CPU, sptag_kdt);
     REGISTER_CONF_ADAPTER(SPTAGBKTConfAdapter, IndexType::SPTAG_BKT_RNT_CPU, sptag_bkt);
+
+    REGISTER_CONF_ADAPTER(HNSWConfAdapter, IndexType::HNSW, hnsw);
 }
 
 }  // namespace engine

core/src/wrapper/VecIndex.cpp

@@ -16,10 +16,12 @@
 // under the License.
 
 #include "wrapper/VecIndex.h"
+
 #include "VecImpl.h"
 #include "knowhere/common/Exception.h"
 #include "knowhere/index/vector_index/IndexBinaryIDMAP.h"
 #include "knowhere/index/vector_index/IndexBinaryIVF.h"
+#include "knowhere/index/vector_index/IndexHNSW.h"
 #include "knowhere/index/vector_index/IndexIDMAP.h"
 #include "knowhere/index/vector_index/IndexIVF.h"
 #include "knowhere/index/vector_index/IndexIVFPQ.h"
@@ -38,6 +40,7 @@
 
 #ifdef MILVUS_GPU_VERSION
 #include <cuda.h>
+
 #include "knowhere/index/vector_index/IndexGPUIDMAP.h"
 #include "knowhere/index/vector_index/IndexGPUIVF.h"
 #include "knowhere/index/vector_index/IndexGPUIVFPQ.h"
@@ -99,6 +102,10 @@ GetVecIndexFactory(const IndexType& type, const Config& cfg) {
             index = std::make_shared<knowhere::IVFSQ>();
             break;
         }
+        case IndexType::HNSW: {
+            index = std::make_shared<knowhere::IndexHNSW>();
+            break;
+        }
 
 #ifdef MILVUS_GPU_VERSION
         case IndexType::FAISS_IVFFLAT_GPU: {

core/src/wrapper/VecIndex.h

@@ -50,6 +50,7 @@ enum class IndexType {
     NSG_MIX,
     FAISS_IVFPQ_MIX,
     SPTAG_BKT_RNT_CPU,
+    HNSW,
     FAISS_BIN_IDMAP = 100,
     FAISS_BIN_IVFLAT_CPU = 101,
 };