[Feature to main] Add binary format support with IVF method in Faiss Engine (#1784)

CHANGELOG.md

@@ -20,6 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 * Add binary format support with HNSW method in Faiss Engine [#1781](https://github.com/opensearch-project/k-NN/pull/1781)
 * Add script scoring support for knn field with binary data type [#1826](https://github.com/opensearch-project/k-NN/pull/1826)
 * Add painless script support for hamming with binary vector data type [#1839](https://github.com/opensearch-project/k-NN/pull/1839)
+* Add binary format support with IVF method in Faiss Engine [#1784](https://github.com/opensearch-project/k-NN/pull/1784)
 ### Enhancements
 * Switch from byte stream to byte ref for serde [#1825](https://github.com/opensearch-project/k-NN/pull/1825)
 ### Bug Fixes

jni/include/faiss_wrapper.h

@@ -29,6 +29,12 @@ namespace knn_jni {
                                      jlong vectorsAddressJ, jint dimJ, jstring indexPathJ, jbyteArray templateIndexJ,
                                      jobject parametersJ);
 
+        // Create an index with ids and vectors. Instead of creating a new index, this function creates the index
+        // based off of the template index passed in. The index is serialized to indexPathJ.
+        void CreateBinaryIndexFromTemplate(knn_jni::JNIUtilInterface * jniUtil, JNIEnv * env, jintArray idsJ,
+                                     jlong vectorsAddressJ, jint dimJ, jstring indexPathJ, jbyteArray templateIndexJ,
+                                     jobject parametersJ);
+
         // Load an index from indexPathJ into memory.
         //
         // Return a pointer to the loaded index
@@ -96,6 +102,13 @@ namespace knn_jni {
         jbyteArray TrainIndex(knn_jni::JNIUtilInterface * jniUtil, JNIEnv * env, jobject parametersJ, jint dimension,
                               jlong trainVectorsPointerJ);
 
+        // Create an empty binary index defined by the values in the Java map, parametersJ. Train the index with
+        // the vector of floats located at trainVectorsPointerJ.
+        //
+        // Return the serialized representation
+        jbyteArray TrainBinaryIndex(knn_jni::JNIUtilInterface * jniUtil, JNIEnv * env, jobject parametersJ, jint dimension,
+                         jlong trainVectorsPointerJ);
+
         /*
          * Perform a range search with filter against the index located in memory at indexPointerJ.
          *

jni/include/org_opensearch_knn_jni_FaissService.h

@@ -43,6 +43,14 @@ JNIEXPORT void JNICALL Java_org_opensearch_knn_jni_FaissService_createBinaryInde
 JNIEXPORT void JNICALL Java_org_opensearch_knn_jni_FaissService_createIndexFromTemplate
   (JNIEnv *, jclass, jintArray, jlong, jint, jstring, jbyteArray, jobject);
 
+/*
+ * Class:     org_opensearch_knn_jni_FaissService
+ * Method:    createBinaryIndexFromTemplate
+ * Signature: ([IJILjava/lang/String;[BLjava/util/Map;)V
+ */
+    JNIEXPORT void JNICALL Java_org_opensearch_knn_jni_FaissService_createBinaryIndexFromTemplate
+      (JNIEnv *, jclass, jintArray, jlong, jint, jstring, jbyteArray, jobject);
+
 /*
  * Class:     org_opensearch_knn_jni_FaissService
  * Method:    loadIndex
@@ -139,6 +147,14 @@ JNIEXPORT void JNICALL Java_org_opensearch_knn_jni_FaissService_initLibrary
 JNIEXPORT jbyteArray JNICALL Java_org_opensearch_knn_jni_FaissService_trainIndex
   (JNIEnv *, jclass, jobject, jint, jlong);
 
+/*
+ * Class:     org_opensearch_knn_jni_FaissService
+ * Method:    trainBinaryIndex
+ * Signature: (Ljava/util/Map;IJ)[B
+ */
+JNIEXPORT jbyteArray JNICALL Java_org_opensearch_knn_jni_FaissService_trainBinaryIndex
+  (JNIEnv *, jclass, jobject, jint, jlong);
+
 /*
  * Class:     org_opensearch_knn_jni_FaissService
  * Method:    transferVectors

jni/src/faiss_wrapper.cpp

@@ -70,6 +70,9 @@ void SetExtraParameters(knn_jni::JNIUtilInterface * jniUtil, JNIEnv *env,
 // Train an index with data provided
 void InternalTrainIndex(faiss::Index * index, faiss::idx_t n, const float* x);
 
+// Train a binary index with data provided
+void InternalTrainBinaryIndex(faiss::IndexBinary * index, faiss::idx_t n, const float* x);
+
 // Converts the int FilterIds to Faiss ids type array.
 void convertFilterIdsToFaissIdType(const int* filterIds, int filterIdsLength, faiss::idx_t* convertedFilterIds);
 
@@ -223,6 +226,76 @@ void knn_jni::faiss_wrapper::CreateIndexFromTemplate(knn_jni::JNIUtilInterface *
     faiss::write_index(&idMap, indexPathCpp.c_str());
 }
 
+void knn_jni::faiss_wrapper::CreateBinaryIndexFromTemplate(knn_jni::JNIUtilInterface * jniUtil, JNIEnv * env, jintArray idsJ,
+                                                     jlong vectorsAddressJ, jint dimJ, jstring indexPathJ,
+                                                     jbyteArray templateIndexJ, jobject parametersJ) {
+    if (idsJ == nullptr) {
+        throw std::runtime_error("IDs cannot be null");
+    }
+
+    if (vectorsAddressJ <= 0) {
+        throw std::runtime_error("VectorsAddress cannot be less than 0");
+    }
+
+    if(dimJ <= 0) {
+        throw std::runtime_error("Vectors dimensions cannot be less than or equal to 0");
+    }
+
+    if (indexPathJ == nullptr) {
+        throw std::runtime_error("Index path cannot be null");
+    }
+
+    if (templateIndexJ == nullptr) {
+        throw std::runtime_error("Template index cannot be null");
+    }
+
+    // Set thread count if it is passed in as a parameter. Setting this variable will only impact the current thread
+    auto parametersCpp = jniUtil->ConvertJavaMapToCppMap(env, parametersJ);
+    if(parametersCpp.find(knn_jni::INDEX_THREAD_QUANTITY) != parametersCpp.end()) {
+        auto threadCount = jniUtil->ConvertJavaObjectToCppInteger(env, parametersCpp[knn_jni::INDEX_THREAD_QUANTITY]);
+        omp_set_num_threads(threadCount);
+    }
+    jniUtil->DeleteLocalRef(env, parametersJ);
+
+    // Read data set
+    // Read vectors from memory address
+    auto *inputVectors = reinterpret_cast<std::vector<uint8_t>*>(vectorsAddressJ);
+    int dim = (int)dimJ;
+    if (dim % 8 != 0) {
+        throw std::runtime_error("Dimensions should be multiply of 8");
+    }
+    int numVectors = (int) (inputVectors->size() / (uint64_t) (dim / 8));
+    int numIds = jniUtil->GetJavaIntArrayLength(env, idsJ);
+    if (numIds != numVectors) {
+        throw std::runtime_error("Number of IDs does not match number of vectors");
+    }
+
+    // Get vector of bytes from jbytearray
+    int indexBytesCount = jniUtil->GetJavaBytesArrayLength(env, templateIndexJ);
+    jbyte * indexBytesJ = jniUtil->GetByteArrayElements(env, templateIndexJ, nullptr);
+
+    faiss::VectorIOReader vectorIoReader;
+    for (int i = 0; i < indexBytesCount; i++) {
+        vectorIoReader.data.push_back((uint8_t) indexBytesJ[i]);
+    }
+    jniUtil->ReleaseByteArrayElements(env, templateIndexJ, indexBytesJ, JNI_ABORT);
+
+    // Create faiss index
+    std::unique_ptr<faiss::IndexBinary> indexWriter;
+    indexWriter.reset(faiss::read_index_binary(&vectorIoReader, 0));
+
+    auto idVector = jniUtil->ConvertJavaIntArrayToCppIntVector(env, idsJ);
+    faiss::IndexBinaryIDMap idMap =  faiss::IndexBinaryIDMap(indexWriter.get());
+    idMap.add_with_ids(numVectors, reinterpret_cast<const uint8_t*>(inputVectors->data()), idVector.data());
+    // Releasing the vectorsAddressJ memory as that is not required once we have created the index.
+    // This is not the ideal approach, please refer this gh issue for long term solution:
+    // https://github.com/opensearch-project/k-NN/issues/1600
+    delete inputVectors;
+    // Write the index to disk
+    std::string indexPathCpp(jniUtil->ConvertJavaStringToCppString(env, indexPathJ));
+    faiss::write_index_binary(&idMap, indexPathCpp.c_str());
+}
+
 jlong knn_jni::faiss_wrapper::LoadIndex(knn_jni::JNIUtilInterface * jniUtil, JNIEnv * env, jstring indexPathJ) {
     if (indexPathJ == nullptr) {
         throw std::runtime_error("Index path cannot be null");
@@ -634,6 +707,57 @@ jbyteArray knn_jni::faiss_wrapper::TrainIndex(knn_jni::JNIUtilInterface * jniUti
     return ret;
 }
 
+jbyteArray knn_jni::faiss_wrapper::TrainBinaryIndex(knn_jni::JNIUtilInterface * jniUtil, JNIEnv * env, jobject parametersJ,
+                                              jint dimensionJ, jlong trainVectorsPointerJ) {
+    // First, we need to build the index
+    if (parametersJ == nullptr) {
+        throw std::runtime_error("Parameters cannot be null");
+    }
+
+    auto parametersCpp = jniUtil->ConvertJavaMapToCppMap(env, parametersJ);
+
+    jobject spaceTypeJ = knn_jni::GetJObjectFromMapOrThrow(parametersCpp, knn_jni::SPACE_TYPE);
+    std::string spaceTypeCpp(jniUtil->ConvertJavaObjectToCppString(env, spaceTypeJ));
+    faiss::MetricType metric = TranslateSpaceToMetric(spaceTypeCpp);
+
+    // Create faiss index
+    jobject indexDescriptionJ = knn_jni::GetJObjectFromMapOrThrow(parametersCpp, knn_jni::INDEX_DESCRIPTION);
+    std::string indexDescriptionCpp(jniUtil->ConvertJavaObjectToCppString(env, indexDescriptionJ));
+
+    std::unique_ptr<faiss::IndexBinary> indexWriter;
+    indexWriter.reset(faiss::index_binary_factory((int) dimensionJ, indexDescriptionCpp.c_str()));
+
+    // Set thread count if it is passed in as a parameter. Setting this variable will only impact the current thread
+    if(parametersCpp.find(knn_jni::INDEX_THREAD_QUANTITY) != parametersCpp.end()) {
+        auto threadCount = jniUtil->ConvertJavaObjectToCppInteger(env, parametersCpp[knn_jni::INDEX_THREAD_QUANTITY]);
+        omp_set_num_threads(threadCount);
+    }
+
+    // Train index if needed
+    auto *trainingVectorsPointerCpp = reinterpret_cast<std::vector<float>*>(trainVectorsPointerJ);
+    int numVectors = trainingVectorsPointerCpp->size()/(int) dimensionJ;
+    if(!indexWriter->is_trained) {
+        InternalTrainBinaryIndex(indexWriter.get(), numVectors, trainingVectorsPointerCpp->data());
+    }
+    jniUtil->DeleteLocalRef(env, parametersJ);
+
+    // Now that indexWriter is trained, we just load the bytes into an array and return
+    faiss::VectorIOWriter vectorIoWriter;
+    faiss::write_index_binary(indexWriter.get(), &vectorIoWriter);
+
+    // Wrap in smart pointer
+    std::unique_ptr<jbyte[]> jbytesBuffer;
+    jbytesBuffer.reset(new jbyte[vectorIoWriter.data.size()]);
+    int c = 0;
+    for (auto b : vectorIoWriter.data) {
+        jbytesBuffer[c++] = (jbyte) b;
+    }
+
+    jbyteArray ret = jniUtil->NewByteArray(env, vectorIoWriter.data.size());
+    jniUtil->SetByteArrayRegion(env, ret, 0, vectorIoWriter.data.size(), jbytesBuffer.get());
+    return ret;
+}
+
 faiss::MetricType TranslateSpaceToMetric(const std::string& spaceType) {
     if (spaceType == knn_jni::L2) {
         return faiss::METRIC_L2;
@@ -692,6 +816,15 @@ void InternalTrainIndex(faiss::Index * index, faiss::idx_t n, const float* x) {
     }
 }
 
+void InternalTrainBinaryIndex(faiss::IndexBinary * index, faiss::idx_t n, const float* x) {
+    if (auto * indexIvf = dynamic_cast<faiss::IndexBinaryIVF*>(index)) {
+        indexIvf->make_direct_map();
+    }
+    if (!index->is_trained) {
+        index->train(n, reinterpret_cast<const uint8_t*>(x));
+    }
+}
+
 std::unique_ptr<faiss::IDGrouperBitmap> buildIDGrouperBitmap(knn_jni::JNIUtilInterface * jniUtil, JNIEnv *env, jintArray parentIdsJ, std::vector<uint64_t>* bitmap) {
     int *parentIdsArray = jniUtil->GetIntArrayElements(env, parentIdsJ, nullptr);
     int parentIdsLength = jniUtil->GetJavaIntArrayLength(env, parentIdsJ);

jni/src/org_opensearch_knn_jni_FaissService.cpp

@@ -90,6 +90,21 @@ JNIEXPORT void JNICALL Java_org_opensearch_knn_jni_FaissService_createIndexFromT
     }
 }
 
+JNIEXPORT void JNICALL Java_org_opensearch_knn_jni_FaissService_createBinaryIndexFromTemplate(JNIEnv * env, jclass cls,
+                                                                                        jintArray idsJ,
+                                                                                        jlong vectorsAddressJ,
+                                                                                        jint dimJ,
+                                                                                        jstring indexPathJ,
+                                                                                        jbyteArray templateIndexJ,
+                                                                                        jobject parametersJ)
+{
+    try {
+        knn_jni::faiss_wrapper::CreateBinaryIndexFromTemplate(&jniUtil, env, idsJ, vectorsAddressJ, dimJ, indexPathJ, templateIndexJ, parametersJ);
+    } catch (...) {
+        jniUtil.CatchCppExceptionAndThrowJava(env);
+    }
+}
+
 JNIEXPORT jlong JNICALL Java_org_opensearch_knn_jni_FaissService_loadIndex(JNIEnv * env, jclass cls, jstring indexPathJ)
 {
     try {
@@ -220,6 +235,19 @@ JNIEXPORT jbyteArray JNICALL Java_org_opensearch_knn_jni_FaissService_trainIndex
     return nullptr;
 }
 
+JNIEXPORT jbyteArray JNICALL Java_org_opensearch_knn_jni_FaissService_trainBinaryIndex(JNIEnv * env, jclass cls,
+                                                                                 jobject parametersJ,
+                                                                                 jint dimensionJ,
+                                                                                 jlong trainVectorsPointerJ)
+{
+    try {
+        return knn_jni::faiss_wrapper::TrainBinaryIndex(&jniUtil, env, parametersJ, dimensionJ, trainVectorsPointerJ);
+    } catch (...) {
+        jniUtil.CatchCppExceptionAndThrowJava(env);
+    }
+    return nullptr;
+}
+
 JNIEXPORT jlong JNICALL Java_org_opensearch_knn_jni_FaissService_transferVectors(JNIEnv * env, jclass cls,
                                                                                  jlong vectorsPointerJ,
                                                                                  jobjectArray vectorsJ)

src/main/java/org/opensearch/knn/common/KNNConstants.java

@@ -67,6 +67,7 @@ public class KNNConstants {
     public static final String SEARCH_SIZE_PARAMETER = "search_size";
 
     public static final String VECTOR_DATA_TYPE_FIELD = "data_type";
+    public static final String MODEL_VECTOR_DATA_TYPE_KEY = VECTOR_DATA_TYPE_FIELD;
     public static final VectorDataType DEFAULT_VECTOR_DATA_TYPE_FIELD = VectorDataType.FLOAT;
 
     public static final String RADIAL_SEARCH_KEY = "radial_search";