architecture

name	architecture
description	Use when exploring codebase structure, understanding index implementations (HNSW, IVF, DISKANN, Sparse, MinHash), working with third-party libraries (faiss, hnswlib, DiskANN, Cardinal), or locating specific functionality

Knowhere Architecture

Directory Structure

Directory	Purpose
include/knowhere/	Public headers
src/index/	Index implementations (flat/, hnsw/, ivf/, gpu/, diskann/, sparse/, minhash/)
src/common/	Threading, tracing, metrics utilities
src/cluster/	Clustering algorithms (KMeans)
tests/ut/	Unit tests
thirdparty/	Forked third-party libraries

Core Components

Index Factory (include/knowhere/index/index_factory.h)

• Singleton factory pattern for creating indexes
• Uses macro-based static registration (KNOWHERE_SIMPLE_REGISTER_GLOBAL)

Index Interface (include/knowhere/index/index.h)

• Template-based Index<IndexNode> wrapper
• Operations: Build, Search, RangeSearch

Configuration (include/knowhere/config.h)

• JSON-based config system
• Compile-time and runtime parameter validation

Data Types (include/knowhere/operands.h)

• fp32, fp16, bf16, int8, bin1 (binary), sparse_u32_f32

Error Handling (include/knowhere/expected.h)

• Custom expected<T> type with Status enum

Metric Types

L2, IP (Inner Product), COSINE, Jaccard, Hamming, BM25

Detailed Reference

• Index types: See index-types.md for each index's capabilities and use cases
• Third-party libraries: See dependencies.md for faiss, hnswlib, DiskANN, Cardinal details