Version 0.3.0

Added

• save() method to HNSWIndex for persisting index state to disk via Python and Rust.
• New persistence.rs module implementing index save/load logic, including manifest and file structure generation.
• PyO3 bindings for persistence-related methods, exposing them to Python.
• Internal unit tests for the save function to ensure correct file output and manifest validation.
• HNSW graph structure persistence via native hnsw-rs file_dump() integration
• Enhanced save workflow with Phase 2 graph serialization support
• Comprehensive Phase 2 integration test suite for full persistence validation
• Complete component loading infrastructure with helper functions for all ZeusDB file types
• load() method to VectorDatabase class for loading saved indexes from disk
• Comprehensive component validation and data consistency checking in load workflow
• Python API integration for load_index function with proper PyO3 bindings
• End-to-end test suite for component loading validation and error handling
• Complete HNSW graph loading functionality using NoData pattern from hnsw-rs
• anndists dependency for NoDist distance type compatibility
• Phase 2 graph structure loading with validation and error handling
• Full persistence roundtrip capability: save and load HNSW graph structures
• Empty index handling with conditional graph file creation for zero-vector scenarios
• Training state preservation with ID collection tracking during persistence
• Storage mode awareness in persistence (quantized_only vs quantized_with_raw handling)
• PQ centroids and codes serialization for complete quantization state preservation
• Compression statistics and memory usage reporting in manifest files
• Directory size calculation and file inventory tracking in manifest generation
• rebuilding_from_persistence flag to prevent training ID contamination during reconstruction
• Smart reconstruction approach using existing add() logic instead of complex graph deserialization
• Thread-safe data access patterns during save operations with proper lock management

Changed

• Refactored hnsw_index.rs to integrate persistence logic and support serialization.
• Updated lib.rs to register the persistence module and ensure all new methods are exposed to Python.
• Enhanced error handling and docstrings for persistence operations.
• Modified HNSW initialization to use fixed max_layer=16 for hnsw-rs dump compatibility
• Updated manifest generation to include HNSW graph files (.hnsw.graph) and exclude data files (.hnsw.data)
• Enhanced save_manifest() with graph file tracking and size calculation
• Replaced placeholder load_index() with complete component loading implementation
• Enhanced lib.rs module exports to include load_index function for Python access
• Updated persistence.rs with comprehensive file loading and validation infrastructure
• Extended persistence.rs with complete HNSW graph loading using HnswIo and ReloadOptions
• Updated test suite to recognize and validate HNSW graph loading success
• Enhanced quantization config validation to include training state and storage mode persistence
• Modified PQ implementation to support set_trained() for persistence restoration
• Updated index reconstruction to use "Simple Reconstruction" pattern for reliability
• Refactored training threshold calculation to be self-healing during load operations
• Enhanced error collection and reporting throughout persistence workflow

Fixed

• Improved reliability of index serialization and file output.
• Addressed edge cases in directory creation and file writing during persistence.
• Resolved critical "nb_layer != NB_MAX_LAYER" error preventing HNSW graph dumps
• Fixed layer count compatibility issue between ZeusDB and hnsw-rs library requirements
• Enabled successful HNSW graph structure serialization for graph files
• Resolved Python binding compilation error for load_index function export
• Fixed missing #[pyfunction] annotation preventing Python module integration
• Established proper API consistency between save and load methods
• Resolved anndists dependency issues for NoDist import compatibility
• Fixed HNSW graph loading import paths for hnsw-rs v0.3.0+ compatibility
• Resolved training ID loss during graph reconstruction by adding persistence rebuild flag
• Fixed PQ training state restoration ensuring loaded instances are properly marked as trained
• Corrected training progress calculation inconsistencies between save/load cycles
• Addressed quantization state contamination during index reconstruction
• Resolved thread safety issues in concurrent data access during persistence operations
• Fixed storage mode detection and raw vector preservation based on configuration
• Prevented training ID re-collection during persistence rebuild operations