# TurboQuant 4-bit Optimization & Index Selection - Task Status

## ✅ All Tasks Complete

- [x] Implement 4-bit nibble packing in `turboquant.rs`
- [x] Add `DistL2u4` distance metric in `distance.rs`
- [x] Update `hnsw_ivf.rs` to use `DistL2u4` for TQ4
- [x] Refine index selection priority in `reader.rs`
- [x] Implement Bloom Filter Cache (`BLOOM_FILTER_CACHE` in `cache.rs`)
- [x] Update `HybridReader::check_bloom_filter` to use the cache
- [x] Add verification tests for Bloom caching (`tests/test_bloom_cache.rs`)
- [x] Integrate RRF scoring
- [x] General Bloom Filter pruning on read path (`tests/test_bloom_pruning.rs`)
- [x] PK acceleration scale test (`tests/test_pk_acceleration.rs` — 5 segments × 10k)
- [x] Fix test compiler warnings (unused imports in `test_bloom_cache.rs`)

## Test Results

| Test | Result |
|---|---|
| `test_bloom_filter_caching` | ✅ PASS |
| `test_bloom_filter_general_query_pruning` | ✅ PASS |
| `test_pk_acceleration_multi_segment` | ✅ PASS |
| `cargo test --lib` (347 tests) | ✅ PASS |
| `test_core_ingestion` | ✅ PASS |
| `test_primary_key` (3 tests) | ✅ PASS |
| `test_index_lifecycle` | ✅ PASS |
| `cargo check --tests` | ✅ No warnings |

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**Status**: ✅ COMPLETE
**Last Updated**: April 14, 2026