gps-denied-desktop/docs/02_components/helpers/h04_faiss_index_manager_spec.md

Faiss Index Manager Helper

Interface Definition

Interface Name: IFaissIndexManager

Interface Methods

class IFaissIndexManager(ABC):
    @abstractmethod
    def build_index(self, descriptors: np.ndarray, index_type: str) -> FaissIndex:
        pass
    
    @abstractmethod
    def add_descriptors(self, index: FaissIndex, descriptors: np.ndarray) -> bool:
        pass
    
    @abstractmethod
    def search(self, index: FaissIndex, query: np.ndarray, k: int) -> Tuple[np.ndarray, np.ndarray]:
        pass
    
    @abstractmethod
    def save_index(self, index: FaissIndex, path: str) -> bool:
        pass
    
    @abstractmethod
    def load_index(self, path: str) -> FaissIndex:
        pass

Component Description

Manages Faiss indices for AnyLoc retrieval (IVF, HNSW options).

API Methods

build_index(descriptors: np.ndarray, index_type: str) -> FaissIndex

Description: Builds Faiss index from descriptors.

Index Types:

• "IVF": Inverted File (fast for large databases)
• "HNSW": Hierarchical Navigable Small World (best accuracy/speed trade-off)
• "Flat": Brute force (exact, slow for large datasets)

Input: (N, D) descriptors array

---

add_descriptors(index: FaissIndex, descriptors: np.ndarray) -> bool

Description: Adds more descriptors to existing index.

---

search(index: FaissIndex, query: np.ndarray, k: int) -> Tuple[np.ndarray, np.ndarray]

Description: Searches for k nearest neighbors.

Output: (distances, indices) - shape (k,)

---

save_index(index: FaissIndex, path: str) -> bool

Description: Saves index to disk for fast startup.

---

load_index(path: str) -> FaissIndex

Description: Loads pre-built index from disk.

Dependencies

External: faiss-gpu or faiss-cpu

Test Cases

1. Build index with 10,000 descriptors → succeeds
2. Search query → returns top-k matches
3. Save/load index → index restored correctly