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| 1 | +"""In-memory storage backend for testing.""" |
| 2 | + |
| 3 | +from __future__ import annotations |
| 4 | + |
| 5 | +from collections.abc import Sequence |
| 6 | +from difflib import SequenceMatcher |
| 7 | + |
| 8 | +from synaptic.models import ( |
| 9 | + ConsolidationLevel, |
| 10 | + Edge, |
| 11 | + Node, |
| 12 | + NodeKind, |
| 13 | +) |
| 14 | + |
| 15 | + |
| 16 | +class MemoryBackend: |
| 17 | + """Dict-based in-memory backend. No external dependencies.""" |
| 18 | + |
| 19 | + __slots__ = ("_edges", "_nodes") |
| 20 | + |
| 21 | + def __init__(self) -> None: |
| 22 | + self._nodes: dict[str, Node] = {} |
| 23 | + self._edges: dict[str, Edge] = {} |
| 24 | + |
| 25 | + async def connect(self) -> None: |
| 26 | + pass |
| 27 | + |
| 28 | + async def close(self) -> None: |
| 29 | + self._nodes.clear() |
| 30 | + self._edges.clear() |
| 31 | + |
| 32 | + # --- Node CRUD --- |
| 33 | + |
| 34 | + async def save_node(self, node: Node) -> None: |
| 35 | + self._nodes[node.id] = node |
| 36 | + |
| 37 | + async def get_node(self, node_id: str) -> Node | None: |
| 38 | + return self._nodes.get(node_id) |
| 39 | + |
| 40 | + async def update_node(self, node: Node) -> None: |
| 41 | + if node.id in self._nodes: |
| 42 | + self._nodes[node.id] = node |
| 43 | + |
| 44 | + async def delete_node(self, node_id: str) -> None: |
| 45 | + self._nodes.pop(node_id, None) |
| 46 | + # Cascade delete edges |
| 47 | + to_delete = [ |
| 48 | + eid |
| 49 | + for eid, e in self._edges.items() |
| 50 | + if e.source_id == node_id or e.target_id == node_id |
| 51 | + ] |
| 52 | + for eid in to_delete: |
| 53 | + del self._edges[eid] |
| 54 | + |
| 55 | + async def list_nodes( |
| 56 | + self, |
| 57 | + *, |
| 58 | + kind: NodeKind | None = None, |
| 59 | + level: ConsolidationLevel | None = None, |
| 60 | + limit: int = 100, |
| 61 | + ) -> list[Node]: |
| 62 | + result: list[Node] = [] |
| 63 | + for node in self._nodes.values(): |
| 64 | + if kind is not None and node.kind != kind: |
| 65 | + continue |
| 66 | + if level is not None and node.level != level: |
| 67 | + continue |
| 68 | + result.append(node) |
| 69 | + if len(result) >= limit: |
| 70 | + break |
| 71 | + return result |
| 72 | + |
| 73 | + # --- Edge CRUD --- |
| 74 | + |
| 75 | + async def save_edge(self, edge: Edge) -> None: |
| 76 | + self._edges[edge.id] = edge |
| 77 | + |
| 78 | + async def get_edges(self, node_id: str, *, direction: str = "both") -> list[Edge]: |
| 79 | + result: list[Edge] = [] |
| 80 | + for edge in self._edges.values(): |
| 81 | + if direction in ("both", "outgoing") and edge.source_id == node_id: |
| 82 | + result.append(edge) |
| 83 | + elif direction in ("both", "incoming") and edge.target_id == node_id: |
| 84 | + result.append(edge) |
| 85 | + return result |
| 86 | + |
| 87 | + async def update_edge(self, edge: Edge) -> None: |
| 88 | + if edge.id in self._edges: |
| 89 | + self._edges[edge.id] = edge |
| 90 | + |
| 91 | + async def delete_edge(self, edge_id: str) -> None: |
| 92 | + self._edges.pop(edge_id, None) |
| 93 | + |
| 94 | + # --- Search --- |
| 95 | + |
| 96 | + async def search_fts(self, query: str, *, limit: int = 20) -> list[Node]: |
| 97 | + query_lower = query.lower() |
| 98 | + terms = query_lower.split() |
| 99 | + scored: list[tuple[Node, int]] = [] |
| 100 | + for node in self._nodes.values(): |
| 101 | + text = f"{node.title} {node.content}".lower() |
| 102 | + hits = sum(1 for t in terms if t in text) |
| 103 | + if hits > 0: |
| 104 | + scored.append((node, hits)) |
| 105 | + scored.sort(key=lambda x: x[1], reverse=True) |
| 106 | + return [n for n, _ in scored[:limit]] |
| 107 | + |
| 108 | + async def search_fuzzy( |
| 109 | + self, query: str, *, limit: int = 20, threshold: float = 0.3 |
| 110 | + ) -> list[Node]: |
| 111 | + scored: list[tuple[Node, float]] = [] |
| 112 | + for node in self._nodes.values(): |
| 113 | + text = f"{node.title} {node.content}" |
| 114 | + ratio = SequenceMatcher(None, query.lower(), text.lower()).ratio() |
| 115 | + if ratio >= threshold: |
| 116 | + scored.append((node, ratio)) |
| 117 | + scored.sort(key=lambda x: x[1], reverse=True) |
| 118 | + return [n for n, _ in scored[:limit]] |
| 119 | + |
| 120 | + async def search_vector(self, embedding: list[float], *, limit: int = 20) -> list[Node]: |
| 121 | + if not embedding: |
| 122 | + return [] |
| 123 | + scored: list[tuple[Node, float]] = [] |
| 124 | + for node in self._nodes.values(): |
| 125 | + if not node.embedding: |
| 126 | + continue |
| 127 | + sim = _cosine_similarity(embedding, node.embedding) |
| 128 | + scored.append((node, sim)) |
| 129 | + scored.sort(key=lambda x: x[1], reverse=True) |
| 130 | + return [n for n, _ in scored[:limit]] |
| 131 | + |
| 132 | + # --- Graph traversal --- |
| 133 | + |
| 134 | + async def get_neighbors(self, node_id: str, *, depth: int = 1) -> list[tuple[Node, Edge]]: |
| 135 | + result: list[tuple[Node, Edge]] = [] |
| 136 | + visited: set[str] = {node_id} |
| 137 | + frontier: set[str] = {node_id} |
| 138 | + |
| 139 | + for _ in range(depth): |
| 140 | + next_frontier: set[str] = set() |
| 141 | + for nid in frontier: |
| 142 | + for edge in self._edges.values(): |
| 143 | + neighbor_id: str | None = None |
| 144 | + if edge.source_id == nid and edge.target_id not in visited: |
| 145 | + neighbor_id = edge.target_id |
| 146 | + elif edge.target_id == nid and edge.source_id not in visited: |
| 147 | + neighbor_id = edge.source_id |
| 148 | + |
| 149 | + if neighbor_id is not None: |
| 150 | + neighbor = self._nodes.get(neighbor_id) |
| 151 | + if neighbor is not None: |
| 152 | + result.append((neighbor, edge)) |
| 153 | + visited.add(neighbor_id) |
| 154 | + next_frontier.add(neighbor_id) |
| 155 | + frontier = next_frontier |
| 156 | + |
| 157 | + return result |
| 158 | + |
| 159 | + # --- Batch --- |
| 160 | + |
| 161 | + async def save_nodes_batch(self, nodes: Sequence[Node]) -> None: |
| 162 | + for node in nodes: |
| 163 | + self._nodes[node.id] = node |
| 164 | + |
| 165 | + async def save_edges_batch(self, edges: Sequence[Edge]) -> None: |
| 166 | + for edge in edges: |
| 167 | + self._edges[edge.id] = edge |
| 168 | + |
| 169 | + # --- Maintenance --- |
| 170 | + |
| 171 | + async def prune_edges(self, *, weight_below: float = 0.1) -> int: |
| 172 | + to_delete = [eid for eid, e in self._edges.items() if e.weight < weight_below] |
| 173 | + for eid in to_delete: |
| 174 | + del self._edges[eid] |
| 175 | + return len(to_delete) |
| 176 | + |
| 177 | + async def decay_vitality(self, *, factor: float = 0.95) -> int: |
| 178 | + count = 0 |
| 179 | + for node in self._nodes.values(): |
| 180 | + node.vitality *= factor |
| 181 | + count += 1 |
| 182 | + return count |
| 183 | + |
| 184 | + |
| 185 | +def _cosine_similarity(a: list[float], b: list[float]) -> float: |
| 186 | + if len(a) != len(b) or not a: |
| 187 | + return 0.0 |
| 188 | + dot = sum(x * y for x, y in zip(a, b, strict=True)) |
| 189 | + norm_a = sum(x * x for x in a) ** 0.5 |
| 190 | + norm_b = sum(x * x for x in b) ** 0.5 |
| 191 | + if norm_a == 0 or norm_b == 0: |
| 192 | + return 0.0 |
| 193 | + return dot / (norm_a * norm_b) |
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