mirror of
https://github.com/HKUDS/LightRAG.git
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432 lines
16 KiB
Python
432 lines
16 KiB
Python
import os
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from dataclasses import dataclass
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from typing import Any, final
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import numpy as np
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from lightrag.types import KnowledgeGraph, KnowledgeGraphNode, KnowledgeGraphEdge
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from lightrag.utils import logger
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from lightrag.base import BaseGraphStorage
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import pipmaster as pm
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if not pm.is_installed("networkx"):
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pm.install("networkx")
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if not pm.is_installed("graspologic"):
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pm.install("graspologic")
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import networkx as nx
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from graspologic import embed
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from .shared_storage import (
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get_storage_lock,
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get_update_flag,
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set_all_update_flags,
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is_multiprocess,
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)
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MAX_GRAPH_NODES = int(os.getenv("MAX_GRAPH_NODES", 1000))
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@final
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@dataclass
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class NetworkXStorage(BaseGraphStorage):
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@staticmethod
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def load_nx_graph(file_name) -> nx.Graph:
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if os.path.exists(file_name):
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return nx.read_graphml(file_name)
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return None
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@staticmethod
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def write_nx_graph(graph: nx.Graph, file_name):
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logger.info(
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f"Writing graph with {graph.number_of_nodes()} nodes, {graph.number_of_edges()} edges"
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)
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nx.write_graphml(graph, file_name)
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@staticmethod
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def _stabilize_graph(graph: nx.Graph) -> nx.Graph:
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"""Refer to https://github.com/microsoft/graphrag/index/graph/utils/stable_lcc.py
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Ensure an undirected graph with the same relationships will always be read the same way.
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"""
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fixed_graph = nx.DiGraph() if graph.is_directed() else nx.Graph()
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sorted_nodes = graph.nodes(data=True)
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sorted_nodes = sorted(sorted_nodes, key=lambda x: x[0])
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fixed_graph.add_nodes_from(sorted_nodes)
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edges = list(graph.edges(data=True))
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if not graph.is_directed():
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def _sort_source_target(edge):
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source, target, edge_data = edge
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if source > target:
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temp = source
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source = target
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target = temp
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return source, target, edge_data
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edges = [_sort_source_target(edge) for edge in edges]
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def _get_edge_key(source: Any, target: Any) -> str:
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return f"{source} -> {target}"
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edges = sorted(edges, key=lambda x: _get_edge_key(x[0], x[1]))
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fixed_graph.add_edges_from(edges)
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return fixed_graph
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def __post_init__(self):
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self._graphml_xml_file = os.path.join(
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self.global_config["working_dir"], f"graph_{self.namespace}.graphml"
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)
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self._storage_lock = None
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self.storage_updated = None
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self._graph = None
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# Load initial graph
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preloaded_graph = NetworkXStorage.load_nx_graph(self._graphml_xml_file)
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if preloaded_graph is not None:
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logger.info(
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f"Loaded graph from {self._graphml_xml_file} with {preloaded_graph.number_of_nodes()} nodes, {preloaded_graph.number_of_edges()} edges"
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)
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else:
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logger.info("Created new empty graph")
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self._graph = preloaded_graph or nx.Graph()
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self._node_embed_algorithms = {
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"node2vec": self._node2vec_embed,
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}
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async def initialize(self):
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"""Initialize storage data"""
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# Get the update flag for cross-process update notification
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self.storage_updated = await get_update_flag(self.namespace)
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# Get the storage lock for use in other methods
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self._storage_lock = get_storage_lock()
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async def _get_graph(self):
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"""Check if the storage should be reloaded"""
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# Acquire lock to prevent concurrent read and write
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async with self._storage_lock:
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# Check if data needs to be reloaded
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if (is_multiprocess and self.storage_updated.value) or (
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not is_multiprocess and self.storage_updated
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):
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logger.info(
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f"Process {os.getpid()} reloading graph {self.namespace} due to update by another process"
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)
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# Reload data
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self._graph = (
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NetworkXStorage.load_nx_graph(self._graphml_xml_file) or nx.Graph()
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)
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# Reset update flag
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if is_multiprocess:
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self.storage_updated.value = False
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else:
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self.storage_updated = False
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return self._graph
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async def has_node(self, node_id: str) -> bool:
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graph = await self._get_graph()
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return graph.has_node(node_id)
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async def has_edge(self, source_node_id: str, target_node_id: str) -> bool:
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graph = await self._get_graph()
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return graph.has_edge(source_node_id, target_node_id)
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async def get_node(self, node_id: str) -> dict[str, str] | None:
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graph = await self._get_graph()
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return graph.nodes.get(node_id)
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async def node_degree(self, node_id: str) -> int:
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graph = await self._get_graph()
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return graph.degree(node_id)
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async def edge_degree(self, src_id: str, tgt_id: str) -> int:
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graph = await self._get_graph()
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return graph.degree(src_id) + graph.degree(tgt_id)
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async def get_edge(
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self, source_node_id: str, target_node_id: str
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) -> dict[str, str] | None:
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graph = await self._get_graph()
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return graph.edges.get((source_node_id, target_node_id))
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async def get_node_edges(self, source_node_id: str) -> list[tuple[str, str]] | None:
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graph = await self._get_graph()
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if graph.has_node(source_node_id):
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return list(graph.edges(source_node_id))
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return None
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async def upsert_node(self, node_id: str, node_data: dict[str, str]) -> None:
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graph = await self._get_graph()
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graph.add_node(node_id, **node_data)
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async def upsert_edge(
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self, source_node_id: str, target_node_id: str, edge_data: dict[str, str]
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) -> None:
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graph = await self._get_graph()
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graph.add_edge(source_node_id, target_node_id, **edge_data)
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async def delete_node(self, node_id: str) -> None:
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graph = await self._get_graph()
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if graph.has_node(node_id):
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graph.remove_node(node_id)
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logger.debug(f"Node {node_id} deleted from the graph.")
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else:
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logger.warning(f"Node {node_id} not found in the graph for deletion.")
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async def embed_nodes(
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self, algorithm: str
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) -> tuple[np.ndarray[Any, Any], list[str]]:
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if algorithm not in self._node_embed_algorithms:
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raise ValueError(f"Node embedding algorithm {algorithm} not supported")
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return await self._node_embed_algorithms[algorithm]()
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# TODO: NOT USED
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async def _node2vec_embed(self):
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graph = await self._get_graph()
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embeddings, nodes = embed.node2vec_embed(
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graph,
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**self.global_config["node2vec_params"],
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)
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nodes_ids = [graph.nodes[node_id]["id"] for node_id in nodes]
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return embeddings, nodes_ids
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async def remove_nodes(self, nodes: list[str]):
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"""Delete multiple nodes
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Args:
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nodes: List of node IDs to be deleted
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"""
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graph = await self._get_graph()
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for node in nodes:
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if graph.has_node(node):
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graph.remove_node(node)
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async def remove_edges(self, edges: list[tuple[str, str]]):
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"""Delete multiple edges
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Args:
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edges: List of edges to be deleted, each edge is a (source, target) tuple
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"""
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graph = await self._get_graph()
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for source, target in edges:
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if graph.has_edge(source, target):
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graph.remove_edge(source, target)
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async def get_all_labels(self) -> list[str]:
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"""
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Get all node labels in the graph
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Returns:
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[label1, label2, ...] # Alphabetically sorted label list
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"""
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graph = await self._get_graph()
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labels = set()
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for node in graph.nodes():
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labels.add(str(node)) # Add node id as a label
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# Return sorted list
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return sorted(list(labels))
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async def get_knowledge_graph(
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self,
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node_label: str,
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max_depth: int = 3,
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min_degree: int = 0,
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inclusive: bool = False,
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) -> KnowledgeGraph:
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"""
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Retrieve a connected subgraph of nodes where the label includes the specified `node_label`.
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Maximum number of nodes is constrained by the environment variable `MAX_GRAPH_NODES` (default: 1000).
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When reducing the number of nodes, the prioritization criteria are as follows:
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1. min_degree does not affect nodes directly connected to the matching nodes
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2. Label matching nodes take precedence
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3. Followed by nodes directly connected to the matching nodes
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4. Finally, the degree of the nodes
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Args:
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node_label: Label of the starting node
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max_depth: Maximum depth of the subgraph
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min_degree: Minimum degree of nodes to include. Defaults to 0
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inclusive: Do an inclusive search if true
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Returns:
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KnowledgeGraph object containing nodes and edges
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"""
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result = KnowledgeGraph()
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seen_nodes = set()
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seen_edges = set()
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graph = await self._get_graph()
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# Initialize sets for start nodes and direct connected nodes
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start_nodes = set()
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direct_connected_nodes = set()
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# Handle special case for "*" label
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if node_label == "*":
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# For "*", return the entire graph including all nodes and edges
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subgraph = (
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graph.copy()
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) # Create a copy to avoid modifying the original graph
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else:
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# Find nodes with matching node id based on search_mode
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nodes_to_explore = []
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for n, attr in graph.nodes(data=True):
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node_str = str(n)
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if not inclusive:
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if node_label == node_str: # Use exact matching
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nodes_to_explore.append(n)
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else: # inclusive mode
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if node_label in node_str: # Use partial matching
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nodes_to_explore.append(n)
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if not nodes_to_explore:
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logger.warning(f"No nodes found with label {node_label}")
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return result
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# Get subgraph using ego_graph from all matching nodes
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combined_subgraph = nx.Graph()
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for start_node in nodes_to_explore:
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node_subgraph = nx.ego_graph(graph, start_node, radius=max_depth)
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combined_subgraph = nx.compose(combined_subgraph, node_subgraph)
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# Get start nodes and direct connected nodes
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if nodes_to_explore:
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start_nodes = set(nodes_to_explore)
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# Get nodes directly connected to all start nodes
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for start_node in start_nodes:
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direct_connected_nodes.update(
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combined_subgraph.neighbors(start_node)
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)
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# Remove start nodes from directly connected nodes (avoid duplicates)
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direct_connected_nodes -= start_nodes
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subgraph = combined_subgraph
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# Filter nodes based on min_degree, but keep start nodes and direct connected nodes
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if min_degree > 0:
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nodes_to_keep = [
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node
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for node, degree in subgraph.degree()
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if node in start_nodes
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or node in direct_connected_nodes
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or degree >= min_degree
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]
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subgraph = subgraph.subgraph(nodes_to_keep)
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# Check if number of nodes exceeds max_graph_nodes
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if len(subgraph.nodes()) > MAX_GRAPH_NODES:
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origin_nodes = len(subgraph.nodes())
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node_degrees = dict(subgraph.degree())
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def priority_key(node_item):
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node, degree = node_item
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# Priority order: start(2) > directly connected(1) > other nodes(0)
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if node in start_nodes:
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priority = 2
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elif node in direct_connected_nodes:
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priority = 1
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else:
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priority = 0
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return (priority, degree)
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# Sort by priority and degree and select top MAX_GRAPH_NODES nodes
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top_nodes = sorted(node_degrees.items(), key=priority_key, reverse=True)[
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:MAX_GRAPH_NODES
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]
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top_node_ids = [node[0] for node in top_nodes]
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# Create new subgraph and keep nodes only with most degree
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subgraph = subgraph.subgraph(top_node_ids)
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logger.info(
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f"Reduced graph from {origin_nodes} nodes to {MAX_GRAPH_NODES} nodes (depth={max_depth})"
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)
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# Add nodes to result
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for node in subgraph.nodes():
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if str(node) in seen_nodes:
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continue
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node_data = dict(subgraph.nodes[node])
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# Get entity_type as labels
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labels = []
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if "entity_type" in node_data:
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if isinstance(node_data["entity_type"], list):
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labels.extend(node_data["entity_type"])
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else:
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labels.append(node_data["entity_type"])
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# Create node with properties
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node_properties = {k: v for k, v in node_data.items()}
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result.nodes.append(
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KnowledgeGraphNode(
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id=str(node), labels=[str(node)], properties=node_properties
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)
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)
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seen_nodes.add(str(node))
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# Add edges to result
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for edge in subgraph.edges():
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source, target = edge
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edge_id = f"{source}-{target}"
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if edge_id in seen_edges:
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continue
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edge_data = dict(subgraph.edges[edge])
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# Create edge with complete information
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result.edges.append(
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KnowledgeGraphEdge(
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id=edge_id,
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type="DIRECTED",
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source=str(source),
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target=str(target),
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properties=edge_data,
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)
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)
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seen_edges.add(edge_id)
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logger.info(
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f"Subgraph query successful | Node count: {len(result.nodes)} | Edge count: {len(result.edges)}"
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)
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return result
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async def index_done_callback(self) -> bool:
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"""Save data to disk"""
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# Check if storage was updated by another process
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if is_multiprocess and self.storage_updated.value:
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# Storage was updated by another process, reload data instead of saving
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logger.warning(
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f"Graph for {self.namespace} was updated by another process, reloading..."
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)
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self._graph = (
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NetworkXStorage.load_nx_graph(self._graphml_xml_file) or nx.Graph()
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)
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# Reset update flag
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self.storage_updated.value = False
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return False # Return error
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# Acquire lock and perform persistence
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async with self._storage_lock:
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try:
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# Save data to disk
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NetworkXStorage.write_nx_graph(self._graph, self._graphml_xml_file)
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# Notify other processes that data has been updated
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await set_all_update_flags(self.namespace)
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# Reset own update flag to avoid self-reloading
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if is_multiprocess:
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self.storage_updated.value = False
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else:
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self.storage_updated = False
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return True # Return success
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except Exception as e:
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logger.error(f"Error saving graph for {self.namespace}: {e}")
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return False # Return error
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return True
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