Files
2026-07-13 12:08:54 +08:00

1348 lines
55 KiB
Python

import os
import asyncio
import random
from dataclasses import dataclass
from typing import final
import configparser
from ..utils import logger, validate_workspace
from ..base import BaseGraphStorage
from ..types import KnowledgeGraph, KnowledgeGraphNode, KnowledgeGraphEdge
from ..kg.shared_storage import get_data_init_lock
import pipmaster as pm
if not pm.is_installed("neo4j"):
pm.install("neo4j")
from neo4j import (
AsyncGraphDatabase,
AsyncManagedTransaction,
)
from neo4j.exceptions import TransientError, ResultFailedError
from dotenv import load_dotenv
# use the .env that is inside the current folder
load_dotenv(dotenv_path=".env", override=False)
MAX_GRAPH_NODES = int(os.getenv("MAX_GRAPH_NODES", 1000))
config = configparser.ConfigParser()
config.read("config.ini", "utf-8")
@final
@dataclass
class MemgraphStorage(BaseGraphStorage):
def __init__(self, namespace, global_config, embedding_func, workspace=None):
# Priority: 1) MEMGRAPH_WORKSPACE env 2) user arg 3) default 'base'
memgraph_workspace = os.environ.get("MEMGRAPH_WORKSPACE")
original_workspace = workspace # Save original value for logging
if memgraph_workspace and memgraph_workspace.strip():
workspace = memgraph_workspace
if not workspace or not str(workspace).strip():
workspace = "base"
super().__init__(
namespace=namespace,
workspace=workspace,
global_config=global_config,
embedding_func=embedding_func,
)
validate_workspace(self.workspace)
# Log after super().__init__() to ensure self.workspace is initialized
if memgraph_workspace and memgraph_workspace.strip():
logger.info(
f"Using MEMGRAPH_WORKSPACE environment variable: '{memgraph_workspace}' (overriding '{original_workspace}/{namespace}')"
)
self._driver = None
def _get_workspace_label(self) -> str:
"""Return sanitized workspace label safe for use as a backtick-quoted identifier in Cypher queries.
Escapes backticks by doubling them to prevent Cypher injection
via the LIGHTRAG-WORKSPACE header, while preserving a 1-to-1 mapping
for all other characters. The returned value is intended to be used
inside backticks (for example, MATCH (n:`{label}`)) and is not
validated as a standalone unquoted identifier.
"""
workspace = self.workspace.strip()
if not workspace:
return "base"
return workspace.replace("`", "``")
async def initialize(self):
async with get_data_init_lock():
URI = os.environ.get(
"MEMGRAPH_URI",
config.get("memgraph", "uri", fallback="bolt://localhost:7687"),
)
USERNAME = os.environ.get(
"MEMGRAPH_USERNAME", config.get("memgraph", "username", fallback="")
)
PASSWORD = os.environ.get(
"MEMGRAPH_PASSWORD", config.get("memgraph", "password", fallback="")
)
DATABASE = os.environ.get(
"MEMGRAPH_DATABASE",
config.get("memgraph", "database", fallback="memgraph"),
)
self._driver = AsyncGraphDatabase.driver(
URI,
auth=(USERNAME, PASSWORD),
)
self._DATABASE = DATABASE
try:
async with self._driver.session(database=DATABASE) as session:
# Create index for base nodes on entity_id if it doesn't exist
try:
workspace_label = self._get_workspace_label()
await session.run(
f"""CREATE INDEX ON :{workspace_label}(entity_id)"""
)
logger.info(
f"[{self.workspace}] Created index on :{workspace_label}(entity_id) in Memgraph."
)
except Exception as e:
# Index may already exist, which is not an error
logger.warning(
f"[{self.workspace}] Index creation on :{workspace_label}(entity_id) may have failed or already exists: {e}"
)
await session.run("RETURN 1")
logger.info(f"[{self.workspace}] Connected to Memgraph at {URI}")
except Exception as e:
logger.error(
f"[{self.workspace}] Failed to connect to Memgraph at {URI}: {e}"
)
raise
async def finalize(self):
if self._driver is not None:
await self._driver.close()
self._driver = None
async def __aexit__(self, exc_type, exc, tb):
await self.finalize()
async def index_done_callback(self):
# Memgraph handles persistence automatically
pass
async def has_node(self, node_id: str) -> bool:
"""
Check if a node exists in the graph.
Args:
node_id: The ID of the node to check.
Returns:
bool: True if the node exists, False otherwise.
Raises:
Exception: If there is an error checking the node existence.
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
result = None
try:
workspace_label = self._get_workspace_label()
query = f"MATCH (n:`{workspace_label}` {{entity_id: $entity_id}}) RETURN count(n) > 0 AS node_exists"
result = await session.run(query, entity_id=node_id)
single_result = await result.single()
await result.consume() # Ensure result is fully consumed
return (
single_result["node_exists"] if single_result is not None else False
)
except Exception as e:
logger.error(
f"[{self.workspace}] Error checking node existence for {node_id}: {str(e)}"
)
if result is not None:
await (
result.consume()
) # Ensure the result is consumed even on error
raise
async def has_edge(self, source_node_id: str, target_node_id: str) -> bool:
"""
Check if an edge exists between two nodes in the graph.
Args:
source_node_id: The ID of the source node.
target_node_id: The ID of the target node.
Returns:
bool: True if the edge exists, False otherwise.
Raises:
Exception: If there is an error checking the edge existence.
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
result = None
try:
workspace_label = self._get_workspace_label()
query = (
f"MATCH (a:`{workspace_label}` {{entity_id: $source_entity_id}})-[r]-(b:`{workspace_label}` {{entity_id: $target_entity_id}}) "
"RETURN COUNT(r) > 0 AS edgeExists"
)
result = await session.run(
query,
source_entity_id=source_node_id,
target_entity_id=target_node_id,
) # type: ignore
single_result = await result.single()
await result.consume() # Ensure result is fully consumed
return (
single_result["edgeExists"] if single_result is not None else False
)
except Exception as e:
logger.error(
f"[{self.workspace}] Error checking edge existence between {source_node_id} and {target_node_id}: {str(e)}"
)
if result is not None:
await (
result.consume()
) # Ensure the result is consumed even on error
raise
async def get_node(self, node_id: str) -> dict[str, str] | None:
"""Get node by its label identifier, return only node properties
Args:
node_id: The node label to look up
Returns:
dict: Node properties if found
None: If node not found
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
try:
workspace_label = self._get_workspace_label()
query = (
f"MATCH (n:`{workspace_label}` {{entity_id: $entity_id}}) RETURN n"
)
result = await session.run(query, entity_id=node_id)
try:
records = await result.fetch(
2
) # Get 2 records for duplication check
if len(records) > 1:
logger.warning(
f"[{self.workspace}] Multiple nodes found with label '{node_id}'. Using first node."
)
if records:
node = records[0]["n"]
node_dict = dict(node)
# Remove workspace label from labels list if it exists
if "labels" in node_dict:
node_dict["labels"] = [
label
for label in node_dict["labels"]
if label != workspace_label
]
return node_dict
return None
finally:
await result.consume() # Ensure result is fully consumed
except Exception as e:
logger.error(
f"[{self.workspace}] Error getting node for {node_id}: {str(e)}"
)
raise
async def node_degree(self, node_id: str) -> int:
"""Get the degree (number of relationships) of a node with the given label.
If multiple nodes have the same label, returns the degree of the first node.
If no node is found, returns 0.
Args:
node_id: The label of the node
Returns:
int: The number of relationships the node has, or 0 if no node found
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
try:
workspace_label = self._get_workspace_label()
query = f"""
MATCH (n:`{workspace_label}` {{entity_id: $entity_id}})
OPTIONAL MATCH (n)-[r]-()
RETURN COUNT(r) AS degree
"""
result = await session.run(query, entity_id=node_id)
try:
record = await result.single()
if not record:
logger.warning(
f"[{self.workspace}] No node found with label '{node_id}'"
)
return 0
degree = record["degree"]
return degree
finally:
await result.consume() # Ensure result is fully consumed
except Exception as e:
logger.error(
f"[{self.workspace}] Error getting node degree for {node_id}: {str(e)}"
)
raise
async def get_all_labels(self) -> list[str]:
"""
Get all existing node labels(entity names) in the database
Returns:
["Person", "Company", ...] # Alphabetically sorted label list
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
result = None
try:
workspace_label = self._get_workspace_label()
query = f"""
MATCH (n:`{workspace_label}`)
WHERE n.entity_id IS NOT NULL
RETURN DISTINCT n.entity_id AS label
ORDER BY label
"""
result = await session.run(query)
labels = []
async for record in result:
labels.append(record["label"])
await result.consume()
return labels
except Exception as e:
logger.error(f"[{self.workspace}] Error getting all labels: {str(e)}")
if result is not None:
await (
result.consume()
) # Ensure the result is consumed even on error
raise
async def get_node_edges(self, source_node_id: str) -> list[tuple[str, str]] | None:
"""Retrieves all edges (relationships) for a particular node identified by its label.
Args:
source_node_id: Label of the node to get edges for
Returns:
list[tuple[str, str]]: List of (source_label, target_label) tuples representing edges
None: If no edges found
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
try:
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
results = None
try:
workspace_label = self._get_workspace_label()
query = f"""MATCH (n:`{workspace_label}` {{entity_id: $entity_id}})
OPTIONAL MATCH (n)-[r]-(connected:`{workspace_label}`)
WHERE connected.entity_id IS NOT NULL
RETURN n.entity_id AS node_entity_id,
connected.entity_id AS connected_entity_id,
startNode(r).entity_id AS start_entity_id"""
results = await session.run(query, entity_id=source_node_id)
edges = []
async for record in results:
node_entity_id = record["node_entity_id"]
connected_entity_id = record["connected_entity_id"]
start_entity_id = record["start_entity_id"]
if not node_entity_id or not connected_entity_id:
continue
# Preserve the original edge direction via startNode(r)
if start_entity_id == node_entity_id:
edges.append((node_entity_id, connected_entity_id))
else:
edges.append((connected_entity_id, node_entity_id))
await results.consume() # Ensure results are consumed
return edges
except Exception as e:
logger.error(
f"[{self.workspace}] Error getting edges for node {source_node_id}: {str(e)}"
)
if results is not None:
await (
results.consume()
) # Ensure results are consumed even on error
raise
except Exception as e:
logger.error(
f"[{self.workspace}] Error in get_node_edges for {source_node_id}: {str(e)}"
)
raise
async def get_edge(
self, source_node_id: str, target_node_id: str
) -> dict[str, str] | None:
"""Get edge properties between two nodes.
Args:
source_node_id: Label of the source node
target_node_id: Label of the target node
Returns:
dict: Edge properties if found, default properties if not found or on error
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
result = None
try:
workspace_label = self._get_workspace_label()
query = f"""
MATCH (start:`{workspace_label}` {{entity_id: $source_entity_id}})-[r]-(end:`{workspace_label}` {{entity_id: $target_entity_id}})
RETURN properties(r) as edge_properties
"""
result = await session.run(
query,
source_entity_id=source_node_id,
target_entity_id=target_node_id,
)
records = await result.fetch(2)
await result.consume()
if records:
edge_result = dict(records[0]["edge_properties"])
for key, default_value in {
"weight": 1.0,
"source_id": None,
"description": None,
"keywords": None,
}.items():
if key not in edge_result:
edge_result[key] = default_value
logger.warning(
f"[{self.workspace}] Edge between {source_node_id} and {target_node_id} is missing property: {key}. Using default value: {default_value}"
)
return edge_result
return None
except Exception as e:
logger.error(
f"[{self.workspace}] Error getting edge between {source_node_id} and {target_node_id}: {str(e)}"
)
if result is not None:
await (
result.consume()
) # Ensure the result is consumed even on error
raise
async def upsert_node(self, node_id: str, node_data: dict[str, str]) -> None:
"""
Upsert a node in the Memgraph database with manual transaction-level retry logic for transient errors.
Args:
node_id: The unique identifier for the node (used as label)
node_data: Dictionary of node properties
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
properties = node_data
if "entity_id" not in properties:
raise ValueError(
"Memgraph: node properties must contain an 'entity_id' field"
)
# Manual transaction-level retry following official Memgraph documentation
max_retries = 100
initial_wait_time = 0.2
backoff_factor = 1.1
jitter_factor = 0.1
for attempt in range(max_retries):
try:
logger.debug(
f"[{self.workspace}] Attempting node upsert, attempt {attempt + 1}/{max_retries}"
)
async with self._driver.session(database=self._DATABASE) as session:
workspace_label = self._get_workspace_label()
async def execute_upsert(tx: AsyncManagedTransaction):
query = f"""
MERGE (n:`{workspace_label}` {{entity_id: $entity_id}})
SET n += $properties
"""
result = await tx.run(
query, entity_id=node_id, properties=properties
)
await result.consume() # Ensure result is fully consumed
await session.execute_write(execute_upsert)
break # Success - exit retry loop
except (TransientError, ResultFailedError) as e:
# Check if the root cause is a TransientError
root_cause = e
while hasattr(root_cause, "__cause__") and root_cause.__cause__:
root_cause = root_cause.__cause__
# Check if this is a transient error that should be retried
is_transient = (
isinstance(root_cause, TransientError)
or isinstance(e, TransientError)
or "TransientError" in str(e)
or "Cannot resolve conflicting transactions" in str(e)
)
if is_transient:
if attempt < max_retries - 1:
# Calculate wait time with exponential backoff and jitter
jitter = random.uniform(0, jitter_factor) * initial_wait_time
wait_time = (
initial_wait_time * (backoff_factor**attempt) + jitter
)
logger.warning(
f"[{self.workspace}] Node upsert failed. Attempt #{attempt + 1} retrying in {wait_time:.3f} seconds... Error: {str(e)}"
)
await asyncio.sleep(wait_time)
else:
logger.error(
f"[{self.workspace}] Memgraph transient error during node upsert after {max_retries} retries: {str(e)}"
)
raise
else:
# Non-transient error, don't retry
logger.error(
f"[{self.workspace}] Non-transient error during node upsert: {str(e)}"
)
raise
except Exception as e:
logger.error(
f"[{self.workspace}] Unexpected error during node upsert: {str(e)}"
)
raise
async def upsert_edge(
self, source_node_id: str, target_node_id: str, edge_data: dict[str, str]
) -> None:
"""
Upsert an edge and its properties between two nodes identified by their labels with manual transaction-level retry logic for transient errors.
Ensures both source and target nodes exist and are unique before creating the edge.
Uses entity_id property to uniquely identify nodes.
Args:
source_node_id (str): Label of the source node (used as identifier)
target_node_id (str): Label of the target node (used as identifier)
edge_data (dict): Dictionary of properties to set on the edge
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
edge_properties = edge_data
# Manual transaction-level retry following official Memgraph documentation
max_retries = 100
initial_wait_time = 0.2
backoff_factor = 1.1
jitter_factor = 0.1
for attempt in range(max_retries):
try:
logger.debug(
f"[{self.workspace}] Attempting edge upsert, attempt {attempt + 1}/{max_retries}"
)
async with self._driver.session(database=self._DATABASE) as session:
async def execute_upsert(tx: AsyncManagedTransaction):
workspace_label = self._get_workspace_label()
query = f"""
MATCH (source:`{workspace_label}` {{entity_id: $source_entity_id}})
WITH source
MATCH (target:`{workspace_label}` {{entity_id: $target_entity_id}})
MERGE (source)-[r:DIRECTED]-(target)
SET r += $properties
RETURN r, source, target
"""
result = await tx.run(
query,
source_entity_id=source_node_id,
target_entity_id=target_node_id,
properties=edge_properties,
)
try:
await result.fetch(2)
finally:
await result.consume() # Ensure result is consumed
await session.execute_write(execute_upsert)
break # Success - exit retry loop
except (TransientError, ResultFailedError) as e:
# Check if the root cause is a TransientError
root_cause = e
while hasattr(root_cause, "__cause__") and root_cause.__cause__:
root_cause = root_cause.__cause__
# Check if this is a transient error that should be retried
is_transient = (
isinstance(root_cause, TransientError)
or isinstance(e, TransientError)
or "TransientError" in str(e)
or "Cannot resolve conflicting transactions" in str(e)
)
if is_transient:
if attempt < max_retries - 1:
# Calculate wait time with exponential backoff and jitter
jitter = random.uniform(0, jitter_factor) * initial_wait_time
wait_time = (
initial_wait_time * (backoff_factor**attempt) + jitter
)
logger.warning(
f"[{self.workspace}] Edge upsert failed. Attempt #{attempt + 1} retrying in {wait_time:.3f} seconds... Error: {str(e)}"
)
await asyncio.sleep(wait_time)
else:
logger.error(
f"[{self.workspace}] Memgraph transient error during edge upsert after {max_retries} retries: {str(e)}"
)
raise
else:
# Non-transient error, don't retry
logger.error(
f"[{self.workspace}] Non-transient error during edge upsert: {str(e)}"
)
raise
except Exception as e:
logger.error(
f"[{self.workspace}] Unexpected error during edge upsert: {str(e)}"
)
raise
async def upsert_nodes_batch(self, nodes: list[tuple[str, dict[str, str]]]) -> None:
"""Batch insert/update multiple nodes using a single UNWIND Cypher query.
Uses the same transient-error retry logic as upsert_node().
Args:
nodes: List of (node_id, node_data) tuples.
"""
if not nodes:
return
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
workspace_label = self._get_workspace_label()
nodes_data = []
for node_id, node_data in nodes:
if "entity_id" not in node_data:
raise ValueError(
"Memgraph: node properties must contain an 'entity_id' field"
)
nodes_data.append({"entity_id": node_id, "props": node_data})
max_retries = 100
initial_wait_time = 0.2
backoff_factor = 1.1
jitter_factor = 0.1
for attempt in range(max_retries):
try:
async with self._driver.session(database=self._DATABASE) as session:
async def execute_batch(tx: AsyncManagedTransaction):
query = f"""
UNWIND $nodes AS row
MERGE (n:`{workspace_label}` {{entity_id: row.entity_id}})
SET n += row.props
"""
result = await tx.run(query, nodes=nodes_data)
await result.consume()
await session.execute_write(execute_batch)
break
except (TransientError, ResultFailedError) as e:
root_cause = e
while hasattr(root_cause, "__cause__") and root_cause.__cause__:
root_cause = root_cause.__cause__
is_transient = (
isinstance(root_cause, TransientError)
or isinstance(e, TransientError)
or "TransientError" in str(e)
or "Cannot resolve conflicting transactions" in str(e)
)
if is_transient:
if attempt < max_retries - 1:
jitter = random.uniform(0, jitter_factor) * initial_wait_time
wait_time = (
initial_wait_time * (backoff_factor**attempt) + jitter
)
logger.warning(
f"[{self.workspace}] Batch node upsert failed. Attempt #{attempt + 1} retrying in {wait_time:.3f}s... Error: {str(e)}"
)
await asyncio.sleep(wait_time)
else:
logger.error(
f"[{self.workspace}] Memgraph transient error during batch node upsert after {max_retries} retries: {str(e)}"
)
raise
else:
logger.error(
f"[{self.workspace}] Non-transient error during batch node upsert: {str(e)}"
)
raise
except Exception as e:
logger.error(
f"[{self.workspace}] Unexpected error during batch node upsert: {str(e)}"
)
raise
async def has_nodes_batch(self, node_ids: list[str]) -> set[str]:
"""Check existence of multiple nodes in a single UNWIND query.
Args:
node_ids: List of node IDs to check.
Returns:
Set of node_ids that exist in the graph.
"""
if not node_ids:
return set()
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
workspace_label = self._get_workspace_label()
try:
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
query = f"""
UNWIND $ids AS id
MATCH (n:`{workspace_label}` {{entity_id: id}})
RETURN n.entity_id AS entity_id
"""
result = await session.run(query, ids=node_ids)
records = await result.data()
await result.consume()
return {r["entity_id"] for r in records}
except Exception as e:
logger.error(
f"[{self.workspace}] Error during batch node existence check: {str(e)}"
)
raise
async def upsert_edges_batch(
self, edges: list[tuple[str, str, dict[str, str]]]
) -> None:
"""Batch insert/update multiple edges using a single UNWIND Cypher query.
Uses the same transient-error retry logic as upsert_edge().
Args:
edges: List of (source_node_id, target_node_id, edge_data) tuples.
"""
if not edges:
return
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
workspace_label = self._get_workspace_label()
edges_data = [
{"src": src, "tgt": tgt, "props": edge_data}
for src, tgt, edge_data in edges
]
max_retries = 100
initial_wait_time = 0.2
backoff_factor = 1.1
jitter_factor = 0.1
for attempt in range(max_retries):
try:
async with self._driver.session(database=self._DATABASE) as session:
async def execute_batch(tx: AsyncManagedTransaction):
query = f"""
UNWIND $edges AS row
MATCH (source:`{workspace_label}` {{entity_id: row.src}})
WITH source, row
MATCH (target:`{workspace_label}` {{entity_id: row.tgt}})
MERGE (source)-[r:DIRECTED]-(target)
SET r += row.props
RETURN r
"""
result = await tx.run(query, edges=edges_data)
await result.consume()
await session.execute_write(execute_batch)
break
except (TransientError, ResultFailedError) as e:
root_cause = e
while hasattr(root_cause, "__cause__") and root_cause.__cause__:
root_cause = root_cause.__cause__
is_transient = (
isinstance(root_cause, TransientError)
or isinstance(e, TransientError)
or "TransientError" in str(e)
or "Cannot resolve conflicting transactions" in str(e)
)
if is_transient:
if attempt < max_retries - 1:
jitter = random.uniform(0, jitter_factor) * initial_wait_time
wait_time = (
initial_wait_time * (backoff_factor**attempt) + jitter
)
logger.warning(
f"[{self.workspace}] Batch edge upsert failed. Attempt #{attempt + 1} retrying in {wait_time:.3f}s... Error: {str(e)}"
)
await asyncio.sleep(wait_time)
else:
logger.error(
f"[{self.workspace}] Memgraph transient error during batch edge upsert after {max_retries} retries: {str(e)}"
)
raise
else:
logger.error(
f"[{self.workspace}] Non-transient error during batch edge upsert: {str(e)}"
)
raise
except Exception as e:
logger.error(
f"[{self.workspace}] Unexpected error during batch edge upsert: {str(e)}"
)
raise
async def delete_node(self, node_id: str) -> None:
"""Delete a node with the specified label
Args:
node_id: The label of the node to delete
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
async def _do_delete(tx: AsyncManagedTransaction):
workspace_label = self._get_workspace_label()
query = f"""
MATCH (n:`{workspace_label}` {{entity_id: $entity_id}})
DETACH DELETE n
"""
result = await tx.run(query, entity_id=node_id)
logger.debug(f"[{self.workspace}] Deleted node with label {node_id}")
await result.consume()
try:
async with self._driver.session(database=self._DATABASE) as session:
await session.execute_write(_do_delete)
except Exception as e:
logger.error(f"[{self.workspace}] Error during node deletion: {str(e)}")
raise
async def remove_nodes(self, nodes: list[str]):
"""Delete multiple nodes
Args:
nodes: List of node labels to be deleted
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
for node in nodes:
await self.delete_node(node)
async def remove_edges(self, edges: list[tuple[str, str]]):
"""Delete multiple edges
Args:
edges: List of edges to be deleted, each edge is a (source, target) tuple
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
for source, target in edges:
async def _do_delete_edge(tx: AsyncManagedTransaction):
workspace_label = self._get_workspace_label()
query = f"""
MATCH (source:`{workspace_label}` {{entity_id: $source_entity_id}})-[r]-(target:`{workspace_label}` {{entity_id: $target_entity_id}})
DELETE r
"""
result = await tx.run(
query, source_entity_id=source, target_entity_id=target
)
logger.debug(
f"[{self.workspace}] Deleted edge from '{source}' to '{target}'"
)
await result.consume() # Ensure result is fully consumed
try:
async with self._driver.session(database=self._DATABASE) as session:
await session.execute_write(_do_delete_edge)
except Exception as e:
logger.error(f"[{self.workspace}] Error during edge deletion: {str(e)}")
raise
async def drop(self) -> dict[str, str]:
"""Drop all data from the current workspace and clean up resources
This method will delete all nodes and relationships in the Memgraph database.
Returns:
dict[str, str]: Operation status and message
- On success: {"status": "success", "message": "data dropped"}
- On failure: {"status": "error", "message": "<error details>"}
Raises:
Exception: If there is an error executing the query
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
try:
async with self._driver.session(database=self._DATABASE) as session:
workspace_label = self._get_workspace_label()
query = f"MATCH (n:`{workspace_label}`) DETACH DELETE n"
result = await session.run(query)
await result.consume()
logger.info(
f"[{self.workspace}] Dropped workspace {workspace_label} from Memgraph database {self._DATABASE}"
)
return {"status": "success", "message": "workspace data dropped"}
except Exception as e:
logger.error(
f"[{self.workspace}] Error dropping workspace {workspace_label} from Memgraph database {self._DATABASE}: {e}"
)
return {"status": "error", "message": str(e)}
async def edge_degree(self, src_id: str, tgt_id: str) -> int:
"""Get the total degree (sum of relationships) of two nodes.
Args:
src_id: Label of the source node
tgt_id: Label of the target node
Returns:
int: Sum of the degrees of both nodes
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
src_degree = await self.node_degree(src_id)
trg_degree = await self.node_degree(tgt_id)
# Convert None to 0 for addition
src_degree = 0 if src_degree is None else src_degree
trg_degree = 0 if trg_degree is None else trg_degree
degrees = int(src_degree) + int(trg_degree)
return degrees
async def get_knowledge_graph(
self,
node_label: str,
max_depth: int = 3,
max_nodes: int = None,
) -> KnowledgeGraph:
"""
Retrieve a connected subgraph of nodes where the label includes the specified `node_label`.
Args:
node_label: Label of the starting node, * means all nodes
max_depth: Maximum depth of the subgraph, Defaults to 3
max_nodes: Maximum nodes to return by BFS, Defaults to 1000
Returns:
KnowledgeGraph object containing nodes and edges, with an is_truncated flag
indicating whether the graph was truncated due to max_nodes limit
"""
# Get max_nodes from global_config if not provided
if max_nodes is None:
max_nodes = self.global_config.get("max_graph_nodes", 1000)
else:
# Limit max_nodes to not exceed global_config max_graph_nodes
max_nodes = min(max_nodes, self.global_config.get("max_graph_nodes", 1000))
workspace_label = self._get_workspace_label()
result = KnowledgeGraph()
seen_nodes = set()
seen_edges = set()
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
try:
if node_label == "*":
# First check total node count to determine if graph is truncated
count_query = (
f"MATCH (n:`{workspace_label}`) RETURN count(n) as total"
)
count_result = None
try:
count_result = await session.run(count_query)
count_record = await count_result.single()
if count_record and count_record["total"] > max_nodes:
result.is_truncated = True
logger.info(
f"Graph truncated: {count_record['total']} nodes found, limited to {max_nodes}"
)
finally:
if count_result:
await count_result.consume()
# Run main query to get nodes with highest degree
main_query = f"""
MATCH (n:`{workspace_label}`)
OPTIONAL MATCH (n)-[r]-()
WITH n, COALESCE(count(r), 0) AS degree
ORDER BY degree DESC
LIMIT $max_nodes
WITH collect({{node: n}}) AS filtered_nodes
UNWIND filtered_nodes AS node_info
WITH collect(node_info.node) AS kept_nodes, filtered_nodes
OPTIONAL MATCH (a)-[r]-(b)
WHERE a IN kept_nodes AND b IN kept_nodes
RETURN filtered_nodes AS node_info,
collect(DISTINCT r) AS relationships
"""
result_set = None
try:
result_set = await session.run(
main_query,
{"max_nodes": max_nodes},
)
record = await result_set.single()
finally:
if result_set:
await result_set.consume()
else:
# Run subgraph query for specific node_label
subgraph_query = f"""
MATCH (start:`{workspace_label}`)
WHERE start.entity_id = $entity_id
OPTIONAL MATCH path = (start)-[*BFS 0..{max_depth}]-(end:`{workspace_label}`)
WHERE path IS NULL OR ALL(n IN nodes(path) WHERE '{workspace_label}' IN labels(n))
WITH start, collect(DISTINCT end) AS discovered_nodes
WITH start, [node IN discovered_nodes WHERE node IS NOT NULL AND node <> start] AS other_nodes
WITH
CASE
WHEN 1 + size(other_nodes) <= $max_nodes THEN [start] + other_nodes
ELSE [start] + other_nodes[0..$max_other_nodes]
END AS limited_nodes,
1 + size(other_nodes) > $max_nodes AS is_truncated
UNWIND limited_nodes AS n
OPTIONAL MATCH (n)-[r]-(m)
WHERE m IN limited_nodes
WITH limited_nodes, collect(DISTINCT r) AS relationships, is_truncated
RETURN
[node IN limited_nodes | {{node: node}}] AS node_info,
[rel IN relationships WHERE rel IS NOT NULL] AS relationships,
is_truncated
"""
result_set = None
try:
result_set = await session.run(
subgraph_query,
{
"entity_id": node_label,
"max_nodes": max_nodes,
"max_other_nodes": max(max_nodes - 1, 0),
},
)
record = await result_set.single()
# If no record found, return empty KnowledgeGraph
if not record:
logger.debug(
f"[{self.workspace}] No nodes found for entity_id: {node_label}"
)
return result
# Check if the result was truncated
if record.get("is_truncated"):
result.is_truncated = True
logger.info(
f"[{self.workspace}] Graph truncated: breadth-first search limited to {max_nodes} nodes"
)
finally:
if result_set:
await result_set.consume()
if record:
for node_info in record["node_info"]:
node = node_info["node"]
node_id = node.id
if node_id not in seen_nodes:
result.nodes.append(
KnowledgeGraphNode(
id=f"{node_id}",
labels=[node.get("entity_id")],
properties=dict(node),
)
)
seen_nodes.add(node_id)
for rel in record["relationships"]:
edge_id = rel.id
if edge_id not in seen_edges:
start = rel.start_node
end = rel.end_node
result.edges.append(
KnowledgeGraphEdge(
id=f"{edge_id}",
type=rel.type,
source=f"{start.id}",
target=f"{end.id}",
properties=dict(rel),
)
)
seen_edges.add(edge_id)
logger.info(
f"[{self.workspace}] Subgraph query successful | Node count: {len(result.nodes)} | Edge count: {len(result.edges)}"
)
except Exception as e:
logger.warning(
f"[{self.workspace}] Memgraph error during subgraph query: {str(e)}"
)
return result
async def get_all_nodes(self) -> list[dict]:
"""Get all nodes in the graph.
Returns:
A list of all nodes, where each node is a dictionary of its properties
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
workspace_label = self._get_workspace_label()
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
query = f"""
MATCH (n:`{workspace_label}`)
RETURN n
"""
result = await session.run(query)
nodes = []
async for record in result:
node = record["n"]
node_dict = dict(node)
# Add node id (entity_id) to the dictionary for easier access
node_dict["id"] = node_dict.get("entity_id")
nodes.append(node_dict)
await result.consume()
return nodes
async def get_all_edges(self) -> list[dict]:
"""Get all edges in the graph.
Returns:
A list of all edges, where each edge is a dictionary of its properties
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
workspace_label = self._get_workspace_label()
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
query = f"""
MATCH (a:`{workspace_label}`)-[r]-(b:`{workspace_label}`)
RETURN DISTINCT a.entity_id AS source, b.entity_id AS target, properties(r) AS properties
"""
result = await session.run(query)
edges = []
async for record in result:
edge_properties = record["properties"]
edge_properties["source"] = record["source"]
edge_properties["target"] = record["target"]
edges.append(edge_properties)
await result.consume()
return edges
async def get_popular_labels(self, limit: int = 300) -> list[str]:
"""Get popular labels by node degree (most connected entities)
Args:
limit: Maximum number of labels(entity names) to return
Returns:
List of labels(entity names) sorted by degree (highest first)
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
result = None
try:
workspace_label = self._get_workspace_label()
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
query = f"""
MATCH (n:`{workspace_label}`)
WHERE n.entity_id IS NOT NULL
OPTIONAL MATCH (n)-[r]-()
WITH n.entity_id AS label, count(r) AS degree
ORDER BY degree DESC, label ASC
LIMIT {limit}
RETURN label
"""
result = await session.run(query)
labels = []
async for record in result:
labels.append(record["label"])
await result.consume()
logger.debug(
f"[{self.workspace}] Retrieved {len(labels)} popular labels (limit: {limit})"
)
return labels
except Exception as e:
logger.error(f"[{self.workspace}] Error getting popular labels: {str(e)}")
if result is not None:
await result.consume()
return []
async def search_labels(self, query: str, limit: int = 50) -> list[str]:
"""Search labels(entity names) with fuzzy matching
Args:
query: Search query string
limit: Maximum number of results to return
Returns:
List of matching labels(entity names) sorted by relevance
"""
if self._driver is None:
raise RuntimeError(
"Memgraph driver is not initialized. Call 'await initialize()' first."
)
query_lower = query.lower().strip()
if not query_lower:
return []
result = None
try:
workspace_label = self._get_workspace_label()
async with self._driver.session(
database=self._DATABASE, default_access_mode="READ"
) as session:
cypher_query = f"""
MATCH (n:`{workspace_label}`)
WHERE n.entity_id IS NOT NULL
WITH n.entity_id AS label, toLower(n.entity_id) AS label_lower
WHERE label_lower CONTAINS $query_lower
WITH label, label_lower,
CASE
WHEN label_lower = $query_lower THEN 1000
WHEN label_lower STARTS WITH $query_lower THEN 500
ELSE 100 - size(label)
END AS score
ORDER BY score DESC, label ASC
LIMIT {limit}
RETURN label
"""
result = await session.run(cypher_query, query_lower=query_lower)
labels = []
async for record in result:
labels.append(record["label"])
await result.consume()
logger.debug(
f"[{self.workspace}] Search query '{query}' returned {len(labels)} results (limit: {limit})"
)
return labels
except Exception as e:
logger.error(f"[{self.workspace}] Error searching labels: {str(e)}")
if result is not None:
await result.consume()
return []