GraphStore

org.llm4s.knowledgegraph.storage.GraphStore
trait GraphStore

Abstract interface for persisting and querying Knowledge Graphs.

All implementations must:

  • Return consistent results for the same operations
  • Use BFS-based traversal by default for consistent result ordering
  • Return Left(Error) consistently for missing nodes/edges
  • Support property filtering uniformly or document limitations
  • Be thread-safe or explicitly document thread-safety guarantees

This trait is designed to be engine-agnostic, allowing implementations for various graph databases (Neo4j, TinkerPop, SPARQL, etc.) while maintaining a consistent interface.

Attributes

Graph
Supertypes
class Object
trait Matchable
class Any
Known subtypes

Members list

Value members

Abstract methods

def deleteEdge(source: String, target: String, relationship: String): Result[Unit]

Deletes a specific edge.

Deletes a specific edge.

Value parameters

relationship

The relationship type

source

The source node ID

target

The target node ID

Attributes

Returns

Right(()) on success or if edge doesn't exist, Left(error) on failure

def deleteNode(id: String): Result[Unit]

Deletes a node and all its connected edges.

Deletes a node and all its connected edges.

Value parameters

id

The node ID to delete

Attributes

Returns

Right(()) on success or if node doesn't exist, Left(error) on failure

def getNeighbors(nodeId: String, direction: Direction): Result[Seq[EdgeNodePair]]

Retrieves neighboring nodes and their connecting edges.

Retrieves neighboring nodes and their connecting edges.

Value parameters

direction

The direction of traversal (Outgoing, Incoming, Both)

nodeId

The ID of the node

Attributes

Returns

Right(Seq of (edge, neighbor node)) on success, Left(error) on failure

def getNode(id: String): Result[Option[Node]]

Retrieves a node by ID.

Retrieves a node by ID.

Value parameters

id

The node ID

Attributes

Returns

Right(Some(node)) if found, Right(None) if not found, Left(error) on failure

def loadAll(): Result[Graph]

Loads the entire graph.

Loads the entire graph.

For implementations backed by external databases, consider pagination or size limits to avoid memory issues with large graphs.

Attributes

Returns

Right(graph) on success, Left(error) on failure

def query(filter: GraphFilter): Result[Graph]

Queries the graph based on filter criteria. Returns a subgraph matching the filter conditions.

Queries the graph based on filter criteria. Returns a subgraph matching the filter conditions.

If propertyKey or propertyValue filters are specified but not supported, the implementation must either apply them or return a clear error.

Value parameters

filter

The filter criteria

Attributes

Returns

Right(subgraph) on success, Left(error) on failure

Computes statistics about the graph.

Computes statistics about the graph.

Attributes

Returns

Right(stats) on success, Left(error) on failure

def traverse(startId: String, config: TraversalConfig): Result[Seq[Node]]

Traverses the graph starting from a node using BFS. All implementations must use Breadth-First Search for consistent result ordering.

Traverses the graph starting from a node using BFS. All implementations must use Breadth-First Search for consistent result ordering.

Missing start node: should return Right(Seq.empty) not an error, since traversal of a non-existent node yields no nodes.

Value parameters

config

Traversal configuration (depth, direction, visited set). The direction parameter controls whether traversal follows outgoing, incoming, or all edges from each node.

startId

The ID of the starting node

Attributes

Returns

Right(Seq of traversed nodes) on success, Left(error) on critical failure

def upsertEdge(edge: Edge): Result[Unit]

Inserts or updates an edge in the graph. Both source and target nodes must exist. If an edge with the same source, target, and relationship already exists, it is replaced.

Inserts or updates an edge in the graph. Both source and target nodes must exist. If an edge with the same source, target, and relationship already exists, it is replaced.

Value parameters

edge

The edge to upsert

Attributes

Returns

Right(()) on success, Left(error) if source or target nodes don't exist

def upsertNode(node: Node): Result[Unit]

Inserts or updates a node in the graph. If the node ID already exists, the existing node is replaced.

Inserts or updates a node in the graph. If the node ID already exists, the existing node is replaced.

Value parameters

node

The node to upsert

Attributes

Returns

Right(()) on success, Left(error) on failure