@xgraph/core
A core graph data structure: multiedged, directed and cyclic
API
class:Graph()
Create a new instance of a Graph.
Graph::setVertex(id: string, type:string, props={})
Set a vertex (create or update) with an id
and a type
.
g.setVertex('foo', 'Person', { name: 'Foo Bar', age: 23 });
Graph::vertex(id:string)
Get a vertex by its id
.
g.vertex('foo').name === 'Foo Bar';
Graph::hasVertex(id:string)
Check if a vertex exists by its id
.
g.hasVertex('foo') === true;
Graph::removeVertex(id:string)
Remove a vertex by its id
and all of its edges.
Returns all of the discarded edges.
g.removeVertex('foo');
Graph::setEdge(originVertexId:string, targetVertexId:string, type:string, properties={})
Ensure an edge of type type
from vertex origin
to vertex target
.
g.setEdge('foo', 'bar', 'friendOf');
Graph::edge(originVertexId:string, targetVertexId:string, type:string)
Get the type
edge from origin
to target
if exists, null
otherwise.
g.edge('foo', 'bar', 'friendOf').type === 'friends';
g.edge('foo', 'bar', 'father') === null;
Graph::hasEdge(originVertexId:string, targetVertexId:string, type?:string)
Check if an edge from origin
to target
exists (specifically of type type
, if given).
g.hasEdge('foo', 'bar', 'friendOf') === true;
Graph::removeEdge(originVertexId:string, targetVertexId:string, type:string)
Remove a type
edge from origin
to target
.
g.removeEdge('foo', 'bar', 'friendOf');
Graph::inEdges(targetVertexId:string), Graph::outEdges(originVertexId:string), Graph::interEdges(originVertexId:string, targetVertexId:string), Graph::allEdges(vertexId:string)
Get all edges to target
, all edges from origin
, all edges from origin
to target
, all edges involving vertexId
- respectively.
Graph::vertices()
An iterator
over all the graph's vertices.
Graph::vertices(type:string)
An iterator
over all the graph's vertices of a given type
.
Graph::vertices(type:string, searchObject:object)
An iterator
over all the graph's vertices of a given type
, filtering using monjo syntax, using Indices where possible.
Graph::vertices(searchObject:object)
An iterator
over all the graph's vertices, filtering using monjo syntax, using Indices where possible.
Note: Using the unIndexed monjo version for all vertices will, inevitaly, be slower than simply using graph.vertices().filter(...)
instead.
Note: Using the type
parameter is syntactic sugar for querying the Graph.TYPE
auto Index, which means that using it with an Index (and especially a Typed Index) will incur an Index Intersection performance penalty.
Graph::toObject(), Graph.fromObject(bareObject)
Serialize and de-serialize the graph
Usage
const Graph = require('@xgraph/core');
const g = new Graph();
g.setVertex('foo', 'Person', { name: 'Foo Bar', age: 23 });
g.setVertex('bar', 'Person', { name: 'Bar Bar', age: 22 });
g.setEdge('foo', 'bar', 'friendOf');
g.outEdges('foo')
.filter(({ type }) => type === 'friendsOf')
.map(({ target }) => g.vertex(target).age); // [22]
Advnced Usage - Indexing
Should you wish to, you may add (and remove) Indices for better querying performances.
Graph::addIndex(prop:string, type?:string)
Create an Index for prop
, possibly limited to only vertices of type type
.
Notice: creating an index of property prop
drops any existing index of that property.
Graph::dropIndex(prop:string)
Drop any existing Index for property prop
;
Graph::hasIndex(prop:string)
Return whether or not an Index for property prop
exists.
Benchmarks
Benchmarks for 1000000 vertices:
Setup [no initial Index]: 2237.697ms
Setup [with initial index]: 3374.034ms
Querying over all vertices, 50 times [no index, no type annotation, monjo syntax]: 7344.953ms
Querying over all vertices, 50 times [no index, with type annotation, monjo syntax]: 29761.764ms
Querying over all vertices, 50 times [no index, no type annotation, classic filter]: 1428.090ms
Querying over all vertices, 50 times [no index, with type annotation, classic filter]: 19563.437ms
Creating an index for all vertices: 439.150ms
Querying over all vertices, 50 times [with index, no type annotation]: 0.431ms
Querying over all vertices, 50 times [with index, with type annotation]: 0.738ms