zhengyi-yang / rust_graph_lib Goto Github PK

Recently I've been using the graph library to design the framework of the experiment, and I encountered several issues.

Shortcomings of StaticGraph.

For single-machine storage, StaticGraph is a perfect fit for an unchanged graph. However, it is very awkward to partition the graph. Look into the following example.

Consider an undirected graph {(0, 1), (0, 2), (0, 3), (1, 3)}. In one single machine, we can maintain the graph as:

offset: [0, 3, 5, 6, 8]
edges: [1, 2, 3, 0, 3, 0, 0, 1]

Now we have two workers w0 and w1. Suppose that we partition the edge according to the src % num_workers.

In w0, we will receive {(0, 1), (0, 2), (0, 3)}, which will be maintained as:

offset: [0, 3, 4, 5, 6]
edges: [1, 2, 3, 0, 0, 0]

In w1, we will receive {(1, 0), (3, 0), (1, 3)}, maintained as:

offset: [0, 2, 4, 4, 6]
edges: [1, 3, 0, 3, 0, 1]

Note that in w1, we still maintain useless slot in the offset for the node of id 2. Actually, we may need to maintain many such useless slots, which contradicts our intention of using this graph storage.