NAME
Resource::Silo::Metadata::DAG - Generic directed (acyclic) graph for dependency tracking
DESCRIPTION
This class is an internal part of Resource::Silo and is subject to change. Its main purpose is to track incomplete resources and detect dependency loops.
ATTRIBUTES
edges_out
edges_in
METHODS
size
Number of vertices in the graph.
list
Lists vertices.
list_sinks
List only vertices with no outgoing edges.
list_predecessors(\@list)
Given a list of vertices, return the list of all their predecessors without the vertices themselves.
contains($name)
Returns true if a vertex named $name is present.
add_edges (\@from, \@to)
Add edges from first vertex to the following ones.
drop_sink_cascade($name)
If $name is a sink, remove it along with any vertex which becomes a sink as a result of the operation, propagating along the edges.
Otherwise do nothing.
find_loop ($start, \@list, \%seen)
Find out whether calling $self->add_dependency([$start], $list) would cause a loop in the graph.
Due to the usage scenario, it's disjoint from adding vertices/edges.
self_check
Check the internal structure of the graph, returning undef if its intact, or an arrayref containing the list of discrepancies otherwise.