class Gem::Resolver::Molinillo::DependencyGraph

A directed acyclic graph that is tuned to hold named dependencies

Constants

Edge: A directed edge of a {DependencyGraph} @attr [Vertex] origin The origin of the directed edge @attr [Vertex] destination The destination of the directed edge @attr [Object] requirement The requirement the directed edge represents

Attributes

vertices[R]

@return [{String => Vertex}] the vertices of the dependency graph, keyed

by {Vertex#name}

Public Class Methods

new() click to toggle source

Initializes an empty dependency graph

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 48
def initialize
  @vertices = {}
end

tsort(vertices) click to toggle source

Topologically sorts the given vertices. @param [Enumerable<Vertex>] vertices the vertices to be sorted, which must

all belong to the same graph.

@return [Array<Vertex>] The sorted vertices.

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 30
def self.tsort(vertices)
  TSort.tsort(
    lambda { |b| vertices.each(&b) },
    lambda { |v, &b| (v.successors & vertices).each(&b) }
  )
end

Public Instance Methods

==(other) click to toggle source

@return [Boolean] whether the two dependency graphs are equal, determined

by a recursive traversal of each {#root_vertices} and its
{Vertex#successors}

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 81
def ==(other)
  return false unless other
  vertices.each do |name, vertex|
    other_vertex = other.vertex_named(name)
    return false unless other_vertex
    return false unless other_vertex.successors.map(&:name).to_set == vertex.successors.map(&:name).to_set
  end
end

add_child_vertex(name, payload, parent_names, requirement) click to toggle source

@param [String] name @param [Object] payload @param [Array<String>] parent_names @param [Object] requirement the requirement that is requiring the child @return [void]

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 95
def add_child_vertex(name, payload, parent_names, requirement)
  vertex = add_vertex(name, payload)
  parent_names.each do |parent_name|
    unless parent_name
      vertex.root = true
      next
    end
    parent_node = vertex_named(parent_name)
    add_edge(parent_node, vertex, requirement)
  end
  vertex
end

add_edge(origin, destination, requirement) click to toggle source

Adds a new {Edge} to the dependency graph @param [Vertex] origin @param [Vertex] destination @param [Object] requirement the requirement that this edge represents @return [Edge] the added edge

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 150
def add_edge(origin, destination, requirement)
  if destination.path_to?(origin)
    raise CircularDependencyError.new([origin, destination])
  end
  add_edge_no_circular(origin, destination, requirement)
end

add_vertex(name, payload, root = false) click to toggle source

Adds a vertex with the given name, or updates the existing one. @param [String] name @param [Object] payload @return [Vertex] the vertex that was added to `self`

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 112
def add_vertex(name, payload, root = false)
  vertex = vertices[name] ||= Vertex.new(name, payload)
  vertex.payload ||= payload
  vertex.root ||= root
  vertex
end

detach_vertex_named(name) click to toggle source

Detaches the {#vertex_named} `name` {Vertex} from the graph, recursively removing any non-root vertices that were orphaned in the process @param [String] name @return [void]

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 123
def detach_vertex_named(name)
  return unless vertex = vertices.delete(name)
  vertex.outgoing_edges.each do |e|
    v = e.destination
    v.incoming_edges.delete(e)
    detach_vertex_named(v.name) unless v.root? || v.predecessors.any?
  end
end

each() { |v| ... } click to toggle source

Enumerates through the vertices of the graph. @return [Array<Vertex>] The graph's vertices.

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 12
def each
  vertices.values.each { |v| yield v }
end

Also aliased as: tsort_each_node

initialize_copy(other) click to toggle source

Initializes a copy of a {DependencyGraph}, ensuring that all {#vertices} are properly copied. @param [DependencyGraph] other the graph to copy.

Calls superclass method

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 55
def initialize_copy(other)
  super
  @vertices = {}
  traverse = lambda do |new_v, old_v|
    return if new_v.outgoing_edges.size == old_v.outgoing_edges.size
    old_v.outgoing_edges.each do |edge|
      destination = add_vertex(edge.destination.name, edge.destination.payload)
      add_edge_no_circular(new_v, destination, edge.requirement)
      traverse.call(destination, edge.destination)
    end
  end
  other.vertices.each do |name, vertex|
    new_vertex = add_vertex(name, vertex.payload, vertex.root?)
    new_vertex.explicit_requirements.replace(vertex.explicit_requirements)
    traverse.call(new_vertex, vertex)
  end
end

inspect() click to toggle source

@return [String] a string suitable for debugging

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 74
def inspect
  "#{self.class}:#{vertices.values.inspect}"
end

root_vertex_named(name) click to toggle source

@param [String] name @return [Vertex,nil] the root vertex with the given name

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 140
def root_vertex_named(name)
  vertex = vertex_named(name)
  vertex if vertex && vertex.root?
end

tsort_each_child(vertex, &block) click to toggle source

@visibility private

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 22
def tsort_each_child(vertex, &block)
  vertex.successors.each(&block)
end

tsort_each_node()

@visibility private

Alias for: each

vertex_named(name) click to toggle source

@param [String] name @return [Vertex,nil] the vertex with the given name

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 134
def vertex_named(name)
  vertices[name]
end

Private Instance Methods

add_edge_no_circular(origin, destination, requirement) click to toggle source

Adds a new {Edge} to the dependency graph without checking for circularity.

# File lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb, line 161
def add_edge_no_circular(origin, destination, requirement)
  edge = Edge.new(origin, destination, requirement)
  origin.outgoing_edges << edge
  destination.incoming_edges << edge
  edge
end