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Class: Gem::Resolver::Molinillo::DependencyGraph

Overview

A directed acyclic graph that is tuned to hold named dependencies

Class Method Summary

Instance Attribute Summary

Instance Method Summary

::Gem::TSort - Included

#each_strongly_connected_component

The iterator version of the #strongly_connected_components method.

#each_strongly_connected_component_from

Iterates over strongly connected component in the subgraph reachable from node.

#strongly_connected_components

Returns strongly connected components as an array of arrays of nodes.

#tsort

Returns a topologically sorted array of nodes.

#tsort_each

The iterator version of the #tsort method.

#tsort_each_child

Should be implemented by a extended class.

#tsort_each_node

Should be implemented by a extended class.

Constructor Details

.newDependencyGraph

Initializes an empty dependency graph

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 55

def initialize
  @vertices = {}
  @log = Log.new
end

Class Method Details

.tsort(vertices) ⇒ Array<Vertex>

Topologically sorts the given vertices.

Parameters:

  • vertices (Enumerable<Vertex>)

    the vertices to be sorted, which must all belong to the same graph.

Returns:

  • (Array<Vertex>)

    The sorted vertices.

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 34

def self.tsort(vertices)
  Gem::TSort.tsort(
    lambda { |b| vertices.each(&b) },
    lambda { |v, &b| (v.successors & vertices).each(&b) }
  )
end

Instance Attribute Details

#logLog (readonly)

Returns:

  • (Log)

    the op log for this graph

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 52

attr_reader :log

#vertices ⇒ {String => Vertex} (readonly)

Returns:

  • ({String => Vertex})

    the vertices of the dependency graph, keyed by Vertex#name

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 49

attr_reader :vertices

Instance Method Details

#==(other) ⇒ Boolean

Parameters:

  • other (DependencyGraph)

Returns:

  • (Boolean)

    whether the two dependency graphs are equal, determined by a recursive traversal of each #root_vertices and its Vertex#successors

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 130

def ==(other)
  return false unless other
  return true if equal?(other)
  vertices.each do |name, vertex|
    other_vertex = other.vertex_named(name)
    return false unless other_vertex
    return false unless vertex.payload == other_vertex.payload
    return false unless other_vertex.successors.to_set == vertex.successors.to_set
  end
end

#add_child_vertex(name, payload, parent_names, requirement) ⇒ void

This method returns an undefined value.

Parameters:

  • name (String)
  • payload (Object)
  • parent_names (Array<String>)
  • requirement (Object)

    the requirement that is requiring the child

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 146

def add_child_vertex(name, payload, parent_names, requirement)
  root = !parent_names.delete(nil) { true }
  vertex = add_vertex(name, payload, root)
  vertex.explicit_requirements << requirement if root
  parent_names.each do |parent_name|
    parent_vertex = vertex_named(parent_name)
    add_edge(parent_vertex, vertex, requirement)
  end
  vertex
end

#add_edge(origin, destination, requirement) ⇒ Edge

Adds a new DependencyGraph::Edge to the dependency graph

Parameters:

  • origin (Vertex)
  • destination (Vertex)
  • requirement (Object)

    the requirement that this edge represents

Returns:

  • (Edge)

    the added edge

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 191

def add_edge(origin, destination, requirement)
  if destination.path_to?(origin)
    raise CircularDependencyError.new(path(destination, origin))
  end
  add_edge_no_circular(origin, destination, requirement)
end

#add_edge_no_circular(origin, destination, requirement) (private)

Adds a new DependencyGraph::Edge to the dependency graph without checking for circularity.

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 219

def add_edge_no_circular(origin, destination, requirement)
  log.add_edge_no_circular(self, origin.name, destination.name, requirement)
end

#add_vertex(name, payload, root = false) ⇒ Vertex

Adds a vertex with the given name, or updates the existing one.

Parameters:

  • name (String)
  • payload (Object)

Returns:

  • (Vertex)

    the vertex that was added to self

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 161

def add_vertex(name, payload, root = false)
  log.add_vertex(self, name, payload, root)
end

#delete_edge(edge) ⇒ Void

Deletes an DependencyGraph::Edge from the dependency graph

Parameters:

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 201

def delete_edge(edge)
  log.delete_edge(self, edge.origin.name, edge.destination.name, edge.requirement)
end

#detach_vertex_named(name) ⇒ Array<Vertex>

Detaches the #vertex_named name DependencyGraph::Vertex from the graph, recursively removing any non-root vertices that were orphaned in the process

Parameters:

  • name (String)

Returns:

  • (Array<Vertex>)

    the vertices which have been detached

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 169

def detach_vertex_named(name)
  log.detach_vertex_named(self, name)
end

#eachArray<Vertex> Also known as: #tsort_each_node

Enumerates through the vertices of the graph.

Returns:

  • (Array<Vertex>)

    The graph’s vertices.

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 15

def each
  return vertices.values.each unless block_given?
  vertices.values.each { |v| yield v }
end

#initialize_copy(other)

Initializes a copy of a DependencyGraph, ensuring that all #vertices are properly copied.

Parameters:

  • other (DependencyGraph)

    the graph to copy.

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 77

def initialize_copy(other)
  super
  @vertices = {}
  @log = other.log.dup
  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

#inspectString

Returns:

  • (String)

    a string suitable for debugging

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 97

def inspect
  "#{self.class}:#{vertices.values.inspect}"
end

#path(from, to) ⇒ Array<Vertex> (private)

Returns the path between two vertices

Parameters:

Returns:

  • (Array<Vertex>)

    the shortest path from from to to

Raises:

  • (ArgumentError)

    if there is no path between the vertices

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 228

def path(from, to)
  distances = Hash.new(vertices.size + 1)
  distances[from.name] = 0
  predecessors = {}
  each do |vertex|
    vertex.successors.each do |successor|
      if distances[successor.name] > distances[vertex.name] + 1
        distances[successor.name] = distances[vertex.name] + 1
        predecessors[successor] = vertex
      end
    end
  end

  path = [to]
  while before = predecessors[to]
    path << before
    to = before
    break if to == from
  end

  unless path.last.equal?(from)
    raise ArgumentError, "There is no path from #{from.name} to #{to.name}"
  end

  path.reverse
end

#rewind_to(tag) ⇒ Void

Rewinds the graph to the state tagged as #tag

Parameters:

  • tag (Object)

    the tag to rewind to

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 70

def rewind_to(tag)
  log.rewind_to(self, tag)
end

#root_vertex_named(name) ⇒ Vertex?

Parameters:

  • name (String)

Returns:

  • (Vertex, nil)

    the root vertex with the given name

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 181

def root_vertex_named(name)
  vertex = vertex_named(name)
  vertex if vertex && vertex.root?
end

#set_payload(name, payload) ⇒ Void

Sets the payload of the vertex with the given name

Parameters:

  • name (String)

    the name of the vertex

  • payload (Object)

    the payload

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 209

def set_payload(name, payload)
  log.set_payload(self, name, payload)
end

#tag(tag) ⇒ Void

Tags the current state of the dependency as the given tag

Parameters:

  • tag (Object)

    an opaque tag for the current state of the graph

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 63

def tag(tag)
  log.tag(self, tag)
end

#to_dot(options = {}) ⇒ String

Parameters:

  • options (Hash) (defaults to: {})

    options for dot output.

Returns:

  • (String)

    Returns a dot format representation of the graph

Raises:

  • (ArgumentError)
[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 103

def to_dot(options = {})
  edge_label = options.delete(:edge_label)
  raise ArgumentError, "Unknown options: #{options.keys}" unless options.empty?

  dot_vertices = []
  dot_edges = []
  vertices.each do |n, v|
    dot_vertices << "  #{n} [label=\"{#{n}|#{v.payload}}\"]"
    v.outgoing_edges.each do |e|
      label = edge_label ? edge_label.call(e) : e.requirement
      dot_edges << "  #{e.origin.name} -> #{e.destination.name} [label=#{label.to_s.dump}]"
    end
  end

  dot_vertices.uniq!
  dot_vertices.sort!
  dot_edges.uniq!
  dot_edges.sort!

  dot = dot_vertices.unshift('digraph G {').push('') + dot_edges.push('}')
  dot.join("\n")
end

#tsort_each_child(vertex, &block) (private)

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 26

def tsort_each_child(vertex, &block)
  vertex.successors.each(&block)
end

#tsort_each_node (private)

Alias for #each.

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 23

alias tsort_each_node each

#vertex_named(name) ⇒ Vertex?

Parameters:

  • name (String)

Returns:

  • (Vertex, nil)

    the vertex with the given name

[ GitHub ]

  
# File 'lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb', line 175

def vertex_named(name)
  vertices[name]
end