Class: Gitgo::Repo::Node

Inherits:
Object
  • Object
show all
Defined in:
lib/gitgo/repo/node.rb

Overview

Nodes are used to cache and provide access to positional information (parents, children, etc) for each node in a graph. Nodes are meant to be read-only objects and should not be modified.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sha, nodes, links, updates) ⇒ Node

Initializes a new Node. The links and updates arrays represent raw linkage information before deconvolution and are not made available because they are changed in the course of deconvolution.



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# File 'lib/gitgo/repo/node.rb', line 25

def initialize(sha, nodes, links, updates)
  @sha = sha
  @nodes = nodes
  @links = links
  @updates = updates
  @deleted = false
  @original = sha
end

Instance Attribute Details

#deleted ⇒ Object

True if self is deleted



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# File 'lib/gitgo/repo/node.rb', line 16

def deleted
  @deleted
end

#nodes ⇒ Object (readonly)

A back reference to the graph nodes this node belongs to.



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# File 'lib/gitgo/repo/node.rb', line 13

def nodes
  @nodes
end

#original ⇒ Object

Set to the sha for the original node this node updates, or the sha for self if self is an original node.



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# File 'lib/gitgo/repo/node.rb', line 20

def original
  @original
end

#sha ⇒ Object (readonly)

The node sha



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# File 'lib/gitgo/repo/node.rb', line 10

def sha
  @sha
end

Instance Method Details

#children ⇒ Object

Returns an array of deconvoluted children for self.



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# File 'lib/gitgo/repo/node.rb', line 66

def children
  @children ||= begin
    children = []
    
    @links.each do |link|
      children.concat nodes[link.original].versions
    end if current?
    
    children
  end
end

#current? ⇒ Boolean

True if self is a current version of a node (ie not deleted or updated).

Returns:

  • (Boolean) 


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# File 'lib/gitgo/repo/node.rb', line 41

def current?
  !deleted && @updates.empty?
end

#deconvolute(original = sha, links = nil, versions = []) ⇒ Object

Deconvolute is a utility method used by a graph to:

  • aggregate links from previous versions to updates

  • determine the current versions for an original node

  • determine the original node for each update

This method is public so that it may be used from a Graph, but should not be called otherwise.



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# File 'lib/gitgo/repo/node.rb', line 91

def deconvolute(original=sha, links=nil, versions=[])
  if original
    @original = original
    @links.concat(links) if links
    @versions = versions if original == sha
  end
  
  case
  when deleted
    # do not register deleted notes as current
    # so that they will fall out of the tree
  when @updates.empty?
    versions << sha
  else
    @updates.each do |update|
      update.deconvolute(original, @links, versions)
    end
  end
  
  versions
end

#inspect ⇒ Object

Returns a string like:

#<Gitgo::Repo::Node:object_id sha="sha">



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# File 'lib/gitgo/repo/node.rb', line 117

def inspect
  "#<#{self.class}:#{object_id} sha=#{sha.inspect}>"
end

#original? ⇒ Boolean

True if self is an original node.

Returns:

  • (Boolean) 


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# File 'lib/gitgo/repo/node.rb', line 35

def original?
  original == sha
end

#parents ⇒ Object

Returns an array of deconvoluted parent for self.



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# File 'lib/gitgo/repo/node.rb', line 51

def parents
  @parents ||= begin
    parents = []
    
    nodes.each_value do |node|
      if node.current? && node.children.include?(sha)
        parents << node.sha
      end
    end if current?
    
    parents
  end
end

#tail? ⇒ Boolean

True if self is a tail (ie current and without children)

Returns:

  • (Boolean) 


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# File 'lib/gitgo/repo/node.rb', line 46

def tail?
  current? && @links.empty?
end

#versions ⇒ Object

Returns an array of current versions for self.



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# File 'lib/gitgo/repo/node.rb', line 79

def versions
  @versions ||= deconvolute(nil)
end