git-analyze-cloned-github-network

#!/usr/bin/env ruby
# Display refs of the current Git repository in a way
# that allows to (hopefully) get an idea of the structure
# of unmerged branches.
#
# (We could do a lot more than now (we are just a small git log
#  wrapper atm), but ... well, the time...)
#
# Released into the public domain. There is no warranty for any damage
# that may occur by using this script!
#
# Author: Stephan Beyer

puts "Building data structure... (this may take some time)"

refs = {}
`git show-ref`.split(/[\r\n]+/).each do |line|
	hash, ref = line.split(/ /)
	refs[hash] = [] if refs[hash].nil?
	refs[hash] << ref
end

$alive = 0
Alive = '-\|/'
def output_alive
	print "#{Alive[$alive]}\r"
	$alive += 1
	$alive %= Alive.length
end

class Revs
	Adj = Struct.new(:children, :parents)

	def initialize
		@revs = {}
	end

	def make(hash)
		@revs[hash] = Adj.new([], []) if @revs[hash].nil?
	end

	def add_child(hash, child)
		@revs[hash].children << child
	end

	def add_parent(hash, parent)
		@revs[hash].parents << parent
	end

	def exists?(hash)
		not @revs[hash].nil?
	end

	def set_parents(hash, parents)
		make(hash)
		parents.each do |parent|
			make(parent)
			add_parent(hash, parent)
			add_child(parent, hash)
		end
	end

	def get_first_parent(hash)
		@revs[hash].parents.first
	end

	def get_tips
		tips = []
		@revs.each do |hash, adj|
			tips << hash if adj.children.empty?
		end
		tips
	end

	def contract_linear
		contracted = false
		@revs.each do |hash, adj|
			if adj.children.length == 1 and adj.parents.length == 1
				child = adj.children.first
				parent = adj.parents.first
				@revs[parent].children.map! do |e|
					e == hash ? child : e
				end.uniq!
				@revs[child].parents.map! do |e|
					e == hash ? parent : e
				end.uniq!
				@revs.delete(hash)
				contracted = true
			end
		end
		contracted
	end

	def contract_uninteresting
		while (contract_linear)
		end
	end
end

# do a breadth-first search from every ref to build a revision graph
revs = Revs.new
refs.each do |hash,_|
	output_alive
	next if revs.exists?(hash)
	queue = [hash]
	while not queue.empty?
		hash = queue.shift
		parents = `git show --pretty=raw #{hash}`.lines.select do |line|
			line[0,7] == 'parent '
		end.map do |line|
			line.chomp![7..-1]
		end
		parents.each do |parent|
			if not revs.exists?(parent)
				queue.push(parent)
			end
		end
		revs.set_parents(hash, parents)
	end
end

revs.contract_uninteresting
revs.get_tips.each do |hash|
	puts "== #{refs[hash].join(', ')} =="
	puts `git log --max-count=10 --pretty=format:'%h [%an, %ai] %s' #{revs.get_first_parent(hash)}..#{hash}`
	puts
end