git_blob.rb

require 'digest/sha1'
require 'zlib'

$objects = {}

class Blob

  def initialize(content)
    header = "blob #{content.length}\0"
    stored_content = header + content
    sha1 = Digest::SHA1.hexdigest(stored_content)
    @compressed_content = Zlib::Deflate.deflate(stored_content)
    @path = ".git/objects" + sha1[0..1] + "/" + sha1[2..-1]
    puts sha1
    return sha1
  end
  
  def save
    $objects[@path.to_sym] = @compressed_content
  end
  
end

content = "some text in a file"

blob = Blob.new(content)
blob.save

git_tree.rb

class Tree

end