a simple kvs using git (rugged)

grip.rb

require 'rugged'
require 'cgi'

class Grip
  def initialize(dir)
    @dir = dir
    @git = Rugged::Repository.new(@dir) rescue git_init
    @author = {email: 'seki@ruby-lang.org', name: 'seki'}
    @message = 'via grip'
  end
  attr_reader :git

  def git_init
    Rugged::Repository.init_at(@dir)
  end

  def to_path(key)
    CGI.escape(key)
  end

  def to_key(path)
    CGI.unescape(path)
  end

  def store(key, value, mtime=Time.now)
    oid = @git.write(value, :blob)
    index = @git.index
    tree = @git.head.target.tree rescue []
    index.read_tree(tree) rescue nil
    path = to_path(key)
    index.add(path: path, oid: oid, mode: 0100644)
    author = {time: mtime}.update(@author)
    parents = @git.empty? ? [] : [@git.head.target].compact
    Rugged::Commit.create(
      @git,
      tree: index.write_tree(@git),
      author: author,
      committer: author,
      parents: parents,
      update_ref: 'HEAD',
      message: "via grip"
    )
    oid
  end

  def []=(key, value)
    store(key, value, Time.now)
  end

  def [](key)
    fetch(key)&.force_encoding("UTF-8")
  end

  def fetch(key)
    path = to_path(key)
    sha = @git.head.target.tree.get_entry(path)&.dig(:oid)
    return nil unless sha
    @git.lookup(sha).content
  end

  def keys
    each_key.to_a
  end

  def each_key
    return to_enum(:each_key) unless block_given?
    @git.head.target.tree.each {|e| yield(to_key(e[:name]))}
  end

  def each
    return to_enum(:each) unless block_given?
    @git.head.target.tree.each {|e|
      yield(to_key(e[:name]), 
            @git.lookup(e[:oid]).content.force_encoding("UTF-8"))
    }
  end

  def history
    w = Rugged::Walker.new(@git)
    w.push(@git.head.target.oid)
    w.each do |commit|
      yield(commit)
    end
    w.reset
    nil
  end
end

if __FILE__ == $0
  g = Grip.new('tmp/grip')
  name = "NS1-5000"
  s = Time.now
  30000.times do |x|
    if x % 100 == 0
      p [x, Time.now - s]
      s = Time.now
    end
    name = name.succ
    g[name] = <<EOS
= #{name}

empty item

== status

* 種類: task / story / bug
* イテレーション: 
* サイン: ((<rwiki>))
* 状態: open
* 見積: 0 / 0
* テスト分類: 
* テストレート: 

== description

== test

* Q: test..
* A: answer..

== history

* #{Time.now.strftime("%Y-%m-%d")} rwiki: open    
EOS
  end
end