Vagrant::DataStore which will be used soon for the dotfile in the project directory

lib/vagrant.rb

@@ -8,9 +8,10 @@ module Vagrant
   # TODO: Move more classes over to the autoload model. We'll
   # start small, but slowly move everything over.
 
-  autoload :CLI,    'vagrant/cli'
-  autoload :Config, 'vagrant/config'
-  autoload :Errors, 'vagrant/errors'
+  autoload :CLI,       'vagrant/cli'
+  autoload :Config,    'vagrant/config'
+  autoload :DataStore, 'vagrant/data_store'
+  autoload :Errors,    'vagrant/errors'
 
   module Command
     autoload :Base,      'vagrant/command/base'

lib/vagrant/config/base.rb

@@ -18,11 +18,18 @@ module Vagrant
         end
       end
 
+      # Converts the configuration to a raw hash.
+      def to_hash
+        instance_variables_hash.inject({}) do |acc, data|
+          k,v = data
+          v = v.to_hash if v.respond_to?(:to_hash)
+          acc[k] = v
+          acc
+        end
+      end
+
       def to_json(*a)
-        opts = a.first if a.first.is_a?(Hash)
-        opts ||= {}
-        result = {}
-        result.merge!('json_class' => self.class.name) if opts[:loadable]
+        result = { 'json_class' => self.class.name }
         result.merge(instance_variables_hash).to_json(*a)
       end
 

lib/vagrant/data_store.rb

@@ -0,0 +1,38 @@
+module Vagrant
+  # The Vagrant data store is a key-value store which is persisted
+  # as JSON in a local file which is specified in the initializer.
+  # The data store itself is accessed via typical hash accessors: `[]`
+  # and `[]=`. If a key is set to `nil`, then it is removed from the
+  # datastore. The data store is only updated on disk when {commit}
+  # is called on the data store itself.
+  class DataStore
+    attr_reader :file_path
+
+    def initialize(file_path)
+      @file_path = file_path
+
+      File.open(file_path, "r") do |f|
+        @data = JSON.parse(f.read)
+      end
+    end
+
+    # Returns the value associated with the `key` in the data
+    # store.
+    def [](key)
+      @data[key]
+    end
+
+    # Sets the value in the data store.
+    def []=(key, value)
+      @data[key] = value
+    end
+
+    # Commits any changes to the data to disk. Even if the data
+    # hasn't changed, it will be reserialized and written to disk.
+    def commit
+      File.open(file_path, "w") do |f|
+        f.write(@data.to_json)
+      end
+    end
+  end
+end

lib/vagrant/provisioners/chef.rb

@@ -36,7 +36,7 @@ module Vagrant
 
         # Set up initial configuration
         data = {
-          :config => env.config,
+          :config => env.config.to_hash,
           :directory => env.config.vm.shared_folders["v-root"][:guestpath],
         }
 

test/vagrant/config/base_test.rb

@@ -21,17 +21,11 @@ class ConfigBaseTest < Test::Unit::TestCase
   end
 
   context "converting to JSON" do
-    should "include magic `json_class` if loadable is set to true" do
+    should "include magic `json_class`" do
       @iv_hash = { "foo" => "bar" }
       @base.expects(:instance_variables_hash).returns(@iv_hash)
       @json = { 'json_class' => @base.class.name }.merge(@iv_hash).to_json
-      assert_equal @json, @base.to_json(:loadable => true)
-    end
-
-    should "convert instance variable hash to json" do
-      @iv_hash = { "foo" => "bar" }
-      @base.expects(:instance_variables_hash).returns(@iv_hash)
-      assert_equal @iv_hash.to_json, @base.to_json
+      assert_equal @json, @base.to_json
     end
 
     should "not include env in the JSON hash" do

test/vagrant/data_store_test.rb

@@ -0,0 +1,33 @@
+require "test_helper"
+
+class DataStoreTest < Test::Unit::TestCase
+  setup do
+    @klass = Vagrant::DataStore
+    @initial_data = { "foo" => "bar" }
+    @db_file = File.expand_path("test/tmp/data_store_test", Vagrant.source_root)
+    File.open(@db_file, "w") { |f| f.write(@initial_data.to_json) }
+
+    @instance = @klass.new(@db_file)
+  end
+
+  teardown do
+    File.delete(@db_file)
+  end
+
+  should "read the data" do
+    assert_equal @initial_data["foo"], @instance["foo"]
+  end
+
+  should "write the data, but not save it right away" do
+    @instance["foo"] = "changed"
+    assert_equal "changed", @instance["foo"]
+    assert_equal @initial_data["foo"], @klass.new(@db_file)["foo"]
+  end
+
+  should "write the data if commit is called" do
+    @instance["foo"] = "changed"
+    @instance.commit
+
+    assert_equal "changed", @klass.new(@db_file)["foo"]
+  end
+end

test/vagrant/provisioners/chef_test.rb

@@ -141,7 +141,7 @@ class ChefProvisionerTest < Test::Unit::TestCase
   context "generating and uploading json" do
     def assert_json
       @vm.ssh.expects(:upload!).with do |json, path|
-        data = JSON.parse(json.read, :object_class => Hash)
+        data = JSON.parse(json.read)
         yield data
         true
       end