Add cache connection to train

Signed-off-by: Jared Quick <jquick@chef.io>

lib/train/plugins/base_connection.rb

@@ -15,17 +15,13 @@ class Train::Plugins::Transport
   class BaseConnection
     include Train::Extras
 
-    # Provide access to the files cache.
-    attr_reader :files
-
     # Create a new Connection instance.
     #
     # @param options [Hash] connection options
     # @yield [self] yields itself for block-style invocation
     def initialize(options = nil)
       @options = options || {}
       @logger = @options.delete(:logger) || Logger.new(STDOUT)
-      @files = {}
       Train::Platforms::Detect::Specifications::OS.load
     end
 

lib/train/plugins/cache_connection.rb

@@ -0,0 +1,38 @@
+# encoding: utf-8
+
+class Train::Plugins::Transport
+  class CacheConnection < BaseConnection
+    # Create a new CacheConnection instance. This instance will cache
+    # file and command operations on the underline connection.
+    #
+    # @param connection [Connection] connection object
+    def initialize(connection)
+      @connection = connection
+      @file_cache = {}
+      @cmd_cache = {}
+
+      @connection.class.instance_methods(false).each do |m|
+        next if %i(run_command file).include?(m)
+        define_singleton_method m do |*args|
+          @connection.send(m, *args)
+        end
+      end
+    end
+
+    def file(path)
+      if @file_cache.key?(path)
+        @file_cache[path]
+      else
+        @file_cache[path] = @connection.file(path)
+      end
+    end
+
+    def run_command(cmd)
+      if @cmd_cache.key?(cmd)
+        @cmd_cache[cmd]
+      else
+        @cmd_cache[cmd] = @connection.run_command(cmd)
+      end
+    end
+  end
+end

lib/train/plugins/transport.rb

@@ -1,7 +1,4 @@
 # encoding: utf-8
-#
-# Author:: Dominik Richter (<dominik.richter@gmail.com>)
-# Author:: Christoph Hartmann (<chris@lollyrock.com>)
 
 require 'logger'
 require 'train/errors'
@@ -14,6 +11,7 @@ class Transport
     Train::Options.attach(self)
 
     require 'train/plugins/base_connection'
+    require 'train/plugins/cache_connection'
 
     # Initialize a new Transport object
     #
@@ -41,6 +39,13 @@ def self.name(name)
       Train::Plugins.registry[name] = self
     end
 
+    # Create a cache connection to the target.
+    #
+    # @return [CacheConnection]
+    def cache_connection
+      CacheConnection.new(connection)
+    end
+
     private
 
     # @return [Logger] logger for reporting information

lib/train/transports/docker.rb

@@ -70,14 +70,13 @@ def close
     end
 
     def file(path)
-      @files[path] ||=\
-        if os.aix?
-          Train::File::Remote::Aix.new(self, path)
-        elsif os.solaris?
-          Train::File::Remote::Unix.new(self, path)
-        else
-          Train::File::Remote::Linux.new(self, path)
-        end
+      if os.aix?
+        Train::File::Remote::Aix.new(self, path)
+      elsif os.solaris?
+        Train::File::Remote::Unix.new(self, path)
+      else
+        Train::File::Remote::Linux.new(self, path)
+      end
     end
 
     def run_command(cmd)

lib/train/transports/local.rb

@@ -37,12 +37,11 @@ def local?
       end
 
       def file(path)
-        @files[path] ||= \
-          if os.windows?
-            Train::File::Local::Windows.new(self, path)
-          else
-            Train::File::Local::Unix.new(self, path)
-          end
+        if os.windows?
+          Train::File::Local::Windows.new(self, path)
+        else
+          Train::File::Local::Unix.new(self, path)
+        end
       end
 
       def login_command

lib/train/transports/mock.rb

@@ -64,6 +64,7 @@ def initialize(conf = nil)
       super(conf)
       mock_os
       @commands = {}
+      @files = {}
     end
 
     def uri

lib/train/transports/ssh_connection.rb

@@ -56,16 +56,15 @@ def close
     end
 
     def file(path)
-      @files[path] ||= \
-        if os.aix?
-          Train::File::Remote::Aix.new(self, path)
-        elsif os.solaris?
-          Train::File::Remote::Unix.new(self, path)
-        elsif os[:name] == 'qnx'
-          Train::File::Remote::Qnx.new(self, path)
-        else
-          Train::File::Remote::Linux.new(self, path)
-        end
+      if os.aix?
+        Train::File::Remote::Aix.new(self, path)
+      elsif os.solaris?
+        Train::File::Remote::Unix.new(self, path)
+      elsif os[:name] == 'qnx'
+        Train::File::Remote::Qnx.new(self, path)
+      else
+        Train::File::Remote::Linux.new(self, path)
+      end
     end
 
     # (see Base::Connection#run_command)

lib/train/transports/winrm_connection.rb

@@ -47,7 +47,7 @@ def close
     end
 
     def file(path)
-      @files[path] ||= Train::File::Remote::Windows.new(self, path)
+      Train::File::Remote::Windows.new(self, path)
     end
 
     def run_command(command)

test/unit/plugins/cache_connection_test.rb

@@ -0,0 +1,46 @@
+# encoding: utf-8
+require 'helper'
+
+describe 'train cache connection' do
+  let(:cls) { Train::Plugins::Transport::BaseConnection }
+  let(:connection) { cls.new({}) }
+  let(:cache_connection) { Train::Plugins::Transport::CacheConnection.new(connection) }
+
+  describe 'create cache connection' do
+    it 'return new cache connection' do
+      cache_connection.must_be_kind_of Train::Plugins::Transport::CacheConnection
+      cache_connection.respond_to?(:run_command).must_equal true
+    end
+  end
+
+  describe 'check instance method fallback' do
+    it 'check os method' do
+      cache_connection.respond_to?(:os).must_equal true
+      cache_connection.respond_to?(:platform).must_equal true
+    end
+
+    it 'check close method' do
+      cache_connection.respond_to?(:close).must_equal true
+    end
+  end
+
+  describe 'load file' do
+    it 'load file with caching' do
+      connection.expects(:file).once.returns('test_file')
+      cache_connection.file('/tmp/test').must_equal('test_file')
+      cache_connection.file('/tmp/test').must_equal('test_file')
+      assert = { '/tmp/test' => 'test_file' }
+      cache_connection.instance_variable_get(:@file_cache).must_equal(assert)
+    end
+  end
+
+  describe 'run command' do
+    it 'run command with caching' do
+      connection.expects(:run_command).once.returns('test_user')
+      cache_connection.run_command('whoami').must_equal('test_user')
+      cache_connection.run_command('whoami').must_equal('test_user')
+      assert = { 'whoami' => 'test_user' }
+      cache_connection.instance_variable_get(:@cmd_cache).must_equal(assert)
+    end
+  end
+end