Serve files without using FileStreamer-like object

Author: lfidnl

.rubocop_todo.yml

@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2016-01-08 12:24:37 -0600 using RuboCop version 0.35.1.
+# on 2016-03-14 21:22:57 +0300 using RuboCop version 0.35.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -11,39 +11,39 @@ Lint/NestedMethodDefinition:
   Exclude:
     - 'lib/grape/util/strict_hash_configuration.rb'
 
-# Offense count: 37
+# Offense count: 39
 Metrics/AbcSize:
-  Max: 51
+  Max: 44
 
 # Offense count: 1
 Metrics/BlockNesting:
   Max: 4
 
-# Offense count: 5
+# Offense count: 6
 # Configuration parameters: CountComments.
 Metrics/ClassLength:
   Max: 281
 
-# Offense count: 23
+# Offense count: 24
 Metrics/CyclomaticComplexity:
   Max: 14
 
-# Offense count: 759
+# Offense count: 853
 # Configuration parameters: AllowURI, URISchemes.
 Metrics/LineLength:
   Max: 215
 
-# Offense count: 45
+# Offense count: 48
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
   Max: 36
 
 # Offense count: 8
 # Configuration parameters: CountComments.
 Metrics/ModuleLength:
-  Max: 272
+  Max: 277
 
-# Offense count: 16
+# Offense count: 15
 Metrics/PerceivedComplexity:
   Max: 16
 
@@ -57,12 +57,12 @@ Style/BlockDelimiters:
     - 'spec/grape/middleware/versioner/header_spec.rb'
     - 'spec/grape/request_spec.rb'
 
-# Offense count: 105
+# Offense count: 111
 # Configuration parameters: Exclude.
 Style/Documentation:
   Enabled: false
 
-# Offense count: 7
+# Offense count: 6
 Style/DoubleNegation:
   Exclude:
     - 'lib/grape/api.rb'

CHANGELOG.md

@@ -1,6 +1,7 @@
 0.15.1 (Next)
 =============
 
+* [#1321](https://github.com/ruby-grape/grape/pull/1321): Serve files without using FileStreamer-like object - [@lfidnl](https://github.com/lfidnl).
 * Your contribution here.
 
 0.15.0 (3/8/2016)

README.md

@@ -2437,61 +2437,23 @@ end
 
 Use `body false` to return `204 No Content` without any data or content-type.
 
-You can also set the response to a file-like object with `file`.
-Note: Rack will read your entire Enumerable before returning a response. If
-you would like to stream the response, see `stream`.
+You can also set the response to a file with `file`.
 
 ```ruby
-class FileStreamer
-  def initialize(file_path)
-    @file_path = file_path
-  end
-
-  def each(&blk)
-    File.open(@file_path, 'rb') do |file|
-      file.each(10, &blk)
-    end
-  end
-end
-
 class API < Grape::API
   get '/' do
-    file FileStreamer.new('file.bin')
+    file '/path/to/file'
   end
 end
 ```
 
-If you want a file-like object to be streamed using Rack::Chunked, use `stream`.
+If you want a file to be streamed using Rack::Chunked, use `stream`.
 
 ```ruby
 class API < Grape::API
   get '/' do
-    stream FileStreamer.new('file.bin')
-  end
-end
-```
-
-If you want to take advantage of `Rack::Sendfile`, which intercepts responses whose body is
-being served from a file and replaces it with a server specific X-Sendfile header, specify `to_path`
-method in your file streamer class which returns path of served file:
-
-```ruby
-class FileStreamer
-  # ...
-
-  def to_path
-    @file_path
+    stream '/path/to/file'
   end
-
-  # ...
-end
-```
-
-Note: don't forget turn on `Rack::Sendfile` middleware in your API:
-
-```ruby
-class API < Grape::API
-  use Rack::Sendfile
 end
 ```
 

lib/grape.rb

@@ -131,8 +131,6 @@ module Util
     autoload :StackableValues
     autoload :InheritableSetting
     autoload :StrictHashConfiguration
-    autoload :FileResponse
-    autoload :SendfileResponse
   end
 
   module DSL
@@ -163,6 +161,13 @@ module Presenters
     extend ActiveSupport::Autoload
     autoload :Presenter
   end
+
+  module ServeFile
+    extend ActiveSupport::Autoload
+    autoload :FileResponse
+    autoload :FileBody
+    autoload :SendfileResponse
+  end
 end
 
 require 'grape/util/content_types'

lib/grape/dsl/inside_route.rb

@@ -191,8 +191,12 @@ def body(value = nil)
       #
       #   GET /file # => "contents of file"
       def file(value = nil)
-        if value
-          @file = Grape::Util::FileResponse.new(value)
+        if value.is_a?(String)
+          file_body = Grape::ServeFile::FileBody.new(value)
+          @file = Grape::ServeFile::FileResponse.new(file_body)
+        elsif !value.is_a?(NilClass)
+          warn '[DEPRECATION] Argument as FileStreamer-like object will be deprecated. Use path to file instead'
+          @file = Grape::ServeFile::FileResponse.new(value)
         else
           @file
         end

lib/grape/middleware/formatter.rb

@@ -34,8 +34,8 @@ def after
       def build_formatted_response(status, headers, bodies)
         headers = ensure_content_type(headers)
 
-        if bodies.is_a?(Grape::Util::FileResponse)
-          Grape::Util::SendfileResponse.new([], status, headers) do |resp|
+        if bodies.is_a?(Grape::ServeFile::FileResponse)
+          Grape::ServeFile::SendfileResponse.new([], status, headers) do |resp|
             resp.body = bodies.file
           end
         else

lib/grape/serve_file/file_body.rb

@@ -0,0 +1,34 @@
+module Grape
+  module ServeFile
+    CHUNK_SIZE = 16_384
+
+    # Class helps send file through API
+    class FileBody
+      attr_reader :path
+
+      # @param path [String]
+      def initialize(path)
+        @path = path
+      end
+
+      # Need for Rack::Sendfile middleware
+      #
+      # @return [String]
+      def to_path
+        path
+      end
+
+      def each
+        File.open(path, 'rb') do |file|
+          while (chunk = file.read(CHUNK_SIZE))
+            yield chunk
+          end
+        end
+      end
+
+      def ==(other)
+        path == other.path
+      end
+    end
+  end
+end

lib/grape/util/file_response.rb renamed to lib/grape/serve_file/file_response.rb

@@ -1,5 +1,5 @@
 module Grape
-  module Util
+  module ServeFile
     # A simple class used to identify responses which represent files and do not
     # need to be formatted or pre-read by Rack::Response
     class FileResponse

lib/grape/util/sendfile_response.rb renamed to lib/grape/serve_file/sendfile_response.rb

@@ -1,5 +1,5 @@
 module Grape
-  module Util
+  module ServeFile
     # Response should respond to to_path method
     # for using Rack::SendFile middleware
     class SendfileResponse < Rack::Response

spec/grape/dsl/inside_route_spec.rb

@@ -179,12 +179,37 @@ def initialize
 
       describe '#file' do
         describe 'set' do
-          before do
-            subject.file 'file'
+          context 'as file path' do
+            let(:file_path) { '/some/file/path' }
+
+            let(:file_response) do
+              file_body = Grape::ServeFile::FileBody.new(file_path)
+              Grape::ServeFile::FileResponse.new(file_body)
+            end
+
+            before do
+              subject.file file_path
+            end
+
+            it 'returns value wrapped in FileResponse' do
+              expect(subject.file).to eq file_response
+            end
           end
 
-          it 'returns value wrapped in FileResponse' do
-            expect(subject.file).to eq Grape::Util::FileResponse.new('file')
+          context 'as object (backward compatibility)' do
+            let(:file_object) { Class.new }
+
+            let(:file_response) do
+              Grape::ServeFile::FileResponse.new(file_object)
+            end
+
+            before do
+              subject.file file_object
+            end
+
+            it 'returns value wrapped in FileResponse' do
+              expect(subject.file).to eq file_response
+            end
           end
         end
 
@@ -195,19 +220,21 @@ def initialize
 
       describe '#stream' do
         describe 'set' do
+          let(:file_object) { Class.new }
+
           before do
             subject.header 'Cache-Control', 'cache'
             subject.header 'Content-Length', 123
             subject.header 'Transfer-Encoding', 'base64'
-            subject.stream 'file'
+            subject.stream file_object
           end
 
           it 'returns value wrapped in FileResponse' do
-            expect(subject.stream).to eq Grape::Util::FileResponse.new('file')
+            expect(subject.stream).to eq Grape::ServeFile::FileResponse.new(file_object)
           end
 
           it 'also sets result of file to value wrapped in FileResponse' do
-            expect(subject.file).to eq Grape::Util::FileResponse.new('file')
+            expect(subject.file).to eq Grape::ServeFile::FileResponse.new(file_object)
           end
 
           it 'sets Cache-Control header to no-cache' do

spec/grape/middleware/formatter_spec.rb

@@ -287,9 +287,9 @@ def to_xml
     let(:app) { ->(_env) { [200, {}, @body] } }
 
     it 'returns Grape::Uril::SendFileReponse' do
-      @body = Grape::Util::FileResponse.new('file')
+      @body = Grape::ServeFile::FileResponse.new('file')
       env = { 'PATH_INFO' => '/somewhere', 'HTTP_ACCEPT' => 'application/json' }
-      expect(subject.call(env)).to be_a(Grape::Util::SendfileResponse)
+      expect(subject.call(env)).to be_a(Grape::ServeFile::SendfileResponse)
     end
   end
 end