Add `:use_accelerate_endpoint` option when using S3

[Amazon S3 Transfer
Acceleration](http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html)
enables fast, easy, and secure transfers of files over long distances
between your client and an S3 bucket. And
[aws-sdk](https://github.com/aws/aws-sdk-ruby) has allowed us to enable
this feature in version 2.3.0 (more detail is
[here](https://github.com/aws/aws-sdk-ruby/pull/1163)).

You can now pass a configuration option (:use_accelerate_endpoint) when
config Paperclip with S3. You can enable the [Amazon S3 Transfer
Acceleration](http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html)
by set this option:
```:use_accelerate_endpoint => true```

[fixes #2291]

NEWS

 master:
 master:
 
 
+* Improvement: Added `:use_accelerate_endpoint` option when using S3 to enable
+  [Amazon S3 Transfer Acceleration](http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html)
 * Improvement: make the fingerprint digest configurable per attachment. The
 * Improvement: make the fingerprint digest configurable per attachment. The
   default remains MD5 but this will change in a future version because it is
   default remains MD5 but this will change in a future version because it is
   not considered secure anymore against intentional file corruption. For more
   not considered secure anymore against intentional file corruption. For more

lib/paperclip/storage/s3.rb

@@ -102,6 +102,8 @@ module Paperclip
     #   Redundancy Storage. RRS enables customers to reduce their
     #   Redundancy Storage. RRS enables customers to reduce their
     #   costs by storing non-critical, reproducible data at lower
     #   costs by storing non-critical, reproducible data at lower
     #   levels of redundancy than Amazon S3's standard storage.
     #   levels of redundancy than Amazon S3's standard storage.
+    # * +use_accelerate_endpoint+: Use accelerate endpoint
+    #   http://docs.aws.amazon.com/AmazonS3/latest/dev/transfer-acceleration.html
     #
     #
     #   You can set storage class on a per style bases by doing the following:
     #   You can set storage class on a per style bases by doing the following:
     #     :s3_storage_class => {
     #     :s3_storage_class => {
@@ -152,6 +154,13 @@ module Paperclip
           @options[:url] = @options[:url].inspect if @options[:url].is_a?(Symbol)
           @options[:url] = @options[:url].inspect if @options[:url].is_a?(Symbol)
 
 
           @http_proxy = @options[:http_proxy] || nil
           @http_proxy = @options[:http_proxy] || nil
+
+          if @options.has_key?(:use_accelerate_endpoint) &&
+              Gem::Version.new(Aws::VERSION) < Gem::Version.new("2.3.0")
+            raise LoadError, ":use_accelerate_endpoint is only available from aws-sdk version 2.3.0. Please upgrade aws-sdk to a newer version."
+          end
+
+          @use_accelerate_endpoint = @options[:use_accelerate_endpoint]
         end
         end
 
 
         Paperclip.interpolates(:s3_alias_url) do |attachment, style|
         Paperclip.interpolates(:s3_alias_url) do |attachment, style|
@@ -232,6 +241,8 @@ module Paperclip
             config[:proxy_uri] = URI::HTTP.build(proxy_opts)
             config[:proxy_uri] = URI::HTTP.build(proxy_opts)
           end
           end
 
 
+          config[:use_accelerate_endpoint] = use_accelerate_endpoint?
+
           [:access_key_id, :secret_access_key, :credential_provider, :credentials].each do |opt|
           [:access_key_id, :secret_access_key, :credential_provider, :credentials].each do |opt|
             config[opt] = s3_credentials[opt] if s3_credentials[opt]
             config[opt] = s3_credentials[opt] if s3_credentials[opt]
           end
           end
@@ -257,6 +268,10 @@ module Paperclip
         s3_bucket.object style_name_as_path(style_name)
         s3_bucket.object style_name_as_path(style_name)
       end
       end
 
 
+      def use_accelerate_endpoint?
+        !!@use_accelerate_endpoint
+      end
+
       def using_http_proxy?
       def using_http_proxy?
         !!@http_proxy
         !!@http_proxy
       end
       end

spec/paperclip/storage/s3_spec.rb

@@ -282,6 +282,59 @@ describe Paperclip::Storage::S3 do
     end
     end
   end
   end
 
 
+  context "use_accelerate_endpoint", if: aws_accelerate_available? do
+    context "defaults to false" do
+      before do
+        rebuild_model(
+          storage: :s3,
+          s3_credentials: {},
+          bucket: "bucket",
+          path: ":attachment/:basename:dotextension",
+          s3_host_name: "s3-ap-northeast-1.amazonaws.com",
+          s3_region: "ap-northeast-1",
+        )
+        @dummy = Dummy.new
+        @dummy.avatar = stringy_file
+        @dummy.stubs(:new_record?).returns(false)
+      end
+
+      it "returns a url based on an :s3_host_name path" do
+        assert_match %r{^//s3-ap-northeast-1.amazonaws.com/bucket/avatars/data[^\.]},
+          @dummy.avatar.url
+      end
+
+      it "uses the S3 client with the use_accelerate_endpoint config is false" do
+        expect(@dummy.avatar.s3_bucket.client.config.use_accelerate_endpoint).to be(false)
+      end
+    end
+
+    context "set to true", if: aws_accelerate_available? do
+      before do
+        rebuild_model(
+          storage: :s3,
+          s3_credentials: {},
+          bucket: "bucket",
+          path: ":attachment/:basename:dotextension",
+          s3_host_name: "s3-accelerate.amazonaws.com",
+          s3_region: "ap-northeast-1",
+          use_accelerate_endpoint: true,
+        )
+        @dummy = Dummy.new
+        @dummy.avatar = stringy_file
+        @dummy.stubs(:new_record?).returns(false)
+      end
+
+      it "returns a url based on an :s3_host_name path" do
+        assert_match %r{^//s3-accelerate.amazonaws.com/bucket/avatars/data[^\.]},
+          @dummy.avatar.url
+      end
+
+      it "uses the S3 client with the use_accelerate_endpoint config is true" do
+        expect(@dummy.avatar.s3_bucket.client.config.use_accelerate_endpoint).to be(true)
+      end
+    end
+  end
+
   context "An attachment that uses S3 for storage and has styles that return different file types" do
   context "An attachment that uses S3 for storage and has styles that return different file types" do
     before do
     before do
       rebuild_model (aws2_add_region).merge storage: :s3,
       rebuild_model (aws2_add_region).merge storage: :s3,

spec/spec_helper.rb

@@ -38,6 +38,7 @@ RSpec.configure do |config|
   config.include TestData
   config.include TestData
   config.include Reporting
   config.include Reporting
   config.extend VersionHelper
   config.extend VersionHelper
+  config.extend ConditionalFilterHelper
   config.mock_framework = :mocha
   config.mock_framework = :mocha
   config.before(:all) do
   config.before(:all) do
     rebuild_model
     rebuild_model

spec/support/conditional_filter_helper.rb

+module ConditionalFilterHelper
+  def aws_accelerate_available?
+    (Gem::Version.new(Aws::VERSION) >= Gem::Version.new("2.3.0"))
+  end
+end