Add Rack 3.0 support

.github/workflows/test.yml

@@ -6,8 +6,14 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-latest ]
-        # Due to https://github.com/actions/runner/issues/849, we have to use quotes for '3.0'
-        ruby: ['2.7', '3.0', '3.1', '3.2', head, truffleruby, truffleruby-head]
+        ruby: [
+          3.1,
+          3.2,
+          3.3,
+          head,
+          truffleruby,
+          truffleruby-head
+        ]
         gemfile: [ rack2, rack3 ]
     runs-on: ${{ matrix.os }}
     env: # $BUNDLE_GEMFILE must be set at the job level, so it is set for all steps

.ruby-version

@@ -1 +1 @@
-3.2.0
+3.1.2

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 2.0.0
+## Changed
+- Minimum supported version of Rack is 3.0.
+
 ## 1.1.0
 ## Changed
 - Removed dependency on `git-version-bump` gem for versioning. `rack-brotli` now only depends on `rack` and `brotli`.

Gemfile

@@ -1,3 +1,10 @@
 source 'https://rubygems.org'
 
 gemspec
+
+gem 'rack', '~> 3'
+
+gem 'bundler'
+gem 'minitest', '~> 5.6'
+gem 'rake', '~> 12', '>= 12.3.3'
+gem 'rdoc', '~> 3.12'

lib/rack/brotli/deflater.rb

@@ -1,17 +1,13 @@
-require "brotli"
-require 'rack/utils'
+# frozen_string_literal: true
+
+require 'brotli'
+require "rack/utils"
+require 'rack/request'
+require 'rack/body_proxy'
 
 module Rack::Brotli
-  # This middleware enables compression of http responses.
-  #
-  # Currently supported compression algorithms:
-  #
-  #   * br
-  #
-  # The middleware automatically detects when compression is supported
-  # and allowed. For example no transformation is made when a cache
-  # directive of 'no-transform' is present, or when the response status
-  # code is one that doesn't allow an entity body.
+  # This middleware enables compression of http responses with the `br` encoding,
+  # when support is detected and allowed.
   class Deflater
     ##
     # Creates Rack::Brotli middleware.
@@ -21,80 +17,107 @@ class Deflater
     #           'if' - a lambda enabling / disabling deflation based on returned boolean value
     #                  e.g use Rack::Brotli, :if => lambda { |env, status, headers, body| body.map(&:bytesize).reduce(0, :+) > 512 }
     #           'include' - a list of content types that should be compressed
-    #           'deflater' - Brotli compression options
+    #           'deflater' - Brotli compression options Hash (see https://brotli.org/encode.html#a4d4 and https://github.com/miyucy/brotli/blob/ea0e058031177e5cc42e361f7d2702a951048a31/ext/brotli/brotli.c#L119-L180)
+    #              - 'mode'
+    #              - 'quality'
+    #              - 'lgwin'
+    #              - 'lgblock'
     def initialize(app, options = {})
       @app = app
 
       @condition = options[:if]
       @compressible_types = options[:include]
-      @deflater_options = { quality: 5 }.merge(options[:deflater] || {})
+      @deflater_options = { quality: 5 }.merge(options.fetch(:deflater, {}))
+      @sync = options.fetch(:sync, true)
     end
 
     def call(env)
-      status, headers, body = @app.call(env)
-      headers = Rack::Utils::HeaderHash.new(headers)
+      status, headers, body = response = @app.call(env)
 
       unless should_deflate?(env, status, headers, body)
-        return [status, headers, body]
+        return response
       end
 
       request = Rack::Request.new(env)
 
-      encoding = Rack::Utils.select_best_encoding(%w(br),
-                                            request.accept_encoding)
-
-      return [status, headers, body] unless encoding
+      encoding = Rack::Utils.select_best_encoding(%w(br identity), request.accept_encoding)
 
       # Set the Vary HTTP header.
-      vary = headers["Vary"].to_s.split(",").map(&:strip)
-      unless vary.include?("*") || vary.include?("Accept-Encoding")
-        headers["Vary"] = vary.push("Accept-Encoding").join(",")
+      vary = headers["vary"].to_s.split(",").map(&:strip)
+      unless vary.include?("*") || vary.any?{|v| v.downcase == 'accept-encoding'}
+        headers["vary"] = vary.push("Accept-Encoding").join(",")
       end
 
       case encoding
       when "br"
-        headers['Content-Encoding'] = "br"
+        headers['content-encoding'] = "br"
         headers.delete(Rack::CONTENT_LENGTH)
-        [status, headers, BrotliStream.new(body, @deflater_options)]
-      when nil
+        response[2] = BrotliStream.new(body, @sync, @deflater_options)
+        response
+      when "identity"
+        response
+      else
+        # Only possible encoding values here are 'br', 'identity', and nil
         message = "An acceptable encoding for the requested resource #{request.fullpath} could not be found."
         bp = Rack::BodyProxy.new([message]) { body.close if body.respond_to?(:close) }
-        [406, {Rack::CONTENT_TYPE => "text/plain", Rack::CONTENT_LENGTH => message.length.to_s}, bp]
+        [406, { Rack::CONTENT_TYPE => "text/plain", Rack::CONTENT_LENGTH => message.length.to_s }, bp]
       end
     end
 
+    # Body class used for encoded responses.
     class BrotliStream
-      include Rack::Utils
 
-      def initialize(body, options)
+      BUFFER_LENGTH = 128 * 1_024
+
+      def initialize(body, sync, br_options)
         @body = body
-        @options = options
+        @br_options = br_options
+        @sync = sync
       end
 
+      # Yield compressed strings to the given block.
       def each(&block)
         @writer = block
-        buffer = ''
-        @body.each { |part|
-          buffer << part
-        }
-        yield ::Brotli.deflate(buffer, @options)
+        br = Brotli::Writer.new(self, @br_options)
+        # @body.each is equivalent to @body.gets (slow)
+        if @body.is_a? ::File # XXX: Should probably be ::IO
+          while part = @body.read(BUFFER_LENGTH)
+            br.write(part)
+            br.flush if @sync
+          end
+        else
+          @body.each { |part|
+            # Skip empty strings, as they would result in no output,
+            # and flushing empty parts could raise an IO error.
+            next if part.empty?
+            br.write(part)
+            br.flush if @sync
+          }
+        end
       ensure
-        @writer = nil
+        br.finish
       end
 
+      # Call the block passed to #each with the compressed data.
+      def write(data)
+        @writer.call(data)
+      end
+
+      # Close the original body if possible.
       def close
         @body.close if @body.respond_to?(:close)
       end
     end
-    
+
     private
 
+    # Whether the body should be compressed.
     def should_deflate?(env, status, headers, body)
       # Skip compressing empty entity body responses and responses with
       # no-transform set.
-      if Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.include?(status) ||
-          headers[Rack::CACHE_CONTROL].to_s =~ /\bno-transform\b/ ||
-         (headers['Content-Encoding'] && headers['Content-Encoding'] !~ /\bidentity\b/)
+      if Rack::Utils::STATUS_WITH_NO_ENTITY_BODY.key?(status.to_i) ||
+        /\bno-transform\b/.match?(headers[Rack::CACHE_CONTROL].to_s) ||
+        headers['content-encoding']&.!~(/\bidentity\b/)
         return false
       end
 
@@ -104,6 +127,10 @@ def should_deflate?(env, status, headers, body)
       # Skip if @condition lambda is given and evaluates to false
       return false if @condition && !@condition.call(env, status, headers, body)
 
+      # No point in compressing empty body, also handles usage with
+      # Rack::Sendfile.
+      return false if headers[Rack::CONTENT_LENGTH] == '0'
+
       true
     end
   end

lib/rack/brotli/version.rb

@@ -2,7 +2,7 @@ module Rack
   module Brotli
     class Version
       def self.to_s
-        '1.1.0'
+        '2.0.0'
       end
     end
   end

rack-brotli.gemspec

@@ -26,13 +26,8 @@ Gem::Specification.new do |s|
 
   s.extra_rdoc_files = %w[README.md COPYING]
 
-  s.add_runtime_dependency 'rack', '>= 1.4', '< 3'
-  s.add_runtime_dependency 'brotli', '>= 0.1.7'
-
-  s.add_development_dependency 'bundler'
-  s.add_development_dependency 'minitest', '~> 5.6'
-  s.add_development_dependency 'rake', '~> 12', '>= 12.3.3'
-  s.add_development_dependency 'rdoc', '~> 3.12'
+  s.add_runtime_dependency 'rack', '>= 3'
+  s.add_runtime_dependency 'brotli', '>= 0.3'
 
   s.homepage = "http://github.com/marcotc/rack-brotli/"
   s.rdoc_options = ["--line-numbers", "--inline-source", "--title", "rack-brotli", "--main", "README"]