Unify work with headers across request/response

Rakefile

@@ -22,7 +22,7 @@ end
 
 require 'yardstick/rake/verify'
 Yardstick::Rake::Verify.new do |verify|
-  verify.threshold = 56.8
+  verify.threshold = 56.7
 end
 
 task :default => [:spec, :rubocop, :verify_measurements]

lib/http/headers.rb

@@ -0,0 +1,55 @@
+require 'forwardable'
+require 'delegate'
+
+module HTTP
+  # Headers Hash wraper with keys normalization
+  class Headers < ::Delegator
+    module Mixin
+      extend Forwardable
+      attr_reader :headers
+      def_delegators :headers, :[], :[]=
+    end
+
+    # Matches HTTP header names when in "Canonical-Http-Format"
+    CANONICAL_HEADER = /^[A-Z][a-z]*(-[A-Z][a-z]*)*$/
+
+    def initialize(obj = {})
+      super({})
+      __setobj__ obj
+    end
+
+    # Transform to canonical HTTP header capitalization
+    def canonicalize_header(header)
+      header.to_s.split(/[\-_]/).map(&:capitalize).join('-')
+    end
+
+    # Obtain the given header
+    def [](name)
+      super(name) || super(canonicalize_header name)
+    end
+
+    # Set a header
+    def []=(name, value)
+      # If we have a canonical header, we're done, canonicalize otherwise
+      name = name.to_s[CANONICAL_HEADER] || canonicalize_header(name)
+
+      # Check if the header has already been set and group
+      value = Array(self[name]) + Array(value) if key? name
+
+      super name, value
+    end
+
+  protected
+
+    # :nodoc:
+    def __getobj__
+      @headers
+    end
+
+    # :nodoc:
+    def __setobj__(obj)
+      @headers = {}
+      obj.each { |k, v| self[k] = v } if obj.respond_to? :each
+    end
+  end
+end

lib/http/request.rb

@@ -1,11 +1,11 @@
-require 'http/header'
+require 'http/headers'
 require 'http/request/writer'
 require 'uri'
 require 'base64'
 
 module HTTP
   class Request
-    include HTTP::Header
+    include HTTP::Headers::Mixin
 
     # The method given was not understood
     class UnsupportedMethodError < RequestError; end
@@ -57,7 +57,7 @@ def method(*args)
     # "Request URI" as per RFC 2616
     # http://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html
     attr_reader :uri
-    attr_reader :headers, :proxy, :body, :version
+    attr_reader :proxy, :body, :version
 
     # :nodoc:
     def initialize(verb, uri, headers = {}, proxy = {}, body = nil, version = '1.1') # rubocop:disable ParameterLists
@@ -68,16 +68,10 @@ def initialize(verb, uri, headers = {}, proxy = {}, body = nil, version = '1.1')
       fail(UnsupportedMethodError, "unknown method: #{verb}") unless METHODS.include?(verb)
       fail(UnsupportedSchemeError, "unknown scheme: #{scheme}") unless SCHEMES.include?(scheme)
 
-      @headers = {}
-      headers.each do |name, value|
-        name = name.to_s
-        key = name[CANONICAL_HEADER]
-        key ||= canonicalize_header(name)
-        @headers[key] = value
-      end
-      @headers['Host'] ||= @uri.host
-
       @proxy, @body, @version = proxy, body, version
+
+      @headers = HTTP::Headers.new(headers)
+      @headers['Host'] ||= @uri.host
     end
 
     # Returns new Request with updated uri
@@ -88,15 +82,10 @@ def redirect(uri)
       req
     end
 
-    # Obtain the given header
-    def [](header)
-      @headers[canonicalize_header(header)]
-    end
-
     # Stream the request to a socket
     def stream(socket)
       include_proxy_authorization_header if using_authenticated_proxy?
-      Request::Writer.new(socket, body, @headers, request_header).stream
+      Request::Writer.new(socket, body, headers, request_header).stream
     end
 
     # Is this request using a proxy?
@@ -112,7 +101,7 @@ def using_authenticated_proxy?
     # Compute and add the Proxy-Authorization header
     def include_proxy_authorization_header
       digest = Base64.encode64("#{proxy[:proxy_username]}:#{proxy[:proxy_password]}").chomp
-      @headers['Proxy-Authorization'] = "Basic #{digest}"
+      headers['Proxy-Authorization'] = "Basic #{digest}"
     end
 
     # Compute HTTP request header for direct or proxy request

lib/http/response.rb

@@ -1,10 +1,10 @@
 require 'delegate'
-require 'http/header'
+require 'http/headers'
 require 'http/content_type'
 
 module HTTP
   class Response
-    include HTTP::Header
+    include HTTP::Headers::Mixin
 
     STATUS_CODES = {
       100 => 'Continue',
@@ -66,7 +66,6 @@ class Response
     SYMBOL_TO_STATUS_CODE.freeze
 
     attr_reader :status
-    attr_reader :headers
     attr_reader :body
     attr_reader :uri
 
@@ -76,37 +75,14 @@ class Response
 
     def initialize(status, version, headers, body, uri = nil) # rubocop:disable ParameterLists
       @status, @version, @body, @uri = status, version, body, uri
-
-      @headers = {}
-      headers.each { |field, value| self[field] = value }
-    end
-
-    # Set a header
-    def []=(name, value)
-      # If we have a canonical header, we're done
-      key = name[CANONICAL_HEADER]
-
-      # Convert to canonical capitalization
-      key ||= canonicalize_header(name)
-
-      # Check if the header has already been set and group
-      if @headers.key? key
-        @headers[key] = Array(@headers[key]) + Array(value)
-      else
-        @headers[key] = value
-      end
+      @headers = HTTP::Headers.new(headers)
     end
 
     # Obtain the 'Reason-Phrase' for the response
     def reason
       STATUS_CODES[@status]
     end
 
-    # Get a header value
-    def [](name)
-      @headers[name] || @headers[canonicalize_header(name)]
-    end
-
     # Returns an Array ala Rack: `[status, headers, body]`
     def to_a
       [status, headers, body.to_s]
@@ -121,7 +97,7 @@ def to_s
     # Parsed Content-Type header
     # @return [HTTP::ContentType]
     def content_type
-      @content_type ||= ContentType.parse @headers['Content-Type']
+      @content_type ||= ContentType.parse headers['Content-Type']
     end
 
     # MIME type of response (if any)
@@ -138,7 +114,7 @@ def charset
 
     # Inspect a response
     def inspect
-      "#<#{self.class}/#{@version} #{status} #{reason} @headers=#{@headers.inspect}>"
+      "#<#{self.class}/#{@version} #{status} #{reason} headers=#{headers.inspect}>"
     end
 
     class BodyDelegator < ::Delegator