default to requesting compressed response

This behavior can be disabled via :compressed => false when initializing
the request.

Closes #270.

Author: igrigorik

lib/em-http/client.rb

@@ -155,11 +155,16 @@ def build_request
 
       # Set the User-Agent if it hasn't been specified
       if !head.key?('user-agent')
-        head['user-agent'] = "EventMachine HttpClient"
+        head['user-agent'] = 'EventMachine HttpClient'
       elsif head['user-agent'].nil?
         head.delete('user-agent')
       end
 
+      # Set the Accept-Encoding header if none is provided
+      if !head.key?('accept-encoding') && req.compressed
+        head['accept-encoding'] = 'gzip, compressed'
+      end
+
       # Set the auth from the URI if given
       head['Authorization'] = @req.uri.userinfo.split(/:/, 2) if @req.uri.userinfo
 

lib/em-http/http_client_options.rb

@@ -1,7 +1,7 @@
 class HttpClientOptions
   attr_reader :uri, :method, :host, :port
   attr_reader :headers, :file, :body, :query, :path
-  attr_reader :keepalive, :pass_cookies, :decoding
+  attr_reader :keepalive, :pass_cookies, :decoding, :compressed
 
   attr_accessor :followed, :redirects
 
@@ -18,6 +18,7 @@ def initialize(uri, options, method)
 
     @pass_cookies = options.fetch(:pass_cookies, true)  # pass cookies between redirects
     @decoding     = options.fetch(:decoding, true)      # auto-decode compressed response
+    @compressed   = options.fetch(:compressed, true)    # auto-negotiated compressed response
 
     set_uri(uri, options[:path], options[:query])
   end

spec/client_spec.rb

@@ -386,7 +386,7 @@ def failed(http=nil)
     }
   end
 
-  it "should detect gzip encoding" do
+  it "should auto-detect and decode gzip encoding" do
     EventMachine.run {
 
       http = EventMachine::HttpRequest.new('http://127.0.0.1:8090/gzip').get :head => {"accept-encoding" => "gzip, compressed"}
@@ -446,6 +446,36 @@ def failed(http=nil)
     }
   end
 
+  it "should default to requesting compressed response" do
+    EventMachine.run {
+
+      http = EventMachine::HttpRequest.new('http://127.0.0.1:8090/echo_accept_encoding').get
+
+      http.errback { failed(http) }
+      http.callback {
+        http.response_header.status.should == 200
+        http.response.should == "gzip, compressed"
+
+        EventMachine.stop
+      }
+    }
+  end
+
+  it "should default to requesting compressed response" do
+    EventMachine.run {
+
+      http = EventMachine::HttpRequest.new('http://127.0.0.1:8090/echo_accept_encoding').get :compressed => false
+
+      http.errback { failed(http) }
+      http.callback {
+        http.response_header.status.should == 200
+        http.response.should == ""
+
+        EventMachine.stop
+      }
+    }
+  end
+
   it "should timeout after 0.1 seconds of inactivity" do
     EventMachine.run {
       t = Time.now.to_i

spec/stallion.rb

@@ -235,6 +235,10 @@ def self.call(env)
       stable.response.write deflater.finish
       stable.response["Content-Encoding"] = "deflate"
 
+    elsif stable.request.path_info == '/echo_accept_encoding'
+      stable.response.status = 200
+      stable.response.write stable.request.env["HTTP_ACCEPT_ENCODING"]
+
     elsif stable.request.env["HTTP_IF_NONE_MATCH"]
       stable.response.status = 304