revactor: implement sendfile and range support

Due to the synchronous nature of Revactor, we can
be certain sendfile won't overstep the userspace
output buffering done by Rev.

3 files changed, 49 insertions, 9 deletions

diff --git a/lib/rainbows/response.rb b/lib/rainbows/response.rb
index 36ecbe2..3e196d1 100644
--- a/lib/rainbows/response.rb
+++ b/lib/rainbows/response.rb
@@ -39,7 +39,7 @@ module Rainbows::Response
     when :WriterThreadSpawn
       body_class = Rainbows::WriterThreadSpawn::MySocket
       range_class = Rainbows::HttpServer
-    when :EventMachine, :NeverBlock, :Revactor
+    when :EventMachine, :NeverBlock
       range_class = nil # :<
     end
     return if body_class.included_modules.include?(Body)
diff --git a/lib/rainbows/revactor.rb b/lib/rainbows/revactor.rb
index 8ec791d..10b7d3c 100644
--- a/lib/rainbows/revactor.rb
+++ b/lib/rainbows/revactor.rb
@@ -61,15 +61,12 @@ module Rainbows::Revactor
 
       if hp.headers?
         headers = HH.new(headers)
-        headers[CONNECTION] = if hp.keepalive? && G.alive
-          KEEP_ALIVE
-        else
-          env = false
-          CLOSE
-        end
+        range = make_range!(env, status, headers) and status = range.shift
+        env = false unless hp.keepalive? && G.alive
+        headers[CONNECTION] = env ? KEEP_ALIVE : CLOSE
         client.write(response_header(status, headers))
       end
-      write_body(client, body)
+      write_body(client, body, range)
     end while env && env.clear && hp.reset.nil?
   rescue ::Revactor::TCP::ReadError
   rescue => e
@@ -83,7 +80,8 @@ module Rainbows::Revactor
   # given a INT, QUIT, or TERM signal)
   def worker_loop(worker) #:nodoc:
     init_worker_process(worker)
-    self.class.__send__(:alias_method, :write_body, :write_body_each)
+    require 'rainbows/revactor/body'
+    self.class.__send__(:include, Rainbows::Revactor::Body)
     RD_ARGS[:timeout] = G.kato if G.kato > 0
     nr = 0
     limit = worker_connections
diff --git a/lib/rainbows/revactor/body.rb b/lib/rainbows/revactor/body.rb
new file mode 100644
index 0000000..1dd01f2
--- /dev/null
+++ b/lib/rainbows/revactor/body.rb
@@ -0,0 +1,42 @@
+# -*- encoding: binary -*-
+# :enddoc:
+module Rainbows::Revactor::Body
+  # TODO non-blocking splice(2) under Linux
+  ALIASES = {
+    :write_body_stream => :write_body_each
+  }
+
+  if IO.method_defined?(:sendfile_nonblock)
+    def write_body_file(client, body, range)
+      sock = client.instance_variable_get(:@_io)
+      pfx = ::Revactor::TCP::Socket === client ? :tcp : :unix
+      write_complete = T[:"#{pfx}_write_complete", client]
+      closed = T[:"#{pfx}_closed", client]
+      offset, count = range ? range : [ 0, body.stat.size ]
+      begin
+        offset += (n = sock.sendfile_nonblock(body, offset, count))
+      rescue Errno::EAGAIN
+        # The @_write_buffer is empty at this point, trigger the
+        # on_readable method which in turn triggers on_write_complete
+        # even though nothing was written
+        client.controller = Actor.current
+        client.__send__(:enable_write_watcher)
+        Actor.receive do |filter|
+          filter.when(write_complete) {}
+          filter.when(closed) { raise Errno::EPIPE }
+        end
+        retry
+      rescue EOFError
+        break
+      end while (count -= n) > 0
+    end
+  else
+    ALIASES[:write_body] = :write_body_each
+  end
+
+  def self.included(klass)
+    ALIASES.each do |new_method, orig_method|
+      klass.__send__(:alias_method, new_method, orig_method)
+    end
+  end
+end