Class: Async::HTTP::Protocol::HTTP1::Server

Inherits:
Connection
  • Object
show all
Defined in:
lib/async/http/protocol/http1/server.rb

Instance Attribute Summary

Attributes inherited from Connection

#count, #version

Instance Method Summary collapse

Methods inherited from Connection

#as_json, #concurrency, #http1?, #http2?, #peer, #reusable?, #to_json, #to_s, #viable?

Constructor Details

#initialize ⇒ Server

Returns a new instance of Server.



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# File 'lib/async/http/protocol/http1/server.rb', line 20

def initialize(...)
  super
  
  @ready = Async::Notification.new
end

Instance Method Details

#closed(error = nil) ⇒ Object 



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# File 'lib/async/http/protocol/http1/server.rb', line 26

def closed(error = nil)
  super
  
  @ready.signal
end

#each(task: Task.current) ⇒ Object

Server loop.



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# File 'lib/async/http/protocol/http1/server.rb', line 63

def each(task: Task.current)
  task.annotate("Reading #{self.version} requests for #{self.class}.")
  
  while request = next_request
    if body = request.body
      finishable = Finishable.new(body)
      request.body = finishable
    end
    
    response = yield(request, self)
    version = request.version
    body = response&.body
    
    if hijacked?
      body&.close
      return
    end
    
    task.defer_stop do
      # If a response was generated, send it:
      if response
        trailer = response.headers.trailer!
        
        # Some operations in this method are long running, that is, it's expected that `body.call(stream)` could literally run indefinitely. In order to facilitate garbage collection, we want to nullify as many local variables before calling the streaming body. This ensures that the garbage collection can clean up as much state as possible during the long running operation, so we don't retain objects that are no longer needed.
        
        if body and protocol = response.protocol
          # We force a 101 response if the protocol is upgraded - HTTP/2 CONNECT will return 200 for success, but this won't be understood by HTTP/1 clients:
          write_response(@version, 101, response.headers)
          
          # At this point, the request body is hijacked, so we don't want to call #finish below.
          request = nil
          response = nil
          
          if body.stream?
            return body.call(write_upgrade_body(protocol))
          else
            write_upgrade_body(protocol, body)
          end
        elsif response.status == 101
          # This code path is to support legacy behavior where the response status is set to 101, but the protocol is not upgraded. This may not be a valid use case, but it is supported for compatibility. We expect the response headers to contain the `upgrade` header.
          write_response(@version, response.status, response.headers)
          
          # Same as above:
          request = nil
          response = nil
          
          if body.stream?
            return body.call(write_tunnel_body(version))
          else
            write_tunnel_body(version, body)
          end
        else
          write_response(@version, response.status, response.headers)
          
          if request.connect? and response.success?
            # Same as above:
            request = nil
            response = nil
            
            if body.stream?
              return body.call(write_tunnel_body(version))
            else
              write_tunnel_body(version, body)
            end
          else
            head = request.head?
            
            # Same as above:
            request = nil
            response = nil
            
            write_body(version, body, head, trailer)
          end
        end
        
        # We are done with the body:
        body = nil
      else
        # If the request failed to generate a response, it was an internal server error:
        write_response(@version, 500, {})
        write_body(version, nil)
        
        request&.finish
      end
      
      if finishable
        finishable.wait(@persistent)
      else
        # Do not remove this line or you will unleash the gods of concurrency hell.
        task.yield
      end
    rescue => error
      # We store error (as a local variable) for later use in the ensure block.
      raise
    ensure
      body&.close(error)
    end
  end
end

#fail_request(status) ⇒ Object 



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# File 'lib/async/http/protocol/http1/server.rb', line 32

def fail_request(status)
  @persistent = false
  write_response(@version, status, {})
  write_body(@version, nil)
rescue => error
  # At this point, there is very little we can do to recover:
  Console.debug(self, "Failed to write failure response!", error)
end

#next_request ⇒ Object 



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# File 'lib/async/http/protocol/http1/server.rb', line 41

def next_request
  if closed?
    return nil
  elsif !idle?
    @ready.wait
  end
  
  # Read an incoming request:
  return unless request = Request.read(self)
  
  unless persistent?(request.version, request.method, request.headers)
    @persistent = false
  end
  
  return request
rescue ::Protocol::HTTP1::BadRequest
  fail_request(400)
  # Conceivably we could retry here, but we don't really know how bad the error is, so it's better to just fail:
  raise
end