`class Rack3`

The Rack 3 adapter provides compatibility with Rack 3.x applications. It handles the conversion between Protocol::HTTP and Rack 3 environments. Unlike Rack 2, this adapter supports streaming responses and has a simpler environment setup.

Definitions

`def self.wrap(app)`

Creates a new adapter instance for the given Rack application. Unlike Rack 2, this adapter doesn't require a class Protocol::Rack::Rewindable wrapper.

Signature

parameter　app　Interface(:call): A Rack application.
returns　Rack3: A new adapter instance.

Implementation

def self.wrap(app)
	self.new(app)
end

`def self.parse_file(...)`

Parses a Rackup file and returns the application. Uses the Rack 3.x interface for parsing Rackup files.

Signature

parameter　path　String: The path to the Rackup file.
returns　Interface(:call): The Rack application.

Implementation

def self.parse_file(...)
	::Rack::Builder.parse_file(...)
end

`def make_environment(request)`

Create a Rack 3 environment hash for the request. Sets up all required Rack 3 environment variables and processes the request. Unlike Rack 2, this adapter doesn't set Rack version or threading flags.

Signature

parameter　request　Protocol::HTTP::Request: The incoming request.
returns　Hash: The Rack 3 environment hash.

Implementation

def make_environment(request)
	request_path, query_string = request.path.split("?", 2)
	server_name, server_port = (request.authority || "").split(":", 2)
	
	env = {
		PROTOCOL_HTTP_REQUEST => request,
		
		RACK_INPUT => Input.new(request.body),
		RACK_ERRORS => $stderr,
		RACK_LOGGER => self.logger,
		
		# The response finished callbacks:
		RACK_RESPONSE_FINISHED => [],
		
		# The HTTP request method, such as "GET" or "POST". This cannot ever be an empty string, and so is always required.
		CGI::REQUEST_METHOD => request.method,
		
		# The initial portion of the request URL's "path" that corresponds to the application object, so that the application knows its virtual "location". This may be an empty string, if the application corresponds to the "root" of the server.
		CGI::SCRIPT_NAME => "",
		
		# The remainder of the request URL's "path", designating the virtual "location" of the request's target within the application. This may be an empty string, if the request URL targets the application root and does not have a trailing slash. This value may be percent-encoded when originating from a URL.
		CGI::PATH_INFO => request_path,
		CGI::REQUEST_PATH => request_path,
		CGI::REQUEST_URI => request.path,
		
		# The portion of the request URL that follows the ?, if any. May be empty, but is always required!
		CGI::QUERY_STRING => query_string || "",
		
		# The server protocol (e.g. HTTP/1.1):
		CGI::SERVER_PROTOCOL => request.version,
		
		# The request scheme:
		RACK_URL_SCHEME => request.scheme,
		
		# I'm not sure what sane defaults should be here:
		CGI::SERVER_NAME => server_name,
	}
	
	# SERVER_PORT is optional but must not be set if it is not present.
	if server_port
		env[CGI::SERVER_PORT] = server_port
	end
	
	self.unwrap_request(request, env)
	
	return env
end

`def wrap_headers(fields)`

Process the rack response headers into a Protocol::HTTP::Headers instance, along with any extra rack. metadata. Unlike Rack 2, this adapter handles array values directly without splitting on newlines.

Signature

parameter　fields　Hash: The raw response headers.
returns　Tuple(Protocol::HTTP::Headers, Hash): The processed headers and metadata.

Implementation

def wrap_headers(fields)
	headers = ::Protocol::HTTP::Headers.new
	meta = {}
	
	fields.each do |key, value|
		key = key.downcase
		
		if key.start_with?("rack.")
			meta[key] = value
		elsif value.is_a?(Array)
			value.each do |value|
				headers[key] = value
			end
		else
			headers[key] = value
		end
	end
	
	return headers, meta
end

`def self.make_response(env, response)`

Convert a Protocol::HTTP::Response into a Rack 3 response tuple. Handles protocol upgrades and streaming responses. Unlike Rack 2, this adapter forces streaming responses by converting the body to a callable.

Signature

parameter　env　Hash: The rack environment.
parameter　response　Protocol::HTTP::Response: The HTTP response.
returns　Tuple(Integer, Hash, Object): The Rack 3 response tuple [status, headers, body].

Implementation

def self.make_response(env, response)
	# These interfaces should be largely compatible:
	headers = response.headers.to_h
	
	self.extract_protocol(env, response, headers)
	
	if body = response.body and body.stream?
		# Force streaming response:
		body = body.method(:call)
	end
	
	[response.status, headers, body]
end