# Copyright, 2018, by Samuel G. D. Williams. <http://www.codeotaku.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
require_relative 'request'
require_relative 'response'
require_relative 'http11'
require 'async/notification'
require 'http/2'
module Async
module HTTP
module Protocol
# A server that supports both HTTP1.0 and HTTP1.1 semantics by detecting the version of the request.
class HTTP2
def self.client(stream)
self.new(::HTTP2::Client.new, stream)
end
def self.server(stream)
self.new(::HTTP2::Server.new, stream)
end
HTTPS = 'https'.freeze
SCHEME = ':scheme'.freeze
METHOD = ':method'.freeze
PATH = ':path'.freeze
AUTHORITY = ':authority'.freeze
REASON = ':reason'.freeze
STATUS = ':status'.freeze
VERSION = 'HTTP/2.0'.freeze
def initialize(controller, stream)
@controller = controller
@stream = stream
@controller.on(:frame) do |data|
@stream.write(data)
@stream.flush
end
@controller.on(:frame_sent) do |frame|
Async.logger.debug(self) {"Sent frame: #{frame.inspect}"}
end
@controller.on(:frame_received) do |frame|
Async.logger.debug(self) {"Received frame: #{frame.inspect}"}
end
@goaway = false
@controller.on(:goaway) do |payload|
Async.logger.error(self) {"goaway: #{payload.inspect}"}
@goaway = true
end
@count = 0
end
def peer
@stream.io
end
attr :count
# Multiple requests can be processed at the same time.
def multiplex
@controller.remote_settings[:settings_max_concurrent_streams]
end
# Can we use this connection to make requests?
def good?
@stream.connected?
end
def reusable?
!@goaway || !@stream.closed?
end
def version
VERSION
end
def start_connection
@reader ||= read_in_background
end
def read_in_background(task: Task.current)
task.async do |nested_task|
nested_task.annotate("#{version} reading data")
while buffer = @stream.read_partial
@controller << buffer
end
Async.logger.debug(self) {"Connection reset by peer!"}
end
end
def close
Async.logger.debug(self) {"Closing connection"}
@reader.stop if @reader
@stream.close
end
class Request < Protocol::Request
def initialize(protocol, stream)
super(nil, nil, nil, VERSION, Headers.new, Body::Writable.new)
@protocol = protocol
@stream = stream
end
def hijack?
false
end
attr :stream
def assign_headers(headers)
headers.each do |key, value|
if key == METHOD
raise BadRequest, "Request method already specified" if @method
@method = value
elsif key == PATH
raise BadRequest, "Request path already specified" if @path
@path = value
elsif key == AUTHORITY
raise BadRequest, "Request authority already specified" if @authority
@authority = value
else
@headers[key] = value
end
end
end
end
def receive_requests(task: Task.current, &block)
# emits new streams opened by the client
@controller.on(:stream) do |stream|
@count += 1
request = Request.new(self, stream)
body = request.body
stream.on(:headers) do |headers|
begin
request.assign_headers(headers)
rescue
Async.logger.error(self) {$!}
stream.headers({
STATUS => "400"
}, end_stream: true)
else
task.async do
generate_response(request, stream, &block)
end
end
end
stream.on(:data) do |chunk|
body.write(chunk.to_s) unless chunk.empty?
end
stream.on(:half_close) do
# We are no longer receiving any more data frames:
body.finish
end
stream.on(:close) do |error|
if error
body.stop(EOFError.new(error))
else
# In theory, we should have received half_close, so there is no need to:
# body.finish
end
end
end
start_connection
@reader.wait
end
# Generate a response to the request. If this fails, the stream is terminated and the error is reported.
private def generate_response(request, stream, &block)
# We need to close the stream if the user code blows up while generating a response:
response = begin
yield(request, stream)
rescue
stream.close(:internal_error)
raise
end
if response
headers = Headers::Merged.new({
STATUS => response.status,
}, response.headers)
if response.body.nil? or response.body.empty?
stream.headers(headers, end_stream: true)
response.body.read if response.body
else
stream.headers(headers, end_stream: false)
response.body.each do |chunk|
stream.data(chunk, end_stream: false)
end
stream.data("", end_stream: true)
end
else
stream.close(:internal_error) unless stream.state == :closed
end
rescue
Async.logger.error(request) {$!}
end
class Response < Protocol::Response
def initialize(protocol, stream)
super(self.version, nil, nil, Headers.new, Body::Writable.new)
@protocol = protocol
@stream = stream
end
def assign_headers(headers)
headers.each do |key, value|
if key == STATUS
@status = value.to_i
elsif key == REASON
@reason = value
else
@headers[key] = value
end
end
end
end
# Used by the client to send requests to the remote server.
def call(request)
@count += 1
stream = @controller.new_stream
response = Response.new(self, stream)
body = response.body
exception = nil
finished = Async::Notification.new
waiting = true
stream.on(:close) do |error|
if waiting
if error
# If the stream was closed due to an error, we will raise it rather than returning normally.
exception = EOFError.new(error)
end
waiting = false
finished.signal
else
# At this point, we are now expecting two events: data and close.
# If we receive close after this point, it's not a request error, but a failure we need to signal to the body.
if error
body.stop(EOFError.new(error))
else
body.finish
end
end
end
stream.on(:headers) do |headers|
response.assign_headers(headers)
# Once we receive the headers, we can return. The body will be read in the background.
waiting = false
finished.signal
end
# This is a little bit tricky due to the event handlers.
# 1/ Caller invokes `response.stop` which causes `body.write` below to fail.
# 2/ We invoke `stream.close(:internal_error)` which eventually triggers `on(:close)` above.
# 3/ Error is set to :internal_error which causes us to call `body.stop` a 2nd time.
# So, we guard against that, by ensuring that `Writable#stop` only stores the first exception assigned to it.
stream.on(:data) do |chunk|
begin
# If the body is stopped, write will fail...
body.write(chunk.to_s) unless chunk.empty?
rescue
# ... so, we close the stream:
stream.close(:internal_error)
end
end
write_request(request, stream)
Async.logger.debug(self) {"Request sent, waiting for signal."}
finished.wait
if exception
raise exception
end
Async.logger.debug(self) {"Stream finished: #{response.inspect}"}
return response
end
private def write_request(request, stream)
headers = Headers::Merged.new({
SCHEME => HTTPS,
METHOD => request.method,
PATH => request.path,
AUTHORITY => request.authority,
}, request.headers)
if request.body.nil? or request.body.empty?
stream.headers(headers, end_stream: true)
request.body.read if request.body
else
begin
stream.headers(headers)
rescue
raise RequestFailed.new
end
request.body.each do |chunk|
stream.data(chunk, end_stream: false)
end
stream.data("")
end
start_connection
@stream.flush
end
end
end
end
end