From 6566c2af5c51317351113574a3365fa918ab4413 Mon Sep 17 00:00:00 2001
From: Yessiest <yessiest@memeware.net>
Date: Mon, 8 Jul 2024 03:50:56 +0400
Subject: [PATCH] synchronous sockets, no more threads

---
 examples/websockets.ru               |  16 ++--
 lib/landline/extensions/websocket.rb | 123 +++++++++++++--------------
 2 files changed, 70 insertions(+), 69 deletions(-)

diff --git a/examples/websockets.ru b/examples/websockets.ru
index 1475584..b74f93f 100644
--- a/examples/websockets.ru
+++ b/examples/websockets.ru
@@ -5,9 +5,6 @@ require 'landline/extensions/websocket'
 
 class Test < Landline::App
   websocket "/test", version: 7 do |socket|
-    socket.on :message do |msg|
-      puts "Client wrote: #{msg}"
-    end
     socket.on :error do |err|
       puts "Error occured: #{err.inspect}"
       puts err.backtrace
@@ -15,12 +12,17 @@ class Test < Landline::App
     socket.on :close do
       puts "Client closed read connection"
     end
-    socket.ready
     socket.write("Hi!")
-    response = socket.read
-    socket.write("You said: #{response}")
+    while (response = socket.read)
+      if response
+        puts "Client wrote: #{response.inspect}"
+      else
+        puts "Client closed read connection"
+      end
+      socket.write("You said: #{response}")
+    end
     socket.write("Goodbye!")
-    socket.close
+    socket.close_write
   rescue Exception => e
     puts e.inspect
     puts e.backtrace
diff --git a/lib/landline/extensions/websocket.rb b/lib/landline/extensions/websocket.rb
index 9678813..c497958 100644
--- a/lib/landline/extensions/websocket.rb
+++ b/lib/landline/extensions/websocket.rb
@@ -95,19 +95,6 @@ module Landline
         )
         @readable = true
         @writable = true
-        @data = Queue.new
-        on :message do |msg|
-          @data.enq(msg)
-        end
-      end
-
-      # Start the main loop for the eventifier
-      # @return [void]
-      def ready
-        return if @ready
-
-        _loop
-        @ready = true
       end
 
       # Send data through websocket
@@ -126,34 +113,30 @@ module Landline
         )
         @io.write(frame.to_s)
       rescue Errno::EPIPE => e
-        @writable = false
         _emit :error, e
         close
       end
 
       # Read data from socket synchronously
-      # @return [String, nil] nil returned if socket closes
+      # @return [WebSocket::Frame::Base, nil] nil if socket received a close event
       def read
         unless @readable
           raise self.class::WebSocketError,
                 "socket closed for reading"
         end
 
-        @data.deq
+        _process_events(proc { _read })
       end
 
-      # Close the socket for reading
-      # @return [void]
-      def close_read
-        _emit :close
-        @readable = false
-        @io.close_read
-      end
+      # Read data from socket without blocking
+      # @return [WebSocket::Frame::Base, nil] nil if socket received a close event
+      def read_nonblock
+        unless @readable
+          raise self.class::WebSocketError,
+                "socket closed for reading"
+        end
 
-      # Close the socket for writing
-      def close_write
-        @writable = false
-        @io.close_write
+        _process_events(proc { _read_nonblock })
       end
 
       # Establish a connection through handshake
@@ -183,62 +166,78 @@ module Landline
         handshake
       end
 
-      # Close the socket
-      # @return [void]
-      def close
-        _close
-        @writable = false
+      # Close socket for reading
+      def close_read
+        raise WebSocketError, 'socket closed for reading' unless @readable
+
+        _emit :close
         @readable = false
+        @io.close_read
       end
 
+      # Close socket for reading
+      def close_write
+        raise WebSocketError, 'socket closed for writing' unless @writable
+
+        write(nil, type: :close)
+        @writable = false
+        @io.close_write
+      end
+
+      # Close the socket entirely
+      def close
+        raise WebSocketError, 'socket closed' unless @writable or @readable
+
+        close_read if @readable
+        close_write if @writable
+      end
+
+      attr_reader :io, :readable, :writable
+
       private
 
-      # Event reading loop
-      # @return [void]
-      def _loop
-        @thread = Thread.new do
-          loop do
-            msg = _read
-            if msg and [:text, :binary].include? msg.type
-              _emit :message, msg
-            elsif msg and msg.type == :close
-              _emit :__close, msg
-              break
-            end
+      # Process incoming websocket events
+      # @param next_frame [#call] callback to get the next frame
+      # @return [WebSocket::Frame::Base, nil]
+      def _process_events(next_frame)
+        loop do
+          frame = next_frame.call
+          case frame.type
+          when :binary, :text, :pong then return frame
+          when :ping
+            write frame.to_s, type: :pong
+          when :close
+            close_read
+            return nil
+          else raise WebSocketError, "unknown frame type #{frame.type}"
           end
-        rescue IOError => e
-          @writable = false
-          _emit :error, e
-          close
-        ensure
-          close_read
         end
       end
 
       # Receive data through websocket
       # @return [String] output from frame
       def _read
-        while (char = @io.getc)
+        while (char = @io.read(1))
           @frame_parser << char
           frame = @frame_parser.next
           return frame if frame
         end
       rescue Errno::ECONNRESET => e
-        @writable = false
         _emit :error, e
         close
       end
 
-      # Close the websocket
-      # @return [void]
-      def _close
-        frame = ::WebSocket::Frame::Outgoing::Server.new(
-          version: @version,
-          type: :close
-        )
-        @io.write(frame.to_s) if @writable
-        sleep 0.1
-        @io.close
+      # Receive data through websocket asynchronously
+      # @return [String] output from frame
+      def _read_nonblock
+        while (char = @io.read_nonblock(1))
+          @frame_parser << char
+          frame = @frame_parser.next
+          return frame if frame
+        end
+      rescue Errno::ECONNRESET => e
+        _emit :error, e
+        close
       end
     end
   end