From 5b721d1eede4123c76ab680380e1950690b69767 Mon Sep 17 00:00:00 2001
From: Marcelo Boeira <me@marceloboeira.com>
Date: Sat, 3 Sep 2016 01:23:08 +0200
Subject: [PATCH] feature: Use channels do deal with memory concurrency

By using a Channel is expected that the memory get no concurrent access,
the Fibers should send all the requests over the Channel. The same will
receive and perform in the received order.

Additional changes:
  - Add a 'request' abstraction, to deal with parsing the received
  message and handling commands
---
 src/bojack/request.cr | 39 ++++++++++++++++++++++++++++++++++
 src/bojack/server.cr  | 49 ++++++++++++-------------------------------
 2 files changed, 52 insertions(+), 36 deletions(-)
 create mode 100644 src/bojack/request.cr

diff --git a/src/bojack/request.cr b/src/bojack/request.cr
new file mode 100644
index 0000000..51edf10
--- /dev/null
+++ b/src/bojack/request.cr
@@ -0,0 +1,39 @@
+require "socket"
+require "logger"
+require "./logger"
+require "./command"
+require "./memory"
+
+module BoJack
+  class Request
+    @logger : ::Logger = BoJack::Logger.instance
+    def initialize(@body : String, @socket : TCPSocket, @memory : BoJack::Memory(String, Array(String))); end
+
+    def perform
+      @logger.info("#{@socket.remote_address} requested: #{@body.strip}")
+      params = parse(@body)
+      command = BoJack::Command.from(params[:command])
+
+      response = command.run(@socket, @memory, params)
+
+      @socket.puts(response)
+    rescue e
+      message = "error: #{e.message}"
+      @logger.error(message)
+      @socket.puts(message)
+    end
+
+    private def parse(body) : Hash(Symbol, String | Array(String))
+      body = body.split(" ").map { |item| item.strip }
+
+      command = body[0]
+      result = Hash(Symbol, String | Array(String)).new
+      result[:command] = command
+
+      result[:key] = body[1] if body[1]?
+      result[:value] = body[2].split(",") if body[2]?
+
+      result
+    end
+  end
+end
diff --git a/src/bojack/server.cr b/src/bojack/server.cr
index 10b626c..0d62ef2 100644
--- a/src/bojack/server.cr
+++ b/src/bojack/server.cr
@@ -1,8 +1,8 @@
 require "socket"
 require "logger"
 require "./logger"
+require "./request"
 require "./memory"
-require "./command"
 require "./logo"
 
 module BoJack
@@ -10,6 +10,8 @@ module BoJack
     @hostname : String
     @port : Int8 | Int16 | Int32 | Int64
     @logger : ::Logger = BoJack::Logger.instance
+    @channel : Channel::Unbuffered(BoJack::Request) = Channel(BoJack::Request).new
+    @memory = BoJack::Memory(String, Array(String)).new
 
     def initialize(@hostname = "127.0.0.1", @port = 5000); end
 
@@ -17,7 +19,6 @@ module BoJack
       server = TCPServer.new(@hostname, @port)
       server.tcp_nodelay = true
       server.recv_buffer_size = 4096
-      memory = BoJack::Memory(String, Array(String)).new
 
       BoJack::Logo.render
 
@@ -29,51 +30,27 @@ module BoJack
         exit
       end
 
+      spawn do
+        loop do
+          if request = @channel.receive
+            request.perform
+          end
+        end
+      end
+
       loop do
         if socket = server.accept
           @logger.info("#{socket.remote_address} connected")
 
           spawn do
             loop do
-              request = socket.gets
-              break unless request
-
-              @logger.info("#{socket.remote_address} requested: #{request.strip}")
-
-              begin
-                params = parse_request(request)
-                command = BoJack::Command.from(params[:command])
-
-                response = command.run(socket, memory, params)
-
-                if command.is_a?(BoJack::Commands::Close)
-                  break
-                end
-
-                socket.puts(response)
-              rescue e
-                message = "error: #{e.message}"
-                @logger.error(message)
-                socket.puts(message)
+              if message = socket.gets
+                @channel.send(BoJack::Request.new(message, socket, @memory))
               end
             end
           end
         end
       end
     end
-
-    private def parse_request(request) : Hash(Symbol, String | Array(String))
-      request = request.split(" ").map { |item| item.strip }
-
-      command = request[0]
-      result = Hash(Symbol, String | Array(String)).new
-      result[:command] = command
-
-      result[:key] = request[1] if request[1]?
-      result[:value] = request[2].split(",") if request[2]?
-
-      result
-    end
   end
-
 end