Support keep alive

Improvements:
  - Response return Content-Length header;
  - HTTP handler run recursive after call;
  - File iterator when call before yield file size.

server/file_read.py

@@ -18,11 +18,16 @@
 #
 
 import logging
+import os
 
 
 log = logging.getLogger(__name__)
 
 def fileiter(filename):
+    log.debug("Calc file %s size" % filename)
+
+    yield os.path.getsize(filename)
+
     log.debug("Open file %s to byte-read" % filename)
 
     with open(filename, "rb") as f:

server/http_handler.py

@@ -48,16 +48,25 @@ class HTTPHandler:
 
     def __write_data(self, data_iter):
         for chunk in data_iter:
+            try:
                 self.write_fd.write(chunk)
                 self.write_fd.flush()
+            except BrokenPipeError:
+                pass
 
     def __read_data(self, size=MAX_REQUEST_LINE_SIZE+1):
+        try:
             return self.read_fd.readline(size)
+        except BrokenPipeError:
+            pass
 
     def __close(self):
+        try:
             self.write_fd.close()
             self.read_fd.close()
             self.conn.close()
+        except BrokenPipeError:
+            pass
 
     def __handle_connection(self):
         """
@@ -258,4 +267,4 @@ class HTTPHandler:
             r = Response(status_code=404, data=b"Not found!")
             self.__write_data(r)
 
-        self.__close()
+        self.__handle_connection()

server/main.py

@@ -27,7 +27,7 @@ def init_server_socket(server_handler):
                 log.info("Accepted connection from %s", addr[0])
 
                 thr_serv_conn = threading.Thread(target=server_handler, args=(conn, addr,), daemon=True)
-                thr_serv_conn.run()
+                thr_serv_conn.start()
 
     except KeyboardInterrupt:
         log.info("Server get keyboard interrupt, bye!")

server/response.py

@@ -51,11 +51,17 @@ class Response:
 
             resp = "HTTP/1.1 {} {}\r\n"
             resp += "Server: cnserv\r\n"
-            resp += "Connection: close\r\n"
+            resp += "Connection: keep-alive\r\n"
+
             for key, val in self.additional_headers.items():
                 resp += "{}: {}\r\n".format(key, val)
-            resp += "\r\n"
 
+            if type(self.data) == bytes:
+                resp += "Content-Length: {}\r\n".format(len(self.data))
+            elif hasattr(self.data, "__iter__"):
+                resp += "Content-Length: {}\r\n".format(next(self.data))
+
+            resp += "\r\n"
             resp = resp.format(self.status_code, STATUS_BY_CODE[self.status_code])
             resp = resp.encode("UTF-8")