Adhere to HTTP 1.1 spec, keep conn open by default

lightbug_http/header.mojo

@@ -214,10 +214,9 @@ struct RequestHeader:
     fn headers(self) -> String:
         return String(self.raw_headers)
 
-    # This is translated to Mojo from Golang FastHTTP
     fn parse(inout self, request_line: String) raises -> None:
         var headers = self.raw_headers
-        
+
         var n = request_line.find(" ")
         if n <= 0:
             raise Error("Cannot find HTTP request method in the request")
@@ -254,6 +253,7 @@ struct RequestHeader:
         s.disable_normalization = self.disable_normalization
 
         while s.next():
+            # The below is based on the code from Golang's FastHTTP library
             if len(s.key) > 0:
                 # Spaces between the header key and colon are not allowed.
                 # See RFC 7230, Section 3.2.4.

lightbug_http/python/server.mojo

@@ -70,6 +70,9 @@ struct PythonServer:
             var conn = self.ln.accept()
             var buf = Bytes()
             var read_len = conn.read(buf)
+            if read_len == 0:
+                conn.close()
+                break
             var first_line_and_headers = next_line(buf)
             var request_line = first_line_and_headers.first_line
             var rest_of_headers = first_line_and_headers.rest

lightbug_http/sys/net.mojo

@@ -220,6 +220,9 @@ struct SysConnection(Connection):
         var bytes_recv = recv(self.fd, new_buf, default_buffer_size, 0)
         if bytes_recv == -1:
             print("Failed to receive message")
+            return 0
+        if bytes_recv == 0:
+            return 0
         var bytes_str = String(new_buf.bitcast[Int8](), bytes_recv)
         buf = bytes_str._buffer
         return bytes_recv

lightbug_http/sys/server.mojo

@@ -83,48 +83,53 @@ struct SysServer:
         Raises:
         If there is an error while serving requests.
         """
-        # var max_worker_count = self.get_concurrency()
-        # TODO: logic for non-blocking read and write here, see for example https://github.com/valyala/fasthttp/blob/9ba16466dfd5d83e2e6a005576ee0d8e127457e2/server.go#L1789
-
         self.ln = ln
 
         while True:
             var conn = self.ln.accept()
             var buf = Bytes()
-            var read_len = conn.read(buf)
-            var request = next_line(buf)
-            var headers_and_body = next_line(request.rest, "\n\n")
-            var request_headers = headers_and_body.first_line
-            var request_body = headers_and_body.rest
-            var uri = URI(request.first_line)
-            try:
-                uri.parse()
-            except e:
-                conn.close()
-                raise Error("Failed to parse request line:" + e.__str__())
-
-            var header = RequestHeader(request_headers._buffer)
-            try:
-                header.parse(request.first_line)
-            except e:
-                conn.close()
-                raise Error("Failed to parse request header: " + e.__str__())
 
-            if header.content_length() != 0 and header.content_length() != (len(request_body) + 1):
-                var remaining_body = Bytes()
-                var remaining_len = header.content_length() - len(request_body + 1)
-                while remaining_len > 0:
-                    var read_len = conn.read(remaining_body)
-                    buf.extend(remaining_body)
-                    remaining_len -= read_len
-
-            var res = handler.func(
-                HTTPRequest(
-                    uri,
-                    buf,
-                    header,
+            while True:
+                var read_len = conn.read(buf)
+                if read_len == 0:
+                    conn.close()
+                    break
+                var request = next_line(buf)
+                var headers_and_body = next_line(request.rest, "\n\n")
+                var request_headers = headers_and_body.first_line
+                var request_body = headers_and_body.rest
+                var uri = URI(request.first_line)
+                try:
+                    uri.parse()
+                except e:
+                    conn.close()
+                    raise Error("Failed to parse request line:" + e.__str__())
+
+                var header = RequestHeader(request_headers._buffer)
+                try:
+                    header.parse(request.first_line)
+                except e:
+                    conn.close()
+                    raise Error("Failed to parse request header: " + e.__str__())
+
+                if header.content_length() != 0 and header.content_length() != (len(request_body) + 1):
+                    var remaining_body = Bytes()
+                    var remaining_len = header.content_length() - len(request_body + 1)
+                    while remaining_len > 0:
+                        var read_len = conn.read(remaining_body)
+                        buf.extend(remaining_body)
+                        remaining_len -= read_len
+
+                var res = handler.func(
+                    HTTPRequest(
+                        uri,
+                        buf,
+                        header,
+                    )
                 )
-            )
-            var res_encoded = encode(res)
-            _ = conn.write(res_encoded)
-            conn.close()
+                var res_encoded = encode(res)
+                _ = conn.write(res_encoded)
+
+                if header.connection_close():
+                    conn.close()
+                    break