diff -r 58cf45497dc0 -r 72ba9635ec5c eric6/E5Network/E5JsonClient.py
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/eric6/E5Network/E5JsonClient.py Sun May 09 14:53:27 2021 +0200
@@ -0,0 +1,157 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2017 - 2021 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing the JSON based client base class.
+"""
+
+import io
+import sys
+import socket
+import select
+import traceback
+import json
+import contextlib
+
+
+class E5JsonClient:
+ """
+ Class implementing a JSON based client base class.
+ """
+ def __init__(self, host, port, idString=""):
+ """
+ Constructor
+
+ @param host ip address the background service is listening
+ @type str
+ @param port port of the background service
+ @type int
+ @param idString assigned client id to be sent back to the server in
+ order to identify the connection
+ @type str
+ """
+ self.__connection = socket.create_connection((host, port))
+ if idString:
+ reply = idString + '\n'
+ self.__connection.sendall(reply.encode('utf8', 'backslashreplace'))
+
+ def sendJson(self, command, params):
+ """
+ Public method to send a single refactoring command to the server.
+
+ @param command command name to be sent
+ @type str
+ @param params dictionary of named parameters for the command
+ @type dict
+ """
+ commandDict = {
+ "jsonrpc": "2.0",
+ "method": command,
+ "params": params,
+ }
+ cmd = json.dumps(commandDict) + '\n'
+ self.__connection.sendall(cmd.encode('utf8', 'backslashreplace'))
+
+ def __receiveJson(self):
+ """
+ Private method to receive a JSON encode command and data from the
+ server.
+
+ @return tuple containing the received command and a dictionary
+ containing the associated data
+ @rtype tuple of (str, dict)
+ """
+ # step 1: receive the data
+ # The JSON RPC string is prefixed by a 9 character long length field.
+ length = self.__connection.recv(9)
+ if len(length) < 9:
+ # invalid length string received
+ return None, None
+
+ length = int(length)
+ data = b''
+ while len(data) < length:
+ newData = self.__connection.recv(length - len(data))
+ if not newData:
+ return None, None
+
+ data += newData
+
+ # step 2: decode and convert the data
+ line = data.decode(
+ 'utf8', 'backslashreplace')
+ try:
+ commandDict = json.loads(line.strip())
+ except (TypeError, ValueError) as err:
+ self.sendJson("ClientException", {
+ "ExceptionType": "ProtocolError",
+ "ExceptionValue": str(err),
+ "ProtocolData": line.strip(),
+ })
+ return None, None
+
+ method = commandDict["method"]
+ params = commandDict["params"]
+
+ return method, params
+
+ def handleCall(self, method, params):
+ """
+ Public method to handle a method call from the server.
+
+ Note: This is an empty implementation that must be overridden in
+ derived classes.
+
+ @param method requested method name
+ @type str
+ @param params dictionary with method specific parameters
+ @type dict
+ """
+ pass
+
+ def run(self):
+ """
+ Public method implementing the main loop of the client.
+ """
+ try:
+ selectErrors = 0
+ while selectErrors <= 10: # selected arbitrarily
+ try:
+ rrdy, wrdy, xrdy = select.select(
+ [self.__connection], [], [])
+
+ # Just waiting for self.__connection. Therefor no check
+ # needed.
+ method, params = self.__receiveJson()
+ if method is None:
+ selectErrors += 1
+ elif method == "Exit":
+ break
+ else:
+ self.handleCall(method, params)
+
+ # reset select errors
+ selectErrors = 0
+
+ except (select.error, KeyboardInterrupt, socket.error):
+ selectErrors += 1
+
+ except Exception:
+ exctype, excval, exctb = sys.exc_info()
+ tbinfofile = io.StringIO()
+ traceback.print_tb(exctb, None, tbinfofile)
+ tbinfofile.seek(0)
+ tbinfo = tbinfofile.read()
+ del exctb
+ self.sendJson("ClientException", {
+ "ExceptionType": str(exctype),
+ "ExceptionValue": str(excval),
+ "Traceback": tbinfo,
+ })
+
+ # Give time to process latest response on server side
+ with contextlib.suppress(socket.error, OSError):
+ self.__connection.shutdown(socket.SHUT_RDWR)
+ self.__connection.close()
