eric6/Debugger/DebuggerInterfacePython.py

# -*- coding: utf-8 -*-

# Copyright (c) 2009 - 2021 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the Python3 debugger interface for the debug server.
"""

import sys
import os
import logging
import shlex
import contextlib

from PyQt5.QtCore import (
    QObject, QProcess, QProcessEnvironment, QTimer
)

from E5Gui.E5Application import e5App
from E5Gui import E5MessageBox

from . import DebugClientCapabilities

import Preferences
import Utilities

from eric6config import getConfig


ClientDefaultCapabilities = DebugClientCapabilities.HasAll


class DebuggerInterfacePython(QObject):
    """
    Class implementing the debugger interface for the debug server for
    Python 3.
    """
    def __init__(self, debugServer, passive):
        """
        Constructor
        
        @param debugServer reference to the debug server
        @type DebugServer
        @param passive flag indicating passive connection mode
        @type bool
        """
        super().__init__()
        
        self.__isNetworked = True
        self.__autoContinue = False
        self.__autoContinued = []
        self.__isStepCommand = False
        
        self.debugServer = debugServer
        self.passive = passive
        self.process = None
        self.__startedVenv = ""
        
        self.queue = []
        self.__master = None
        self.__connections = {}
        self.__pendingConnections = []
        self.__inShutdown = False
        
        # set default values for capabilities of clients
        self.clientCapabilities = ClientDefaultCapabilities
        
        # set translation function
        self.translate = self.__identityTranslation
        
        if passive:
            # set translation function
            if Preferences.getDebugger("PathTranslation"):
                self.translateRemote = Preferences.getDebugger(
                    "PathTranslationRemote")
                self.translateRemoteWindows = "\\" in self.translateRemote
                self.translateLocal = Preferences.getDebugger(
                    "PathTranslationLocal")
                self.translateLocalWindows = "\\" in self.translateLocal
                self.translate = self.__remoteTranslation
            else:
                self.translate = self.__identityTranslation
        
        # attribute to remember the name of the executed script
        self.__scriptName = ""
    
    def __identityTranslation(self, fn, remote2local=True):
        """
        Private method to perform the identity path translation.
        
        @param fn filename to be translated
        @type str
        @param remote2local flag indicating the direction of translation
            (False = local to remote, True = remote to local [default])
        @type bool
        @return translated filename
        @rtype str
        """
        return fn
    
    def __remoteTranslation(self, fn, remote2local=True):
        """
        Private method to perform the path translation.
        
        @param fn filename to be translated
        @type str
        @param remote2local flag indicating the direction of translation
            (False = local to remote, True = remote to local [default])
        @type bool
        @return translated filename
        @rtype str
        """
        if remote2local:
            path = fn.replace(self.translateRemote, self.translateLocal)
            if self.translateLocalWindows:
                path = path.replace("/", "\\")
        else:
            path = fn.replace(self.translateLocal, self.translateRemote)
            if not self.translateRemoteWindows:
                path = path.replace("\\", "/")
        
        return path
    
    def __startProcess(self, program, arguments, environment=None,
                       workingDir=None):
        """
        Private method to start the debugger client process.
        
        @param program name of the executable to start
        @type str
        @param arguments arguments to be passed to the program
        @type list of str
        @param environment dictionary of environment settings to pass
        @type dict of str
        @param workingDir directory to start the debugger client in
        @type str
        @return the process object
        @rtype QProcess or None
        """
        proc = QProcess()
        if environment is not None:
            env = QProcessEnvironment()
            for key, value in list(environment.items()):
                env.insert(key, value)
            proc.setProcessEnvironment(env)
        args = arguments[:]
        if workingDir:
            proc.setWorkingDirectory(workingDir)
        proc.start(program, args)
        if not proc.waitForStarted(10000):
            proc = None
        
        return proc
    
    def startRemote(self, port, runInConsole, venvName, originalPathString,
                    workingDir=None, configOverride=None):
        """
        Public method to start a remote Python interpreter.
        
        @param port port number the debug server is listening on
        @type int
        @param runInConsole flag indicating to start the debugger in a
            console window
        @type bool
        @param venvName name of the virtual environment to be used
        @type str
        @param originalPathString original PATH environment variable
        @type str
        @param workingDir directory to start the debugger client in
        @type str
        @param configOverride dictionary containing the global config override
            data
        @type dict
        @return client process object, a flag to indicate a network connection
            and the name of the interpreter in case of a local execution
        @rtype tuple of (QProcess, bool, str)
        """
        global origPathEnv
        
        if not venvName:
            venvName = Preferences.getDebugger("Python3VirtualEnv")
        venvManager = e5App().getObject("VirtualEnvManager")
        interpreter = venvManager.getVirtualenvInterpreter(venvName)
        execPath = venvManager.getVirtualenvExecPath(venvName)
        if interpreter == "":
            # use the interpreter used to run eric for identical variants
            interpreter = sys.executable.replace("w.exe", ".exe")
        if interpreter == "":
            E5MessageBox.critical(
                None,
                self.tr("Start Debugger"),
                self.tr(
                    """<p>No suitable Python3 environment configured.</p>""")
            )
            return None, False, ""
        
        self.__inShutdown = False
        
        debugClientType = Preferences.getDebugger("DebugClientType3")
        if debugClientType == "standard":
            debugClient = os.path.join(getConfig('ericDir'),
                                       "DebugClients", "Python",
                                       "DebugClient.py")
        else:
            debugClient = Preferences.getDebugger("DebugClient3")
            if debugClient == "":
                debugClient = os.path.join(sys.path[0],
                                           "DebugClients", "Python",
                                           "DebugClient.py")
        
        if configOverride and configOverride["enable"]:
            redirect = str(configOverride["redirect"])
        else:
            redirect = str(Preferences.getDebugger("Python3Redirect"))
        noencoding = (Preferences.getDebugger("Python3NoEncoding") and
                      '--no-encoding' or '')
        multiprocessEnabled = (
            '--multiprocess' if Preferences.getDebugger("MultiProcessEnabled")
            else ''
        )
        
        if Preferences.getDebugger("RemoteDbgEnabled"):
            ipaddr = self.debugServer.getHostAddress(False)
            rexec = Preferences.getDebugger("RemoteExecution")
            rhost = Preferences.getDebugger("RemoteHost")
            if rhost == "":
                rhost = "localhost"
            if rexec:
                args = Utilities.parseOptionString(rexec) + [
                    rhost, interpreter, debugClient]
                if noencoding:
                    args.append(noencoding)
                if multiprocessEnabled:
                    args.append(multiprocessEnabled)
                args.extend([str(port), redirect, ipaddr])
                if Utilities.isWindowsPlatform():
                    if not os.path.splitext(args[0])[1]:
                        for ext in [".exe", ".com", ".cmd", ".bat"]:
                            prog = Utilities.getExecutablePath(args[0] + ext)
                            if prog:
                                args[0] = prog
                                break
                else:
                    args[0] = Utilities.getExecutablePath(args[0])
                process = self.__startProcess(args[0], args[1:],
                                              workingDir=workingDir)
                if process is None:
                    E5MessageBox.critical(
                        None,
                        self.tr("Start Debugger"),
                        self.tr(
                            """<p>The debugger backend could not be"""
                            """ started.</p>"""))
                
                # set translation function
                if Preferences.getDebugger("PathTranslation"):
                    self.translateRemote = Preferences.getDebugger(
                        "PathTranslationRemote")
                    self.translateRemoteWindows = "\\" in self.translateRemote
                    self.translateLocal = Preferences.getDebugger(
                        "PathTranslationLocal")
                    self.translate = self.__remoteTranslation
                    self.translateLocalWindows = "\\" in self.translateLocal
                else:
                    self.translate = self.__identityTranslation
                return process, self.__isNetworked, ""
        
        # set translation function
        self.translate = self.__identityTranslation
        
        # setup the environment for the debugger
        if Preferences.getDebugger("DebugEnvironmentReplace"):
            clientEnv = {}
        else:
            clientEnv = os.environ.copy()
            if originalPathString:
                clientEnv["PATH"] = originalPathString
        envlist = shlex.split(
            Preferences.getDebugger("DebugEnvironment"))
        for el in envlist:
            try:
                key, value = el.split('=', 1)
                clientEnv[str(key)] = str(value)
            except ValueError:
                pass
        if execPath:
            if "PATH" in clientEnv:
                clientEnv["PATH"] = os.pathsep.join(
                    [execPath, clientEnv["PATH"]])
            else:
                clientEnv["PATH"] = execPath
        
        ipaddr = self.debugServer.getHostAddress(True)
        if runInConsole or Preferences.getDebugger("ConsoleDbgEnabled"):
            ccmd = Preferences.getDebugger("ConsoleDbgCommand")
            if ccmd:
                args = Utilities.parseOptionString(ccmd) + [
                    interpreter, os.path.abspath(debugClient)]
                if noencoding:
                    args.append(noencoding)
                if multiprocessEnabled:
                    args.append(multiprocessEnabled)
                args.extend([str(port), '0', ipaddr])
                args[0] = Utilities.getExecutablePath(args[0])
                process = self.__startProcess(args[0], args[1:], clientEnv,
                                              workingDir=workingDir)
                if process is None:
                    E5MessageBox.critical(
                        None,
                        self.tr("Start Debugger"),
                        self.tr(
                            """<p>The debugger backend could not be"""
                            """ started.</p>"""))
                return process, self.__isNetworked, interpreter
        
        args = [debugClient]
        if noencoding:
            args.append(noencoding)
        if multiprocessEnabled:
            args.append(multiprocessEnabled)
        args.extend([str(port), redirect, ipaddr])
        process = self.__startProcess(interpreter, args, clientEnv,
                                      workingDir=workingDir)
        if process is None:
            self.__startedVenv = ""
            E5MessageBox.critical(
                None,
                self.tr("Start Debugger"),
                self.tr(
                    """<p>The debugger backend could not be started.</p>"""))
        else:
            self.__startedVenv = venvName
        
        return process, self.__isNetworked, interpreter
    
    def startRemoteForProject(self, port, runInConsole, venvName,
                              originalPathString, workingDir=None,
                              configOverride=None):
        """
        Public method to start a remote Python interpreter for a project.
        
        @param port port number the debug server is listening on
        @type int
        @param runInConsole flag indicating to start the debugger in a
            console window
        @type bool
        @param venvName name of the virtual environment to be used
        @type str
        @param originalPathString original PATH environment variable
        @type str
        @param workingDir directory to start the debugger client in
        @type str
        @param configOverride dictionary containing the global config override
            data
        @type dict
        @return client process object, a flag to indicate a network connection
            and the name of the interpreter in case of a local execution
        @rtype tuple of (QProcess, bool, str)
        """
        global origPathEnv
        
        project = e5App().getObject("Project")
        if not project.isDebugPropertiesLoaded():
            return None, self.__isNetworked, ""
        
        # start debugger with project specific settings
        debugClient = project.getDebugProperty("DEBUGCLIENT")
        if not venvName:
            venvName = project.getDebugProperty("VIRTUALENV")
        if not venvName and project.getProjectLanguage() == "Python3":
            venvName = Preferences.getDebugger("Python3VirtualEnv")
        
        if configOverride and configOverride["enable"]:
            redirect = str(configOverride["redirect"])
        else:
            redirect = str(project.getDebugProperty("REDIRECT"))
        noencoding = (
            '--no-encoding' if project.getDebugProperty("NOENCODING") else ''
        )
        multiprocessEnabled = (
            '--multiprocess' if Preferences.getDebugger("MultiProcessEnabled")
            else ''
        )
        
        venvManager = e5App().getObject("VirtualEnvManager")
        interpreter = venvManager.getVirtualenvInterpreter(venvName)
        execPath = venvManager.getVirtualenvExecPath(venvName)
        if (
            interpreter == "" and
            project.getProjectLanguage().startswith("Python")
        ):
            interpreter = sys.executable.replace("w.exe", ".exe")
        if interpreter == "":
            E5MessageBox.critical(
                None,
                self.tr("Start Debugger"),
                self.tr(
                    """<p>No suitable Python3 environment configured.</p>""")
            )
            return None, self.__isNetworked, ""
        
        self.__inShutdown = False
        
        if project.getDebugProperty("REMOTEDEBUGGER"):
            ipaddr = self.debugServer.getHostAddress(False)
            rexec = project.getDebugProperty("REMOTECOMMAND")
            rhost = project.getDebugProperty("REMOTEHOST")
            if rhost == "":
                rhost = "localhost"
            if rexec:
                args = Utilities.parseOptionString(rexec) + [
                    rhost, interpreter, debugClient]
                if noencoding:
                    args.append(noencoding)
                if multiprocessEnabled:
                    args.append(multiprocessEnabled)
                args.extend([str(port), redirect, ipaddr])
                if Utilities.isWindowsPlatform():
                    if not os.path.splitext(args[0])[1]:
                        for ext in [".exe", ".com", ".cmd", ".bat"]:
                            prog = Utilities.getExecutablePath(args[0] + ext)
                            if prog:
                                args[0] = prog
                                break
                else:
                    args[0] = Utilities.getExecutablePath(args[0])
                process = self.__startProcess(args[0], args[1:],
                                              workingDir=workingDir)
                if process is None:
                    E5MessageBox.critical(
                        None,
                        self.tr("Start Debugger"),
                        self.tr(
                            """<p>The debugger backend could not be"""
                            """ started.</p>"""))
                # set translation function
                if project.getDebugProperty("PATHTRANSLATION"):
                    self.translateRemote = project.getDebugProperty(
                        "REMOTEPATH")
                    self.translateRemoteWindows = "\\" in self.translateRemote
                    self.translateLocal = project.getDebugProperty("LOCALPATH")
                    self.translateLocalWindows = "\\" in self.translateLocal
                    self.translate = self.__remoteTranslation
                else:
                    self.translate = self.__identityTranslation
                return process, self.__isNetworked, ""
            else:
                # remote shell command is missing
                return None, self.__isNetworked, ""
        
        # set translation function
        self.translate = self.__identityTranslation
        
        # setup the environment for the debugger
        if project.getDebugProperty("ENVIRONMENTOVERRIDE"):
            clientEnv = {}
        else:
            clientEnv = os.environ.copy()
            if originalPathString:
                clientEnv["PATH"] = originalPathString
        envlist = shlex.split(
            project.getDebugProperty("ENVIRONMENTSTRING"))
        for el in envlist:
            try:
                key, value = el.split('=', 1)
                clientEnv[str(key)] = str(value)
            except ValueError:
                pass
        if execPath:
            if "PATH" in clientEnv:
                clientEnv["PATH"] = os.pathsep.join(
                    [execPath, clientEnv["PATH"]])
            else:
                clientEnv["PATH"] = execPath
        
        ipaddr = self.debugServer.getHostAddress(True)
        if runInConsole or project.getDebugProperty("CONSOLEDEBUGGER"):
            ccmd = (project.getDebugProperty("CONSOLECOMMAND") or
                    Preferences.getDebugger("ConsoleDbgCommand"))
            if ccmd:
                args = Utilities.parseOptionString(ccmd) + [
                    interpreter, os.path.abspath(debugClient)]
                if noencoding:
                    args.append(noencoding)
                if multiprocessEnabled:
                    args.append(multiprocessEnabled)
                args.extend([str(port), '0', ipaddr])
                args[0] = Utilities.getExecutablePath(args[0])
                process = self.__startProcess(args[0], args[1:], clientEnv,
                                              workingDir=workingDir)
                if process is None:
                    E5MessageBox.critical(
                        None,
                        self.tr("Start Debugger"),
                        self.tr(
                            """<p>The debugger backend could not be"""
                            """ started.</p>"""))
                return process, self.__isNetworked, interpreter
        
        args = [debugClient]
        if noencoding:
            args.append(noencoding)
        if multiprocessEnabled:
            args.append(multiprocessEnabled)
        args.extend([str(port), redirect, ipaddr])
        process = self.__startProcess(interpreter, args, clientEnv,
                                      workingDir=workingDir)
        if process is None:
            self.__startedVenv = ""
            E5MessageBox.critical(
                None,
                self.tr("Start Debugger"),
                self.tr(
                    """<p>The debugger backend could not be started.</p>"""))
        else:
            self.__startedVenv = venvName
        
        return process, self.__isNetworked, interpreter
    
    def getClientCapabilities(self):
        """
        Public method to retrieve the debug clients capabilities.
        
        @return debug client capabilities
        @rtype int
        """
        return self.clientCapabilities
    
    def newConnection(self, sock):
        """
        Public slot to handle a new connection.
        
        @param sock reference to the socket object
        @type QTcpSocket
        @return flag indicating success
        @rtype bool
        """
        self.__pendingConnections.append(sock)
        
        sock.readyRead.connect(lambda: self.__parseClientLine(sock))
        sock.disconnected.connect(lambda: self.__socketDisconnected(sock))
        
        return True
    
    def __assignDebuggerId(self, sock, debuggerId):
        """
        Private method to set the debugger id for a recent debugger connection
        attempt.
        
        @param sock reference to the socket object
        @type QTcpSocket
        @param debuggerId id of the connected debug client
        @type str
        """
        if sock in self.__pendingConnections:
            self.__connections[debuggerId] = sock
            self.__pendingConnections.remove(sock)
            
            if self.__master is None:
                self.__master = debuggerId
                # Get the remote clients capabilities
                self.remoteCapabilities(debuggerId)
            
            self.debugServer.signalClientDebuggerId(debuggerId)
            
            if debuggerId == self.__master:
                self.__flush()
                self.debugServer.masterClientConnected()
            
            self.debugServer.initializeClient(debuggerId)
            
            # perform auto-continue except for master
            if (
                debuggerId != self.__master and
                self.__autoContinue and
                not self.__isStepCommand
            ):
                QTimer.singleShot(
                    0, lambda: self.remoteContinue(debuggerId))
    
    def __socketDisconnected(self, sock):
        """
        Private slot handling a socket disconnecting.
        
        @param sock reference to the disconnected socket
        @type QTcpSocket
        """
        for debuggerId in self.__connections:
            if self.__connections[debuggerId] is sock:
                del self.__connections[debuggerId]
                if debuggerId == self.__master:
                    self.__master = None
                if debuggerId in self.__autoContinued:
                    self.__autoContinued.remove(debuggerId)
                if not self.__inShutdown:
                    self.debugServer.signalClientDisconnected(debuggerId)
                break
        else:
            if sock in self.__pendingConnections:
                self.__pendingConnections.remove(sock)
        
        if not self.__connections:
            # no active connections anymore
            with contextlib.suppress(RuntimeError):
                self.debugServer.signalLastClientExited()
                # debug server object might have been deleted already
                # ignore this
            self.__autoContinued.clear()
            self.debugServer.startClient()
    
    def getDebuggerIds(self):
        """
        Public method to return the IDs of the connected debugger backends.
        
        @return list of connected debugger backend IDs
        @rtype list of str
        """
        return sorted(self.__connections.keys())
    
    def __flush(self):
        """
        Private slot to flush the queue.
        """
        if self.__master:
            # Send commands that were waiting for the connection.
            for cmd in self.queue:
                self.__writeJsonCommandToSocket(
                    cmd, self.__connections[self.__master])
        
        self.queue = []
    
    def shutdown(self):
        """
        Public method to cleanly shut down.
        
        It closes our sockets and shuts down the debug clients.
        (Needed on Win OS)
        """
        if not self.__master:
            return
        
        self.__inShutdown = True
        
        while self.__connections:
            debuggerId, sock = self.__connections.popitem()
            self.__shutdownSocket(sock)
        
        while self.__pendingConnections:
            sock = self.__pendingConnections.pop()
            self.__shutdownSocket(sock)
        
        # reinitialize
        self.queue = []
        
        self.__master = None
    
    def __shutdownSocket(self, sock):
        """
        Private slot to shut down a socket.
        
        @param sock reference to the socket
        @type QTcpSocket
        """
        # do not want any slots called during shutdown
        sock.readyRead.disconnect()
        sock.disconnected.disconnect()

        # close down socket, and shut down client as well.
        self.__sendJsonCommand("RequestShutdown", {}, sock=sock)
        sock.flush()
        sock.close()
        
        sock.setParent(None)
        sock.deleteLater()
        del sock
    
    def isConnected(self):
        """
        Public method to test, if a debug client has connected.
        
        @return flag indicating the connection status
        @rtype bool
        """
        return bool(self.__connections)
    
    def remoteEnvironment(self, env):
        """
        Public method to set the environment for a program to debug, run, ...
        
        @param env environment settings
        @type dict
        """
        self.__sendJsonCommand("RequestEnvironment", {"environment": env},
                               self.__master)
    
    def remoteLoad(self, fn, argv, wd, traceInterpreter=False,
                   autoContinue=True, enableMultiprocess=False):
        """
        Public method to load a new program to debug.
        
        @param fn the filename to debug
        @type str
        @param argv the commandline arguments to pass to the program
        @type str
        @param wd the working directory for the program
        @type str
        @param traceInterpreter flag indicating if the interpreter library
            should be traced as well
        @type bool
        @param autoContinue flag indicating, that the debugger should not
            stop at the first executable line
        @type bool
        @param enableMultiprocess flag indicating to perform multiprocess
            debugging
        @type bool
        """
        self.__autoContinue = autoContinue
        self.__scriptName = os.path.abspath(fn)
        self.__isStepCommand = False
        
        wd = self.translate(wd, False)
        fn = self.translate(os.path.abspath(fn), False)
        self.__sendJsonCommand("RequestLoad", {
            "workdir": wd,
            "filename": fn,
            "argv": Utilities.parseOptionString(argv),
            "traceInterpreter": traceInterpreter,
            "multiprocess": enableMultiprocess,
        }, self.__master)
    
    def remoteRun(self, fn, argv, wd):
        """
        Public method to load a new program to run.
        
        @param fn the filename to run
        @type str
        @param argv the commandline arguments to pass to the program
        @type str
        @param wd the working directory for the program
        @type str
        """
        self.__scriptName = os.path.abspath(fn)
        
        wd = self.translate(wd, False)
        fn = self.translate(os.path.abspath(fn), False)
        self.__sendJsonCommand("RequestRun", {
            "workdir": wd,
            "filename": fn,
            "argv": Utilities.parseOptionString(argv),
        }, self.__master)
    
    def remoteCoverage(self, fn, argv, wd, erase=False):
        """
        Public method to load a new program to collect coverage data.
        
        @param fn the filename to run
        @type str
        @param argv the commandline arguments to pass to the program
        @type str
        @param wd the working directory for the program
        @type str
        @param erase flag indicating that coverage info should be
            cleared first
        @type bool
        """
        self.__scriptName = os.path.abspath(fn)
        
        wd = self.translate(wd, False)
        fn = self.translate(os.path.abspath(fn), False)
        self.__sendJsonCommand("RequestCoverage", {
            "workdir": wd,
            "filename": fn,
            "argv": Utilities.parseOptionString(argv),
            "erase": erase,
        }, self.__master)
    
    def remoteProfile(self, fn, argv, wd, erase=False):
        """
        Public method to load a new program to collect profiling data.
        
        @param fn the filename to run
        @type str
        @param argv the commandline arguments to pass to the program
        @type str
        @param wd the working directory for the program
        @type str
        @param erase flag indicating that timing info should be cleared
            first
        @type bool
        """
        self.__scriptName = os.path.abspath(fn)
        
        wd = self.translate(wd, False)
        fn = self.translate(os.path.abspath(fn), False)
        self.__sendJsonCommand("RequestProfile", {
            "workdir": wd,
            "filename": fn,
            "argv": Utilities.parseOptionString(argv),
            "erase": erase,
        }, self.__master)
    
    def remoteStatement(self, debuggerId, stmt):
        """
        Public method to execute a Python statement.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param stmt the Python statement to execute.
        @type str
        """
        self.__sendJsonCommand("ExecuteStatement", {
            "statement": stmt,
        }, debuggerId)
    
    def remoteStep(self, debuggerId):
        """
        Public method to single step the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__isStepCommand = True
        self.__sendJsonCommand("RequestStep", {}, debuggerId)
    
    def remoteStepOver(self, debuggerId):
        """
        Public method to step over the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__isStepCommand = True
        self.__sendJsonCommand("RequestStepOver", {}, debuggerId)
    
    def remoteStepOut(self, debuggerId):
        """
        Public method to step out the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__isStepCommand = True
        self.__sendJsonCommand("RequestStepOut", {}, debuggerId)
    
    def remoteStepQuit(self, debuggerId):
        """
        Public method to stop the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__isStepCommand = True
        self.__sendJsonCommand("RequestStepQuit", {}, debuggerId)
    
    def remoteContinue(self, debuggerId, special=False):
        """
        Public method to continue the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param special flag indicating a special continue operation
        @type bool
        """
        self.__isStepCommand = False
        self.__sendJsonCommand("RequestContinue", {
            "special": special,
        }, debuggerId)
    
    def remoteContinueUntil(self, debuggerId, line):
        """
        Public method to continue the debugged program to the given line
        or until returning from the current frame.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param line the new line, where execution should be continued to
        @type int
        """
        self.__isStepCommand = False
        self.__sendJsonCommand("RequestContinueUntil", {
            "newLine": line,
        }, debuggerId)
    
    def remoteMoveIP(self, debuggerId, line):
        """
        Public method to move the instruction pointer to a different line.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param line the new line, where execution should be continued
        @type int
        """
        self.__sendJsonCommand("RequestMoveIP", {
            "newLine": line,
        }, debuggerId)
    
    def remoteBreakpoint(self, debuggerId, fn, line, setBreakpoint, cond=None,
                         temp=False):
        """
        Public method to set or clear a breakpoint.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param fn filename the breakpoint belongs to
        @type str
        @param line linenumber of the breakpoint
        @type int
        @param setBreakpoint flag indicating setting or resetting a breakpoint
        @type bool
        @param cond condition of the breakpoint
        @type str
        @param temp flag indicating a temporary breakpoint
        @type bool
        """
        debuggerList = ([debuggerId] if debuggerId
                        else list(self.__connections.keys()))
        for debuggerId in debuggerList:
            self.__sendJsonCommand("RequestBreakpoint", {
                "filename": self.translate(fn, False),
                "line": line,
                "temporary": temp,
                "setBreakpoint": setBreakpoint,
                "condition": cond,
            }, debuggerId)
    
    def remoteBreakpointEnable(self, debuggerId, fn, line, enable):
        """
        Public method to enable or disable a breakpoint.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param fn filename the breakpoint belongs to
        @type str
        @param line linenumber of the breakpoint
        @type int
        @param enable flag indicating enabling or disabling a breakpoint
        @type bool
        """
        debuggerList = ([debuggerId] if debuggerId
                        else list(self.__connections.keys()))
        for debuggerId in debuggerList:
            self.__sendJsonCommand("RequestBreakpointEnable", {
                "filename": self.translate(fn, False),
                "line": line,
                "enable": enable,
            }, debuggerId)
    
    def remoteBreakpointIgnore(self, debuggerId, fn, line, count):
        """
        Public method to ignore a breakpoint the next couple of occurrences.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param fn filename the breakpoint belongs to
        @type str
        @param line linenumber of the breakpoint
        @type int
        @param count number of occurrences to ignore
        @type int
        """
        debuggerList = ([debuggerId] if debuggerId
                        else list(self.__connections.keys()))
        for debuggerId in debuggerList:
            self.__sendJsonCommand("RequestBreakpointIgnore", {
                "filename": self.translate(fn, False),
                "line": line,
                "count": count,
            }, debuggerId)
    
    def remoteWatchpoint(self, debuggerId, cond, setWatch, temp=False):
        """
        Public method to set or clear a watch expression.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param cond expression of the watch expression
        @type str
        @param setWatch flag indicating setting or resetting a watch expression
        @type bool
        @param temp flag indicating a temporary watch expression
        @type bool
        """
        debuggerList = ([debuggerId] if debuggerId
                        else list(self.__connections.keys()))
        for debuggerId in debuggerList:
            # cond is combination of cond and special (s. watch expression
            # viewer)
            self.__sendJsonCommand("RequestWatch", {
                "temporary": temp,
                "setWatch": setWatch,
                "condition": cond,
            }, debuggerId)
    
    def remoteWatchpointEnable(self, debuggerId, cond, enable):
        """
        Public method to enable or disable a watch expression.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param cond expression of the watch expression
        @type str
        @param enable flag indicating enabling or disabling a watch expression
        @type bool
        """
        debuggerList = ([debuggerId] if debuggerId
                        else list(self.__connections.keys()))
        for debuggerId in debuggerList:
            # cond is combination of cond and special (s. watch expression
            # viewer)
            self.__sendJsonCommand("RequestWatchEnable", {
                "condition": cond,
                "enable": enable,
            }, debuggerId)
    
    def remoteWatchpointIgnore(self, debuggerId, cond, count):
        """
        Public method to ignore a watch expression the next couple of
        occurrences.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param cond expression of the watch expression
        @type str
        @param count number of occurrences to ignore
        @type int
        """
        debuggerList = ([debuggerId] if debuggerId
                        else list(self.__connections.keys()))
        for debuggerId in debuggerList:
            # cond is combination of cond and special (s. watch expression
            # viewer)
            self.__sendJsonCommand("RequestWatchIgnore", {
                "condition": cond,
                "count": count,
            }, debuggerId)
    
    def remoteRawInput(self, debuggerId, inputString):
        """
        Public method to send the raw input to the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param inputString the raw input
        @type str
        """
        self.__sendJsonCommand("RawInput", {
            "input": inputString,
        }, debuggerId)
    
    def remoteThreadList(self, debuggerId):
        """
        Public method to request the list of threads from the client.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__sendJsonCommand("RequestThreadList", {}, debuggerId)
    
    def remoteSetThread(self, debuggerId, tid):
        """
        Public method to request to set the given thread as current thread.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param tid id of the thread
        @type int
        """
        self.__sendJsonCommand("RequestThreadSet", {
            "threadID": tid,
        }, debuggerId)
    
    def remoteClientStack(self, debuggerId):
        """
        Public method to request the stack of the main thread.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__sendJsonCommand("RequestStack", {}, debuggerId)
    
    def remoteClientVariables(self, debuggerId, scope, filterList, framenr=0,
                              maxSize=0):
        """
        Public method to request the variables of the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param scope the scope of the variables (0 = local, 1 = global)
        @type int
        @param filterList list of variable types to filter out
        @type list of str
        @param framenr framenumber of the variables to retrieve
        @type int
        @param maxSize maximum size the formatted value of a variable will
            be shown. If it is bigger than that, a 'too big' indication will
            be given (@@TOO_BIG_TO_SHOW@@).
        @type int
        """
        self.__sendJsonCommand("RequestVariables", {
            "frameNumber": framenr,
            "scope": scope,
            "filters": filterList,
            "maxSize": maxSize,
        }, debuggerId)
    
    def remoteClientVariable(self, debuggerId, scope, filterList, var,
                             framenr=0, maxSize=0):
        """
        Public method to request the variables of the debugged program.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param scope the scope of the variables (0 = local, 1 = global)
        @type int
        @param filterList list of variable types to filter out
        @type list of str
        @param var list encoded name of variable to retrieve
        @type list of str
        @param framenr framenumber of the variables to retrieve
        @type int
        @param maxSize maximum size the formatted value of a variable will
            be shown. If it is bigger than that, a 'too big' indication will
            be given (@@TOO_BIG_TO_SHOW@@).
        @type int
        """
        self.__sendJsonCommand("RequestVariable", {
            "variable": var,
            "frameNumber": framenr,
            "scope": scope,
            "filters": filterList,
            "maxSize": maxSize,
        }, debuggerId)
    
    def remoteClientDisassembly(self, debuggerId):
        """
        Public method to ask the client for the latest traceback disassembly.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__sendJsonCommand("RequestDisassembly", {}, debuggerId)
    
    def remoteClientSetFilter(self, debuggerId, scope, filterStr):
        """
        Public method to set a variables filter list.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param scope the scope of the variables (0 = local, 1 = global)
        @type int
        @param filterStr regexp string for variable names to filter out
        @type str
        """
        self.__sendJsonCommand("RequestSetFilter", {
            "scope": scope,
            "filter": filterStr,
        }, debuggerId)
    
    def setCallTraceEnabled(self, debuggerId, on):
        """
        Public method to set the call trace state.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param on flag indicating to enable the call trace function
        @type bool
        """
        self.__sendJsonCommand("RequestCallTrace", {
            "enable": on,
        }, debuggerId)
    
    def remoteNoDebugList(self, debuggerId, noDebugList):
        """
        Public method to set a list of programs not to be debugged.
        
        The programs given in the list will not be run under the control
        of the multi process debugger.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param noDebugList list of Python programs not to be debugged
        @type list of str
        """
        self.__sendJsonCommand("RequestSetNoDebugList", {
            "noDebug": noDebugList,
        }, debuggerId)
    
    def remoteBanner(self):
        """
        Public slot to get the banner info of the remote client.
        """
        self.__sendJsonCommand("RequestBanner", {})
    
    def remoteCapabilities(self, debuggerId):
        """
        Public slot to get the debug clients capabilities.
        
        @param debuggerId ID of the debugger backend
        @type str
        """
        self.__sendJsonCommand("RequestCapabilities", {}, debuggerId)
    
    def remoteCompletion(self, debuggerId, text):
        """
        Public slot to get the a list of possible commandline completions
        from the remote client.
        
        @param debuggerId ID of the debugger backend
        @type str
        @param text the text to be completed
        @type str
        """
        self.__sendJsonCommand("RequestCompletion", {
            "text": text,
        }, debuggerId)
    
    def remoteUTDiscover(self, syspath, workdir, discoveryStart):
        """
        Public method to perform a test case discovery.
        
        @param syspath list of directories to be added to sys.path on the
            remote side
        @type list of str
        @param workdir path name of the working directory
        @type str
        @param discoveryStart directory to start auto-discovery at
        @type str
        """
        self.__sendJsonCommand("RequestUTDiscover", {
            "syspath": [] if syspath is None else syspath,
            "workdir": workdir,
            "discoverystart": discoveryStart,
        })
    
    def remoteUTPrepare(self, fn, tn, tfn, failed, cov, covname, coverase,
                        syspath, workdir, discover, discoveryStart, testCases,
                        debug):
        """
        Public method to prepare a new unittest run.
        
        @param fn name of file to load
        @type str
        @param tn name of test to load
        @type str
        @param tfn test function name to load tests from
        @type str
        @param failed list of failed test, if only failed test should be run
        @type list of str
        @param cov flag indicating collection of coverage data is requested
        @type bool
        @param covname name of file to be used to assemble the coverage caches
            filename
        @type str
        @param coverase flag indicating erasure of coverage data is requested
        @type bool
        @param syspath list of directories to be added to sys.path on the
            remote side
        @type list of str
        @param workdir path name of the working directory
        @type str
        @param discover flag indicating to discover the tests automatically
        @type bool
        @param discoveryStart directory to start auto-discovery at
        @type str
        @param testCases list of test cases to be loaded
        @type list of str
        @param debug flag indicating to run unittest with debugging
        @type bool
        """
        if fn:
            self.__scriptName = os.path.abspath(fn)
            
            fn = self.translate(os.path.abspath(fn), False)
        else:
            self.__scriptName = "unittest discover"
        
        self.__sendJsonCommand("RequestUTPrepare", {
            "filename": fn,
            "testname": tn,
            "testfunctionname": tfn,
            "failed": failed,
            "coverage": cov,
            "coveragefile": covname,
            "coverageerase": coverase,
            "syspath": [] if syspath is None else syspath,
            "workdir": workdir,
            "discover": discover,
            "discoverystart": discoveryStart,
            "testcases": [] if testCases is None else testCases,
            "debug": debug,
        })
    
    def remoteUTRun(self, debug, failfast):
        """
        Public method to start a unittest run.
        
        @param debug flag indicating to run unittest with debugging
        @type bool
        @param failfast flag indicating to stop at the first error
        @type bool
        """
        if debug:
            self.__autoContinue = True
        self.__sendJsonCommand("RequestUTRun", {
            "debug": debug,
            "failfast": failfast,
        })
    
    def remoteUTStop(self):
        """
        Public method to stop a unittest run.
        """
        self.__sendJsonCommand("RequestUTStop", {})
    
    def __parseClientLine(self, sock):
        """
        Private method to handle data from the client.
        
        @param sock reference to the socket to read data from
        @type QTcpSocket
        """
        while sock and sock.canReadLine():
            qs = sock.readLine()
            line = bytes(qs).decode(
                encoding=Preferences.getSystem("StringEncoding"))
            
            logging.debug("<Debug-Server> %s", line)
##            print("Server: ", line)    ## debug    # __IGNORE_WARNING_M891__
            
            self.__handleJsonCommand(line, sock)
    
    def __handleJsonCommand(self, jsonStr, sock):
        """
        Private method to handle a command or response serialized as a
        JSON string.
        
        @param jsonStr string containing the command or response received
            from the debug backend
        @type str
        @param sock reference to the socket the data was received from
        @type QTcpSocket
        """
        import json
        
        try:
            commandDict = json.loads(jsonStr.strip())
        except (TypeError, ValueError) as err:
            E5MessageBox.critical(
                None,
                self.tr("Debug Protocol Error"),
                self.tr("""<p>The response received from the debugger"""
                        """ backend could not be decoded. Please report"""
                        """ this issue with the received data to the"""
                        """ eric bugs email address.</p>"""
                        """<p>Error: {0}</p>"""
                        """<p>Data:<br/>{1}</p>""").format(
                    str(err), Utilities.html_encode(jsonStr.strip())),
                E5MessageBox.StandardButtons(
                    E5MessageBox.Ok))
            return
        
        method = commandDict["method"]
        params = commandDict["params"]
        
        if method == "DebuggerId":
            self.__assignDebuggerId(sock, params["debuggerId"])
        
        elif method == "ClientOutput":
            self.debugServer.signalClientOutput(
                params["text"], params["debuggerId"])
        
        elif method in ["ResponseLine", "ResponseStack"]:
            # Check if obsolete thread was clicked
            if params["stack"] == []:
                # Request updated list
                self.remoteThreadList(params["debuggerId"])
                return
            for s in params["stack"]:
                s[0] = self.translate(s[0], True)
            cf = params["stack"][0]
            if (
                self.__autoContinue and
                params["debuggerId"] not in self.__autoContinued
            ):
                self.__autoContinued.append(params["debuggerId"])
                QTimer.singleShot(
                    0, lambda: self.remoteContinue(params["debuggerId"]))
            else:
                self.debugServer.signalClientLine(
                    cf[0], int(cf[1]), params["debuggerId"],
                    method == "ResponseStack", threadName=params["threadName"])
                self.debugServer.signalClientStack(
                    params["stack"], params["debuggerId"],
                    threadName=params["threadName"])
        
        elif method == "CallTrace":
            isCall = params["event"].lower() == "c"
            fromInfo = params["from"]
            toInfo = params["to"]
            self.debugServer.signalClientCallTrace(
                isCall,
                fromInfo["filename"], str(fromInfo["linenumber"]),
                fromInfo["codename"],
                toInfo["filename"], str(toInfo["linenumber"]),
                toInfo["codename"],
                params["debuggerId"])
        
        elif method == "ResponseVariables":
            self.debugServer.signalClientVariables(
                params["scope"], params["variables"], params["debuggerId"])
        
        elif method == "ResponseVariable":
            self.debugServer.signalClientVariable(
                params["scope"], [params["variable"]] + params["variables"],
                params["debuggerId"])
        
        elif method == "ResponseThreadList":
            self.debugServer.signalClientThreadList(
                params["currentID"], params["threadList"],
                params["debuggerId"])
        
        elif method == "ResponseThreadSet":
            self.debugServer.signalClientThreadSet(params["debuggerId"])
        
        elif method == "ResponseCapabilities":
            self.clientCapabilities = params["capabilities"]
            if params["debuggerId"] == self.__master:
                # signal only for the master connection
                self.debugServer.signalClientCapabilities(
                    params["capabilities"],
                    params["clientType"],
                    self.__startedVenv,
                )
        
        elif method == "ResponseBanner":
            if params["debuggerId"] == self.__master:
                # signal only for the master connection
                self.debugServer.signalClientBanner(
                    params["version"],
                    params["platform"],
                    self.__startedVenv,
                )
        
        elif method == "ResponseOK":
            self.debugServer.signalClientStatement(False, params["debuggerId"])
        
        elif method == "ResponseContinue":
            self.debugServer.signalClientStatement(True, params["debuggerId"])
        
        elif method == "RequestRaw":
            self.debugServer.signalClientRawInput(
                params["prompt"], params["echo"], params["debuggerId"])
        
        elif method == "ResponseBPConditionError":
            fn = self.translate(params["filename"], True)
            self.debugServer.signalClientBreakConditionError(
                fn, params["line"], params["debuggerId"])
        
        elif method == "ResponseClearBreakpoint":
            fn = self.translate(params["filename"], True)
            self.debugServer.signalClientClearBreak(
                fn, params["line"], params["debuggerId"])
        
        elif method == "ResponseWatchConditionError":
            self.debugServer.signalClientWatchConditionError(
                params["condition"], params["debuggerId"])
        
        elif method == "ResponseClearWatch":
            self.debugServer.signalClientClearWatch(
                params["condition"], params["debuggerId"])
        
        elif method == "ResponseDisassembly":
            self.debugServer.signalClientDisassembly(
                params["disassembly"], params["debuggerId"])
        
        elif method == "ResponseException":
            exctype = params["type"]
            excmessage = params["message"]
            stack = params["stack"]
            if stack:
                for stackEntry in stack:
                    stackEntry[0] = self.translate(stackEntry[0], True)
                if stack[0] and stack[0][0] == "<string>":
                    for stackEntry in stack:
                        if stackEntry[0] == "<string>":
                            stackEntry[0] = self.__scriptName
                        else:
                            break
            
            self.debugServer.signalClientException(
                exctype, excmessage, stack, params["debuggerId"],
                params["threadName"])
        
        elif method == "ResponseSyntax":
            self.debugServer.signalClientSyntaxError(
                params["message"], self.translate(params["filename"], True),
                params["linenumber"], params["characternumber"],
                params["debuggerId"], params["threadName"])
        
        elif method == "ResponseSignal":
            self.debugServer.signalClientSignal(
                params["message"], self.translate(params["filename"], True),
                params["linenumber"], params["function"], params["arguments"],
                params["debuggerId"])
        
        elif method == "ResponseExit":
            self.__scriptName = ""
            self.debugServer.signalClientExit(
                params["program"], params["status"], params["message"],
                params["debuggerId"])
            if params["debuggerId"] == self.__master:
                self.debugServer.signalMainClientExit()
        
        elif method == "PassiveStartup":
            self.debugServer.passiveStartUp(
                self.translate(params["filename"], True), params["exceptions"],
                params["debuggerId"])
        
        elif method == "ResponseCompletion":
            self.debugServer.signalClientCompletionList(
                params["completions"], params["text"], params["debuggerId"])
        
        ###################################################################
        ## Unit test related stuff is not done with multi processing
        ###################################################################
        
        elif method == "ResponseUTDiscover":
            self.debugServer.clientUtDiscovered(
                params["testCasesList"], params["exception"],
                params["message"])
        
        elif method == "ResponseUTPrepared":
            self.debugServer.clientUtPrepared(
                params["count"], params["exception"], params["message"])
        
        elif method == "ResponseUTFinished":
            self.debugServer.clientUtFinished(params["status"])
        
        elif method == "ResponseUTStartTest":
            self.debugServer.clientUtStartTest(
                params["testname"], params["description"])
        
        elif method == "ResponseUTStopTest":
            self.debugServer.clientUtStopTest()
        
        elif method == "ResponseUTTestFailed":
            self.debugServer.clientUtTestFailed(
                params["testname"], params["traceback"], params["id"])
        
        elif method == "ResponseUTTestErrored":
            self.debugServer.clientUtTestErrored(
                params["testname"], params["traceback"], params["id"])
        
        elif method == "ResponseUTTestSkipped":
            self.debugServer.clientUtTestSkipped(
                params["testname"], params["reason"], params["id"])
        
        elif method == "ResponseUTTestFailedExpected":
            self.debugServer.clientUtTestFailedExpected(
                params["testname"], params["traceback"], params["id"])
        
        elif method == "ResponseUTTestSucceededUnexpected":
            self.debugServer.clientUtTestSucceededUnexpected(
                params["testname"], params["id"])
    
    def __sendJsonCommand(self, command, params, debuggerId="", sock=None):
        """
        Private method to send a single command to the client.
        
        @param command command name to be sent
        @type str
        @param params dictionary of named parameters for the command
        @type dict
        @param debuggerId id of the debug client to send the command to
        @type str
        @param sock reference to the socket object to be used (only used if
            debuggerId is not given)
        @type QTcpSocket
        """
        import json
        
        commandDict = {
            "jsonrpc": "2.0",
            "method": command,
            "params": params,
        }
        cmd = json.dumps(commandDict) + '\n'
        
        if debuggerId and debuggerId in self.__connections:
            sock = self.__connections[debuggerId]
        elif sock is None and self.__master is not None:
            sock = self.__connections[self.__master]
        if sock is not None:
            self.__writeJsonCommandToSocket(cmd, sock)
        else:
            self.queue.append(cmd)
    
    def __writeJsonCommandToSocket(self, cmd, sock):
        """
        Private method to write a JSON command to the socket.
        
        @param cmd JSON command to be sent
        @type str
        @param sock reference to the socket to write to
        @type QTcpSocket
        """
        data = cmd.encode('utf8', 'backslashreplace')
        length = "{0:09d}".format(len(data))
        sock.write(length.encode() + data)
        sock.flush()


def createDebuggerInterfacePython3(debugServer, passive):
    """
    Module function to create a debugger interface instance.
    
        
    @param debugServer reference to the debug server
    @type DebugServer
    @param passive flag indicating passive connection mode
    @type bool
    @return instantiated debugger interface
    @rtype DebuggerInterfacePython
    """
    return DebuggerInterfacePython(debugServer, passive)


def getRegistryData():
    """
    Module function to get characterizing data for the supported debugger
    interfaces.
    
    @return list of tuples containing the client type, the client capabilities,
        the client file type associations and a reference to the creation
        function
    @rtype list of tuple of (str, int, list of str, function)
    """
    py3Exts = []
    for ext in Preferences.getDebugger("Python3Extensions").split():
        if ext.startswith("."):
            py3Exts.append(ext)
        else:
            py3Exts.append(".{0}".format(ext))
    
    registryData = []
    if py3Exts:
        registryData.append(
            ("Python3", ClientDefaultCapabilities, py3Exts,
                createDebuggerInterfacePython3)
        )
    
    return registryData