Introduce a Python module structure

This is a simple move of Python code that wraps common QEMU
functionality, and are used by a number of different tests
and scripts.

By treating that code as a real Python module, we can more easily:
 * reuse code
 * have a proper place for the module's own unittests
 * apply a more consistent style
 * generate documentation

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Caio Carrara <ccarrara@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190206162901.19082-2-crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>

4 files changed, 7 insertions, 258 deletions

diff --git a/scripts/qmp/__init__.py b/scripts/qmp/__init__.py
deleted file mode 100644
index e69de29bb2..0000000000
--- a/scripts/qmp/__init__.py
+++ /dev/null
diff --git a/scripts/qmp/qemu-ga-client b/scripts/qmp/qemu-ga-client
index e8cb7646a0..30cf8a9a0d 100755
--- a/scripts/qmp/qemu-ga-client
+++ b/scripts/qmp/qemu-ga-client
@@ -37,10 +37,13 @@
 #
 
 from __future__ import print_function
+import os
+import sys
 import base64
 import random
 
-import qmp
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
+from qemu import qmp
 
 
 class QemuGuestAgent(qmp.QEMUMonitorProtocol):
diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
index 770140772d..9fec46e2ed 100755
--- a/scripts/qmp/qmp-shell
+++ b/scripts/qmp/qmp-shell
@@ -66,7 +66,6 @@
 # sent to QEMU, which is useful for debugging and documentation generation.
 
 from __future__ import print_function
-import qmp
 import json
 import ast
 import readline
@@ -76,6 +75,9 @@ import errno
 import atexit
 import shlex
 
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
+from qemu import qmp
+
 class QMPCompleter(list):
     def complete(self, text, state):
         for cmd in self:
diff --git a/scripts/qmp/qmp.py b/scripts/qmp/qmp.py
deleted file mode 100644
index 5c8cf6a056..0000000000
--- a/scripts/qmp/qmp.py
+++ /dev/null
@@ -1,256 +0,0 @@
-# QEMU Monitor Protocol Python class
-#
-# Copyright (C) 2009, 2010 Red Hat Inc.
-#
-# Authors:
-#  Luiz Capitulino <lcapitulino@redhat.com>
-#
-# This work is licensed under the terms of the GNU GPL, version 2.  See
-# the COPYING file in the top-level directory.
-
-import json
-import errno
-import socket
-import logging
-
-
-class QMPError(Exception):
-    pass
-
-
-class QMPConnectError(QMPError):
-    pass
-
-
-class QMPCapabilitiesError(QMPError):
-    pass
-
-
-class QMPTimeoutError(QMPError):
-    pass
-
-
-class QEMUMonitorProtocol(object):
-
-    #: Logger object for debugging messages
-    logger = logging.getLogger('QMP')
-    #: Socket's error class
-    error = socket.error
-    #: Socket's timeout
-    timeout = socket.timeout
-
-    def __init__(self, address, server=False):
-        """
-        Create a QEMUMonitorProtocol class.
-
-        @param address: QEMU address, can be either a unix socket path (string)
-                        or a tuple in the form ( address, port ) for a TCP
-                        connection
-        @param server: server mode listens on the socket (bool)
-        @raise socket.error on socket connection errors
-        @note No connection is established, this is done by the connect() or
-              accept() methods
-        """
-        self.__events = []
-        self.__address = address
-        self.__sock = self.__get_sock()
-        self.__sockfile = None
-        if server:
-            self.__sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-            self.__sock.bind(self.__address)
-            self.__sock.listen(1)
-
-    def __get_sock(self):
-        if isinstance(self.__address, tuple):
-            family = socket.AF_INET
-        else:
-            family = socket.AF_UNIX
-        return socket.socket(family, socket.SOCK_STREAM)
-
-    def __negotiate_capabilities(self):
-        greeting = self.__json_read()
-        if greeting is None or "QMP" not in greeting:
-            raise QMPConnectError
-        # Greeting seems ok, negotiate capabilities
-        resp = self.cmd('qmp_capabilities')
-        if "return" in resp:
-            return greeting
-        raise QMPCapabilitiesError
-
-    def __json_read(self, only_event=False):
-        while True:
-            data = self.__sockfile.readline()
-            if not data:
-                return
-            resp = json.loads(data)
-            if 'event' in resp:
-                self.logger.debug("<<< %s", resp)
-                self.__events.append(resp)
-                if not only_event:
-                    continue
-            return resp
-
-    def __get_events(self, wait=False):
-        """
-        Check for new events in the stream and cache them in __events.
-
-        @param wait (bool): block until an event is available.
-        @param wait (float): If wait is a float, treat it as a timeout value.
-
-        @raise QMPTimeoutError: If a timeout float is provided and the timeout
-                                period elapses.
-        @raise QMPConnectError: If wait is True but no events could be
-                                retrieved or if some other error occurred.
-        """
-
-        # Check for new events regardless and pull them into the cache:
-        self.__sock.setblocking(0)
-        try:
-            self.__json_read()
-        except socket.error as err:
-            if err[0] == errno.EAGAIN:
-                # No data available
-                pass
-        self.__sock.setblocking(1)
-
-        # Wait for new events, if needed.
-        # if wait is 0.0, this means "no wait" and is also implicitly false.
-        if not self.__events and wait:
-            if isinstance(wait, float):
-                self.__sock.settimeout(wait)
-            try:
-                ret = self.__json_read(only_event=True)
-            except socket.timeout:
-                raise QMPTimeoutError("Timeout waiting for event")
-            except:
-                raise QMPConnectError("Error while reading from socket")
-            if ret is None:
-                raise QMPConnectError("Error while reading from socket")
-            self.__sock.settimeout(None)
-
-    def connect(self, negotiate=True):
-        """
-        Connect to the QMP Monitor and perform capabilities negotiation.
-
-        @return QMP greeting dict
-        @raise socket.error on socket connection errors
-        @raise QMPConnectError if the greeting is not received
-        @raise QMPCapabilitiesError if fails to negotiate capabilities
-        """
-        self.__sock.connect(self.__address)
-        self.__sockfile = self.__sock.makefile()
-        if negotiate:
-            return self.__negotiate_capabilities()
-
-    def accept(self):
-        """
-        Await connection from QMP Monitor and perform capabilities negotiation.
-
-        @return QMP greeting dict
-        @raise socket.error on socket connection errors
-        @raise QMPConnectError if the greeting is not received
-        @raise QMPCapabilitiesError if fails to negotiate capabilities
-        """
-        self.__sock.settimeout(15)
-        self.__sock, _ = self.__sock.accept()
-        self.__sockfile = self.__sock.makefile()
-        return self.__negotiate_capabilities()
-
-    def cmd_obj(self, qmp_cmd):
-        """
-        Send a QMP command to the QMP Monitor.
-
-        @param qmp_cmd: QMP command to be sent as a Python dict
-        @return QMP response as a Python dict or None if the connection has
-                been closed
-        """
-        self.logger.debug(">>> %s", qmp_cmd)
-        try:
-            self.__sock.sendall(json.dumps(qmp_cmd).encode('utf-8'))
-        except socket.error as err:
-            if err[0] == errno.EPIPE:
-                return
-            raise socket.error(err)
-        resp = self.__json_read()
-        self.logger.debug("<<< %s", resp)
-        return resp
-
-    def cmd(self, name, args=None, cmd_id=None):
-        """
-        Build a QMP command and send it to the QMP Monitor.
-
-        @param name: command name (string)
-        @param args: command arguments (dict)
-        @param cmd_id: command id (dict, list, string or int)
-        """
-        qmp_cmd = {'execute': name}
-        if args:
-            qmp_cmd['arguments'] = args
-        if cmd_id:
-            qmp_cmd['id'] = cmd_id
-        return self.cmd_obj(qmp_cmd)
-
-    def command(self, cmd, **kwds):
-        """
-        Build and send a QMP command to the monitor, report errors if any
-        """
-        ret = self.cmd(cmd, kwds)
-        if "error" in ret:
-            raise Exception(ret['error']['desc'])
-        return ret['return']
-
-    def pull_event(self, wait=False):
-        """
-        Pulls a single event.
-
-        @param wait (bool): block until an event is available.
-        @param wait (float): If wait is a float, treat it as a timeout value.
-
-        @raise QMPTimeoutError: If a timeout float is provided and the timeout
-                                period elapses.
-        @raise QMPConnectError: If wait is True but no events could be
-                                retrieved or if some other error occurred.
-
-        @return The first available QMP event, or None.
-        """
-        self.__get_events(wait)
-
-        if self.__events:
-            return self.__events.pop(0)
-        return None
-
-    def get_events(self, wait=False):
-        """
-        Get a list of available QMP events.
-
-        @param wait (bool): block until an event is available.
-        @param wait (float): If wait is a float, treat it as a timeout value.
-
-        @raise QMPTimeoutError: If a timeout float is provided and the timeout
-                                period elapses.
-        @raise QMPConnectError: If wait is True but no events could be
-                                retrieved or if some other error occurred.
-
-        @return The list of available QMP events.
-        """
-        self.__get_events(wait)
-        return self.__events
-
-    def clear_events(self):
-        """
-        Clear current list of pending events.
-        """
-        self.__events = []
-
-    def close(self):
-        self.__sock.close()
-        self.__sockfile.close()
-
-    def settimeout(self, timeout):
-        self.__sock.settimeout(timeout)
-
-    def get_sock_fd(self):
-        return self.__sock.fileno()
-
-    def is_scm_available(self):
-        return self.__sock.family == socket.AF_UNIX