Merge remote-tracking branch 'remotes/ehabkost/tags/python-next-pull-request' into staging

Python queue, 2017-09-15

# gpg: Signature made Sat 16 Sep 2017 00:14:01 BST
# gpg:                using RSA key 0x2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/python-next-pull-request:
  qemu.py: include debug information on launch error
  qemu.py: improve message on negative exit code
  qemu.py: use os.path.null instead of /dev/null
  qemu.py: avoid writing to stdout/stderr
  qemu.py: fix is_running() return before first launch()
  qtest.py: Few pylint/style fixes
  qmp.py: Avoid overriding a builtin object
  qmp.py: Avoid "has_key" usage
  qmp.py: Use object-based class for QEMUMonitorProtocol
  qmp.py: Couple of pylint/style fixes
  qemu.py: Use custom exceptions rather than Exception
  qemu.py: Simplify QMP key-conversion
  qemu.py: Use iteritems rather than keys()
  qemu|qtest: Avoid dangerous arguments
  qemu.py: Pylint/style fixes

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 32 insertions, 21 deletions

diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
index 860ffb27f2..be449de621 100755
--- a/scripts/qmp/qmp-shell
+++ b/scripts/qmp/qmp-shell
@@ -106,7 +106,7 @@ class FuzzyJSON(ast.NodeTransformer):
 #       _execute_cmd()). Let's design a better one.
 class QMPShell(qmp.QEMUMonitorProtocol):
     def __init__(self, address, pretty=False):
-        qmp.QEMUMonitorProtocol.__init__(self, self.__get_address(address))
+        super(QMPShell, self).__init__(self.__get_address(address))
         self._greeting = None
         self._completer = None
         self._pretty = pretty
@@ -281,7 +281,7 @@ class QMPShell(qmp.QEMUMonitorProtocol):
         return True
 
     def connect(self, negotiate):
-        self._greeting = qmp.QEMUMonitorProtocol.connect(self, negotiate)
+        self._greeting = super(QMPShell, self).connect(negotiate)
         self.__completer_setup()
 
     def show_banner(self, msg='Welcome to the QMP low-level shell!'):
diff --git a/scripts/qmp/qmp.py b/scripts/qmp/qmp.py
index 62d3651967..ef12e8a1a0 100644
--- a/scripts/qmp/qmp.py
+++ b/scripts/qmp/qmp.py
@@ -13,19 +13,30 @@ import errno
 import socket
 import sys
 
+
 class QMPError(Exception):
     pass
 
+
 class QMPConnectError(QMPError):
     pass
 
+
 class QMPCapabilitiesError(QMPError):
     pass
 
+
 class QMPTimeoutError(QMPError):
     pass
 
-class QEMUMonitorProtocol:
+
+class QEMUMonitorProtocol(object):
+
+    #: Socket's error class
+    error = socket.error
+    #: Socket's timeout
+    timeout = socket.timeout
+
     def __init__(self, address, server=False, debug=False):
         """
         Create a QEMUMonitorProtocol class.
@@ -42,6 +53,7 @@ class QEMUMonitorProtocol:
         self.__address = address
         self._debug = debug
         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)
@@ -56,7 +68,7 @@ class QEMUMonitorProtocol:
 
     def __negotiate_capabilities(self):
         greeting = self.__json_read()
-        if greeting is None or not greeting.has_key('QMP'):
+        if greeting is None or "QMP" not in greeting:
             raise QMPConnectError
         # Greeting seems ok, negotiate capabilities
         resp = self.cmd('qmp_capabilities')
@@ -78,8 +90,6 @@ class QEMUMonitorProtocol:
                     continue
             return resp
 
-    error = socket.error
-
     def __get_events(self, wait=False):
         """
         Check for new events in the stream and cache them in __events.
@@ -89,8 +99,8 @@ class QEMUMonitorProtocol:
 
         @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.
+        @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:
@@ -167,38 +177,41 @@ class QEMUMonitorProtocol:
             print >>sys.stderr, "QMP:<<< %s" % resp
         return resp
 
-    def cmd(self, name, args=None, id=None):
+    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 id: command id (dict, list, string or int)
+        @param cmd_id: command id (dict, list, string or int)
         """
-        qmp_cmd = { 'execute': name }
+        qmp_cmd = {'execute': name}
         if args:
             qmp_cmd['arguments'] = args
-        if id:
-            qmp_cmd['id'] = id
+        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 ret.has_key('error'):
+        if "error" in ret:
             raise Exception(ret['error']['desc'])
         return ret['return']
 
     def pull_event(self, wait=False):
         """
-        Get and delete the first available QMP event.
+        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.
+        @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.
         """
@@ -217,8 +230,8 @@ class QEMUMonitorProtocol:
 
         @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.
+        @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.
         """
@@ -235,8 +248,6 @@ class QEMUMonitorProtocol:
         self.__sock.close()
         self.__sockfile.close()
 
-    timeout = socket.timeout
-
     def settimeout(self, timeout):
         self.__sock.settimeout(timeout)