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[Qemu-devel] [PULL 08/10] scripts: qmp-shell: Expand support for QMP exp
From: |
Luiz Capitulino |
Subject: |
[Qemu-devel] [PULL 08/10] scripts: qmp-shell: Expand support for QMP expressions |
Date: |
Fri, 8 May 2015 09:34:09 -0400 |
From: John Snow <address@hidden>
This includes support for [] expressions, single-quotes in
QMP expressions (which is not strictly a part of JSON), and
the ability to use "True", "False" and "None" literals instead
of JSON's equivalent true, false, and null literals.
qmp-shell currently allows you to describe values as
JSON expressions:
key={"key":{"key2":"val"}}
But it does not currently support arrays, which are needed
for serializing and deserializing transactions:
key=[{"type":"drive-backup","data":{...}}]
qmp-shell also only currently accepts doubly quoted strings
as-per JSON spec, but QMP allows single quotes.
Lastly, python allows you to utilize "True" or "False" as
boolean literals, but JSON expects "true" or "false". Expand
qmp-shell to allow the user to type either, converting to the
correct type.
As a consequence of the above, the key=val parsing is also improved
to give better error messages if a key=val token is not provided.
CAVEAT: The parser is still extremely rudimentary and does not
expect to find spaces in {} nor [] expressions. This patch does
not improve this functionality.
Signed-off-by: John Snow <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Tested-by: Kashyap Chamarthy <address@hidden>
Signed-off-by: Luiz Capitulino <address@hidden>
---
scripts/qmp/qmp-shell | 63 ++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 47 insertions(+), 16 deletions(-)
diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
index a9632ec..7f2c554 100755
--- a/scripts/qmp/qmp-shell
+++ b/scripts/qmp/qmp-shell
@@ -32,6 +32,7 @@
import qmp
import json
+import ast
import readline
import sys
import pprint
@@ -51,6 +52,19 @@ class QMPShellError(Exception):
class QMPShellBadPort(QMPShellError):
pass
+class FuzzyJSON(ast.NodeTransformer):
+ '''This extension of ast.NodeTransformer filters literal "true/false/null"
+ values in an AST and replaces them by proper "True/False/None" values that
+ Python can properly evaluate.'''
+ def visit_Name(self, node):
+ if node.id == 'true':
+ node.id = 'True'
+ if node.id == 'false':
+ node.id = 'False'
+ if node.id == 'null':
+ node.id = 'None'
+ return node
+
# TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
# _execute_cmd()). Let's design a better one.
class QMPShell(qmp.QEMUMonitorProtocol):
@@ -88,23 +102,40 @@ class QMPShell(qmp.QEMUMonitorProtocol):
# clearing everything as it doesn't seem to matter
readline.set_completer_delims('')
- def __cli_expr(self, tokens, parent):
- for arg in tokens:
- opt = arg.split('=')
+ def __parse_value(self, val):
+ try:
+ return int(val)
+ except ValueError:
+ pass
+
+ if val.lower() == 'true':
+ return True
+ if val.lower() == 'false':
+ return False
+ if val.startswith(('{', '[')):
+ # Try first as pure JSON:
try:
- if(len(opt) > 2):
- opt[1] = '='.join(opt[1:])
- value = int(opt[1])
+ return json.loads(val)
except ValueError:
- if opt[1] == 'true':
- value = True
- elif opt[1] == 'false':
- value = False
- elif opt[1].startswith('{'):
- value = json.loads(opt[1])
- else:
- value = opt[1]
- optpath = opt[0].split('.')
+ pass
+ # Try once again as FuzzyJSON:
+ try:
+ st = ast.parse(val, mode='eval')
+ return ast.literal_eval(FuzzyJSON().visit(st))
+ except SyntaxError:
+ pass
+ except ValueError:
+ pass
+ return val
+
+ def __cli_expr(self, tokens, parent):
+ for arg in tokens:
+ (key, _, val) = arg.partition('=')
+ if not val:
+ raise QMPShellError("Expected a key=value pair, got '%s'" %
arg)
+
+ value = self.__parse_value(val)
+ optpath = key.split('.')
curpath = []
for p in optpath[:-1]:
curpath.append(p)
@@ -117,7 +148,7 @@ class QMPShell(qmp.QEMUMonitorProtocol):
if type(parent[optpath[-1]]) is dict:
raise QMPShellError('Cannot use "%s" as both leaf and
non-leaf key' % '.'.join(curpath))
else:
- raise QMPShellError('Cannot set "%s" multiple times' %
opt[0])
+ raise QMPShellError('Cannot set "%s" multiple times' % key)
parent[optpath[-1]] = value
def __build_cmd(self, cmdline):
--
1.9.3
- [Qemu-devel] [PULL 00/10] QMP queue, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 03/10] qobject: Clean up around qtype_code, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 02/10] QJSON: Use OBJECT_CHECK, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 05/10] json-parser: Accept 'null' in QMP, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 04/10] qobject: Add a special null QObject, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 07/10] scripts: qmp-shell: refactor helpers, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 06/10] MAINTAINERS: New maintainer for QMP and QAPI, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 01/10] monitor: add memory search commands s, sp, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 08/10] scripts: qmp-shell: Expand support for QMP expressions,
Luiz Capitulino <=
- [Qemu-devel] [PULL 09/10] scripts: qmp-shell: add transaction subshell, Luiz Capitulino, 2015/05/08
- [Qemu-devel] [PULL 10/10] scripts: qmp-shell: Add verbose flag, Luiz Capitulino, 2015/05/08
- Re: [Qemu-devel] [PULL 00/10] QMP queue, Peter Maydell, 2015/05/11