Commit Graph

12 Commits

Author SHA1 Message Date
Marc-André Lureau
d709bbf3b1 include/qapi: add g_autoptr support for qobject types
Need wrappers for qobject_unref() calls, which is a macro.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-10-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00
Markus Armbruster
998da0b158 qobject: Factor JSON writer out of qobject_to_json()
We have two JSON writers written in C: qobject/qjson.c provides
qobject_to_json(), and migration/qjson.c provides a more low level
imperative interface.  They don't share code.  The latter tacitly
limits numbers to int64_t, and strings contents to characters that
don't need escaping.

Factor out qobject_to_json()'s JSON writer as qobject/json-writer.c.
Straightforward, except for numbers: since the writer is to be
independent of QObject, it can't use qnum_to_string().  Open-code it
instead.  This is actually an improvement of sorts, because it
liberates qnum_to_string() from JSON's needs: its JSON-related FIXMEs
move to the JSON writer, where they belong.

The next commit will replace migration/qjson.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-16-armbru@redhat.com>
2020-12-19 10:39:16 +01:00
Markus Armbruster
80d71121b7 qobject: Move internals to qobject-internal.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-9-armbru@redhat.com>
2020-12-19 10:38:43 +01:00
Markus Armbruster
f917eed306 qobject: Fix qnum_to_string() to use sufficient precision
We should serialize numbers to JSON so that they deserialize back to
the same number.  We fail to do so.

The culprit is qnum_to_string(): it uses format %f with trailing '0'
trimmed.  Results in pretty output for "nice" numbers, but is prone to
nasty rounding errors.  For instance, numbers between 0 and 0.0000005
get flushed to zero.

Where exactly the incorrect rounding can bite is tiresome to gauge.
Here's my take.

* In QMP output, type 'number':

  - query-blockstats value avg_rd_queue_depth

  - QMP query-migrate values mbps, cache-miss-rate, encoding-rate,
    busy-rate, compression-rate.

  Relatively harmless, I guess.

* In tracing QMP input.  Harmless.

* In qemu-ga output, type 'number': guest-get-users value login-time.
  Harmless.

* In output of HMP qom-get.  Harmless.

Not affected, because double values don't actually occur there (I
think):

* QMP output, type 'any':

  * qom-get value

  * qom-list, qom-list-properties value default-value

  * query-cpu-model-comparison, query-cpu-model-baseline,
    query-cpu-model-expansion value props.

* qemu-img --output json output.

* "json:" pseudo-filenames generated by bdrv_refresh_filename().

* The rbd block driver's "=keyvalue-pairs" hack.

* In -object help on property default values.  Aside: use of JSON
  feels inappropriate here.

* Output of HMP qom-get.

* Argument conversion to QemuOpts for qdev_device_add() and HMP with
  qemu_opts_from_qdict()

  QMP and HMP device_add, virtio-net failover primary creation,
  xen-usb "usb-host" creation, HMP netdev_add, object_add.

* The uses of qobject_input_visitor_new_flat_confused()

  As far as I can tell, none of the visited types contain double
  values.

* Dumping ImageInfoSpecific with dump_qobject()

Fix by formatting with %.17g.  17 decimal digits always suffice for
IEEE double.

The change to expected test output illustrates the effect: the
rounding errors are gone, but some seemingly "nice" numbers now get
converted to not so nice strings, e.g. 0.42 to "0.41999999999999998".
This is because 0.42 is not representable exactly in double.  It's
more accurate in this example than strictly necessary, though.

If ugly accuracy bothers us, we can we can try using the least number
of digits that still converts back to the same double.  In this
example, "0.42" would do.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201210161452.2813491-7-armbru@redhat.com>
2020-12-19 10:37:16 +01:00
Markus Armbruster
812ce33ead qobject: Drop superfluous includes of qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-53-armbru@redhat.com>
2018-08-24 20:26:37 +02:00
Max Reitz
cb51b976ba qapi: Remove qobject_to_X() functions
They are no longer needed now.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-5-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-19 14:58:36 -05:00
Max Reitz
7dc847ebba qapi: Replace qobject_to_X(o) by qobject_to(X, o)
This patch was generated using the following Coccinelle script:

@@
expression Obj;
@@
(
- qobject_to_qnum(Obj)
+ qobject_to(QNum, Obj)
|
- qobject_to_qstring(Obj)
+ qobject_to(QString, Obj)
|
- qobject_to_qdict(Obj)
+ qobject_to(QDict, Obj)
|
- qobject_to_qlist(Obj)
+ qobject_to(QList, Obj)
|
- qobject_to_qbool(Obj)
+ qobject_to(QBool, Obj)
)

and a bit of manual fix-up for overly long lines and three places in
tests/check-qjson.c that Coccinelle did not find.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-4-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: swap order from qobject_to(o, X), rebase to master, also a fix
to latent false-positive compiler complaint about hw/i386/acpi-build.c]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-19 14:58:36 -05:00
Markus Armbruster
5ee9d2fe9e Include qapi/qmp/qobject.h exactly where needed
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-11-armbru@redhat.com>
2018-02-09 13:52:15 +01:00
Markus Armbruster
e688df6bc4 Include qapi/error.h exactly where needed
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.

While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
2018-02-09 13:50:17 +01:00
Max Reitz
b38dd678a2 qapi: Add qobject_is_equal()
This generic function (along with its implementations for different
types) determines whether two QObjects are equal.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20171114180128.17076-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:30 +01:00
Marc-André Lureau
61a8f418b2 qnum: add uint type
In order to store integer values between INT64_MAX and UINT64_MAX, add
a uint64_t internal representation.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170607163635.17635-10-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-20 14:31:31 +02:00
Marc-André Lureau
01b2ffcedd qapi: merge QInt and QFloat in QNum
We would like to use a same QObject type to represent numbers, whether
they are int, uint, or floats. Getters will allow some compatibility
between the various types if the number fits other representations.

Add a few more tests while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170607163635.17635-7-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[parse_stats_intervals() simplified a bit, comment in
test_visitor_in_int_overflow() tidied up, suppress bogus warnings]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-06-20 14:31:31 +02:00