[libvirt] [PATCH v2 02/10] Add qemuMonitorJSONGetObjectProperty() method for QMP qom-get command

[Michal Privoznik]

On 08.07.2013 21:20, John Ferlan wrote:
> Add a new qemuMonitorJSONGetObjectProperty() method to support invocation
> of the 'qom-get' JSON monitor command with a provided path, property, and
> expected data type return. The qemuMonitorJSONObjectProperty is similar to
> virTypedParameter; however, a future patch will extend it a bit to include
> a void pointer to balloon driver statistic data.
> 
> The provided test will execute a qom-get on "/machine/i440fx" which will
> return a property "realized".
> ---
>  src/qemu/qemu_monitor_json.c | 86 ++++++++++++++++++++++++++++++++++++++++++++
>  src/qemu/qemu_monitor_json.h | 34 ++++++++++++++++++
>  tests/qemumonitorjsontest.c  | 48 +++++++++++++++++++++++++
>  3 files changed, 168 insertions(+)
> 
> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
> index fc2b65f..db107f1 100644
> --- a/src/qemu/qemu_monitor_json.c
> +++ b/src/qemu/qemu_monitor_json.c
> @@ -4642,6 +4642,92 @@ void qemuMonitorJSONListPathFree(qemuMonitorJSONListPathPtr paths)
>      VIR_FREE(paths);
>  }
>  
> +
> +int qemuMonitorJSONGetObjectProperty(qemuMonitorPtr mon,
> +                                     const char *path,
> +                                     const char *property,
> +                                     qemuMonitorJSONObjectPropertyPtr prop)
> +{
> +    int ret;
> +    virJSONValuePtr cmd;
> +    virJSONValuePtr reply = NULL;
> +    virJSONValuePtr data;
> +    const char *tmp;
> +
> +    if (!(cmd = qemuMonitorJSONMakeCommand("qom-get",
> +                                           "s:path", path,
> +                                           "s:property", property,
> +                                           NULL)))
> +        return -1;
> +
> +    ret = qemuMonitorJSONCommand(mon, cmd, &reply);
> +
> +    if (ret == 0)
> +        ret = qemuMonitorJSONCheckError(cmd, reply);
> +
> +    if (ret < 0)
> +        goto cleanup;
> +
> +    ret = -1;
> +
> +    if (!(data = virJSONValueObjectGet(reply, "return"))) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                       _("qom-get reply was missing return data"));
> +        goto cleanup;
> +    }
> +
> +    switch (prop->type) {

switch ((qemuMonitorJSONObjectPropertyType) prop->type) {

> +    /* Simple cases of boolean, int, long, uint, ulong, double, and string
> +     * will receive return value as part of {"return": xxx} statement
> +     */
> +    case QEMU_MONITOR_OBJECT_PROPERTY_BOOLEAN:
> +        ret = virJSONValueGetBoolean(data, &prop->val.b);
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_INT:
> +        ret = virJSONValueGetNumberInt(data, &prop->val.i);
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_LONG:
> +        ret = virJSONValueGetNumberLong(data, &prop->val.l);
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_UINT:
> +        ret = virJSONValueGetNumberUint(data, &prop->val.ui);
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_ULONG:
> +        ret = virJSONValueGetNumberUlong(data, &prop->val.ul);
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_DOUBLE:
> +        ret = virJSONValueGetNumberDouble(data, &prop->val.d);
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_STRING:
> +        tmp = virJSONValueGetString(data);
> +        if (tmp && VIR_STRDUP(prop->val.str, tmp) < 0)
> +            goto cleanup;
> +        if (tmp)
> +            ret = 0;
> +        break;
> +    case QEMU_MONITOR_OBJECT_PROPERTY_LAST:
> +    default:

Drop 'default' as it prevents compiler to check completeness coverage of enum in this switch(). The _LAST can be dropped as well among with virReportError() and subsequent cleanup then.

> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("qom-get invalid object property type %d"),
> +                       prop->type);
> +        goto cleanup;
> +    }
> +
> +    if (ret == -1) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                       _("qom-get reply was missing return data"));
> +        goto cleanup;
> +    }
> +
> +    ret = 0;
> +cleanup:
> +    virJSONValueFree(cmd);
> +    virJSONValueFree(reply);
> +
> +    return ret;
> +}
> +
> +
>  int qemuMonitorJSONGetObjectProps(qemuMonitorPtr mon,
>                                    const char *type,
>                                    char ***props)
> diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
> index e7ce145..e6bbd62 100644
> --- a/src/qemu/qemu_monitor_json.h
> +++ b/src/qemu/qemu_monitor_json.h
> @@ -348,6 +348,40 @@ int qemuMonitorJSONGetObjectListPaths(qemuMonitorPtr mon,
>  
>  void qemuMonitorJSONListPathFree(qemuMonitorJSONListPathPtr paths);
>  
> +/* Flags for the 'type' field in _qemuMonitorJSONObjectProperty */
> +typedef enum {
> +    QEMU_MONITOR_OBJECT_PROPERTY_BOOLEAN=1,
> +    QEMU_MONITOR_OBJECT_PROPERTY_INT,
> +    QEMU_MONITOR_OBJECT_PROPERTY_LONG,
> +    QEMU_MONITOR_OBJECT_PROPERTY_UINT,
> +    QEMU_MONITOR_OBJECT_PROPERTY_ULONG,
> +    QEMU_MONITOR_OBJECT_PROPERTY_DOUBLE,
> +    QEMU_MONITOR_OBJECT_PROPERTY_STRING,
> +
> +    QEMU_MONITOR_OBJECT_PROPERTY_LAST
> +} qemuMonitorJSONObjectPropertyType;
> +
> +typedef struct _qemuMonitorJSONObjectProperty qemuMonitorJSONObjectProperty;
> +typedef qemuMonitorJSONObjectProperty *qemuMonitorJSONObjectPropertyPtr;
> +struct _qemuMonitorJSONObjectProperty {
> +    int type;    /* qemuMonitorJSONObjectPropertyType */
> +    union {
> +        bool b;
> +        int i;

Huh, syntax-check fails at this ^^^ line thinking @i is a loop variable. I guess you'll need to add an exception to cfg.mk:

diff --git a/cfg.mk b/cfg.mk
index c6a097e..2936280 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -985,4 +985,4 @@ exclude_file_name_regexp--sc_prohibit_include_public_headers_brackets = \
   ^(python/|tools/|examples/|include/libvirt/(virterror|libvirt-(qemu|lxc))\.h$$)
 
 exclude_file_name_regexp--sc_prohibit_int_ijk = \
-  ^(src/remote_protocol-structs|src/remote/remote_protocol.x|cfg.mk|include/)$
+  ^(src/remote_protocol-structs|src/remote/remote_protocol.x|cfg.mk|include/|src/qemu/qemu_monitor_json.h)$



> +        long long l;
> +        unsigned int ui;
> +        unsigned long long ul;
> +        double d;
> +        char *str;
> +    } val;
> +};
> +
> +int qemuMonitorJSONGetObjectProperty(qemuMonitorPtr mon,
> +                                     const char *path,
> +                                     const char *property,
> +                                     qemuMonitorJSONObjectPropertyPtr prop)
> +    ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3) ATTRIBUTE_NONNULL(4);
> +
>  int qemuMonitorJSONGetObjectProps(qemuMonitorPtr mon,
>                                    const char *type,
>                                    char ***props)


Michal