virsh: add helpers for getting domain XML for XPath purposes

In virsh we quite often get the domain XML just to initialize the XPath
parser so that we can extract information.

Add helpers which will simplify this by wrapping the getting of the XML
and parsing it along with error reporting.

Additionally a second helper also gets the domain object from the
parameters and releases it so that functions which need the XML as only
source of data can be simplified further.
This commit is contained in:
Peter Krempa 2017-04-11 16:51:32 +02:00
parent 4f4c3b1397
commit c8a637c7d0
2 changed files with 68 additions and 0 deletions

View File

@ -22,6 +22,7 @@
#include "virfile.h"
#include "virstring.h"
#include "viralloc.h"
static virDomainPtr
virshLookupDomainInternal(vshControl *ctl,
@ -172,3 +173,50 @@ virshDomainSnapshotFree(virDomainSnapshotPtr snap)
vshSaveLibvirtHelperError();
virDomainSnapshotFree(snap); /* sc_prohibit_obj_free_apis_in_virsh */
}
int
virshDomainGetXMLFromDom(vshControl *ctl,
virDomainPtr dom,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
{
char *desc = NULL;
if (!(desc = virDomainGetXMLDesc(dom, flags))) {
vshError(ctl, _("Failed to get domain description xml"));
return -1;
}
*xml = virXMLParseStringCtxt(desc, _("(domain_definition)"), ctxt);
VIR_FREE(desc);
if (!(*xml)) {
vshError(ctl, _("Failed to parse domain description xml"));
return -1;
}
return 0;
}
int
virshDomainGetXML(vshControl *ctl,
const vshCmd *cmd,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
{
virDomainPtr dom;
int ret;
if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
return -1;
ret = virshDomainGetXMLFromDom(ctl, dom, flags, xml, ctxt);
virshDomainFree(dom);
return ret;
}

View File

@ -21,6 +21,8 @@
# include "virsh.h"
# include <libxml/parser.h>
# include <libxml/xpath.h>
virDomainPtr
virshLookupDomainBy(vshControl *ctl,
@ -55,4 +57,22 @@ virshStreamSink(virStreamPtr st,
size_t nbytes,
void *opaque);
int
virshDomainGetXMLFromDom(vshControl *ctl,
virDomainPtr dom,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(4)
ATTRIBUTE_NONNULL(5) ATTRIBUTE_RETURN_CHECK;
int
virshDomainGetXML(vshControl *ctl,
const vshCmd *cmd,
unsigned int flags,
xmlDocPtr *xml,
xmlXPathContextPtr *ctxt)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(4)
ATTRIBUTE_NONNULL(5) ATTRIBUTE_RETURN_CHECK;
#endif /* VIRSH_UTIL_H */