From c8a637c7d03b0c9211cbe16d9d88911c495e7162 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Tue, 11 Apr 2017 16:51:32 +0200
Subject: [PATCH] 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.
---
 tools/virsh-util.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++
 tools/virsh-util.h | 20 +++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/tools/virsh-util.c b/tools/virsh-util.c
index 79a38bb234..4b86e29cbd 100644
--- a/tools/virsh-util.c
+++ b/tools/virsh-util.c
@@ -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;
+}
diff --git a/tools/virsh-util.h b/tools/virsh-util.h
index 2b5aedfba5..64cef23c02 100644
--- a/tools/virsh-util.h
+++ b/tools/virsh-util.h
@@ -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 */