[libvirt] [PATCH 02/22] virsh: Extract common code from cmdCPU{Compare, Baseline}

[Jiri Denemark]

Both cpu-compare and cpu-baseline commands accept more that just CPU
definition XML(s). For users' convenience they are able to extract the
CPU definition(s) even from domain XML or capabilities XML. The main
differences between the two commands is in the number of CPU definitions
they expect: cpu-compare wants only one CPU definition while
cpu-baseline expects one or more CPUs.

The extracted code forms a new vshExtractCPUDefXML function.

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---
 tools/virsh-host.c | 160 +++++++++++++++++++++------------------------
 1 file changed, 75 insertions(+), 85 deletions(-)

diff --git a/tools/virsh-host.c b/tools/virsh-host.c
index 6d6e3cfc85..51497db385 100644
--- a/tools/virsh-host.c
+++ b/tools/virsh-host.c
@@ -1106,6 +1106,72 @@ cmdURI(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
     return true;
 }
 
+
+/* Extracts the CPU definition XML strings from a file which may contain either
+ *  - just the CPU definitions,
+ *  - domain XMLs, or
+ *  - capabilities XMLs.
+ *
+ * Returns NULL terminated string list.
+ */
+static char **
+vshExtractCPUDefXMLs(vshControl *ctl,
+                     const char *xmlFile)
+{
+    char **cpus = NULL;
+    char *buffer = NULL;
+    char *xmlStr = NULL;
+    xmlDocPtr xml = NULL;
+    xmlXPathContextPtr ctxt = NULL;
+    xmlNodePtr *nodes = NULL;
+    size_t i;
+    int n;
+
+    if (virFileReadAll(xmlFile, VSH_MAX_XML_FILE, &buffer) < 0)
+        goto error;
+
+    if (virAsprintf(&xmlStr, "<container>%s</container>", buffer) < 0)
+        goto error;
+
+    if (!(xml = virXMLParseStringCtxt(xmlStr, xmlFile, &ctxt)))
+        goto error;
+
+    n = virXPathNodeSet("/container/cpu|"
+                        "/container/domain/cpu|"
+                        "/container/capabilities/host/cpu",
+                        ctxt, &nodes);
+    if (n < 0)
+        goto error;
+
+    if (n == 0) {
+        vshError(ctl, _("File '%s' does not contain any <cpu> element or "
+                        "valid domain or capabilities XML"), xmlFile);
+        goto error;
+    }
+
+    cpus = vshCalloc(ctl, n + 1, sizeof(const char *));
+
+    for (i = 0; i < n; i++) {
+        if (!(cpus[i] = virXMLNodeToString(xml, nodes[i]))) {
+            vshSaveLibvirtError();
+            goto error;
+        }
+    }
+
+ cleanup:
+    VIR_FREE(buffer);
+    VIR_FREE(xmlStr);
+    xmlFreeDoc(xml);
+    xmlXPathFreeContext(ctxt);
+    VIR_FREE(nodes);
+    return cpus;
+
+ error:
+    virStringListFree(cpus);
+    goto cleanup;
+}
+
+
 /*
  * "cpu-compare" command
  */
@@ -1133,13 +1199,9 @@ cmdCPUCompare(vshControl *ctl, const vshCmd *cmd)
 {
     const char *from = NULL;
     bool ret = false;
-    char *buffer;
     int result;
-    char *snippet = NULL;
+    char **cpus = NULL;
     unsigned int flags = 0;
-    xmlDocPtr xml = NULL;
-    xmlXPathContextPtr ctxt = NULL;
-    xmlNodePtr node;
     virshControlPtr priv = ctl->privData;
 
     if (vshCommandOptBool(cmd, "error"))
@@ -1148,27 +1210,10 @@ cmdCPUCompare(vshControl *ctl, const vshCmd *cmd)
     if (vshCommandOptStringReq(ctl, cmd, "file", &from) < 0)
         return false;
 
-    if (virFileReadAll(from, VSH_MAX_XML_FILE, &buffer) < 0)
+    if (!(cpus = vshExtractCPUDefXMLs(ctl, from)))
         return false;
 
-    /* try to extract the CPU element from as it would appear in a domain XML*/
-    if (!(xml = virXMLParseStringCtxt(buffer, from, &ctxt)))
-        goto cleanup;
-
-    if ((node = virXPathNode("/cpu|"
-                             "/domain/cpu|"
-                              "/capabilities/host/cpu", ctxt))) {
-        if (!(snippet = virXMLNodeToString(xml, node))) {
-            vshSaveLibvirtError();
-            goto cleanup;
-        }
-    } else {
-        vshError(ctl, _("File '%s' does not contain a <cpu> element or is not "
-                        "a valid domain or capabilities XML"), from);
-        goto cleanup;
-    }
-
-    result = virConnectCompareCPU(priv->conn, snippet, flags);
+    result = virConnectCompareCPU(priv->conn, cpus[0], flags);
 
     switch (result) {
     case VIR_CPU_COMPARE_INCOMPATIBLE:
@@ -1196,10 +1241,7 @@ cmdCPUCompare(vshControl *ctl, const vshCmd *cmd)
     ret = true;
 
  cleanup:
-    VIR_FREE(buffer);
-    VIR_FREE(snippet);
-    xmlXPathFreeContext(ctxt);
-    xmlFreeDoc(xml);
+    virStringListFree(cpus);
 
     return ret;
 }
@@ -1235,17 +1277,9 @@ cmdCPUBaseline(vshControl *ctl, const vshCmd *cmd)
 {
     const char *from = NULL;
     bool ret = false;
-    char *buffer;
     char *result = NULL;
     char **list = NULL;
     unsigned int flags = 0;
-    int count = 0;
-
-    xmlDocPtr xml = NULL;
-    xmlNodePtr *node_list = NULL;
-    xmlXPathContextPtr ctxt = NULL;
-    virBuffer buf = VIR_BUFFER_INITIALIZER;
-    size_t i;
     virshControlPtr priv = ctl->privData;
 
     if (vshCommandOptBool(cmd, "features"))
@@ -1256,65 +1290,21 @@ cmdCPUBaseline(vshControl *ctl, const vshCmd *cmd)
     if (vshCommandOptStringReq(ctl, cmd, "file", &from) < 0)
         return false;
 
-    if (virFileReadAll(from, VSH_MAX_XML_FILE, &buffer) < 0)
+    if (!(list = vshExtractCPUDefXMLs(ctl, from)))
         return false;
 
-    /* add a separate container around the xml */
-    virBufferStrcat(&buf, "<container>", buffer, "</container>", NULL);
-    if (virBufferError(&buf))
-        goto no_memory;
-
-    VIR_FREE(buffer);
-    buffer = virBufferContentAndReset(&buf);
-
-
-    if (!(xml = virXMLParseStringCtxt(buffer, from, &ctxt)))
-        goto cleanup;
-
-    if ((count = virXPathNodeSet("//cpu[not(ancestor::cpus)]",
-                                 ctxt, &node_list)) == -1)
-        goto cleanup;
-
-    if (count == 0) {
-        vshError(ctl, _("No host CPU specified in '%s'"), from);
-        goto cleanup;
-    }
-
-    list = vshCalloc(ctl, count, sizeof(const char *));
-
-    for (i = 0; i < count; i++) {
-        if (!(list[i] = virXMLNodeToString(xml, node_list[i]))) {
-            vshSaveLibvirtError();
-            goto cleanup;
-        }
-    }
-
-    result = virConnectBaselineCPU(priv->conn,
-                                   (const char **)list, count, flags);
+    result = virConnectBaselineCPU(priv->conn, (const char **)list,
+                                   virStringListLength((const char **)list),
+                                   flags);
 
     if (result) {
         vshPrint(ctl, "%s", result);
         ret = true;
     }
 
- cleanup:
-    xmlXPathFreeContext(ctxt);
-    xmlFreeDoc(xml);
     VIR_FREE(result);
-    if (list != NULL && count > 0) {
-        for (i = 0; i < count; i++)
-            VIR_FREE(list[i]);
-    }
-    VIR_FREE(list);
-    VIR_FREE(buffer);
-    VIR_FREE(node_list);
-
+    virStringListFree(list);
     return ret;
-
- no_memory:
-    vshError(ctl, "%s", _("Out of memory"));
-    ret = false;
-    goto cleanup;
 }
 
 /*
-- 
2.17.0