virDomainObjGetMessages: Refactor using GPtrArray

Simplify the function especially by rewriting it using GPtrArray to
construct the string list, especially for the upcoming case when the
number of added elements will not be known beforehand and when
hypervisor specific data will be added.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

src/conf/domain_conf.c

@@ -31685,53 +31685,31 @@ virHostdevIsPCIDevice(const virDomainHostdevDef *hostdev)
 /**
  * virDomainObjGetMessages:
  * @vm: domain object
- * @msgs: pointer to a variable to store messages
+ * @m: GPtrArray to be filled with messages
  * @flags: zero or more virDomainMessageType flags
- *
- * Returns number of messages stored in @msgs, -1 otherwise.
  */
-int
+void
 virDomainObjGetMessages(virDomainObj *vm,
-                        char ***msgs,
+                        GPtrArray *m,
                         unsigned int flags)
 {
     size_t i = 0;
-    size_t n = 0;
-    int nmsgs = 0;
-    int rv = -1;
-
-    *msgs = NULL;
 
     if (!flags || (flags & VIR_DOMAIN_MESSAGE_TAINTING)) {
-        nmsgs += __builtin_popcount(vm->taint);
-        *msgs = g_renew(char *, *msgs, nmsgs+1);
-
         for (i = 0; i < VIR_DOMAIN_TAINT_LAST; i++) {
             if (vm->taint & (1 << i)) {
-                (*msgs)[n++] = g_strdup_printf(
-                    _("tainted: %1$s"),
-                    _(virDomainTaintMessageTypeToString(i)));
+                g_ptr_array_add(m, g_strdup_printf(_("tainted: %1$s"),
+                                                   _(virDomainTaintMessageTypeToString(i))));
             }
         }
     }
 
     if (!flags || (flags & VIR_DOMAIN_MESSAGE_DEPRECATION)) {
-        nmsgs += vm->ndeprecations;
-        *msgs = g_renew(char *, *msgs, nmsgs+1);
-
         for (i = 0; i < vm->ndeprecations; i++) {
-            (*msgs)[n++] = g_strdup_printf(
-                _("deprecated configuration: %1$s"),
-                vm->deprecations[i]);
+            g_ptr_array_add(m, g_strdup_printf(_("deprecated configuration: %1$s"),
+                                               vm->deprecations[i]));
         }
     }
-
-    if (*msgs)
-        (*msgs)[nmsgs] = NULL;
-
-    rv = nmsgs;
-
-    return rv;
 }
 
 bool

src/conf/domain_conf.h

@@ -4588,9 +4588,9 @@ bool
 virHostdevIsPCIDevice(const virDomainHostdevDef *hostdev)
     ATTRIBUTE_NONNULL(1);
 
-int
+void
 virDomainObjGetMessages(virDomainObj *vm,
-                        char ***msgs,
+                        GPtrArray *m,
                         unsigned int flags);
 
 bool

src/libxl/libxl_driver.c

@@ -6575,6 +6575,7 @@ libxlDomainGetMessages(virDomainPtr dom,
                       char ***msgs,
                       unsigned int flags)
 {
+    g_autoptr(GPtrArray) m = g_ptr_array_new_with_free_func(g_free);
     virDomainObj *vm = NULL;
     int ret = -1;
 
@@ -6587,7 +6588,13 @@ libxlDomainGetMessages(virDomainPtr dom,
     if (virDomainGetMessagesEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
-    ret = virDomainObjGetMessages(vm, msgs, flags);
+    virDomainObjGetMessages(vm, m, flags);
+
+    ret = m->len;
+    if (m->len > 0) {
+        g_ptr_array_add(m, NULL);
+        *msgs = (char **) g_ptr_array_steal(m, NULL);
+    }
 
  cleanup:
     virDomainObjEndAPI(&vm);

src/qemu/qemu_driver.c

@@ -19834,6 +19834,7 @@ qemuDomainGetMessages(virDomainPtr dom,
                       char ***msgs,
                       unsigned int flags)
 {
+    g_autoptr(GPtrArray) m = g_ptr_array_new_with_free_func(g_free);
     virDomainObj *vm = NULL;
     int rv = -1;
 
@@ -19846,7 +19847,13 @@ qemuDomainGetMessages(virDomainPtr dom,
     if (virDomainGetMessagesEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
 
-    rv = virDomainObjGetMessages(vm, msgs, flags);
+    virDomainObjGetMessages(vm, m, flags);
+
+    rv = m->len;
+    if (m->len > 0) {
+        g_ptr_array_add(m, NULL);
+        *msgs = (char **) g_ptr_array_steal(m, NULL);
+    }
 
  cleanup:
     virDomainObjEndAPI(&vm);

src/test/test_driver.c

@@ -9522,6 +9522,7 @@ testDomainGetMessages(virDomainPtr dom,
                       char ***msgs,
                       unsigned int flags)
 {
+    g_autoptr(GPtrArray) m = g_ptr_array_new_with_free_func(g_free);
     virDomainObj *vm = NULL;
     int rv = -1;
 
@@ -9531,7 +9532,13 @@ testDomainGetMessages(virDomainPtr dom,
     if (!(vm = testDomObjFromDomain(dom)))
         return -1;
 
-    rv = virDomainObjGetMessages(vm, msgs, flags);
+    virDomainObjGetMessages(vm, m, flags);
+
+    rv = m->len;
+    if (m->len > 0) {
+        g_ptr_array_add(m, NULL);
+        *msgs = (char **) g_ptr_array_steal(m, NULL);
+    }
 
     virDomainObjEndAPI(&vm);
     return rv;