From c6bb2746933bbe65877a5f8a8d60e100b0bf8a59 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Mon, 21 Feb 2022 16:52:54 +0100
Subject: [PATCH] virsh: cmdEvent: Rewrite questionable event registration
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The code registering the event handlers in 'cmdEvent' had too many
blocks of code conditional on whether just one event is being listened
to or all events.

The code can be greatly simplified by uniting the code paths and having
only one branch when filling the list of events we want to listen for.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 tools/virsh-domain-event.c | 70 +++++++++++++++++++-------------------
 1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/tools/virsh-domain-event.c b/tools/virsh-domain-event.c
index 51571dffad..1a2f1cb6e0 100644
--- a/tools/virsh-domain-event.c
+++ b/tools/virsh-domain-event.c
@@ -274,6 +274,7 @@ typedef struct virshDomainEventCallback virshDomainEventCallback;
 
 struct virshDomEventData {
     vshControl *ctl;
+    int event;
     bool loop;
     int *count;
     bool timestamp;
@@ -885,10 +886,10 @@ cmdEvent(vshControl *ctl, const vshCmd *cmd)
     g_autoptr(virshDomain) dom = NULL;
     bool ret = false;
     int timeout = 0;
-    virshDomEventData *data = NULL;
+    g_autofree virshDomEventData *data = NULL;
+    size_t ndata = 0;
     size_t i;
     const char *eventName = NULL;
-    int event = -1;
     bool all = vshCommandOptBool(cmd, "all");
     bool loop = vshCommandOptBool(cmd, "loop");
     bool timestamp = vshCommandOptBool(cmd, "timestamp");
@@ -900,59 +901,59 @@ cmdEvent(vshControl *ctl, const vshCmd *cmd)
     VSH_EXCLUSIVE_OPTIONS("list", "event");
 
     if (vshCommandOptBool(cmd, "list")) {
-        for (event = 0; event < VIR_DOMAIN_EVENT_ID_LAST; event++)
-            vshPrint(ctl, "%s\n", virshDomainEventCallbacks[event].name);
+        for (i = 0; i < G_N_ELEMENTS(virshDomainEventCallbacks); i++)
+            vshPrint(ctl, "%s\n", virshDomainEventCallbacks[i].name);
         return true;
     }
 
     if (vshCommandOptStringReq(ctl, cmd, "event", &eventName) < 0)
         return false;
-    if (eventName) {
-        for (event = 0; event < VIR_DOMAIN_EVENT_ID_LAST; event++)
-            if (STREQ(eventName, virshDomainEventCallbacks[event].name))
-                break;
-        if (event == VIR_DOMAIN_EVENT_ID_LAST) {
-            vshError(ctl, _("unknown event type %s"), eventName);
-            return false;
-        }
-    } else if (!all) {
+
+    if (!eventName && !all) {
         vshError(ctl, "%s",
                  _("one of --list, --all, or --event <type> is required"));
         return false;
     }
 
-    if (all) {
-        data = g_new0(virshDomEventData, VIR_DOMAIN_EVENT_ID_LAST);
-        for (i = 0; i < VIR_DOMAIN_EVENT_ID_LAST; i++) {
-            data[i].ctl = ctl;
-            data[i].loop = loop;
-            data[i].count = &count;
-            data[i].timestamp = timestamp;
-            data[i].cb = &virshDomainEventCallbacks[i];
-            data[i].id = -1;
-        }
-    } else {
+    if (eventName)
         data = g_new0(virshDomEventData, 1);
-        data[0].ctl = ctl;
-        data[0].loop = vshCommandOptBool(cmd, "loop");
-        data[0].count = &count;
-        data[0].timestamp = timestamp;
-        data[0].cb = &virshDomainEventCallbacks[event];
-        data[0].id = -1;
+    else
+        data = g_new0(virshDomEventData, G_N_ELEMENTS(virshDomainEventCallbacks));
+
+    for (i = 0; i < G_N_ELEMENTS(virshDomainEventCallbacks); i++) {
+        if (eventName &&
+            STRNEQ(eventName, virshDomainEventCallbacks[i].name))
+            continue;
+
+        data[i].event = i;
+        data[i].ctl = ctl;
+        data[i].loop = loop;
+        data[i].count = &count;
+        data[i].timestamp = timestamp;
+        data[i].cb = &virshDomainEventCallbacks[i];
+        data[i].id = -1;
+        ndata++;
     }
+
+    if (ndata == 0) {
+        vshError(ctl, _("unknown event type %s"), eventName);
+        return false;
+    }
+
     if (vshCommandOptTimeoutToMs(ctl, cmd, &timeout) < 0)
         goto cleanup;
 
-    if (vshCommandOptBool(cmd, "domain"))
+    if (vshCommandOptBool(cmd, "domain")) {
         if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
             goto cleanup;
+    }
 
     if (vshEventStart(ctl, timeout) < 0)
         goto cleanup;
 
-    for (i = 0; i < (all ? VIR_DOMAIN_EVENT_ID_LAST : 1); i++) {
+    for (i = 0; i < ndata; i++) {
         if ((data[i].id = virConnectDomainEventRegisterAny(priv->conn, dom,
-                                                           all ? i : event,
+                                                           data[i].event,
                                                            data[i].cb->cb,
                                                            &data[i],
                                                            NULL)) < 0) {
@@ -985,12 +986,11 @@ cmdEvent(vshControl *ctl, const vshCmd *cmd)
  cleanup:
     vshEventCleanup(ctl);
     if (data) {
-        for (i = 0; i < (all ? VIR_DOMAIN_EVENT_ID_LAST : 1); i++) {
+        for (i = 0; i < ndata; i++) {
             if (data[i].id >= 0 &&
                 virConnectDomainEventDeregisterAny(priv->conn, data[i].id) < 0)
                 ret = false;
         }
-        VIR_FREE(data);
     }
     return ret;
 }