Optimize user dashboard loading (#33686) (#33708)

Backport #33686 by @lunny

Fix #33582
Fix #31698

When a user login, the dashboard should load all feed belongs to him
with no any conditions. The complicated conditions should be applied
only for another user view this user's profile.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/activities/action_list.go

@@ -208,9 +208,31 @@ func GetFeeds(ctx context.Context, opts GetFeedsOptions) (ActionList, int64, err
 		return nil, 0, fmt.Errorf("need at least one of these filters: RequestedUser, RequestedTeam, RequestedRepo")
 	}
 
-	cond, err := ActivityQueryCondition(ctx, opts)
-	if err != nil {
-		return nil, 0, err
+	var err error
+	var cond builder.Cond
+	// if the actor is the requested user or is an administrator, we can skip the ActivityQueryCondition
+	if opts.Actor != nil && opts.RequestedUser != nil && (opts.Actor.IsAdmin || opts.Actor.ID == opts.RequestedUser.ID) {
+		cond = builder.Eq{
+			"user_id": opts.RequestedUser.ID,
+		}.And(
+			FeedDateCond(opts),
+		)
+
+		if !opts.IncludeDeleted {
+			cond = cond.And(builder.Eq{"is_deleted": false})
+		}
+
+		if !opts.IncludePrivate {
+			cond = cond.And(builder.Eq{"is_private": false})
+		}
+		if opts.OnlyPerformedBy {
+			cond = cond.And(builder.Eq{"act_user_id": opts.RequestedUser.ID})
+		}
+	} else {
+		cond, err = ActivityQueryCondition(ctx, opts)
+		if err != nil {
+			return nil, 0, err
+		}
 	}
 
 	actions := make([]*Action, 0, opts.PageSize)