通过单独count和distinct的方式获取帖子列表的参与人数

app/service/forumThreadService.js

@@ -784,10 +784,15 @@ function getSubThreads(doc, sort, callback) {
     if (sort) {
         sortBy = sort;
     }
+    async.parallel([function(cb){
+       ForumThread.distinct('from', conditions, cb);
+    },function(cb){
+       countAllByFid(conditions, cb);
+    },function(cb){
         ForumThread.find(conditions, subThreadFields).populate('from', 'icon').limit(Number(20)).sort(sortBy).exec(function(err, docs) {
             if (err) {
                 console.error(err);
-            callback(err, null);
+                cb(err, null);
             } else {
                 var list = [];   //用户去重
                 _.forEach(docs, function(one, i) {
@@ -802,14 +807,20 @@ function getSubThreads(doc, sort, callback) {
                     }
                 });
                 var obj = {};
-            obj.docTotal = docs.length;
-            obj.total = list.length;
                 obj.items = list;
-
                 var newDoc = doc.toObject();
                 newDoc.subThreads = obj;
-
-            callback(null, newDoc);
+                cb(null, newDoc);
+            }
+        });
+    }],function(err, results){
+        if (err) {
+            callback(err);
+        } else {
+            var lastResult = results[2];
+            lastResult.subThreads.docTotal = result[1] || 0;
+            lastResult.subThreads.total = result[0];
+            callback(null, lastResult);
         }
     });
 }