moving mixing logic into mix_results helper/suggest

controller/suggest.js

@@ -46,15 +46,8 @@ function setup( backend, query, query_mixer ){
     
     async.parallel(async_query, function(err, results) {
       // results is equal to: {a: docs, b: docs, c: docs}
-      var splice_length = parseInt((SIZE / Object.keys(results).length), 10);
       var results_keys = Object.keys(async_query);
-      
+      var combined = suggest.mix_results(results, results_keys, SIZE);
-      var combined = [];
-      results_keys.forEach(function(key){
-        combined = combined.concat(suggest.sort_by_score(results[key]).splice(0,splice_length));
-      });
-      
-      combined = suggest.dedup(combined);
       suggest.respond(combined);
     });
   

helper/suggest.js

@@ -17,21 +17,46 @@ function setup(backend, res, next) {
     });
   };
 
-  var dedup = function(combined) {
-    var unique_ids = [];
-    return combined.filter(function(item, pos) {
-      if (unique_ids.indexOf(item.text) === -1) {
-        unique_ids.push(item.text);
-        return true;
-      }
-      return false;
-    });
-  };
-
   var sort_by_score = function(combined) {
-    return combined.sort(function(a,b) {
+    return combined.map(function(doc) {
+      return doc.sort(function(a,b) {
         return b.score - a.score;
       });
+    }).reduce(function(a,b) { //flatten
+      return a.concat(b);
+    });
+  };
+
+  var mix_results = function(results, results_keys, size) {
+    var i = 0;
+    var j = 0;
+    var l = results_keys.length;
+    var combined = [];
+    var unique_ids = [];
+
+    while (i<size && l > 0) {
+      if (results[results_keys[j]].length) {
+        combined[j] = combined[j] || [];
+
+        var res = results[results_keys[j]][0];
+        if (unique_ids.indexOf(res.text) === -1) {
+          combined[j].push(res);
+          unique_ids.push(res.text);
+          i++;
+        } 
+        results[results_keys[j]].splice(0,1);
+      } else {
+        results_keys.splice(j,1);
+        l = results_keys.length;
+        j--;
+      }
+      j++;
+      if (j%l === 0) {
+        j=0;
+      }
+    }
+    
+    return sort_by_score(combined);
   };
   
   var reply = function(res, docs) {
@@ -77,9 +102,7 @@ function setup(backend, res, next) {
 
   return {
     query_backend: query_backend,
-    dedup: dedup,
+    mix_results: mix_results,
-    sort_by_score: sort_by_score,
-    reply: reply,
     respond: respond
   };