Queries: fix multi key sorting

src/queries/query.js

@@ -40,12 +40,23 @@
   /**
    * A sort function to sort items by key
    *
-   * @param  {String} key The key to sort on
-   * @param  {String} [way="ascending"] 'ascending' or 'descending'
+   * @param  {Array} sort_list List of couples [key, direction]
    * @return {Function} The sort function
    */
-  function sortFunction(key, way, key_schema) {
-    var result, cast_to;
+  function generateSortFunction(key_schema, sort_list) {
+    return function sortByMultipleIndex(a, b) {
+      var result,
+        cast_to,
+        key = sort_list[0][0],
+        way = sort_list[0][1],
+        i,
+        l,
+        a_string_array,
+        b_string_array,
+        f_a,
+        f_b,
+        tmp;
+
       if (way === 'descending') {
         result = 1;
       } else if (way === 'ascending') {
@@ -54,6 +65,7 @@
         throw new TypeError("Query.sortFunction(): " +
                             "Argument 2 must be 'ascending' or 'descending'");
       }
+
       if (key_schema !== undefined &&
           key_schema.key_set !== undefined &&
           key_schema.key_set[key] !== undefined &&
@@ -63,10 +75,17 @@
         } else {
           cast_to = key_schema.key_set[key].cast_to;
         }
-      return function (a, b) {
-        var f_a = cast_to(a[key]), f_b = cast_to(b[key]);
+        f_a = cast_to(a[key]);
+        f_b = cast_to(b[key]);
         if (typeof f_b.cmp === 'function') {
-          return result * f_b.cmp(f_a);
+          tmp = result * f_b.cmp(f_a);
+          if (tmp !== 0) {
+            return tmp;
+          }
+          if (sort_list.length > 1) {
+            return generateSortFunction(key_schema, sort_list.slice(1))(a, b);
+          }
+          return tmp;
         }
         if (f_a > f_b) {
           return -result;
@@ -74,30 +93,35 @@
         if (f_a < f_b) {
           return result;
         }
+        if (sort_list.length > 1) {
+          return generateSortFunction(key_schema, sort_list.slice(1))(a, b);
+        }
         return 0;
-      };
       }
-    return function (a, b) {
+
       // this comparison is 5 times faster than json comparison
-      var i, l;
-      a = metadataValueToStringArray(a[key]) || [];
-      b = metadataValueToStringArray(b[key]) || [];
-      l = a.length > b.length ? a.length : b.length;
+      a_string_array = metadataValueToStringArray(a[key]) || [];
+      b_string_array = metadataValueToStringArray(b[key]) || [];
+      l = Math.max(a_string_array.length, b_string_array.length);
       for (i = 0; i < l; i += 1) {
-        if (a[i] === undefined) {
+        if (a_string_array[i] === undefined) {
           return result;
         }
-        if (b[i] === undefined) {
+        if (b_string_array[i] === undefined) {
           return -result;
         }
-        if (a[i] > b[i]) {
+        if (a_string_array[i] > b_string_array[i]) {
           return -result;
         }
-        if (a[i] < b[i]) {
+        if (a_string_array[i] < b_string_array[i]) {
           return result;
         }
       }
+      if (sort_list.length > 1) {
+        return generateSortFunction(key_schema, sort_list.slice(1))(a, b);
+      }
       return 0;
+
     };
   }
 
@@ -110,19 +134,14 @@
    * @return {Array} The filtered list
    */
   function sortOn(sort_on_option, list, key_schema) {
-    var sort_index;
     if (!Array.isArray(sort_on_option)) {
       throw new TypeError("jioquery.sortOn(): " +
                           "Argument 1 is not of type 'array'");
     }
-    for (sort_index = sort_on_option.length - 1; sort_index >= 0;
-         sort_index -= 1) {
-      list.sort(sortFunction(
-        sort_on_option[sort_index][0],
-        sort_on_option[sort_index][1],
-        key_schema
+    list.sort(generateSortFunction(
+      key_schema,
+      sort_on_option
     ));
-    }
     return list;
   }
 

test/queries/tests.js

@@ -594,4 +594,30 @@
           .always(start);
       });
   });*/
+
+  test('Multiple sort_on options', function () {
+    var i,
+      len = 1000,
+      doc_list = [];
+    for (i = 0; i < len; i += 1) {
+      doc_list.push({s: 'b', i: i});
+    }
+
+    stop();
+    expect(1);
+    jIO.QueryFactory.create("").exec(
+      doc_list,
+      {
+        sort_on: [['s', 'ascending'], ['i', 'ascending']],
+        limit: [0, 2]
+      }
+    )
+      .then(function (list) {
+        deepEqual(list, [
+          {s: 'b', i: 0},
+          {s: 'b', i: 1}
+        ], 'Document list is sorted');
+      }).always(start);
+  });
+
 }));