Added optimization to avoid extra bnode sorting.

jsonld.php

@@ -1884,13 +1884,19 @@ class JsonLdProcessor
       }
 
       // keep sorting and naming blank nodes until they are all named
+      $resort = true;
       while(count($bnodes) > 0)
+      {
+         if($resort)
          {
             usort($bnodes, array($this, 'deepCompareBlankNodes'));
+         }
 
          // name all bnodes according to the first bnode's relation mappings
+         // (if it has mappings then a resort will be necessary)
          $bnode = array_shift($bnodes);
          $iri = $bnode->{'@subject'}->{'@iri'};
+         $resort = ($this->serializations->$iri->{'props'} !== null);
          $dirs = array('props', 'refs');
          foreach($dirs as $dir)
          {
@@ -1921,6 +1927,9 @@ class JsonLdProcessor
                }
             }
 
+            // only clear serializations if resorting is necessary
+            if($resort)
+            {
                // only keep non-canonically named bnodes
                $tmp = $bnodes;
                $bnodes = array();
@@ -1939,6 +1948,7 @@ class JsonLdProcessor
                }
             }
          }
+      }
 
       // sort property lists that now have canonically-named bnodes
       foreach($edges->props as $key => $value)