Initial modifications for XML-based sheet readers to use XMLReader via streaming for large files in the listWorksheetNames() and listWorksheetInfo() methods... still needs some additional work for merged cells to work correctly, but gives a hell of a memory boost and executes more quickly - the same principles will be applied to the core data readers, but that still requires a lot more work. However, when completed, the effort should be worth it for both speed and memory usage, and the code should be a lot cleaner for the core data reader as well

Classes/PHPExcel/Shared/ZipStreamWrapper.php

@@ -100,6 +100,24 @@ class PHPExcel_Shared_ZipStreamWrapper {
         return true;
     }
 
+    /**
+	 * Implements support for fstat().
+	 *
+	 * @return  boolean
+     */
+    public function statName() {
+        return $this->_fileNameInArchive;
+    }
+
+    /**
+	 * Implements support for fstat().
+	 *
+	 * @return  boolean
+     */
+    public function url_stat() {
+        return $this->statName( $this->_fileNameInArchive );
+    }
+
     /**
 	 * Implements support for fstat().
 	 *