1. when download zip file, push down the download in chunks;

[acontent.git] / docs / include / classes / FileUtility.class.php

diff --git a/docs/include/classes/FileUtility.class.php b/docs/include/classes/FileUtility.class.php
index 1c93c0f..04213c1 100644 (file)
--- a/docs/include/classes/FileUtility.class.php
+++ b/docs/include/classes/FileUtility.class.php
@@ -379,5 +379,33 @@ class FileUtility {
                closedir($dh);
                return '';
        }
+
+       /**
+        * This function is mainly used to download big zip files that are created by ATutor.
+        * For example, download common cartridge, content package, backup.
+        * Note that the file is only in binary, as fopen($filename, "rb"). 
+        * Don't use it to read open text/html files
+        * 
+        * When downloading large files exceeding 1M, instead of use readfile() to read
+        * the whole file into memory once at a time, push down 1M at a time. This way can
+        * download whatever size of the file regardless of php memory limit.
+        */  
+       function readfile_in_chunks($filename) {
+               $filesize = intval(sprintf("%u", filesize($filename)));
+               $chunk_size = 1024 * 1024;
+               
+               if ($filesize > $chunk_size) {
+                       $fp = fopen($filename, "rb");
+                       while (!feof($fp))
+                       {
+                               echo fread($fp, $chunk_size);
+                               ob_flush();
+                               flush();
+                       }
+                       fclose($fp);
+               } else {
+                       readfile($filename);
+               }
+       }
 }
 ?>
\ No newline at end of file