commit f18e5ec63aaad242b709da701895571cc44c8b94
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Mon Sep 16 17:08:29 2013 +0100

    More fixes to zip stuff

diff --git a/lib/filestorage/zip_packer.php b/lib/filestorage/zip_packer.php
index 175a552..fd9d003 100644
--- a/lib/filestorage/zip_packer.php
+++ b/lib/filestorage/zip_packer.php
@@ -36,6 +36,20 @@ require_once("$CFG->libdir/filestorage/zip_archive.php");
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class zip_packer extends file_packer {
+    /**
+     * @var int Start of processing or last time archive was reopened.
+     */
+    protected $opentime;
+    
+    /**
+     * @var string Path of current archive.
+     */
+    protected $archivepath;
+
+    /**
+     * @var int After building a zip for this many seconds, finalise changes.
+     */
+    const ARCHIVE_ACTIONS_TIME_LIMIT = 10;
 
     /**
      * Zip files and store the result in file storage.
@@ -87,6 +101,42 @@ class zip_packer extends file_packer {
     }
 
     /**
+     * 
+     * @param zip_archive $ziparch
+     * @return bool True if archive is OK, false if an error has occurred
+     */
+    protected function before_archive_action(zip_archive $ziparch) {
+        $now = $this->get_current_time();
+        if ($now < $this->opentime + self::ARCHIVE_ACTIONS_TIME_LIMIT) {
+            return true;
+        }
+
+        // Close archive and clear action count.
+print_object(date('H:i:s') . ': CLOSING ARCHIVE'); flush();
+        $result = $ziparch->close();
+        if (!$result) {
+            return false;
+        }
+
+        // Record reopen time. Note that this is NOT the same as $now because
+        // it might take ages to do the close call.
+        $this->opentime = time();
+
+print_object(date('H:i:s') . ': REOPENING ARCHIVE (close took ' . ($this->opentime - $now) . 's)'); flush();
+        // Reopen archive.
+        return $ziparch->open($this->archivefile, file_archive::OPEN);
+    }
+
+    /**
+     * Gets current time. Wrapper around time() so we can unit-test.
+     *
+     * @return int Current time
+     */
+    protected function get_current_time() {
+        return time();
+    }
+
+    /**
      * Zip files and store the result in os file.
      *
      * @param array $files array with zip paths as keys (archivepath=>ospathname or archivepath=>stored_file or archivepath=>array('content_as_string'))
@@ -101,6 +151,8 @@ class zip_packer extends file_packer {
         if (!$ziparch->open($archivefile, file_archive::OVERWRITE)) {
             return false;
         }
+        $this->archivefile = $archivefile;
+        $this->opentime = time();
 
         $abort = false;
         foreach ($files as $archivepath => $file) {
@@ -132,6 +184,7 @@ class zip_packer extends file_packer {
 
             } else if (is_array($file)) {
                 $content = reset($file);
+                $this->before_archive_action($ziparch);
                 if (!$ziparch->add_file_from_string($archivepath, $content)) {
                     debugging("Can not zip '$archivepath' file", DEBUG_DEVELOPER);
                     if (!$ignoreinvalidfiles) {
@@ -174,6 +227,9 @@ class zip_packer extends file_packer {
      * @return bool success
      */
     private function archive_stored($ziparch, $archivepath, $file, file_progress $progress = null) {
+        if (!$this->before_archive_action($ziparch)) {
+            return false;
+        }
         $result = $file->archive_file($ziparch, $archivepath);
         if (!$result) {
             return false;
@@ -217,6 +273,10 @@ class zip_packer extends file_packer {
      */
     private function archive_pathname($ziparch, $archivepath, $file,
             file_progress $progress = null) {
+        // Record archive action (if required).
+        if (!$this->before_archive_action($ziparch)) {
+            return false;
+        }
         // Record progress each time this function is called.
         if ($progress) {
             $progress->progress();