Add helper functions to table class

1 files changed, 39 insertions, 0 deletions

diff --git a/app/class/table.class.php b/app/class/table.class.php
index 62f95d3..0edff9d 100644
--- a/app/class/table.class.php
+++ b/app/class/table.class.php
@@ -168,6 +168,45 @@ abstract class table
         $query = "DELETE FROM views WHERE guid = '" . $guid . "' OR viewer = '" . $guid . "'";
         $this->db->query($query);
     }
+
+    /*
+     * Get a random sha256 blob, returned as a hexadecimal string
+     */
+    public function getBlob() : string
+    {
+        return hash("sha256", openssl_random_pseudo_bytes(64));
+    }
+
+    /*
+     * Get current timestamp as a string for object database purposes
+     */
+    private function getCurrentTimestamp() : string
+    {
+        $query = "SELECT now() AS stamp";
+        $res = $this->db->query($query);
+        return $res[0]['stamp'];
+    }
+
+    /*
+     * Check whether the given GUID exists
+     */
+    private function isGUID(string $guid) : bool
+    {
+        $guid = $this->db->esc($guid);
+        $query = "SELECT guid FROM objects WHERE guid = '" . $guid . "'";
+        $res = $this->db->query($query);
+        return count($res) > 0;
+    }
+
+    /*
+     * Get a new, unique GUID for a new system object
+     */
+    private function getNewGUID() : string
+    {
+        do $guid = substr($this->getBlob(), 0, 8);
+        while ($this->isGUID($guid));
+        return $guid;
+    }
 }
 
 ?>