Separate the calls to unserialize() and file_get_contents() so that the size...

Separate the calls to unserialize() and file_get_contents() so that the size of the file contents can be logged in the debug message.

src/lib/default/filestatemachine.php

@@ -126,10 +126,11 @@ class FileStateMachine implements IStateMachine {
         // Read current sync state
         $filename = $this->getFullFilePath($devid, $type, $key, $counter);
 
-        ZLog::Write(LOGLEVEL_DEBUG, sprintf("FileStateMachine->GetState() on file: '%s'", $filename));
-
         if(file_exists($filename)) {
-            return unserialize(file_get_contents($filename));
+            $contents = file_get_contents($filename);
+            $bytes = strlen($contents);
+            ZLog::Write(LOGLEVEL_DEBUG, sprintf("FileStateMachine->GetState() read '%d' bytes from file: '%s'", $bytes, $filename ));
+            return unserialize($contents);
         }
         // throw an exception on all other states, but not FAILSAVE as it's most of the times not there by default
         else if ($type !== IStateMachine::FAILSAVE)