let the scanner run forever

server/djrandom/scanner/scanner.py

 import os
 import optparse
 import logging
+import time
 from djrandom import daemonize
 from djrandom import utils
 from djrandom.model.mp3 import MP3
@@ -22,12 +23,15 @@ class Scanner(object):
             setattr(mp3, key, value)
         mp3.index(self.idx)
 
-    def scan_db(self):
+    def scan_db(self, run_once):
         """Scan the database for new files."""
         while True:
             mp3 = MP3.query.filter_by(ready=False).limit(1).first()
             if not mp3:
+                if run_once:
                     break
+                time.sleep(30)
+                continue
             log.info('processing %s' % mp3.sha1)
             try:
                 self.process(mp3)
@@ -39,14 +43,15 @@ class Scanner(object):
             Session.commit()
 
 
-def run_scanner(xapian_db_dir, db_url):
+def run_scanner(xapian_db_dir, db_url, run_once):
     init_db(db_url)
     scanner = Scanner(xapian_db_dir)
-    scanner.scan_db()
+    scanner.scan_db(run_once)
 
 
 def main():
     parser = optparse.OptionParser()
+    parser.add_option('--once', action='store_true')
     parser.add_option('--xapian_db_dir')
     parser.add_option('--db_url')
     daemonize.add_standard_options(parser)
@@ -60,8 +65,11 @@ def main():
     if args:
         parser.error('Too many arguments')
 
+    if opts.once:
+        opts.foreground = True
+
     daemonize.daemonize(opts, run_scanner,
-                        (opts.xapian_db_dir, opts.db_url))
+                        (opts.xapian_db_dir, opts.db_url, opts.once))
 
 
 if __name__ == '__main__':