code: def update():
      '''
      Update the cache file for the bucket.
      '''
  
      metadata = _init()
  
      if S3_SYNC_ON_UPDATE:
          # sync the buckets to the local cache
          log.info('Syncing local cache from S3...')
          for saltenv, env_meta in six.iteritems(metadata):
              for bucket_files in _find_files(env_meta):
                  for bucket, files in six.iteritems(bucket_files):
                      for file_path in files:
                          cached_file_path = _get_cached_file_name(bucket, saltenv, file_path)
                          log.info('%s - %s : %s', bucket, saltenv, file_path)
  
                          # load the file from S3 if it's not in the cache or it's old
                          _get_file_from_s3(metadata, saltenv, bucket, file_path, cached_file_path)
  
          log.info('Sync local cache from S3 completed.'f update():
      '''
      Update the cache file for the bucket.
      '''
  
      metadata = _init()
  
      if S3_SYNC_ON_UPDATE:
          # sync the buckets to the local cache
          log.info('Syncing local cache from S3...')
          for saltenv, env_meta in six.iteritems(metadata):
              for bucket_files in _find_files(env_meta):
                  for bucket, files in six.iteritems(bucket_files):
                      for file_path in files:
                          cached_file_path = _get_cached_file_name(bucket, saltenv, file_path)
                          log.info('%s - %s : %s', bucket, saltenv, file_path)
  
                          # load the file from S3 if it's not in the cache or it's old
                          _get_file_from_s3(metadata, saltenv, bucket, file_path, cached_file_path)
  
          log.info('Sync local cache from S3 completed.')
docs: Update the cache file for the bucket.