The indexer package contains all classes to create a new search-index.

### Indexer Structure

The indexer loops over all OLAT data to analyse and generate a new index. The indexer structure is given through the spring config defaultconfig.xml at org.olat.search.service._spring. Each indexer analyse his content and pass tha context to his child elements.
E.g. GroupIndexer goes further to GroupFolderIndexer, GroupForumIndexer, GroupWikiIndexer for each group.

### Indexer Single-Thread / Multi-Thread Mode

The indexer can runs in two modes :

Single Thread
  Only one thread does the hole work, analyse olat data, read file content and write index-data to index-file.
Multi-Thread
  Main thread analyse the olat-data. One or more FolderIndexerWorker read data form file-system. One or more IndexWriter writes index-data to index-file. The