4. SkyOS Tour - Index Feeder, Queries and File Attributes

Submitted by Robert Szeleney on Fri, 2006-01-13 08:52.

Index Feeder

The Index Feeder is a service which continuously runs in the background and examins all new or updated files on a SkyFS volume. For each file, the plugin-based Index Feeder will try to extract as much information as possible from the file. This information will then be attached to the file in the form of attributes, which makes it possible to quickly search for it by using the SkyFS Index and Live Queries. Additionally, file content gets indexed into a SQL database.
Using the Index
Feeder you can quickly search for file metadata (for instance song artist, bitmap dimension) and for file content from various file formats like text files, documents, pdfs,...

The Index feeder itself does nothing more than listen for file events and notify the Index Feeder plugins. The Index Feeder plugins are responsible for meta data extraction and content indexing. For instance, there are Index Feeder plugins for Audio/Video files (MP3, OGG, WMV, WAV, DivX, etc.), PDF, Bitmaps (PNG, BMP, JPEG, GIF, etc.) any many more.

Furthermore, without such an Index Feeder, one would have to use
special programs to create meta data attributes from files. Because of the Index Feeder, you will not have to do this manually. The Index Feeder will always examine your files when they are created or modified.
Because of this, searching for a bitmap file created with your "Sony TSC3 Digicam" or a song from your favorite artis will take a fraction of a second only.

Summary:
The Index Feeder:

  • Creates and manages a SQL based file content Index, to quickly search for file content
  • Creates SkyFS attributes for well known file types and attaches them to the file itself
  • Provides an API for applications to search files for meta data (attributes) and file content
  • Provides a common control (WidgetCategoryView) to visualize and handle search results
  • With the CategoryWidget every application can make use of this new search functionality and can display the search results it in a common way to the user.
Index Feeder Video
Click here to download the video in AVI format. (18MB, Camtasia Techsmith Codec required for windows or newest MPlayer for Linux).
Click here to download the video in EXE format. (18MB, Player included).