Plug-ins are responsible for retrieving, processing and storing data. Each time you run backup, restoration or synchronization, data stream is passed through a series of plug-ins.

There are three types of plug-ins:

For convenience of terminology, term “plug-in” in this manual is used to refer to Data Source and Storage plug-ins, and all processing options are referred to as “filters”.

Understanding Plug-ins

Simply speaking, plug-ins contain instructions on what needs to be done to copy the data. Instructions are plug-in-specific and depend on direction of copying. For example, copying from a database plug-in (backing up) will use SELECT statements, and copying into a database (restoring) will use CREATE and INSERT statements.

Each plug-in creates a virtual file system and allows working with its data as with “common” files and folders. All plug-ins support the same set of operations, which allows the program’s core to work with abstract data stream without knowing any details about it. To learn more, please see Plug-in File Systems.

Plug-ins and Filters in the Architecture

Plug-ins are a part of Workstation, and therefore are platform-specific. For example, 32-bit version of Workstation will not be able to access data of 64-bit version of Microsoft Exchange Server.

Say that you want to back up a local file to an FTP server, with ZIP compression. To perform this operation, Workstation must have the Computer and FTP plug-ins, and the ZIP filter. Also, Server must have a valid FTP Configuration for the FTP plug-in. Architecturally, the scheme works as follows:

  1. Workstation receives a command to copy Computer\[Path to Local File] to FTP\FTP Configuration\[Path to FTP Folder], with ZIP filter.
  2. Workstation requests a file from the file system of the Computer plug-in.
  3. The Computer plug-in starts reading the file from the local computer’s hard drive. The respective data stream is sent to Workstation.
  4. Workstation sends the data stream to the ZIP filter.
  5. The ZIP filter performs “on-the-fly” compression and sends the data stream back to Workstation.
  6. Workstation sends the compressed data stream to the FTP plug-in.
  7. The FTP plug-in receives the data stream and a path the data must be written to. The path includes FTP Configuration which contains server address and authorization parameters. The plug-in connects to the FTP server and uploads the respective file.

Technically, Workstation doesn’t “know” anything about the data it copies and about filters it uses to process it. It takes a data stream from Data Source plug-in, passes it through Filters, and then sends it to Storage plug-in.

You can learn more about plug-ins in the next chapters.

User Manual contents

Who uses Handy Backup?