core.DataSource plugin

[skipor]

We want go use different data sources for Providers, but not create multiple providers with same decoding logic.
Proposed, to create core.DataSource plugin, that will contain logic of getting encoded ammo bytes, and use it as nested plugin in Providers that takes bytes from somewhere and decodes them.

Here some draft:

type DataSource {
    // Open opens data source. 
    // Returned source can be file, socket, string or byte reader, or anything else, that implements
    // more that io.Reader, so it's ok to check if source is io.Seeker, and seek if it is.
    // Specific type checking (*os.File, for example) highly not recommended - use interfaces.
    Open() (source io.Closer, err error)
}

What DataSources can be implemented:

• file (filepath to open)
• socket (some string, that can be passed to net.Listen)
• url (http/https URL to download)
• inline (string inlined to config)

[skipor]

Let's also add DataSinkcore plugin, that will contains logic of encoding and saving stream of bytes from Aggregators