Main Data-Base

The Main structure is the runtime equivalent of a .blend file: it stores all IDs representing the whole data of the current file.

It also stores runtime-only data, like the full version of all linked IDs and some short-life helping information like relationships between data-blocks.

It is defined, along with its core API, in BKE_main.hh.

ID storage in Main

One list by id type, ordered by name, with linked IDs after local ones.