Looking for detailed description of how OVD works

I have been unable to find a plugin that does what I want it to do.  I won't explain because I have had so many suggestions and none of them work.  I am at a point where I feel like I should just write my own OVD plugin.  I have done considerable research but the available data is lacking.  I need to understand how each of the methods in the BasePlugin template class work, when they are called, both in the context of searches by what I would call a "target" adapter (LDAP Adapter to AD for example), in context