localrepo: extract resolving of opener options to standalone functions Requirements and config options are converted into a dict which is available to the store vfs to consult. This is how storage options are communicated from the repo layer to the storage layer. Currently, we do that option resolution in a private method on the repo instance. And there is a single method doing that resolution. Opener options are logically specific to the storage backend they apply to. And, opener options may wish to influence how the repo object/type is constructed. So it makes sense to have more granular storage option resolution that occurs before the repo object is instantiated. This commit extracts the code for resolving opener options into new module-level functions. These functions are run before the repo instance is constructed. As part of the code move, we split the option resolution into generic and revlog-specific options. After this commit, we no longer add revlog-specific options to repos that don't have a revlog requirement. Some of these opener options and associated config options might make sense on alternate storage backends. We can always reuse config options and opener option names for other backends. But we shouldn't be passing opener options to storage backends that won't recognize them. I haven't done it here, but after this commit it should be possible for store backends to validate the set of opener options it receives. Because localrepository.openerreqs is no longer used after this commit, it has been removed. I'm not super thrilled about the code outside of localrepo that is adding requirements and updating opener options. We'll probably want to create a more formal API for that use case that constructs a new repo instance and poisons the old repo object. But this was a pre-existing issue and can be dealt with later. I have little doubt it will cause me troubles as I continue to refactor how repository objects are instantiated. .. api:: ``localrepository.openerreqs`` has been removed. Override ``localrepo.resolvestorevfsoptions()`` to add custom opener options. .. api:: ``localrepository._applyopenerreqs()`` has been removed. Use ``localrepo.resolvestorevfsoptions()`` to add custom opener options. Differential Revision: https://phab.mercurial-scm.org/D4576