Module b.fetch

Copying of history from one branch to another.

The basic plan is that every branch knows the history of everything that has merged into it. As the first step of a merge, pull, or branch operation we copy history from the source into the destination branch.

The copying is done in a slightly complicated order. We don't want to add a revision to the store until everything it refers to is also stored, so that if a revision is present we can totally recreate it. However, we can't know what files are included in a revision until we read its inventory. So we query the inventory store of the source for the ids we need, and then pull those ids and then return to the inventories.

Line #	Kind	Name	Docs
63	Class	RepoFetcher	Pull revisions and texts from one repository to another.
252	Class	GenericRepoFetcher	This is a generic repo to repo fetcher.
287	Class	KnitRepoFetcher	This is a knit format repository specific fetcher.
318	Class	Inter1and2Helper	Helper for operations that convert data from model 1 and 2
418	Class	Model1toKnit2Fetcher	Fetch from a Model1 repository into a Knit2 repository
437	Class	Knit1to2Fetcher	Fetch from a Knit1 repository into a Knit2 repository
457	Class	RemoteToOtherFetcher	Undocumented