Re: [PATCH v3 2/4] path: optimize common dir checking

[Michael Haggerty <mhagger@alum.mit.edu>]

On 08/14/2015 10:04 PM, David Turner wrote:
> On Fri, 2015-08-14 at 10:04 -0700, Junio C Hamano wrote:
>> [...]
>> So I think we should have *three* functions:
>>
>>  - git_workspace_name(void) returns some name that uniquely
>>    identifies the current workspace among the workspaces linked to
>>    the same repository.
> 
> Random side note: the present workspace path name component is not
> acceptable for this if alternate ref backends use a single db for
> storage across all workspaces.  That's because you might create a
> workspace at foo, then manually rm -r it, and then create a new one also
> named foo.  The database wouldn't know about this series of events, and
> would then have stale per-workspace refs for foo.

The reference backend should clearly have functions that are called on
the creation and destruction of a workspace. In these functions the
backend could initialize / clean up any reference-related resources
associated with that workspace.

These functions can be empty for the filesystem backend.

> That said, with my lmdb backend, I've been falling back to the files
> backend for per-workspace refs.  This also means I don't have to worry
> about expiring per-workspace refs when a workspace is removed. 
> 
> I could change this, but IIRC, there are a fair number of things that
> care about the existence of a file called HEAD, so the fallback was
> easier.  (That is, the other way was a giant hassle).

OK, so the functions can be empty for the lmdb backend, too :-)

> [...]
> For this patch series, I don't think we need to change anything [...]
> Implementing
> Junio's proposal would not affect this series; it would just be an
> additional patch on top (or beforehand).

OK.

> [...]

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu