The strip code used a trick to lower the cost of branchcache update after a
strip. However is less necessary since we have branchcache collaboration.
Invalid branchcache are likely to be cheaply rebuilt again a near subset of the
repo.
Moreover, this trick would need update to be relevant in the now filtered
repository world. It currently update the unfiltered branchcache that few people
cares about. Make it smarter on that aspect would need complexes update of the
calling logic
So this mechanism is:
- Arguably needed,
- Currently irrelevant,
- Hard to update
and I'm dropping it.
We now update the branchcache in all case by courtesy of the read only reader.
This changeset have a few expected impact on the testsuite are different cache
are updated.
The `commitctx` and `addchangegroup` methods of repo upgrade branchcache after
completion. This behavior aims to keep the branchcache in sync for read only
process as hgweb. See b4909adfc093 for details.
Since changelog filtering is used, those calls only update the cache for unfiltered repo.
One of no interest for typical read only process like hgweb.
Note: By chance in basic case, `repo.unfiltered() == repo.filtered('unserved')`
This changesets have the "unserved" cache updated instead. I think this is the
only cache that matter for hgweb.
We could imagine updating all possible branchcaches instead but:
- I'm not sure it would have any benefit impact. It may even increase the odd of
all cache being invalidated.
- This is more complicated change.
So I'm going for updating a single cache only which is already better that
updating a cache nobody cares about.
This changeset have a few expected impact on the testsuite are different cache
are updated.
git patches may require copies to be handled out-of-order. For instance, take
the following sequence:
* modify a
* copy a into b
Here, we have to generate b from a before its modification. To do so,
applydiff() was scanning for copy metadata and performing the copies before
processing the other changes in-order. While smart and efficient, this approach
complicates things by handling file copies and file creations at different
places and times. While a new file must not exist before being patched a copied
file already exists before applying the first hunk.
Instead of copying the files at their final destination before patching, we
store them in a temporary file location and retrieve them when patching. The
filestore always stores file content in real files but nothing prevents adding
a cache layer. The filestore class was kept separate from fsbackend for at
least two reasons:
- This class is likely to be reused as a temporary result store for a future
repository patching call (entries just have to be extended to contain copy
sources).
- Delegating this role to backends might be more efficient in a repository
backend case: the source files are already available in the repository itself
and do not need to be copied again. It also means that third-parties backend
would have to implement two other methods. If we ever decide to merge the
filestore feature into backend, a minimalistic approach would be to compose
with filestore directly. Keep in mind this copy overhead only applies for
copy/rename sources, and may even be reduced to copy sources which have to
handled ahead of time.
