nodemap: add a todo list for getting out of experimental This is all the requirement I can think off. More might be added as they emerge. The first ones are mostly simple technical matters that will be taken care of soon. The question about the "status" of the persistent nodemap and the revlogs that will use it requires more discussion and thinking. Differential Revision: https://phab.mercurial-scm.org/D8181

rust-nodemap: automatically use the rust index for persistent nodemap The persistent nodemap requires the rust index to be used to provides any gains. So we automatically enable it for revlog using the persistent nodemap. We keep it off for other revset because now that the rust revlog fully initialise the nodemap using it everywhere introduce a fairly significant regression (eg: hg diff moving from 0.8s to 2.3s on mozilla-try) Differential Revision: https://phab.mercurial-scm.org/D8164

nodemap: use data from the index in debugnodemap --dump-new It is better to run the actual code when generating a new nodemap cache from scratch. So we do. Differential Revision: https://phab.mercurial-scm.org/D8163

rust-nodemap: also clear Rust data in `clearcaches` Differential Revision: https://phab.mercurial-scm.org/D8161

rust-nodemap: add binding to `nodemap_update_data` Differential Revision: https://phab.mercurial-scm.org/D8160

rust-nodemap: add binding for `nodemap_data_incremental` Differential Revision: https://phab.mercurial-scm.org/D8159

rust-nodemap: add binding for `nodemap_data_all` Differential Revision: https://phab.mercurial-scm.org/D8158

rust-nodemap: use proper Index API instead of using the C API Differential Revision: https://phab.mercurial-scm.org/D8157

rust-nodemap: add utils for propagating errors This also updates the copyright notice Differential Revision: https://phab.mercurial-scm.org/D8156

rust-nodemap: add utils to create `Node`s from Python objects Differential Revision: https://phab.mercurial-scm.org/D8155

rust-index: add `append` method to cindex/Index This will be used by `MixedIndex` in a later patch. Differential Revision: https://phab.mercurial-scm.org/D8154

rust-index: moved constructor in separate impl block with the upcoming addition of the nodemap logic, it's going to become more complicated. Being in the separate impl block has the advantage to be subject to rustfmt, whereas code inside macro calls isn't. Differential Revision: https://phab.mercurial-scm.org/D8153

revlog: using two new functions in C capsule from Rust code We expose `index_length` and `index_node` in the C capsule, so that the Rust representation of the C index can implement the `RevlogIndex` trait. Because our `Node` is actually a one-field struct, we have to decorate it for direct FFI exchange with the C `char*` It would be a good thing to get a length from the C layer, but doing so right now would probably interfere with the upcoming changes that will happen there for the hash length. Differential Revision: https://phab.mercurial-scm.org/D8152

nodemap: refresh the persistent data on nodemap creation The logic to read the data and validate the docket are still in python, so we need to "help" whatever compiled code live in the index to refresh it. Otherwise clearing the cache could lead to an expensive full recomputation and disk update even when the persisted data are still valid. Differential Revision: https://phab.mercurial-scm.org/D8174

tests: check availability of pyflakes by trying to import pyflakes module Since e397c6d74652, we use the pyflakes module instead of the pyflakes executable. As was pointed out during the review, the hghave check can be rewritten to try to import the pyflakes module instead of spawning a new subprocess.

nodemap: deal with the "debugupdatecache" case using a "fake" transaction We are going to need more and more methods of the transaction. So lets change approach. The `hg debugupdatecache` case do not need a transaction, because has the repositories locked, but is not adding any "store" data to it. Differential Revision: https://phab.mercurial-scm.org/D8186

changelog: change the implementation of `_divertopener` During a transaction, new data to the changelog index are "diverted". The previous implementat ways pretty basic, we need something better to be able to use the changelog vfs fully during transaction. (eg: accessing the vfs options). Differential Revision: https://phab.mercurial-scm.org/D8185

nodemap: test that an outdated nodemap can catch up If the persistent nodemap does not contains all revision that the index contains, this is should be detected and dealt with. We add a test for this case. Differential Revision: https://phab.mercurial-scm.org/D8183

nodemap: document the docket attributes More documentation rarely hurts. Differential Revision: https://phab.mercurial-scm.org/D8182

git: key off `git` in .hg/requires rather than separate file Differential Revision: https://phab.mercurial-scm.org/D8265

git: correctly handle p1() on dirstate when underlying git repo is empty This shows up in my next change, which ends up making an empty git repo and then running hg. Differential Revision: https://phab.mercurial-scm.org/D8271

rust: clean remains of direct-ffi code Since b55bec1ea972, the cext entry poitn have been removed, so we drop the code for consistency.

heptapod-ci: use the new `--rust/--no-rust` flag to run the tests

run-tests: add option for running with and without Rust extensions This provide a simple and clear way to run the test with or without rust.

run-tests: rename "pure" variable to setup_opts There are more useful flag than just `--pure`. We clarify the variable name before adding more options.

setup-rust: add a --no-rust flag This new flag will make sure the rust extension will not be build. If neither `--rust` nor `--no-rust` is specified the `HGWITHRUSTEXT` is used.

cext: drop the WITH_RUST block These were used by the `direct-ffi` mode that just got dropped.

setup: use printf instead of print Yuya Nishihara pointed `printf` to me, so I will respect the cargo cult.

git: don't fail import when pygit2 is not install `test-duplicateoptions.py` was failing on py2 for be because I didn't have pygit2 installed. It failed because we depend on pygit2 at import time. This patch makes it so we successfully load the git extension even if pygit2 doesn't exist -- we just won't be able to use it in that case. Differential Revision: https://phab.mercurial-scm.org/D8268

hghave: add a check for pygit2 This will make it easy to use availability of pygit2 as in conditions such as `#if pygit2` and `(pygit2 !)`. It also makes it a little clearer why the test case skipped (when that happens). Differential Revision: https://phab.mercurial-scm.org/D8267