Added tag 6.8rc0 for changeset 6454c117c6a4

branching: merge default into stable for 6.8rc0

relnotes: add 6.8rc0

branch3: use an explicitely experimental name for files Since this format is still experimental, we don't want to have to side-step the `branch3` name in case people do start using it before it's stable.

obsolete: simplify relevantmarker Drop duplicate assignment from a merge failure. Save one loop iteration by exploiting that pendingnodes will be seennodes after the first round anyway, so just pre-initialize the set accordingly. From Anton Shestakov's review on !867. Performance difference for my test case is in the noise.

exchange: improve computation of relevant markers for large repos Find the candidates for nodes with relevant markers by going over all markers instead of iterating over all nodes. Most nodes will not have markers anyway. Further optimize the code by allowing revsets as well, which reduces the materialization cost.

branching: merge stable into default

narrow: add a test for linkrev computation done during widen This new tests show that the linkrev computed and sent by the server might end up being wrong during a widen operation.

obsolete: quote the feature name This makes it at least somewhat clearer that hg is talking about some specific feature and not just outdated code.

branching: merge stable into default

clonebundles: add missing newline to legacy response This seems to have been removed in 6.5 (likely by 60f9602b413e).

dirstate: remove the python-side whitelist of allowed matchers This whitelist is too permissive because it allows matchers that contain disallowed ones deep inside, for example through `intersectionmatcher`. It is also too restrictive because it doesn't pass through some of the matchers we support, such as `patternmatcher`. It's also unnecessary because unsupported matchers raise `FallbackError` and we fall back anyway. Making this change makes more of the tests use rust code path, and therefore subtly change behavior. For example, rust status in largefiles repos seems to have strange behavior.

match: make `was_tampered_with` work recursively This is useful if we are to use it outside of Rust, when deciding whether or not to do some fast-path operation with a given matcher.

largefiles: mark more matchers as having been tampered with These happened to slip through the cracks earlier because they weren't caught by tests. Now that we're enabling rust fast path more widely these start breaking.

branching: merge stable into default

hgrc: search XDG_CONFIG_HOME on mac Searching for hgrc was special cased not to look through ~/.config/hg on Mac, but that’s unnecessary: Macs support it as do other unix based systems. There are plenty tools that use it there, e.g. git, and people expect it to work, e.g. "https://stackoverflow.com/questions/72499837/mercurial-on-macos-doesnt-read-config-hg-hgrc". Initial code introduced in 354020079723.

base-revsets: use an author that actually exercises a lot of changesets This was caught in my big find-and-replace: d4ba4d51f85f. The point of `base-revsets` is to give revsets that will give a good coverage of the repository. Using Pierre-Yves as the second largest committer (in terms of number of changesets) seems like a good idea.

match: simplify the rust-side file pattern kind parsing There's no need to add the ':' characters if we're simply pattern matching against constants next.

match: share code between includematcher and patternmatcher No need to have this duplication.

matchers: support patternmatcher in rust

match: avoid rust fast path if the matcher was tampered with Otherwise the fast path does not respect the modifications made by the extension (concretely largefiles, but other extensions can start using that too)

largefiles: track if a matcher was tampered with This is used to make sure rust fast path is not taken for the modified matchers.

branching: merge stable into default

tags-cache: directly perform a monimal walk for hgtagsfnodescache warming We do something narrower than the path retrieving data. So lets use dedicated code instead. This provides further useful speedup: ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.debug.debug-update-cache # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.pre-state = warm before-this-series: 19.947581 skip-fnode-filter: 18.916804 (-5.17%, -1.03) use-rev-num: 17.493725 (-12.30%, -2.45) this-changesets: 15.919466 (-20.19%, -4.03)

tags-cache: directly operate on rev-num warming hgtagsfnodescache Not having to goes through nodeid speed up things notably. ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.debug.debug-update-cache # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.pre-state = warm before-this-series: 19.947581 before-this-changes: 18.916804 (-5.17%, -1.03) this-changesets: 17.493725 (-12.30%, -2.45)

tags-cache: skip the filternode step if we are not going to use it When warming the hgtagsfnodescache, we don't need the actual result, so we can simply skip the part that "filter" fnode we read from the cache. So provide a quite visible speed up to the top level `hg debugupdatecache` function. ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.debug.debug-update-cache # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.pre-state = warm before: 19.947581 after: 18.916804 (-5.17%, -1.03)

tags-cache: add a dedicated warm cache function to hgtagsfnodescache Having a dedicated API point will help to optimize that specific usage. Right doing a full phases weam takes a long time, even when the cache is already filled.

outgoing: add a simple fastpath when there is no common This further speed up case like `hg bundle --all` for larger repository. ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.command.bundle # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.revs = all # benchmark.variants.type = none-streamv2 before: 316.749699 after: 311.165461 (-1.76%, -5.58) There is further work to be done in this area like not doing any outgoing computation in the stream case for example. however the recent changes already gives use a large win for a small amount of local work. ### benchmark.name = hg.command.bundle # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.revs = all # benchmark.variants.type = none-streamv2 ## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog pre-%ln-change: 1.263859 the-%ln-change: 0.700229 (-44.60%, -0.56) prev-changeset: 0.496050 (-60.75%, -0.77) this-changeset: 0.495243 (-60.81%, -0.77) ## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog pre-%ln-change: 2.975765 the-%ln-change: 1.870798 (-37.13%, -1.10) prev-changeset: 1.461583 (-50.88%, -1.51) this-changeset: 1.469185 (-50.63%, -1.51) ## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog pre-%ln-change: 4.540080 the-%ln-change: 3.401700 (-25.07%, -1.14) prev-changeset: 2.915810 (-35.78%, -1.62) this-changeset: 2.911643 (-35.87%, -1.63) ## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog pre-%ln-change: 10.138396 the-%ln-change: 7.750458 (-23.55%, -2.39) prev-changeset: 6.665565 (-34.25%, -3.47) this-changeset: 6.672078 (-34.19%, -3.47) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog pre-%ln-change: 399.484481 the-%ln-change: 346.508952 (-13.26%, -52.98) prev-changeset: 316.749699 (-20.71%, -82.73) this-changeset: 311.165461 (-22.11%, -88.32)

outgoing: rework the handling of the `missingroots` case to be faster The previous implementation was slow, to the point it was taking a significant amount of `hg bundle --type none-streamv2` call. We rework the code to compute the same value much faster, making the operation disappear from the `hg bundle --type none-streamv2` profile. Someone would remark that producing a streamclone does not requires an `outgoing` object. However that is a matter for another day. There is other user of `missingroots` (non stream `hg bundle` call for example), and they will also benefit from this rework. We implement an old TODO in the process, directly computing the missing and common attribute as we have most element at hand already. ### benchmark.name = hg.command.bundle # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.revs = all # benchmark.variants.type = none-streamv2 ## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog before: 7.750458 after: 6.665565 (-14.00%, -1.08) ## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog before: 0.700229 after: 0.496050 (-29.16%, -0.20) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog before: 346.508952 after: 316.749699 (-8.59%, -29.76) ## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog before: 3.401700 after: 2.915810 (-14.28%, -0.49) ## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog before: 1.870798 after: 1.461583 (-21.87%, -0.41) note: this whole `missingroots` of outgoing has a limited number of callers and could likely be replace by something simpler (like taking an explicit "missing_revs" set for example). However this is a wider change and we focus on a small impact, quick rework that does not change the API for now.

proxy-vfs: also proxy the `audit` attribute In the previous changeset, we had to do a little dance to access the useful `audit` attribute. We now provide a proper accessors to it. We don't update the code in `perf.py` because it has to remain compatible with older version of Mercurial. This will just be nicer in the future.

perf: clear vfs audit_cache before each run When generating a stream clone, we spend a large amount of time auditing path. Before this changes, the first run was warming the vfs cache for the other runs, leading to a large runtime difference and a "faulty" reported timing for the operation. We now clear this important cache between run to get a more realistic timing. Below are some example of median time change when clearing these cases. The maximum time for a run did not changed significantly. ### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog # benchmark.name = hg.perf.exchange.stream.generate # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.version = latest no-clearing: 17.289905 cache-clearing: 21.587965 (+24.86%, +4.30) ## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog no-clearing: 32.670748 cache-clearing: 40.467095 (+23.86%, +7.80) ## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog no-clearing: 37.838858 cache-clearing: 46.072749 (+21.76%, +8.23) ## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog no-clearing: 32.969395 cache-clearing: 39.646209 (+20.25%, +6.68) In addition, this significantly reduce the timing difference between the performance command, from the perf extensions and a `real `hg bundle` call producing a stream bundle. Some significant differences remain especially on the "mozilla-try" repositories, but they are now smaller. Note that some of that difference will actually not be attributable to the stream generation (like maybe phases or branch map computation). Below are some benchmarks done on a currently draft changeset fixing some unrelated slowness in `hg bundle` (34a78972af409d1ff37c29e60f6ca811ad1a457d) ### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default hg.perf.exchange.stream.generate: 21.587965 hg.command.bundle: 24.301799 (+12.57%, +2.71) ## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog hg.perf.exchange.stream.generate: 40.467095 hg.command.bundle: 44.831317 (+10.78%, +4.36) ## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog hg.perf.exchange.stream.generate: 39.646209 hg.command.bundle: 45.395258 (+14.50%, +5.75) ## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog hg.perf.exchange.stream.generate: 46.072749 hg.command.bundle: 55.882608 (+21.29%, +9.81) ## data-env-vars.name = mozilla-try-2023-03-22-zlib-general-delta hg.perf.exchange.stream.generate: 334.716708 hg.command.bundle: 377.856767 (+12.89%, +43.14) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog hg.perf.exchange.stream.generate: 302.972301 hg.command.bundle: 326.098755 (+7.63%, +23.13)

perf: start recording total time after warming The warming might be costly and this should not affect the "time profile" of the actual collection.

perf: run the gc before each run The python garbage collector is a large source of performance troubles, we run it right before the timed section to reduce the change for the gc to add noise to the benchmark.

perf: allow profiling of more than one run By default, we still profile the first run only. However profiling more run help to understand side effect from one run to the other. So we add an option to be able to do so.

profiler: flush after writing the profiler output Otherwise, the profiler output might only partially appears until the next flush of the buffer. Since profiling often happens for long operation, the next flush can be a long time away.

stream-clone: disable gc for the entry listing section for the v2 format This is similar to the change we did for the v3 format in 6e4c8366c5ce. The benchmark bellow show this gives us a notable gains, especially on larger repositories. ### benchmark.name = hg.perf.stream-locked-section # benchmark.name = hg.perf.stream-locked-section # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.version = v2 ## data-env-vars.name = pypy-2018-08-01-zstd-sparse-revlog 5e931bf8707c: 0.503820 ~~~~~ 1106d1bf695e: 0.470078 (-6.70%, -0.03) ## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog 5e931bf8707c: 0.535756 ~~~~~ 1106d1bf695e: 0.490249 (-8.49%, -0.05) ## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog 5e931bf8707c: 1.327041 ~~~~~ 1106d1bf695e: 1.174636 (-11.48%, -0.15) ## data-env-vars.name = netbeans-2018-08-01-zstd-sparse-revlog 5e931bf8707c: 2.439158 ~~~~~ 1106d1bf695e: 2.220515 (-8.96%, -0.22) ## data-env-vars.name = netbeans-2019-11-07-zstd-sparse-revlog 5e931bf8707c: 2.630794 ~~~~~ 1106d1bf695e: 2.261473 (-14.04%, -0.37) ## data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog 5e931bf8707c: 5.769002 ~~~~~ 1106d1bf695e: 5.062000 (-12.26%, -0.71) ## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog 5e931bf8707c: 13.351750 ~~~~~ 1106d1bf695e: 12.346655 (-7.53%, -1.01) ## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog 5e931bf8707c: 10.772939 ~~~~~ 1106d1bf695e: 9.495407 (-11.86%, -1.28) ## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog 5e931bf8707c: 10.864297 ~~~~~ 1106d1bf695e: 9.475597 (-12.78%, -1.39) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog 5e931bf8707c: 17.448335 ~~~~~ 1106d1bf695e: 16.027474 (-8.14%, -1.42)

phases: rework the logic of _pushdiscoveryphase to bound complexity This rework the various graph traversal in _pushdiscoveryphase to keep the complexity in check. This is done though a couple of things: - first, limiting the space we have to explore, for example, if we are not in publishing push, we don't need to consider remote draft roots that are also draft locally, as there is nothing to be moved there. - avoid unbounded descendant computation, and use the faster "rev between" computation. This provide a massive boost to performance when exchanging with repository with a massive amount of draft, like mozilla-try: ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.command.push # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = default ## benchmark.variants.revs = any-1-extra-rev before: 20.346590 seconds after: 11.232059 seconds (-38.15%, -7.48 seconds) ## benchmark.variants.revs = any-100-extra-rev before: 24.752051 seconds after: 15.367412 seconds (-37.91%, -9.38 seconds) After this changes, the push operation is still quite too slow. Some of this can be attributed to general phases slowness (reading all the roots from disk for example) and other know slowness (not using persistent-nodemap, branchmap, tags, etc. We are also working on them, but with this series, phase discovery during push no longer showing up in profile and this is a pretty nice and bit low-hanging fruit out of the way. ### (same case as the above) # benchmark.variants.revs = any-1-extra-rev pre-%ln-change: 44.235070 this-changeset: 11.232059 seconds (-74.61%, -33.00 seconds) # benchmark.variants.revs = any-100-extra-rev pre-%ln-change: 49.234697 this-changeset: 15.367412 seconds (-68.79%, -33.87 seconds) Note that with this change, the `hg push` performance is now much closer to the `hg pull` performance, even it still lagging behind a bit. (and the overall performance are still too slow). ### data-env-vars.name = mozilla-try-2023-03-22-ds2-pnm # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.pulled-delta-reuse-policy = default # bin-env-vars.hg.flavor = rust ## benchmark.variants.revs = any-1-extra-rev hg.command.pull: 6.517450 hg.command.push: 11.219888 ## benchmark.variants.revs = any-100-extra-rev hg.command.pull: 10.160991 hg.command.push: 14.251107 ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.pulled-delta-reuse-policy = default ## bin-env-vars.hg.flavor = default ## benchmark.variants.revs = any-1-extra-rev hg.command.pull: 8.577772 hg.command.push: 11.232059 ## bin-env-vars.hg.flavor = default ## benchmark.variants.revs = any-100-extra-rev hg.command.pull: 13.152976 hg.command.push: 15.367412 ## bin-env-vars.hg.flavor = rust ## benchmark.variants.revs = any-1-extra-rev hg.command.pull: 8.731982 hg.command.push: 11.178751 ## bin-env-vars.hg.flavor = rust ## benchmark.variants.revs = any-100-extra-rev hg.command.pull: 13.184236 hg.command.push: 15.620843

phases: introduce a performant efficient way to access revision in a set This will be useful in the next changesets.

phases: use revision number in `_pushdiscoveryphase` We now reach our target checkpoint in terms of rev-num conversion. The `_pushdiscoveryphase` function is now performing graph computation based on revision number only. Avoiding repeated conversion from node-id to rev-num. See previous changeset updated `new_heads` for rationnal. Again, time saved in the 100 milliseconds order of magnitude for the mozilla-try benchmark I have been using. However, wow that the logic is done using revision number, we can look into having better logic in the next changesets, which will provide a much bigger speedup.

phases: move RemotePhasesSummary to revision number This continue our quest to align more logic on revision number instead of node-ids. The motivation is similar to the change to `new_heads` and `analyze_remote_phases` a few changeset earlier. Again, we take this as an opportunity to rename the class, and the attribute to the new naming scheme. This will highlight the need for code update for any code using it an expecting node-ids. Many of the rev-num → node-id conversion we had to introduce in the previous changesets can now be removed. More will be removed in the future as we continue to align code toward rev-num usage. time saved in the 100 milliseconds order of magnitude for the mozilla-try benchmark I have been using.

phases: stop using `repo.set` in `remotephasessummary` The `repository.set` create changectx on the fly, an expensive operation. Using `repo.revs` and a direct rev-num → node-id translation will be significantly faster. This is especially true as we prepare ourself to no longer do the rev-num → node-id transalation there. The speedup is a bit lost in the overall noisyness of the slow phase discovery algorithm, but it save a small amount of time in my benchmark.

phases: use revision number in analyze_remote_phases Same logic as the previous change to `new_heads`, see rationnal there. This avoids a small number of `nodes -> revs` conversion speeding thing up in the 100 milliseconds order of magnitude for the worses cases. However, the rest of the logic is noisy enough that it hardly matters for now.

phases: use revision number in new_heads All graph operations will be done using revision numbers, so passing nodes only means they will eventually get converted to revision numbers internally. As part of an effort to align the code on using revision number we make the `phases.newheads` function operated on revision number, taking them as input and using them in returns, instead of the node-id it used to consume and produce. This is part of multiple changesets effort to translate more part of the logic, but is done step by step to facilitate the identification of issue that might arise in mercurial core and extensions. To make the change simpler to handle for third party extensions, we also rename the function, using a more modern form. This will help detecting the different between the node-id version and the rev-num version. I also take this as an opportunity to add some comment about possible performance improvement for the future. They don't matter too much now, but they are worse exploring in a while.

phases: convert remote phase root to node while reading them This is currently a bit silly as we will convert them back to node right after, but that is an intermediate step before doing more disruptive changes.

phases: more compact error handling in analyzeremotephases using an intermediate variable result in more readable code, so let us use it.

push: rework the computation of fallbackheads to be correct The previous computation tried to be smart but ended up being wrong. This was caught by phase movement test while reworking the phase discovery logic to be faster. The previous logic was failing to catch case where the pushed set was not based on a common heads (i.e. when the discovery seemed to have "over discovered" content, outside the pushed set) In the following graph, `e` is a common head and we `hg push -r f`. We need to detect `c` as a fallback heads and we previous failed to do so:: e | d f |/ c | b | a The performance impact of the change seems minimal. On the most impacted repository at hand (mozilla-try), the slowdown seems mostly mixed in the overall noise `hg push` but seems to be in the hundred of milliseconds order of magnitude. When using rust, we seems to be a bit faster, probably because we leverage more accelaratd internals. I added a couple of performance related common for further investigation later on.

revset: stop serializing node when using "%ln" Turning hundred of thousand of node from node to hex and back can be slow… what about we stop doing it? In many case were we are using node id we should be using revision id. However this is not a good reason to have a stupidly slow implementation of "%ln". This caught my attention again because the phase discovery during push make an extensive use of "%ln" or huge set. In absolute, that phase discovery probably should use "%ld" and need to improves its algorithmic complexity, but improving "%ln" seems simple and long overdue. This greatly speeds up `hg push` on repository with many drafts. Here are some relevant poulpe benchmarks: ### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog # benchmark.name = hg.command.push # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = all-out-heads # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = default ## benchmark.variants.revs = any-1-extra-rev before: 44.235070 after: 20.416329 (-53.85%, -23.82) ## benchmark.variants.revs = any-100-extra-rev before: 49.234697 after: 26.519829 (-46.14%, -22.71) ### benchmark.name = hg.command.bundle # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.revs = all # benchmark.variants.type = none-streamv2 ## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog before: 10.138396 after: 7.750458 (-23.55%, -2.39) ## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog before: 1.263859 after: 0.700229 (-44.60%, -0.56) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog before: 399.484481 after: 346.5089 (-13.26%, -52.98) ## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog before: 4.540080 after: 3.401700 (-25.07%, -1.14) ## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog before: 2.975765 after: 1.870798 (-37.13%, -1.10)

bundlespec: drop unused _bundlespecvariants dictionary Why do we have a `_bundlespecvariants`?

bundlespec: type the _bundlespeccontentopts dictionary If only we had a tool to detect the kind of stupid error we just fixed… ho wait.

bundlespec: fix the "streamv2" and "streamv3-exp" variant In c4aab3661f25, we broken this feature by adding unicode instead of bytes to the dictionary. On the other hand, this feature was never tested, so augment the tests to tests this.

perf: create the temporary target next to the source in stream-consume See inline comment for rational.

bundlespec: rationalize the way we specify stream bundle version Instead of having weird dedicated option for each version (v2, v3, etc) we reuse the same "stream" parameters. This is consistent with the ability to request a stream clone using "none-v2;stream=v2". This changeset introduce no user visible change, this is pure internal cleaning.

bundle: do no check the changegroup version if no changegroup is included We don't need to check the compatibility of something we will not use. In practice this was getting in the was of `streamv2` bundles on a narrow repository as the 'cg.version=02' value was rejected by this checks.

perf-stream-consume: use the source repository config when applying This might contains critical configuration for the benchmark, like enabling of extensions like narrow.

unbundle: move most of the logic on cmdutil to help debug::unbundle reuse This make sure `hg debug::unbundle` focus on the core logic.

postincoming: move to cmdutil This looks like a good place for it to live.

postincoming: avoid computing branchhead if no report will be posted This otherwise defeat some of the branch v3 optimization.

streamclone: stop listing files for entries that have no volatile files This will save a lot of python related time. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.04 seconds prev-change: 24.51 seconds (-30%) prev-change: 20.88 seconds (-40%) prev-change: 14.22 seconds (-60%) this-change: 11.58 seconds (-67% from baseline; -18% from prev)

stream-clone: disable gc for the initial section for the v3 format The number of small container created turn Python in a gc-frenzy that seriously impact performance. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.04 seconds prev-change: 24.51 seconds (-30%) prev-change: 20.88 seconds (-40%) this-change: 14.22 seconds (-60% from baseline; -31% from prev)

stream-clone: disable gc for `_entries_walk` duration The number of small container created turn Python in a gc-frenzy that seriously impact performance. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.04 seconds prev-change: 24.51 seconds (-30%) this-change: 20.88 seconds (-40% from baseline; -15% from previous changes)

nocg: make the utility work are both a decorator and context manager In some case, the context manager version will be simpler.

stream-clone: stop getting the file size of all file in v3 The point of v3 is to do less work in the locked section. It was currently not the case. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.03 seconds this-change: 24.50 seconds (-30%)

stream: in v3, skip the "size" fast path if the entries as some unknown size We are about to prefetch size during the lock less in the v3 case. So we need to avoid trying to use that prefetched size when it is not available. See next changeset for the motivation.

perf-stream-locked-section: advertise the right version key in the help As the v3 format is still experimental, its key is "v3-exp". The help text was not pointing that out. (we also fix `perf::stream-generate` in the process)