view relnotes/6.1 @ 50671:e06d1a779eb6

store: stop relying on a `revlog_type` property

We want to know if a file is related to a revlog, but the rest is dealt with
differently already, so we simplify things further.

as a bonus, this cleanup This provides a small but noticeable  speedup.

The number below use `hg perf::stream-locked-section` to measure the time spend
in the locked section of the streaming clone. Number are run on various
repository and compare different steps.:

1) the effect of this patchs,
2) the effect of the cleanup series,
2) current state compared to because large refactoring.

All benchmarks are run on linux with Python 3.10.7.


### Effect of this patch
# mercurial-2018-08-01-zstd-sparse-revlog
  # benchmark.name         = perf-stream-locked-section
before:   0.030246 seconds
after:    0.029274 seconds   (-3.21%)
# pypy-2018-08-01-zstd-sparse-revlog
before:   0.545012 seconds
after:    0.520872 seconds   (-4.43%)
# netbeans-2018-08-01-zstd-sparse-revlog
before:   2.719939 seconds
after:    2.626791 seconds   (-3.42%)
# mozilla-central-2018-08-01-zstd-sparse-revlog
before:   6.304179 seconds
after:    6.096700 seconds   (-3.29%)
# mozilla-try-2019-02-18-zstd-sparse-revlog
before:  14.142687 seconds
after:   13.640779 seconds   (-3.55%)

### Effect of this series

A small but sizeable speedup

# mercurial-2018-08-01-zstd-sparse-revlog
before:  0.031122 seconds
after:   0.029274 seconds   (-5.94%)
# pypy-2018-08-01-zstd-sparse-revlog
before:  0.589970 seconds
after:   0.520872 seconds  (-11.71%)
# netbeans-2018-08-01-zstd-sparse-revlog
before:  2.980300 seconds
after:   2.626791 seconds  (-11.86%)
# mozilla-central-2018-08-01-zstd-sparse-revlog
before:  6.863204 seconds
after:   6.096700 seconds  (-11.17%)
# mozilla-try-2019-02-18-zstd-sparse-revlog
before: 14.921393 seconds
after:  13.640779 seconds   (-8.58%)


### Current state compared to the pre-refactoring state

The refactoring introduced multiple string manipulation and dictionary creation
that seems to induce a signifiant slowdown
Slowdown

# mercurial-2018-08-01-zstd-sparse-revlog
6.4.3:  0.019459 seconds
after:  0.029274 seconds  (+50.44%)
## pypy-2018-08-01-zstd-sparse-revlog
6.4.3:  0.290715 seconds
after:  0.520872 seconds  (+79.17%)
# netbeans-2018-08-01-zstd-sparse-revlog
6.4.3:  1.403447 seconds
after:  2.626791 seconds  (+87.17%)
# mozilla-central-2018-08-01-zstd-sparse-revlog
6.4.3:  3.163549 seconds
after:  6.096700 seconds  (+92.72%)
# mozilla-try-2019-02-18-zstd-sparse-revlog
6.4.3:  6.702184 seconds
after: 13.640779 seconds (+103.53%)

'''This is the last release to support Python 2. Mercurial is Python 3 only starting with 6.2'''

= Mercurial 6.1.4 =

 * url: raise error if CONNECT request to proxy was unsuccessful
 * docker: avoid /tmp write access issues by fixing permissions
 * logcmdutil: use the same data as {file*} template keywords (issue6642)
 * commit: allow to close branch when committing change over a closed head
 * rust-status: don't trigger dirstate v1 rewrite when only v2 data is changed
 * purge: prevent a silly crash with --confirm --files
 * rust: relax im-rc dependency to allow minor updates"
 * Improve PyPy support
 * Improve Py3 error handling
 * Documentation fixes

= Mercurial 6.1.3 =

'''security: '''
 * narrow_widen_acl: enforce narrowacl in narrow_widen (SEC) 6b10151b9621

'''normal notes: '''
 * censor: fix [hg update] away from a revision with censored files
 * amend: stop losing copies when amending
 * rhg: strengthen dirstate v2 writing in broken filesystems
 * work around some broken DLL imports in Windows
 * worker: adapt _blockingreader to work around a python3.8.[0-1] bug (issue6444)
 * rhg: correctly handle the case where diffs are encoded relative to nullrev
 * fix bugs and race-conditions in the Mercurial test runner
 * chg: ignore already closed fds when cleaning up

= Mercurial 6.1.2 =

 * Improve Windows test suite
 * Fix `debuglock` not ignoring a missing lockfile when forcing a lock
 * Improve help of `ui.large-file-limit`
 * Set the large-file-limit to 10MB (from 10MiB) for clarity
 * While rewriting desc hashes, ignore ambiguous prefix "hashes"
 * Fix a crash in partial amend with copies
 * Fix a py3 compatiblity bug
 * Fix incorrect metadata causing dirstate-v2 data loss in edge case
 * Fix cleanup of old dirstate-v2 data files when using `rhg`
 * Make reference to `.hg/last_message.txt` relative in commit
 * Fix an infinite hang when `rhg` is used in the background
 * Fix Python DLL loading bug in Windows
 * Add `--docket` flag to `debugstate` to check out dirstate-v2 metadata
 * Remove `debugdirstateignorepatternhash` in favor of `debugstate --docket`
 * Fix incorrect metadata causing systematic complete dirstate-v2 rewrite

= Mercurial 6.1.1 =

 * Fix Rust compilation on `aarcch64`
 * Fix Rust compilation on architectures where `char` is unsigned
 * When the merge tool uses `$output`, don't leave markers in `$local`
 * Improve test suite support on big-endian platforms
 * Cap the number of concurrent threads to 16 in Rust `hg status` to prevent huge speed regression at higher thread counts
 * Fix `amend` with copies in extras
 * Abort if commit we're trying to `unamend` was not created by `hg [un]amend`
 * Fix file name in the pullbundle help text
 * Fix an issue with data not being correctly reset in the C implementation of dirstate-v2
 * Fix issue6673 where some tags were missing from cache after a merge
 * Fix stream-cloning a repo with empty requirements
 * Fix a false warning about content-divergence creation
 * Fix silly blackbox entries when hg is interrupted
 * Fix unsoundness (no known exploits) in Rust extensions (see cfd270d83169 and dd6b67d5c256)
 * Fix Rust dirstate counters not being updated correctly leading to some potential bugs (none known)
 * Stop relying on a compiler implementation detail in Rust HgPath

= Mercurial 6.1 =

== New Features ==
  * Added a way of specifying required extensions that prevent Mercurial from starting if they are not found. See `hg help config.extensions`.
  * Merge conflict markers have been made clearer (see backwards compatibility below)
  * Improve detailed error codes
  * Added a hint about mangled whitespace on bad patch
  * Explain which order the commits are presented in `chistedit`
  * Introduce a `dirstate-tracked-hint` feature to help automation keep track of changes to tracked files. See `hg help config.use-dirstate-tracked-hint`.
  * Shared repositories can be upgraded if the upgrade is specific to the share. For now, this only applies to `dirstate-v2` and `dirstate-tracked-hint`.
  * When using the `narrow` extension, non-conflicting changes to files outside of the narrow specification can now be merged.
  * When cloning a repository using stream-clone, the client can now control the repository format variants to use as long as the stream content does not restrict that variant.

== Default Format Change ==

These changes affect newly created repositories (or new clones) done with Mercurial 6.1.

  * The `share-safe` format variant is now enabled by default. It makes configuration and requirements more consistent across repository and their shares. This introduces a behavior change as shares from a repository using the new format will also use their main repository's configuration. See `hg help config.format.use-share-safe` for details about the feature and the available options for auto-upgrading existing shares.


== New Experimental Features ==
  * The pure Rust version of Mercurial called `rhg` added support for most common invocations of `hg status`. See `hg help rust.rhg` for details on how to try it out.
  * `rhg` supports narrow clones and sparse checkouts.

== Bug Fixes ==

  * '''Obsolete revisions are skipped while computing heads. In conjunction with the `evolve` extension >= 10.5.0, this leads to massive exchange (push/pull) speedups in repositories with a lot of heads and/or obsolete revisions.'''
  * Stream-clones now properly advertise all requirements needed. This can result in the stream-clone feature being disabled for some clients using < 6.0.2. A small bugfix patch for these older client is available if necessary.
  * The `--no-check` and `--no-merge` flags now properly overwrite the behavior from `commands.update.check`
  * `rhg`'s fallback detection is more robust in general in the presence of more advanced configs
  * `rhg`'s `blackbox` now supports milliseconds by default and uses the same ISO 8601 format as the Python implementation
  * Fix `rhg` crash on non-generaldelta revlogs
  * The `lfs`, `largefiles` and `sparse` extensions now correctly take the appropriate lock before writing requirements 
  * The `notify` extension does not produce errors anymore if a revision is not found
  * Remove unnecessary and overly strict check for divergence in `hg fix`
  * Windows compatibility improvements
  * Miscellaneous Python 3 and typing improvements
  * Many other small or internal fixes

== Backwards Compatibility Changes ==

  * The use of `share-safe`, means shares (of new repositories) will also use their main repository's configuration see the `Default Format Change` section for details.
  * The fix to stream-clone requirements advertising means some requirements previously (wrongly) omitted are now sent. This can confuse client using a Mercurial version < 6.0.2. The client would consider these requirements unsupported even if it actually know them. If you encounter this, either upgrade your client or apply the necessary patch.
  * The labels passed to merge tools have changed slightly. Merge tools can get labels passed to them if you include `$labellocal`, `$labelbase`, and/or `$labelother` in the `merge-tool.<tool name>.args` configuration. These labels used to have some space-padding, and truncation to fit within 72 columns. Both the padding and the truncation has been removed.
  * Some of the text in labels passed to merge tools has changed. For example, in conflicts while running `hg histedit`, the labels used to be "local", "base", and "histedit". They are now "already edited", "parent of current change", and "current change", respectively.
  * The computation of namedbranch heads now ignores obsolete revisions. User of the Changeset Evolution feature may see a change in location and numbers of heads of each named branches (and topic).
  * The remotefilelog extension now requires an appropriate excludepattern for subrepositories.
  * `debugsparse`'s interface has been reworked to be more flexible. Since it's a debug command it is not actually a breaking change, but it is worth noting here.
  * Temporary files for merges are now all inside a `hgmerge` directory instead of at the root of `TMPDIR`. The corresponding experimental `mergetempdirprefix` config option has been removed.

== Internal API Changes ==

  * The dirstate API received minor modifications.

== Miscellaneous ==

  * Removed exchange-v2. It was a prototype that had never been in a working state and had been left untouched since 2017.