F36 Change: Plocate as the default locate implementation (Self-Contained Change proposal)

[Ben Cotton]

https://fedoraproject.org/wiki/Changes/Plocate_as_the_default_locate_impleme...

== Summary ==
The venerable `mlocate` program is replaced by `plocate` — a
compatible reimplementation that is faster and uses less disk space.

== Owner ==
* Name: [[User:Zbyszek| Zbigniew Jędrzejewski-Szmek]]
* Email: zbyszek at in.waw.pl
* Name: [[User:Msekleta| Michal Sekletár]]
* Email: msekleta at redhat.com

== Detailed Description ==
Plocate is a newer implementation of `locate`/`mlocate` that using
`liburing` and `libzstd` for speed.
The database it creates on disk is also smaller.
Debian recently switched to `plocate` as the default implementation
(https://lwn.net/Articles/846405/).

It doesn't seem useful to maintain multiple locate implementations.
Thus the new package Conflicts with the old one, so they cannot be
installed in parallel.

The plan is:
# F35: `plocate` is made available for testing
# F36: `mlocate` is replaced by `plocate` in comps
# F37 or F38: `mlocate` will be retired (or given away, if somebody
wants to pick it up)

== Benefit to Fedora ==
We save some cpu cycles and disk sectors by using a more modern
implementation of a common tool.

== Scope ==
* Proposal owners:
** package `mlocate` (Review bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1931141, DONE)
** submit a pull request to comps with `s/mlocate/plocate/`

* Other developers: install plocate locally and test if it works as
expected on F35 and other versions

* Release engineering: n/a

* Policies and guidelines: n/a
* Trademark approval: n/a
* Alignment with Objectives: none

== Upgrade/compatibility impact ==
The upgrade should be mostly invisible. It is possible that somebody
might be relying on some very specific `mlocate` behaviour or parsing
the `mlocate` database directly, but no such cases are currently
known.

== How To Test ==
# Install `plocate` (`sudo dnf install plocate --allowerasing`)
# Wait for `plocate-updatedb.service` to finish (`sudo systemctl start
plocate-updatedb.service`)
# Use `plocate pattern` or `plocate -r <regexp>` to search for files.

== User Experience ==
Users should not notice the difference. Installing `plocate`
automatically removes `mlocate`. The new implementation is generally
compatible with the old one in all common cases, and provides some
additional options.

== Dependencies ==
None.

== Contingency Plan ==
* Contingency mechanism: (What to do?  Who will do it?) N/A (not a
System Wide Change)
* Contingency deadline: N/A (not a System Wide Change)
* Blocks release? N/A (not a System Wide Change)

== Documentation ==
N/A (not a System Wide Change)

== Release Notes ==
`plocate` is now used as the default provider of `/usr/bin/locate`
instead of `mlocate`.