view mercurial/help/dates.txt @ 39872:733db72f0f54

revlog: move revision verification out of verify

File revision verification is performing low-level checks of file
storage, namely that flags are appropriate and revision data can
be resolved.

Since these checks are somewhat revlog-specific and may not
be appropriate for alternate storage backends, this commit moves
those checks from verify.py to revlog.py.

Because we're now emitting warnings/errors that apply to specific
revisions, we taught the iverifyproblem interface to expose the
problematic node and to report this node in verify output. This
was necessary to prevent unwanted test changes.

After this change, revlog.verifyintegrity() and file verify code
in verify.py both iterate over revisions and resolve their fulltext.
But they do so in separate loops. (verify.py needs to resolve
fulltexts as part of calling renamed() - at least when using revlogs.)
This should add overhead.

But on the mozilla-unified repo:

$ hg verify
before: time: real 700.640 secs (user 585.520+0.000 sys 23.480+0.000)
after:  time: real 682.380 secs (user 570.370+0.000 sys 22.240+0.000)

I'm not sure what's going on. Maybe avoiding the filelog attribute
proxies shaved off enough time to offset the losses? Maybe fulltext
resolution has less overhead than I thought?

I've left a comment indicating the potential for optimization. But
because it doesn't produce a performance regression on a large
repository, I'm not going to worry about it.

Differential Revision: https://phab.mercurial-scm.org/D4745

Some commands allow the user to specify a date, e.g.:

- backout, commit, import, tag: Specify the commit date.
- log, revert, update: Select revision(s) by date.

Many date formats are valid. Here are some examples:

- ``Wed Dec 6 13:18:29 2006`` (local timezone assumed)
- ``Dec 6 13:18 -0600`` (year assumed, time offset provided)
- ``Dec 6 13:18 UTC`` (UTC and GMT are aliases for +0000)
- ``Dec 6`` (midnight)
- ``13:18`` (today assumed)
- ``3:39`` (3:39AM assumed)
- ``3:39pm`` (15:39)
- ``2006-12-06 13:18:29`` (ISO 8601 format)
- ``2006-12-6 13:18``
- ``2006-12-6``
- ``12-6``
- ``12/6``
- ``12/6/6`` (Dec 6 2006)
- ``today`` (midnight)
- ``yesterday`` (midnight)
- ``now`` - right now

Lastly, there is Mercurial's internal format:

- ``1165411109 0`` (Wed Dec 6 13:18:29 2006 UTC)

This is the internal representation format for dates. The first number
is the number of seconds since the epoch (1970-01-01 00:00 UTC). The
second is the offset of the local timezone, in seconds west of UTC
(negative if the timezone is east of UTC).

The log command also accepts date ranges:

- ``<DATE`` - at or before a given date/time
- ``>DATE`` - on or after a given date/time
- ``DATE to DATE`` - a date range, inclusive
- ``-DAYS`` - within a given number of days of today