Mercurial > hg
view mercurial/help/dates.txt @ 31956:c13ff31818b0
ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
author | Bryan O'Sullivan <bryano@fb.com> |
---|---|
date | Tue, 11 Apr 2017 14:54:12 -0700 |
parents | 7bec3f697d76 |
children |
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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