Commit Graph

12 Commits

Author SHA1 Message Date
Joe Tsai 1a78f240b5
tstime: add DefaultClock (#9691)
In almost every single use of Clock, there is a default behavior
we want to use when the interface is nil,
which is to use the the standard time package.

The Clock interface exists only for testing,
and so tests that care about mocking time
can adequately plumb the the Clock down the stack
and through various data structures.

However, the problem with Clock is that there are many
situations where we really don't care about mocking time
(e.g., measuring execution time for a log message),
where making sure that Clock is non-nil is not worth the burden.
In fact, in a recent refactoring, the biggest pain point was
dealing with nil-interface panics when calling tstime.Clock methods
where mocking time wasn't even needed for the relevant tests.
This required wasted time carefully reviewing the code to
make sure that tstime.Clock was always populated,
and even then we're not statically guaranteed to avoid a nil panic.

Ideally, what we want are default methods on Go interfaces,
but such a language construct does not exist.
However, we can emulate that behavior by declaring
a concrete type that embeds the interface.
If the underlying interface value is nil,
it provides some default behavior (i.e., use StdClock).

This provides us a nice balance of two goals:
* We can plumb tstime.DefaultClock in all relevant places
  for use with mocking time in the tests that care.
* For all other logic that don't care about,
  we never need to worry about whether tstime.DefaultClock
  is nil or not. This is especially relevant in production code
  where we don't want to panic.

Longer-term, we may want to perform a large-scale change
where we rename Clock to ClockInterface
and rename DefaultClock to just Clock.

Updates #cleanup

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2023-10-12 16:01:17 -07:00
Claire Wang 0573f6e953
tstime: add Since method (#8622)
Updates #8463

Signed-off-by: Claire Wang <claire@tailscale.com>
2023-07-14 16:50:17 -04:00
Adrian Dewhurst 92fb80d55f tstest, tstime: mockable timers and tickers
This change introduces tstime.Clock which is the start of a mockable
interface for use with testing other upcoming code changes.

Fixes #8463

Change-Id: I59eabc797828809194575736615535d918242ec4
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
2023-07-07 11:13:03 -04:00
Joe Tsai 7e6c5a2db4
tstime: rely on stdlib parse functionality (#7482)
The time.Parse function has been optimized to the point
where it is faster than our custom implementation.
See upstream changes in:

* https://go.dev/cl/429862
* https://go.dev/cl/425197
* https://go.dev/cl/425116

Performance:

	BenchmarkGoParse3339/Z     38.75 ns/op    0 B/op    0 allocs/op
	BenchmarkGoParse3339/TZ    54.02 ns/op    0 B/op    0 allocs/op
	BenchmarkParse3339/Z       40.17 ns/op    0 B/op    0 allocs/op
	BenchmarkParse3339/TZ      87.06 ns/op    0 B/op    0 allocs/op

We can see that the stdlib implementation is now faster.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2023-03-06 18:05:51 -08:00
Joe Tsai 9112e78925
tstime: add Sleep (#7480)
Sleep is an interruptible sleep variation.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2023-03-06 17:40:38 -08:00
Will Norris 71029cea2d all: update copyright and license headers
This updates all source files to use a new standard header for copyright
and license declaration.  Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.

This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.

Updates #6865

Signed-off-by: Will Norris <will@tailscale.com>
2023-01-27 15:36:29 -08:00
Joe Tsai ec1e67b1ab
tstime: fix ParseDuration for '6' digit (#6363)
The cutset provided to strings.TrimRight was missing the digit '6',
making it such that we couldn't parse something like "365d".

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2022-11-16 21:01:09 -08:00
Mihai Parparita 9214b293e3 tstime: add ParseDuration helper function
More expressive than time.ParseDuration, also accepting d (days) and
w (weeks) literals.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2022-09-28 18:07:27 -07:00
Josh Bleecher Snyder aa9d7f4665 tstime: add Parse3339B, for byte slices
Use go4.org/mem for memory safety.
A slight performance hit, but a huge performance win
for clients who start with a []byte.
The perf hit is due largely to the MapHash call, which adds ~25ns.
That is necessary to keep the fast path allocation-free.

name                     old time/op    new time/op    delta
GoParse3339/Z-8             281ns ± 1%     283ns ± 2%     ~     (p=0.366 n=9+9)
GoParse3339/TZ-8            509ns ± 0%     510ns ± 1%     ~     (p=0.059 n=9+9)
GoParse3339InLocation-8     330ns ± 1%     330ns ± 0%     ~     (p=0.802 n=10+6)
Parse3339/Z-8              69.3ns ± 1%    74.4ns ± 1%   +7.45%  (p=0.000 n=9+10)
Parse3339/TZ-8              110ns ± 1%     140ns ± 3%  +27.42%  (p=0.000 n=9+10)
ParseInt-8                 8.20ns ± 1%    8.17ns ± 1%     ~     (p=0.452 n=9+9)

name                     old alloc/op   new alloc/op   delta
GoParse3339/Z-8             0.00B          0.00B          ~     (all equal)
GoParse3339/TZ-8             160B ± 0%      160B ± 0%     ~     (all equal)
GoParse3339InLocation-8     0.00B          0.00B          ~     (all equal)
Parse3339/Z-8               0.00B          0.00B          ~     (all equal)
Parse3339/TZ-8              0.00B          0.00B          ~     (all equal)

name                     old allocs/op  new allocs/op  delta
GoParse3339/Z-8              0.00           0.00          ~     (all equal)
GoParse3339/TZ-8             3.00 ± 0%      3.00 ± 0%     ~     (all equal)
GoParse3339InLocation-8      0.00           0.00          ~     (all equal)
Parse3339/Z-8                0.00           0.00          ~     (all equal)
Parse3339/TZ-8               0.00           0.00          ~     (all equal)


Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-11-19 14:47:11 -08:00
David Anderson b925e18f70 tstime: hand-implement parseInt for specific needs of rfc3339 parsing.
Makes parsing 4.6x faster.

name         old time/op  new time/op  delta
ParseInt-12  32.1ns ± 1%   6.9ns ± 2%  -78.55%  (p=0.000 n=10+9)

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-04-14 12:36:55 -07:00
Brad Fitzpatrick febdac0499 tstime: write Parse3339 parse that doesn't use time.Parse
It doesn't allocate and it's half the time of time.Parse (which
allocates), and 2/3rds the time of time.ParseInLocation (which
doesn't).

Go with a UTC time:

BenchmarkGoParse3339/Z-8                 2200995               534 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339/Z-8                 2254816               554 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339/Z-8                 2159504               522 ns/op               0 B/op          0 allocs/op

Go allocates with a "-08:00" suffix instead of ending in "Z":

BenchmarkGoParse3339/TZ-8                1276491               884 ns/op             144 B/op          3 allocs/op
BenchmarkGoParse3339/TZ-8                1355858               942 ns/op             144 B/op          3 allocs/op
BenchmarkGoParse3339/TZ-8                1385484               911 ns/op             144 B/op          3 allocs/op

Go doesn't allocate if you use time.ParseInLocation, but then you need
to parse the string to find the location anyway, so might as well go
all the way (below).

BenchmarkGoParse3339InLocation-8         1912254               597 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339InLocation-8         1980043               612 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339InLocation-8         1891366               612 ns/op               0 B/op          0 allocs/op

Parsing RFC3339 ourselves, UTC:

BenchmarkParse3339/Z-8                   3889220               307 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/Z-8                   3718500               309 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/Z-8                   3621231               303 ns/op               0 B/op          0 allocs/op

Parsing RFC3339 ourselves, with timezone (w/ *time.Location fetched
from sync.Map)

BenchmarkParse3339/TZ-8                  3019612               418 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/TZ-8                  2921618               401 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/TZ-8                  3031671               408 ns/op               0 B/op          0 allocs/op

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-06 08:19:17 -07:00
Brad Fitzpatrick d503dee6f1 tstime: add new package for time utilities, starting with Parse3339
Go's time.Parse always allocates a FixedZone for time strings not in
UTC (ending in "Z"). This avoids that allocation, at the cost of
adding a cache.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-05 20:05:49 -07:00