delta/go-git.git/src/strings/strings_test.go, branch dev.inline

strings: ignore allocation test in cover mode

2016-11-01T18:29:31+00:00

Fixes #17699

Change-Id: I7ea29a3fc2ca13d9d7e3044cbb8ea22e3435d423
Reviewed-on: https://go-review.googlesource.com/32484
Run-TryBot: Brad Fitzpatrick 
Reviewed-by: Rob Pike

bytes, strings: optimize for ASCII sets

2016-10-28T17:37:04+00:00

In a large codebase within Google, there are thousands of uses of:
	ContainsAny|IndexAny|LastIndexAny|Trim|TrimLeft|TrimRight

An analysis of their usage shows that over 97% of them only use character
sets consisting of only ASCII symbols.

Uses of ContainsAny|IndexAny|LastIndexAny:
	 6% are 1   character  (e.g., "\n" or " ")
	58% are 2-4 characters (e.g., "<>" or "\r\n\t ")
	24% are 5-9 characters (e.g., "()[]*^$")
	10% are 10+ characters (e.g., "+-=&|>
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick 
Reviewed-by: Martin Möhrmann

bytes, strings: fix regression in IndexRune

2016-10-26T23:02:27+00:00

In all previous versions of Go, the behavior of IndexRune(s, r)
where r was utf.RuneError was that it would effectively return the
index of any invalid UTF-8 byte sequence (include RuneError).
Optimizations made in http://golang.org/cl/28537 and
http://golang.org/cl/28546 altered this undocumented behavior such
that RuneError would only match on the RuneError rune itself.

Although, the new behavior is arguably reasonable, it did break code
that depended on the previous behavior. Thus, we add special checks
to ensure that we preserve the old behavior.

There is a slight performance hit for correctness:
	benchmark                   old ns/op     new ns/op     delta
	BenchmarkIndexRune/10-4     19.3          21.6          +11.92%
	BenchmarkIndexRune/32-4     33.6          35.2          +4.76%
This only occurs on small strings. The performance hit for larger strings
is neglible and not shown.

Fixes #17611

Change-Id: I1d863a741213d46c40b2e1724c41245df52502a5
Reviewed-on: https://go-review.googlesource.com/32123
Run-TryBot: Joe Tsai 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick

strings, bytes: panic if Repeat overflows or if given a negative count

2016-10-01T15:47:35+00:00

Panic if Repeat is given a negative count or
if the value of (len(*) * count) is detected
to overflow.
We panic because we cannot change the
signature of Repeat to return an error.

Fixes #16237

Change-Id: I9f5ba031a5b8533db0582d7a672ffb715143f3fb
Reviewed-on: https://go-review.googlesource.com/29954
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick

strings: use AVX2 for Index if available

2016-09-07T10:43:13+00:00

IndexHard4-4      1.50ms ± 2%  0.71ms ± 0%  -52.36%  (p=0.000 n=20+19)

This also fixes a bug, that caused a string of length 16 to use
two 8-byte comparisons instead of one 16-byte. And adds a test for
cases when partial_match fails.

Change-Id: I1ee8fc4e068bb36c95c45de78f067c822c0d9df0
Reviewed-on: https://go-review.googlesource.com/22551
Run-TryBot: Ilya Tocar 
TryBot-Result: Gobot Gobot 
Reviewed-by: Keith Randall

strings: make IndexRune faster

2016-09-07T01:03:10+00:00

re-implement IndexRune by Index which is well optimized to get
performance gain.

name                   old time/op  new time/op  delta
IndexRune-4            30.2ns ± 1%  28.3ns ± 1%   -6.22%  (p=0.000 n=20+19)
IndexRuneLongString-4   156ns ± 1%    49ns ± 1%  -68.72%  (p=0.000 n=19+19)
IndexRuneFastPath-4    10.6ns ± 2%  10.0ns ± 1%   -6.30%  (p=0.000 n=18+18)

Change-Id: Ie663b8f7860ca51892dd4be182fca3caa5f8ae61
Reviewed-on: https://go-review.googlesource.com/28546
Reviewed-by: Brad Fitzpatrick 
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot

strings: fix and reenable amd64 Index for 17-31 byte strings

2016-05-27T22:57:32+00:00

Fixes #15689

Change-Id: I56d0103738cc35cd5bc5e77a0e0341c0dd55530e
Reviewed-on: https://go-review.googlesource.com/23440
Reviewed-by: Keith Randall 
Run-TryBot: Ilya Tocar 
TryBot-Result: Gobot Gobot 
Reviewed-by: Nigel Tao

strings: fix Contains on amd64

2016-05-15T05:21:03+00:00

The 17-31 byte code is broken.  Disabled it.

Added a bunch of tests to at least cover the cases
in indexShortStr.  I'll channel Brad and wonder why
this CL ever got in without any tests.

Fixes #15679

Change-Id: I84a7b283a74107db865b9586c955dcf5f2d60161
Reviewed-on: https://go-review.googlesource.com/23106
Reviewed-by: Brad Fitzpatrick 
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot

all: use SeekStart, SeekCurrent, SeekEnd

2016-05-06T00:10:41+00:00

CL/19862 (f79b50b8d5bc159561c1dcf7c17e2a0db96a9a11) recently introduced the constants
SeekStart, SeekCurrent, and SeekEnd to the io package. We should use these constants
consistently throughout the code base.

Updates #15269

Change-Id: If7fcaca7676e4a51f588528f5ced28220d9639a2
Reviewed-on: https://go-review.googlesource.com/22097
Reviewed-by: Brad Fitzpatrick 
Run-TryBot: Joe Tsai 
TryBot-Result: Gobot Gobot

strings: improve explode and correct comment

2016-04-13T04:54:03+00:00

Merges explodetests into splittests which already contain
some of the tests that cover explode.

Adds a test to cover the utf8.RuneError branch in explode.

name      old time/op  new time/op  delta
Split1-2  14.9ms ± 0%  14.2ms ± 0%  -4.06%  (p=0.000 n=47+49)

Change-Id: I00f796bd2edab70e926ea9e65439d820c6a28254
Reviewed-on: https://go-review.googlesource.com/21609
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Gobot Gobot 
Reviewed-by: Ian Lance Taylor