delta/go-git.git/src/bytes/buffer.go, branch dev.go2go

bufio, bytes, strings: handle negative runes in WriteRune

2021-02-24T04:01:25+00:00

Updates #43254

Change-Id: I7d4bf3b99cc36ca2156af5bb01a1c595419d1d3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/280492
Reviewed-by: Emmanuel Odeke 
Reviewed-by: Rob Pike 
Trust: Emmanuel Odeke 
Run-TryBot: Emmanuel Odeke 
TryBot-Result: Go Bot

bytes: remove obsolete comment

2019-05-28T02:52:39+00:00

Change-Id: Iec4348eb674c8c64497c82e5d7cd656736cfcebd
GitHub-Last-Rev: 462c323960be0ca1c126c051ab97f72949bdc2b6
GitHub-Pull-Request: golang/go#32225
Reviewed-on: https://go-review.googlesource.com/c/go/+/178797
Reviewed-by: Brad Fitzpatrick

bytes: hoist error creation out of function

2019-02-26T22:57:25+00:00

generating frame information in errors will cause this
function to no longer be inlined.

Updates #29934.

Change-Id: I1d7bc11707f1872d7315f627bfb9a12afa41e358
Reviewed-on: https://go-review.googlesource.com/c/161760
Run-TryBot: Marcel van Lohuizen 
TryBot-Result: Gobot Gobot 
Reviewed-by: Russ Cox 
Reviewed-by: Brad Fitzpatrick

all: use "reports whether" consistently instead of "returns whether"

2018-12-02T15:12:26+00:00

Follow-up for CL 147037 and after Brad noticed the "returns whether"
pattern during the review of CL 150621.

Go documentation style for boolean funcs is to say:

    // Foo reports whether ...
    func Foo() bool

(rather than "returns whether")

Created with:

    $ perl -i -npe 's/returns whether/reports whether/' $(git grep -l "returns whether" | grep -v vendor)

Change-Id: I15fe9ff99180ad97750cd05a10eceafdb12dc0b4
Reviewed-on: https://go-review.googlesource.com/c/150918
Run-TryBot: Tobias Klauser 
Reviewed-by: Brad Fitzpatrick

bytes: remove bootstrap array from Buffer

2018-09-06T19:33:18+00:00

Rationale: small buffer optimization does not work and it has
made things slower since 2014. Until we can make it work,
we should prefer simpler code that also turns out to be more
efficient.

With this change, it's possible to use
NewBuffer(make([]byte, 0, bootstrapSize)) to get the desired
stack-allocated initial buffer since escape analysis can
prove the created slice to be non-escaping.

New implementation key points:

    - Zero value bytes.Buffer performs better than before
    - You can have a truly stack-allocated buffer, and it's not even limited to 64 bytes
    - The unsafe.Sizeof(bytes.Buffer{}) is reduced significantly
    - Empty writes don't cause allocations

Buffer benchmarks from bytes package:

    name                       old time/op    new time/op    delta
    ReadString-8                 9.20µs ± 1%    9.22µs ± 1%     ~     (p=0.148 n=10+10)
    WriteByte-8                  28.1µs ± 0%    26.2µs ± 0%   -6.78%  (p=0.000 n=10+10)
    WriteRune-8                  64.9µs ± 0%    65.0µs ± 0%   +0.16%  (p=0.000 n=10+10)
    BufferNotEmptyWriteRead-8     469µs ± 0%     461µs ± 0%   -1.76%  (p=0.000 n=9+10)
    BufferFullSmallReads-8        108µs ± 0%     108µs ± 0%   -0.21%  (p=0.000 n=10+10)

    name                       old speed      new speed      delta
    ReadString-8               3.56GB/s ± 1%  3.55GB/s ± 1%     ~     (p=0.165 n=10+10)
    WriteByte-8                 146MB/s ± 0%   156MB/s ± 0%   +7.26%  (p=0.000 n=9+10)
    WriteRune-8                 189MB/s ± 0%   189MB/s ± 0%   -0.16%  (p=0.000 n=10+10)

    name                       old alloc/op   new alloc/op   delta
    ReadString-8                 32.8kB ± 0%    32.8kB ± 0%     ~     (all equal)
    WriteByte-8                   0.00B          0.00B          ~     (all equal)
    WriteRune-8                   0.00B          0.00B          ~     (all equal)
    BufferNotEmptyWriteRead-8    4.72kB ± 0%    4.67kB ± 0%   -1.02%  (p=0.000 n=10+10)
    BufferFullSmallReads-8       3.44kB ± 0%    3.33kB ± 0%   -3.26%  (p=0.000 n=10+10)

    name                       old allocs/op  new allocs/op  delta
    ReadString-8                   1.00 ± 0%      1.00 ± 0%     ~     (all equal)
    WriteByte-8                    0.00           0.00          ~     (all equal)
    WriteRune-8                    0.00           0.00          ~     (all equal)
    BufferNotEmptyWriteRead-8      3.00 ± 0%      3.00 ± 0%     ~     (all equal)
    BufferFullSmallReads-8         3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=10+10)

The most notable thing in go1 benchmarks is reduced allocs in HTTPClientServer (-1 alloc):

    HTTPClientServer-8           64.0 ± 0%      63.0 ± 0%  -1.56%  (p=0.000 n=10+10)

For more explanations and benchmarks see the referenced issue.

Updates #7921

Change-Id: Ica0bf85e1b70fb4f5dc4f6a61045e2cf4ef72aa3
Reviewed-on: https://go-review.googlesource.com/133715
Reviewed-by: Martin Möhrmann 
Reviewed-by: Robert Griesemer 
Reviewed-by: Brad Fitzpatrick

bytes: note that NewBuffer's initial size can change

2018-08-29T22:36:49+00:00

bytes.NewBuffer's documentation says it can be used to set the initial
size of the buffer. The current wording is:

> It can also be used to size the internal buffer for writing.

This may led users to believe that the buffer (its backing array) is
fixed in size and won't grow, which isn't true (subsequent Write calls
will expand the backing array as needed).

Change the doc to make it clearer that NewBuffer just sets the initial
size of the buffer.

Fixes #27242

Change-Id: I2a8cb5bee02ca2c1657ef59e2cf1434c7a9bd397
Reviewed-on: https://go-review.googlesource.com/132035
Reviewed-by: Dominik Honnef 
Reviewed-by: Ian Lance Taylor

bytes: re-slice buffer to its previous length after call to grow()

2018-05-29T19:46:33+00:00

Fixes #25435

The added test fails without the re-slice and passes with it.

Change-Id: I5ebc2a737285eb116ecc5938d8bf49050652830f
GitHub-Last-Rev: 454ddad7df8d56a1d0e05a999ed8277c5516ce01
GitHub-Pull-Request: golang/go#25436
Reviewed-on: https://go-review.googlesource.com/113495
Reviewed-by: Brad Fitzpatrick 
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot

bytes: mention strings.Builder in Buffer.String docs

2017-11-30T01:46:50+00:00

Fixes #22778

Change-Id: I37f7a59c15828aa720fe787fff42fb3ef17729c7
Reviewed-on: https://go-review.googlesource.com/80815
Reviewed-by: Ian Lance Taylor

bytes: don't use an iota for the readOp constants

2017-11-19T16:37:43+00:00

As per the comments in golang.org/cl/78617. Also leaving a comment here,
to make sure noone else thinks to re-introduce the iota like I did.

Change-Id: I2a2275998b81896eaa0e9d5ee0197661ebe84acf
Reviewed-on: https://go-review.googlesource.com/78676
Run-TryBot: Daniel Martí 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick

bytes: make all readOp constants actually typed

2017-11-18T17:07:05+00:00

This is a regression introduced in golang.org/cl/28817. That change got
rid of the iota, which meant that the type was no longer applied to all
the constant names.

Re-add the iota starting at -1, simplifying the code and adding the
types once more.

Change-Id: I38bd0e04f8d298196bccd33651e29f5011401a8d
Reviewed-on: https://go-review.googlesource.com/78617
Run-TryBot: Daniel Martí 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick