delta/go-git.git/src/encoding/binary, branch dev.cmdgo

encoding/binary: limit bytes read by Uvarint to <= 10

2021-03-08T18:49:14+00:00

Limits the number of bytes that can be consumed by Uvarint
to MaxVarintLen64 (10) to avoid wasted computations.
With this change, if Uvarint reads more than MaxVarintLen64
bytes, it'll return the erroring byte count of n=-(MaxVarintLen64+1)
which is -11, as per the function signature.

Updated some tests to reflect the new change in expectations of n
when the number of bytes to be read exceeds the limits..

Fixes #41185

Change-Id: Ie346457b1ddb0214b60c72e81128e24d604d083d
Reviewed-on: https://go-review.googlesource.com/c/go/+/299531
Run-TryBot: Emmanuel Odeke 
TryBot-Result: Go Bot 
Reviewed-by: Keith Randall 
Trust: Emmanuel Odeke

all: update references to symbols moved from io/ioutil to io

2020-10-20T18:41:18+00:00

The old ioutil references are still valid, but update our code
to reflect best practices and get used to the new locations.

Code compiled with the bootstrap toolchain
(cmd/asm, cmd/dist, cmd/compile, debug/elf)
must remain Go 1.4-compatible and is excluded.
Also excluded vendored code.

For #41190.

Change-Id: I6d86f2bf7bc37a9d904b6cee3fe0c7af6d94d5b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/263142
Trust: Russ Cox 
Run-TryBot: Russ Cox 
TryBot-Result: Go Bot 
Reviewed-by: Emmanuel Odeke

encoding/binary: remove TODO in Write and add benchmarks

2020-09-23T03:14:03+00:00

Benchmarks:
goos: linux
goarch: amd64
BenchmarkReadSlice1000Uint8s-8           4097088               296 ns/op        3381.06 MB/s
BenchmarkWriteSlice1000Uint8s-8          4372588               271 ns/op        3694.96 MB/s

Change-Id: I5b6ef0da5052e3381ee9c714bbff541c11ed0259
Reviewed-on: https://go-review.googlesource.com/c/go/+/246837
Run-TryBot: Alberto Donizetti 
TryBot-Result: Go Bot 
Reviewed-by: Alberto Donizetti 
Reviewed-by: Ian Lance Taylor 
Trust: Alberto Donizetti

encoding/binary: replace constant literals with named constant (cleanup)

2020-08-25T16:06:28+00:00

Follow-up on https://golang.org/cl/247120.

Brought to my attention by Luke McCoy.

Change-Id: I4530c96fb164d23b0ce5311f2cecb1964f2dea74
Reviewed-on: https://go-review.googlesource.com/c/go/+/249837
Reviewed-by: Katie Hockman

encoding/binary: read at most MaxVarintLen64 bytes in ReadUvarint

2020-08-06T17:24:10+00:00

This CL ensures that ReadUvarint consumes only a limited
amount of input (instead of an unbounded amount).

On some inputs, ReadUvarint could read an arbitrary number
of bytes before deciding to return an overflow error.
After this CL, ReadUvarint returns that same overflow
error sooner, after reading at most MaxVarintLen64 bytes.

Fix authored by Robert Griesemer and Filippo Valsorda.

Thanks to Diederik Loerakker, Jonny Rhea, Raúl Kripalani,
and Preston Van Loon for reporting this.

Fixes #40618
Fixes CVE-2020-16845

Change-Id: Ie0cb15972f14c38b7cf7af84c45c4ce54909bb8f
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/812099
Reviewed-by: Filippo Valsorda 
Reviewed-on: https://go-review.googlesource.com/c/go/+/247120
Run-TryBot: Katie Hockman 
TryBot-Result: Gobot Gobot 
Reviewed-by: Alexander Rakoczy

encoding/binary: add float support to fast path

2019-11-08T18:35:59+00:00

This adds float type support to the main switch blocks in Read and
Write, instead of falling back to reflection. This gives a considerable
speedup for the float types:

ReadFloats-8                 129ns ± 9%       70ns ± 8%   -46.02%  (p=0.001 n=7+7)
WriteFloats-8                131ns ± 6%       86ns ±11%   -34.59%  (p=0.001 n=7+7)
ReadSlice1000Float32s-8     14.6µs ±14%      4.8µs ±12%   -67.29%  (p=0.001 n=7+7)
WriteSlice1000Float32s-8    16.4µs ±20%      4.7µs ± 8%   -71.01%  (p=0.001 n=7+7)

Change-Id: I0be99d068b07d10dd6eb1137b45eff6f7c216b87
GitHub-Last-Rev: 4ff326e99ca35977d819f0ba29c10d9efc7e811c
GitHub-Pull-Request: golang/go#31803
Reviewed-on: https://go-review.googlesource.com/c/go/+/174959
Reviewed-by: Brad Fitzpatrick

encoding/binary: make Read return an error when data is not a pointer

2019-11-08T18:00:31+00:00

Make binary.Read return an error when passed `data` argument is not
a pointer to a fixed-size value or a slice of fixed-size values.

Fixes #32927

Change-Id: I04f48be55fe9b0cc66c983d152407d0e42cbcd95
Reviewed-on: https://go-review.googlesource.com/c/go/+/184957
Reviewed-by: Brad Fitzpatrick

encoding/binary: cache struct sizes to speed up Read and Write

2019-11-01T20:16:01+00:00

A majority of work is spent in dataSize when en/decoding the same
struct over and over again. This wastes a lot of work, since
the result doesn't change for a given reflect.Value.

Cache the result of the function for structs, so that subsequent
calls to dataSize can avoid doing work.

    name         old time/op    new time/op     delta
    ReadStruct     1.00µs ± 1%     0.37µs ± 1%   -62.99%  (p=0.029 n=4+4)
    WriteStruct    1.00µs ± 3%     0.37µs ± 1%   -62.69%  (p=0.008 n=5+5)

    name         old speed      new speed       delta
    ReadStruct   75.1MB/s ± 1%  202.9MB/s ± 1%  +170.16%  (p=0.029 n=4+4)
    WriteStruct  74.8MB/s ± 3%  200.4MB/s ± 1%  +167.96%  (p=0.008 n=5+5)

Fixes #34471

Change-Id: Ic5d987ca95f1197415ef93643a0af6fc1224fdf0
Reviewed-on: https://go-review.googlesource.com/c/go/+/199539
Reviewed-by: Brad Fitzpatrick 
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot

all: simplify code using "gofmt -s -w"

2019-05-06T22:19:22+00:00

Most changes are removing redundant declaration of type when direct
instantiating value of map or slice, e.g. []T{T{}} become []T{{}}.

Small changes are removing the high order of subslice if its value
is the length of slice itself, e.g. T[:len(T)] become T[:].

The following file is excluded due to incompatibility with go1.4,

- src/cmd/compile/internal/gc/ssa.go

Change-Id: Id3abb09401795ce1e6da591a89749cba8502fb26
Reviewed-on: https://go-review.googlesource.com/c/go/+/166437
Run-TryBot: Dave Cheney 
TryBot-Result: Gobot Gobot 
Reviewed-by: Ian Lance Taylor

encoding/binary: simplify Read and Write

2018-09-04T14:52:30+00:00

There's no need to manually manage the backing slice for bs.
Removing it simplifies the code, removes some allocations,
and speeds it up slightly.

Fixes #27403

name                     old time/op    new time/op    delta
ReadSlice1000Int32s-8      6.39µs ± 1%    6.31µs ± 1%   -1.37%  (p=0.000 n=27+27)
ReadStruct-8               1.25µs ± 2%    1.23µs ± 2%   -1.06%  (p=0.003 n=30+29)
ReadInts-8                  301ns ± 0%     297ns ± 1%   -1.21%  (p=0.000 n=27+30)
WriteInts-8                 325ns ± 1%     320ns ± 1%   -1.59%  (p=0.000 n=26+29)
WriteSlice1000Int32s-8     6.60µs ± 0%    6.52µs ± 0%   -1.23%  (p=0.000 n=28+27)
PutUint16-8                0.72ns ± 2%    0.71ns ± 2%     ~     (p=0.286 n=30+30)
PutUint32-8                0.71ns ± 1%    0.71ns ± 0%   -0.42%  (p=0.003 n=30+25)
PutUint64-8                0.78ns ± 2%    0.78ns ± 0%   -0.55%  (p=0.001 n=30+27)
LittleEndianPutUint16-8    0.57ns ± 0%    0.57ns ± 0%     ~     (all equal)
LittleEndianPutUint32-8    0.57ns ± 0%    0.57ns ± 0%     ~     (all equal)
LittleEndianPutUint64-8    0.57ns ± 0%    0.57ns ± 0%     ~     (all equal)
PutUvarint32-8             23.1ns ± 1%    23.1ns ± 1%     ~     (p=0.925 n=26+29)
PutUvarint64-8             57.5ns ± 2%    57.3ns ± 1%     ~     (p=0.338 n=30+26)
[Geo mean]                 23.0ns         22.9ns        -0.61%

name                     old speed      new speed      delta
ReadSlice1000Int32s-8     626MB/s ± 1%   634MB/s ± 1%   +1.38%  (p=0.000 n=27+27)
ReadStruct-8             60.2MB/s ± 2%  60.8MB/s ± 2%   +1.08%  (p=0.002 n=30+29)
ReadInts-8                100MB/s ± 1%   101MB/s ± 1%   +1.24%  (p=0.000 n=27+30)
WriteInts-8              92.2MB/s ± 1%  93.6MB/s ± 1%   +1.56%  (p=0.000 n=26+29)
WriteSlice1000Int32s-8    606MB/s ± 0%   614MB/s ± 0%   +1.24%  (p=0.000 n=28+27)
PutUint16-8              2.80GB/s ± 1%  2.80GB/s ± 1%     ~     (p=0.095 n=28+29)
PutUint32-8              5.61GB/s ± 1%  5.62GB/s ± 1%     ~     (p=0.069 n=27+28)
PutUint64-8              10.2GB/s ± 1%  10.2GB/s ± 0%   +0.15%  (p=0.039 n=27+27)
LittleEndianPutUint16-8  3.50GB/s ± 1%  3.50GB/s ± 1%     ~     (p=0.552 n=30+29)
LittleEndianPutUint32-8  7.01GB/s ± 1%  7.02GB/s ± 1%     ~     (p=0.160 n=29+27)
LittleEndianPutUint64-8  14.0GB/s ± 1%  14.0GB/s ± 1%     ~     (p=0.413 n=29+29)
PutUvarint32-8            174MB/s ± 1%   173MB/s ± 1%     ~     (p=0.648 n=25+30)
PutUvarint64-8            139MB/s ± 2%   140MB/s ± 1%     ~     (p=0.271 n=30+26)
[Geo mean]                906MB/s        911MB/s        +0.55%

name                     old alloc/op   new alloc/op   delta
ReadSlice1000Int32s-8      4.14kB ± 0%    4.13kB ± 0%   -0.19%  (p=0.000 n=30+30)
ReadStruct-8                 200B ± 0%      200B ± 0%     ~     (all equal)
ReadInts-8                  64.0B ± 0%     32.0B ± 0%  -50.00%  (p=0.000 n=30+30)
WriteInts-8                  112B ± 0%       64B ± 0%  -42.86%  (p=0.000 n=30+30)
WriteSlice1000Int32s-8     4.14kB ± 0%    4.13kB ± 0%   -0.19%  (p=0.000 n=30+30)
PutUint16-8                 0.00B          0.00B          ~     (all equal)
PutUint32-8                 0.00B          0.00B          ~     (all equal)
PutUint64-8                 0.00B          0.00B          ~     (all equal)
LittleEndianPutUint16-8     0.00B          0.00B          ~     (all equal)
LittleEndianPutUint32-8     0.00B          0.00B          ~     (all equal)
LittleEndianPutUint64-8     0.00B          0.00B          ~     (all equal)
PutUvarint32-8              0.00B          0.00B          ~     (all equal)
PutUvarint64-8              0.00B          0.00B          ~     (all equal)
[Geo mean]                   476B           370B       -22.22%

name                     old allocs/op  new allocs/op  delta
ReadSlice1000Int32s-8        3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=30+30)
ReadStruct-8                 16.0 ± 0%      16.0 ± 0%     ~     (all equal)
ReadInts-8                   8.00 ± 0%      8.00 ± 0%     ~     (all equal)
WriteInts-8                  14.0 ± 0%      14.0 ± 0%     ~     (all equal)
WriteSlice1000Int32s-8       3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.000 n=30+30)
PutUint16-8                  0.00           0.00          ~     (all equal)
PutUint32-8                  0.00           0.00          ~     (all equal)
PutUint64-8                  0.00           0.00          ~     (all equal)
LittleEndianPutUint16-8      0.00           0.00          ~     (all equal)
LittleEndianPutUint32-8      0.00           0.00          ~     (all equal)
LittleEndianPutUint64-8      0.00           0.00          ~     (all equal)
PutUvarint32-8               0.00           0.00          ~     (all equal)
PutUvarint64-8               0.00           0.00          ~     (all equal)
[Geo mean]                   6.94           5.90       -14.97%

Change-Id: I3790b93e4190d98621d5f2c47e42929a18f56c2e
Reviewed-on: https://go-review.googlesource.com/133135
Run-TryBot: Josh Bleecher Snyder 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick