tree 860c30875efcf8637876eb38c37a1051a49e98fa
parent b0a944684d78a6b7c1f2bb6864fa910385d5b97a
author Damien Neil <dneil@google.com> 1658337134 -0700
committer Damien Neil <dneil@google.com> 1658419285 +0000

internal/impl: improve MessageInfo.New performance

Calling the ProtoReflect method of the newly-constructed
message avoids an allocation in MessageInfo.MessageOf in
the common case of a generated message with an optimized
ProtoReflect method.

Benchmark for creating an empty message, darwin/arm64 M1 laptop:

    name                 old time/op    new time/op    delta
    EmptyMessage/New-10    32.1ns ± 2%    23.7ns ± 2%  -26.06%  (p=0.000 n=10+9)

    name                 old alloc/op   new alloc/op   delta
    EmptyMessage/New-10     64.0B ± 0%     48.0B ± 0%  -25.00%  (p=0.000 n=10+10)

    name                 old allocs/op  new allocs/op  delta
    EmptyMessage/New-10      2.00 ± 0%      1.00 ± 0%  -50.00%  (p=0.000 n=10+10)

Change-Id: Ifa3c3ffa8edc76f78399306d0f4964eae4aacd28
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/418677
Reviewed-by: Michael Stapelberg <stapelberg@google.com>
Reviewed-by: Lasse Folger <lassefolger@google.com>