Reuse compression buffer

[ash2k]

Use case(s) - what problem will this feature solve?

gRPC's compression code allocates a bytes.Buffer for each sent message. This code is responsible for 25% of RAM allocations in my program.

grpc-go/rpc_util.go

Line 658 in d41b01d

cbuf := &bytes.Buffer{}

Proposed Solution

Reuse bytes.Buffer using a sync.Pool.

Alternatives Considered

Additional Context

[jzelinskie]

To the folks interested in this behavior that are open to using third-party dependencies, I suggest https://github.com/mostynb/go-grpc-compression

It's got a lot of more efficient algorithms, too.

[easwars]

We've made some recent changes to introduce a new encoding API which addresses this issue. See: #7356

Would appreciate your feedback on how the new changes work for you.

Also, I'm closing this, and if you still have issues, please use #6619 or file a new issue. Thanks.