previously, if native block cannot be unmarshaled, wg.Done wasn't called by unmarshal work.
It leads to connection blocking and possible dead-lock at client side
* lib/protoparser: changes ParseStream for native format
uses reader instead of http.Request
updates app/vmagent and app/vmagent method usage
* app/vmctl: add verify-block subcommand
it allows to check exported from VictoriaMetrics data block in native format
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2362
Update app/vmctl/README.md
Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
Previously bytesutil.Resize() was copying the original byte slice contents to a newly allocated slice.
This wasted CPU cycles and memory bandwidth in some places, where the original slice contents wasn't needed
after slize resizing. Switch such places to bytesutil.ResizeNoCopy().
Rename the original bytesutil.Resize() function to bytesutil.ResizeWithCopy() for the sake of improved readability.
Additionally, allocate new slice with `make()` instead of `append()`. This guarantees that the capacity of the allocated slice
exactly matches the requested size. The `append()` could return a slice with bigger capacity as an optimization for further `append()` calls.
This could result in excess memory usage when the returned byte slice was cached (for instance, in lib/blockcache).
Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2007
