tree 703e0caf0fb4ce1701391b03d574b0400e9217d7
parent e9cf376ae5073378de687595a0370d8860cfe28d
author Ewout van Bekkum <ewout@google.com> 1600909519 -0700
committer CQ Bot Account <commit-bot@chromium.org> 1600982362 +0000

pw_protobuf: Adds serialized size of field keys

Adds size_t pw::protobuf::SizeOfFieldKey(uint32_t field_number) to
help better estimate the serialized size cost for specific fields
which can be much smaller than kMaxSizeOfFieldKey.

Note that the API does not ask for the wiretype which is in the
actual field key (AKA tag) as it does not impact the serialized
size and only makes the API more verbose.

To enable this, pw::varint::{EncodedSize,ZigZagEncodedSize} were
changed to be constexpr, where the C functions invoke C++ instead.

Change-Id: Icbe4250e7acc8131bec9ec5c145e0074591777f6
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/18848
Reviewed-by: Wyatt Hepler <hepler@google.com>
Commit-Queue: Ewout van Bekkum <ewout@google.com>