commit fb5f2ca113295de9a149082e5401420c56e12fc4
author Jonathon Reinhart <jrreinhart@google.com> Wed Aug 30 20:39:28 2023 +0000
committer CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Aug 30 20:39:28 2023 +0000
tree b72792cc94ff50bd0cfadca93c02829159a09097
parent 3011a52d1c50c87f6ec03ecbb6e23c02b265dc82

pw_protobuf: Expose max_size, max_count in generated header file

For fields with max_size or max_count set in the codegen options,
generate a constant (static constexpr size_t) named k{FieldName}MaxSize
which is set to that size.

The constant is defined in the message namespace.

Use this constant in the Message struct field definitions
and in the calculation of kMaxEncodedSizeBytes.

For example, see this diff of the generated file
out/protocol_buffer/gen/pw_i2c/protos.proto_library/pwpb/pw_i2c/i2c.pwpb.h:

   namespace I2cWriteRequest {
   // ...
  +static constexpr size_t kRegisterAddressMaxSize = 4;
  +static constexpr size_t kValueMaxSize = 32;
   // ...
   }

   // ...

   struct I2cWriteRequest::Message {
     uint32_t bus_index;
     uint32_t target_address;
  -  ::pw::Vector<std::byte, 4> register_address;
  -  ::pw::Vector<std::byte, 32> value;
  +  ::pw::Vector<std::byte, kRegisterAddressMaxSize> register_address;
  +  ::pw::Vector<std::byte, kValueMaxSize> value;
     // ...
   };

   namespace I2cWriteRequest {
   inline constexpr size_t kMaxEncodedSizeBytes =
     ::pw::protobuf::SizeOfFieldUint32(static_cast<uint32_t>(Fields::kBusIndex)) +
     ::pw::protobuf::SizeOfFieldUint32(static_cast<uint32_t>(Fields::kTargetAddress)) +
  -  ::pw::protobuf::SizeOfDelimitedFieldWithoutValue(static_cast<uint32_t>(Fields::kRegisterAddress)) + 4 +
  -  ::pw::protobuf::SizeOfDelimitedFieldWithoutValue(static_cast<uint32_t>(Fields::kValue)) + 32;
  +  ::pw::protobuf::SizeOfDelimitedFieldWithoutValue(static_cast<uint32_t>(Fields::kRegisterAddress)) + kRegisterAddressMaxSize +
  +  ::pw::protobuf::SizeOfDelimitedFieldWithoutValue(static_cast<uint32_t>(Fields::kValue)) + kValueMaxSize;

   inline constexpr size_t kScratchBufferSizeBytes = 0;
   }  // namespace I2cWriteRequest

Test: ninja -C out
Bug: 297364973
Change-Id: I165da974e1e17699bd87ddb2311df4efb1808804
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/168973
Reviewed-by: Alexei Frolov <frolv@google.com>
Pigweed-Auto-Submit: Jonathon Reinhart <jrreinhart@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>