Difference between revisions of "Protobuf notes"
m (Add protobuf.dev links.) |
m (Entering some notes on nanopb and pb_callback_t for accessing nested protobuf messages.) |
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* https://protobuf.dev/getting-started/cpptutorial/ | * https://protobuf.dev/getting-started/cpptutorial/ | ||
* https://protobuf.dev/programming-guides/proto3/ | * https://protobuf.dev/programming-guides/proto3/ | ||
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| + | When compiling nanopb Protobuf library as part of C language programs, nested Protobuf messages require use of nanopb defined function type `pb_callback_t` in order to encode and to decode those nested messages. Some examples of this on github: | ||
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| + | * https://github.com/particle-iot/device-os/blob/9338b13b1e611f1b57f71f702795c2ca71142c1f/proto_defs/src/cloud/describe.pb.h#L9 | ||
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| + | * https://github.com/hello/kitsune/blob/6a28afa80dd4547907e58341a84bd0b5bec5d88e/kitsune/protobuf/periodic.pb.h#L11 | ||
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| + | In the first example an early on file instance of `pb_callback_t` occurs on [https://github.com/particle-iot/device-os/blob/9338b13b1e611f1b57f71f702795c2ca71142c1f/proto_defs/src/cloud/describe.pb.h#L56 line 56]. | ||
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== [[#top|^]] References To Sort == | == [[#top|^]] References To Sort == | ||
Revision as of 04:42, 6 October 2024
Introduction:
When compiling nanopb Protobuf library as part of C language programs, nested Protobuf messages require use of nanopb defined function type `pb_callback_t` in order to encode and to decode those nested messages. Some examples of this on github:
In the first example an early on file instance of `pb_callback_t` occurs on line 56.
^ References To Sort
Protobuf references, somewhat arbitrary starting point yet introduces some key topics of Protobuf standard and use cases:
- https://www.crankuptheamps.com/blog/posts/2017/10/12/protobuf-battle-of-the-syntaxes/
- https://www.educative.io/edpresso/what-is-the-difference-between-protocol-buffers-and-json
JSON supported data types:
First Protobuf .proto file, compiles using `protoc-c`, part of a package available with Ubuntu 20.04:
// syntax = "proto3";
syntax = "proto2";
// Notes:
// $ protoc-c --c_out=. ./first.proto
message sensorUpdates {
required int32 message_id = 1;
optional float vrms = 2;
}
. . . It appears that the integer values which message elements are assigned as tantamount to key names in JSON.
^ Nanopb
2022-01-08 Saturday
- https://github.com/nanopb/nanopb/blob/master/generator/proto/nanopb.proto
- https://jpa.kapsi.fi/nanopb/docs/whats_new.html
- https://jpa.kapsi.fi/nanopb/docs/
Cmake script to locate Nanopb headers and sources:
