score-feo

Rust setup

You can build the Rust code both with bazel and with cargo. The CI will run both builds and ensure neither one is broken.

Bazel specific commands

Lint Rust code (clippy)

bazel build --config=lint-rust //...

Bazel quick-start

The recommended way to run bazel is with bazelisk. On linux, this means downloading the binary from the releases page and symlinking it to bazel somewhere on the PATH.

Bazel examples

Build the whole workspace

bazel build //...

Test the whole workspace

bazel test //...

Query for targets

bazel query //...

Run example rust binary

bazel run //examples/rust/greeter:greeter_rust

Profiling

CPU

Samply is a convenient tool to profile perf based. The main goal is to simplify the usage of perf and provide a web interface to analyze the results without the need to perform manual steps.

Get your copy of samply:

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/mstange/samply/releases/download/samply-v0.12.0/samply-installer.sh | sh

Profile:

cargo build --example hello_tracing --profile profiling
samply record target/profiling/examples/hello_tracing
# ...
# <ctrl-c>

Samply will spawn a webserver on https://127.0.0.1:3000 by default. Open and enjoy the results. The Firefox Profiler requires Firefox or Chrome (Safari is not supported).

Memory

Easiest way to profile memory usage is to use bytehound. It is a tool that can be used to profile memory usage of a binary or verify that a binary is allocation free. It supports Linux only at the moment.

Install bytehound with the following commands:

wget https://github.com/koute/bytehound/releases/download/0.11.0/bytehound-x86_64-unknown-linux-gnu.tgz
tar xzf bytehound-x86_64-unknown-linux-gnu.tgz bytehound libbytehound.so 
mv bytehound libbytehound.so $HOME/.cargo/bin

Record something with bytehound:

LD_PRELOAD=$HOME/.cargo/bin/libbytehound.so target/debug/examples/hello_tracing
# ...
# <ctrl-c>

Done with recording. Analyze the recording by

bytehound server memory-profiling_*.dat
# [2025-01-16T10:15:18Z INFO  server_core] Trying to load "memory-profiling_hello_tracing_1737022463_1792106.dat"...
# [2025-01-16T10:15:18Z INFO  cli_core::loader] Loaded data in 0s 099
# [2025-01-16T10:15:18Z INFO  actix_server::builder] Starting 96 workers
# [2025-01-16T10:15:18Z INFO  actix_server::builder] Starting server on 127.0.0.1:8080

Click on the link in the output to open the browser and see the results. Setup ssh port forwarding if needed when working remote (ssh -L 8080:localhost:8080 host).