Developing Gram

See the platform-specific instructions for building Gram from source:

Keychain access

Gram stores secrets in the system keychain.

However, when running a development build of Gram on macOS (and perhaps other platforms) trying to access the keychain results in a lot of keychain prompts that require entering your password over and over.

On macOS this is caused by the development build not having a stable identity. Even if you choose the "Always Allow" option, the OS will still prompt you for your password again the next time something changes in the binary.

This quickly becomes annoying and impedes development speed.

That is why, by default, when running a development build of Gram an alternative credential provider is used in order to bypass the system keychain.

Note: This is only the case for development builds. For all non-development release channels the system keychain is always used.

If you need to test something out using the real system keychain in a development build, run Gram with the following environment variable set:

GRAM_DEVELOPMENT_USE_KEYCHAIN=1

Performance Measurements

Gram includes a frame time measurement system that can be used to profile how long it takes to render each frame. This is particularly useful when comparing rendering performance between different versions or when optimizing frame rendering code.

Using GRAM_MEASUREMENTS

To enable performance measurements, set the GRAM_MEASUREMENTS environment variable:

export GRAM_MEASUREMENTS=1

When enabled, Gram will print frame rendering timing information to stderr, showing how long each frame takes to render.

Performance Comparison Workflow

Here's a typical workflow for comparing frame rendering performance between different versions:

  1. Enable measurements:

    export GRAM_MEASUREMENTS=1

  2. Test the first version:

    • Checkout the commit you want to measure
    • Run Gram in release mode and use it for 5-10 seconds: cargo run --release &> version-a

  3. Test the second version:

    • Checkout another commit you want to compare
    • Run Gram in release mode and use it for 5-10 seconds: cargo run --release &> version-b

  4. Generate comparison:

    script/histogram version-a version-b

The script/histogram tool can accept as many measurement files as you like and will generate a histogram visualization comparing the frame rendering performance data between the provided versions.

Using util_macros::perf

For benchmarking unit tests, annotate them with the #[perf] attribute from the util_macros crate. Then run cargo perf-test -p $CRATE to benchmark them. See the rustdoc documentation on crates/util_macros and tooling/perf for in-depth examples and explanations.