Benchmark Rbs

Benchmark RBS Indexing

Compare Rubydex indexing performance between main and the current topic branch using

the RBS core and stdlib directories.

Target paths

Clone the https://github.com/ruby/rbs.git repository under the repository root and use

the following paths as benchmark targets:

• tmp/rbs/core
• tmp/rbs/stdlib

The tmp/ directory is at the rubydex repository root. Create it if it doesn't exist.

Steps

0. Record branch names and commit SHAs

Before building, record the current branch name and commit SHA, and the main branch SHA.

These will be used in the results table, e.g. main (abc1234) and my-branch (def5678).

TOPIC_BRANCH=$(git branch --show-current)
TOPIC_SHA=$(git rev-parse --short HEAD)
MAIN_SHA=$(git rev-parse --short main)

Also record the RBS repository branch and SHA after cloning:

RBS_BRANCH=$(git -C tmp/rbs branch --show-current)
RBS_SHA=$(git -C tmp/rbs rev-parse --short HEAD)

Print the RBS version in the results, e.g. rbs: master (abc1234).

1. Build the current branch (release)

cargo build --release
cp rust/target/release/rubydex_cli tmp/rubydex_cli_branch

2. Build main (release)

git stash
git checkout main
cargo build --release
cp rust/target/release/rubydex_cli tmp/rubydex_cli_main
git checkout -
git stash pop

3. Run benchmarks

Run each binary 3 times and take the median. Use utils/mem-use for memory and time

measurement. Pass both core and stdlib together as a single benchmark run.

# Main
utils/mem-use tmp/rubydex_cli_main tmp/rbs/core tmp/rbs/stdlib --stats

# Branch
utils/mem-use tmp/rubydex_cli_branch tmp/rbs/core tmp/rbs/stdlib --stats

4. Compare results

Present a table comparing:

| Branch | Max RSS (MB) | Indexing (s) | Resolution (s) |

|--------|-------------|-------------|----------------|

| main (MAIN_SHA) | ... | ... | ... |

| TOPIC_BRANCH (TOPIC_SHA) | ... | ... | ... |

Include the delta (absolute and %) for RSS and each time metric.

Metrics

• Max RSS: Maximum Resident Set Size — the peak physical memory used by the process,

reported by /usr/bin/time -l.

• Indexing time: Time spent in the indexing phase (parsing files and extracting

definitions/references), reported by the --stats flag's internal timer.

• Resolution time: Time spent in the resolution phase (computing fully qualified names,

resolving constants, linearizing ancestors), reported by the --stats flag's internal timer.

Notes

• Run each measurement 3 times and use the median to account for variance (±5% is normal).
• Make sure no other heavy processes are running during benchmarks.