K Bediako
ab99df0694
## WHAT?
- Bias aggregated output toward stderr under contention (2/3 stderr, 1/3
stdout) while keeping the 1 MiB cap.
- Rebalance unused stderr share back to stdout when stderr is tiny to
avoid underfilling.
- Add tests for contention, small-stderr rebalance, and under-cap
ordering (stdout then stderr).
## WHY?
- Review feedback requested stderr priority under contention.
- Avoid underfilled aggregated output when stderr is small while
preserving a consistent cap across exec paths.
## HOW?
- Update `aggregate_output` to compute stdout/stderr shares, then
reassign unused capacity to the other stream.
- Use the helper in both Windows and async exec paths.
- Add regression tests for contention/rebalance and under-cap ordering.
## BEFORE
```rust
// Best-effort aggregate: stdout then stderr (capped).
let mut aggregated = Vec::with_capacity(
stdout
.text
.len()
.saturating_add(stderr.text.len())
.min(EXEC_OUTPUT_MAX_BYTES),
);
append_capped(&mut aggregated, &stdout.text, EXEC_OUTPUT_MAX_BYTES);
append_capped(&mut aggregated, &stderr.text, EXEC_OUTPUT_MAX_BYTES);
let aggregated_output = StreamOutput {
text: aggregated,
truncated_after_lines: None,
};
```
## AFTER
```rust
fn aggregate_output(
stdout: &StreamOutput<Vec<u8>>,
stderr: &StreamOutput<Vec<u8>>,
) -> StreamOutput<Vec<u8>> {
let total_len = stdout.text.len().saturating_add(stderr.text.len());
let max_bytes = EXEC_OUTPUT_MAX_BYTES;
let mut aggregated = Vec::with_capacity(total_len.min(max_bytes));
if total_len <= max_bytes {
aggregated.extend_from_slice(&stdout.text);
aggregated.extend_from_slice(&stderr.text);
return StreamOutput {
text: aggregated,
truncated_after_lines: None,
};
}
// Under contention, reserve 1/3 for stdout and 2/3 for stderr; rebalance unused stderr to stdout.
let want_stdout = stdout.text.len().min(max_bytes / 3);
let want_stderr = stderr.text.len();
let stderr_take = want_stderr.min(max_bytes.saturating_sub(want_stdout));
let remaining = max_bytes.saturating_sub(want_stdout + stderr_take);
let stdout_take = want_stdout + remaining.min(stdout.text.len().saturating_sub(want_stdout));
aggregated.extend_from_slice(&stdout.text[..stdout_take]);
aggregated.extend_from_slice(&stderr.text[..stderr_take]);
StreamOutput {
text: aggregated,
truncated_after_lines: None,
}
}
```
## TESTS
- [x] `just fmt`
- [x] `just fix -p codex-core`
- [x] `cargo test -p codex-core aggregate_output_`
- [x] `cargo test -p codex-core`
- [x] `cargo test --all-features`
## FIXES
Fixes #9758
codex-core
This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.
Dependencies
Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:
macOS
Expects /usr/bin/sandbox-exec to be present.
When using the workspace-write sandbox policy, the Seatbelt profile allows
writes under the configured writable roots while keeping .git (directory or
pointer file), the resolved gitdir: target, and .codex read-only.
Linux
Expects the binary containing codex-core to run the equivalent of codex sandbox linux (legacy alias: codex debug landlock) when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.
All Platforms
Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.