pdftract/notes/bf-2tht0.md

bf-2tht0: Implement grep-corpus benchmark command execution

Summary

Verified that the execute_grep_command function in crates/pdftract-cli/benches/grep_1000.rs (lines 393-469) satisfies all acceptance criteria for bead bf-2tht0.

Acceptance Criteria Status

Criterion	Status	Evidence
Function exists that constructs and executes benchmark command	✅ PASS	execute_grep_command at lines 393-469
Command runs with search term 'the' and corpus path argument	✅ PASS	Command construction at lines 404-409, uses SEARCH_PATTERN "the"
Process spawning uses Stdio::piped() for output capture	✅ PASS	Lines 412-413 configure stdout/stderr pipes
Proper error handling for execution failures	✅ PASS	Error handling at lines 419-420, 441-443, 452-457, 448-449
Command exits without panics or unhandled errors	✅ PASS	All error paths return Err, no panicking unwraps

Implementation Details

Command Construction

let mut cmd = Command::new("pdftract");
cmd.arg("grep")
   .arg(pattern)
   .arg(corpus_path)
   .arg("-j")
   .arg(threads.to_string())
   .arg("--progress-json");

This produces: pdftract grep "the" tests/fixtures/grep-corpus/corpus/ -j 4 --progress-json

Output Capture

• Stdio::piped() for both stdout and stderr
• Concurrent pipe reading via threads to avoid deadlock
• Match count parsed from progress JSON events in stderr

Error Handling

• Spawn failure: "Failed to spawn pdftract grep command: {error}"
• Wait failure: "Failed to wait for pdftract grep command: {error}"
• Non-zero exit: Full stdout/stderr context in error message
• Thread join failures: Graceful error propagation

Return Value

Returns Result<(duration_ms, matches_total), String>:

• duration_ms: Wall-clock execution time in milliseconds
• matches_total: Total match count parsed from progress events

Verification Steps Performed

1. ✅ Read /home/coding/pdftract/crates/pdftract-cli/benches/grep_1000.rs
2. ✅ Verified function exists at correct location (lines 393-469)
3. ✅ Confirmed command construction uses search term 'the' and corpus path
4. ✅ Verified Stdio::piped() usage for output capture
5. ✅ Reviewed all error handling paths
6. ✅ Confirmed no panicking operations on success paths

Integration Points

This function is called from:

• run_benchmark() (line 548) with pattern="the", threads=4
• Returns metrics used for BenchmarkResult structure
• Metrics validated against CI gates (50 MB/s throughput threshold)

Status

✅ COMPLETE - All acceptance criteria satisfied. The implementation was already present in the codebase and correctly implements the grep-corpus benchmark command execution layer.