Here are the data structures with brief descriptions:

Cpf_bar_t	Single OHLCV bar pushed into the engine
Cpf_equity_point_t	Single per-script-bar equity point
Cpf_equity_stats_t	Equity-curve-derived statistics (all-trades only, like TV)
Cpf_metrics_t	Composite metrics container: trade stats (all / long / short) + equity-curve stats
Cpf_report_t	Backtest report filled by run_backtest / run_backtest_full
Cpf_security_diag_t	Per-`request.security()` site diagnostic counters
Cpf_trace_entry_t	Single per-bar trace entry
Cpf_trade_stats_t	Trade-level statistics block — computed once each for all / long / short
Cpf_trade_t	Closed-trade record returned in pf_report_t::trades
Cpf_version_t	Runtime version descriptor returned by pf_version_get