保留模拟器失败调用前的委托与执行状态

crates/fidc-core/src/portfolio.rs

@@ -715,6 +715,27 @@ pub struct PortfolioState {
     stock_pool_states: std::collections::BTreeMap<String,crate::stock_pool_state::StockPoolExecutionState>,
 }
 
+pub(crate) struct PortfolioCheckpoint {
+    saved: PortfolioState,
+    position_order: Option<Vec<String>>,
+}
+
+impl PortfolioCheckpoint {
+    pub(crate) fn restore(mut self, current: &mut PortfolioState) {
+        if let Some(order) = self.position_order.take() {
+            let mut positions = IndexMap::with_capacity(order.len());
+            for symbol in order {
+                let position = self.saved.positions.shift_remove(&symbol)
+                    .or_else(|| current.positions.shift_remove(&symbol))
+                    .expect("unchanged checkpoint position must remain present");
+                positions.insert(symbol, position);
+            }
+            self.saved.positions = positions;
+        }
+        *current = self.saved;
+    }
+}
+
 #[derive(Debug, Clone)]
 pub struct PendingCashFlow {
     pub payable_date: NaiveDate,
@@ -734,6 +755,29 @@ pub(crate) struct SuccessorConversionOutcome {
 }
 
 impl PortfolioState {
+    /// Ordinary single-security orders need not duplicate every other lot.
+    /// Complex portfolio intents request the complete checkpoint instead.
+    pub(crate) fn checkpoint(&self, symbols: Option<&BTreeSet<String>>) -> PortfolioCheckpoint {
+        let Some(symbols) = symbols else {
+            return PortfolioCheckpoint { saved: self.clone(), position_order: None };
+        };
+        PortfolioCheckpoint {
+            saved: Self {
+                initial_cash: self.initial_cash, units: self.units, cash: self.cash,
+                external_cash_flow_total: self.external_cash_flow_total,
+                cash_liabilities: self.cash_liabilities, management_fee_rate: self.management_fee_rate,
+                management_fees: self.management_fees,
+                // prune_flat_positions can remove an unrelated zero row.
+                positions: self.positions.iter().filter(|(symbol, position)| position.quantity == 0 || symbols.contains(*symbol))
+                    .map(|(symbol, position)| (symbol.clone(), position.clone())).collect(),
+                cash_receivables: self.cash_receivables.clone(), pending_cash_flows: self.pending_cash_flows.clone(),
+                day_sold_symbols: self.day_sold_symbols.clone(), corporate_predecessors: self.corporate_predecessors.clone(),
+                stock_pool_states: self.stock_pool_states.clone(),
+            },
+            position_order: Some(self.positions.keys().cloned().collect()),
+        }
+    }
+
     pub fn new(initial_cash: f64) -> Self {
         let initial_cash = fixed_money(initial_cash, "initial cash")
             .expect("initial cash must be finite fixed-point money");
@@ -1647,6 +1691,35 @@ mod tests {
         BenchmarkSnapshot, CandidateEligibility, DailyFactorSnapshot, DailyMarketSnapshot, DataSet,
         PriceField,
     };
+
+    #[test]
+    fn scoped_checkpoint_restores_order_flat_rows_and_progress_without_copying_untouched_lots() {
+        let date = NaiveDate::from_ymd_opt(2026,9,15).unwrap();
+        let mut portfolio = PortfolioState::new(10000.);
+        portfolio.position_mut("000001.SZ").buy(date,100,10.);
+        portfolio.position_mut("000002.SZ").buy(date,200,10.);
+        portfolio.position_mut("000003.SZ").buy(date,100,10.);
+        portfolio.position_mut("000003.SZ").sell(100,11.).unwrap();
+        let flat_realized = portfolio.position("000003.SZ").unwrap().realized_pnl;
+        let untouched_lots = portfolio.position("000002.SZ").unwrap().lots.as_ptr();
+        let before = portfolio.financial_replay_identity();
+        let order = portfolio.positions.keys().cloned().collect::<Vec<_>>();
+        let checkpoint = portfolio.checkpoint(Some(&BTreeSet::from(["000001.SZ".into(), "000004.SZ".into()])));
+        assert!(!checkpoint.saved.positions.contains_key("000002.SZ"));
+        portfolio.position_mut("000001.SZ").sell(100,11.).unwrap();
+        portfolio.prune_flat_positions();
+        portfolio.position_mut("000004.SZ").buy(date,100,12.);
+        portfolio.apply_cash_delta(100.).unwrap();
+        portfolio.stock_pool_states.insert("changed".into(), Default::default());
+        checkpoint.restore(&mut portfolio);
+        assert_eq!(portfolio.financial_replay_identity(), before);
+        assert_eq!(portfolio.positions.keys().cloned().collect::<Vec<_>>(), order);
+        assert_eq!(portfolio.position("000002.SZ").unwrap().lots.as_ptr(), untouched_lots);
+        assert_eq!(portfolio.position("000003.SZ").unwrap().realized_pnl, flat_realized);
+        assert!(portfolio.stock_pool_states.is_empty());
+        assert!(portfolio.position("000004.SZ").is_none());
+    }
+
     #[test]
     fn cash_ledger_accumulates_micro_yuan_exactly() {
         let mut portfolio = PortfolioState::new(1_000_000.0);