优化日线候选和成交量窗口索引

crates/fidc-core/src/data.rs

@@ -487,6 +487,7 @@ struct SymbolPriceSeries {
     last_prefix: Vec<f64>,
     valid_volume_sum_prefix: Vec<f64>,
     valid_volume_count_prefix: Vec<usize>,
+    valid_volume_start_by_count: Vec<usize>,
 }
 
 #[derive(Debug, Clone)]
@@ -706,6 +707,14 @@ impl SymbolPriceSeries {
                     + usize::from(valid),
             );
         }
+        let valid_volume_count = valid_volume_count_prefix
+            .last()
+            .copied()
+            .unwrap_or_default();
+        let mut valid_volume_start_by_count = vec![0usize; valid_volume_count + 1];
+        for (index, count) in valid_volume_count_prefix.iter().copied().enumerate() {
+            valid_volume_start_by_count[count] = index;
+        }
 
         Self {
             symbol,
@@ -735,6 +744,7 @@ impl SymbolPriceSeries {
             last_prefix,
             valid_volume_sum_prefix,
             valid_volume_count_prefix,
+            valid_volume_start_by_count,
         }
     }
 
@@ -883,9 +893,8 @@ impl SymbolPriceSeries {
             return None;
         }
         let target_count = valid_count - lookback;
-        let start = self.valid_volume_count_prefix[..=end]
-            .partition_point(|count| *count <= target_count)
-            .saturating_sub(1);
+        let start = *self.valid_volume_start_by_count.get(target_count)?;
+        debug_assert!(start <= end);
         Some((start, end))
     }
 
@@ -2326,6 +2335,20 @@ impl DataSet {
             .unwrap_or_default()
     }
 
+    pub fn factor_snapshot_rows_on(&self, date: NaiveDate) -> &[Arc<DailyFactorSnapshot>] {
+        self.factor_by_date
+            .get(&date)
+            .map(Vec::as_slice)
+            .unwrap_or(&[])
+    }
+
+    pub fn factor_symbol_ids_on(&self, date: NaiveDate) -> &[u32] {
+        self.factor_symbol_ids_by_date
+            .get(&date)
+            .map(Vec::as_slice)
+            .unwrap_or(&[])
+    }
+
     pub fn factor_text_snapshots_on(&self, date: NaiveDate) -> Vec<&FactorTextValue> {
         self.factor_text_by_date
             .get(&date)