server: snapshot

crates/brk_query/src/impl/mining/dateindex_iter.rs

@@ -0,0 +1,71 @@
+use brk_computer::Computer;
+use brk_types::{DateIndex, Height, Timestamp};
+use vecdb::{GenericStoredVec, IterableVec, VecIndex};
+
+/// Helper for iterating over dateindex ranges with sampling.
+pub struct DateIndexIter<'a> {
+    computer: &'a Computer,
+    start_di: DateIndex,
+    end_di: DateIndex,
+    step: usize,
+}
+
+impl<'a> DateIndexIter<'a> {
+    pub fn new(computer: &'a Computer, start_height: usize, end_height: usize) -> Self {
+        let start_di = computer
+            .indexes
+            .height_to_dateindex
+            .read_once(Height::from(start_height))
+            .unwrap_or_default();
+        let end_di = computer
+            .indexes
+            .height_to_dateindex
+            .read_once(Height::from(end_height))
+            .unwrap_or_default();
+
+        let total = end_di.to_usize().saturating_sub(start_di.to_usize()) + 1;
+        let step = (total / 200).max(1);
+
+        Self {
+            computer,
+            start_di,
+            end_di,
+            step,
+        }
+    }
+
+    /// Iterate and collect entries using the provided transform function.
+    pub fn collect<T, F>(&self, mut transform: F) -> Vec<T>
+    where
+        F: FnMut(DateIndex, Timestamp, Height) -> Option<T>,
+    {
+        let total = self
+            .end_di
+            .to_usize()
+            .saturating_sub(self.start_di.to_usize())
+            + 1;
+        let mut timestamps = self
+            .computer
+            .chain
+            .timeindexes_to_timestamp
+            .dateindex_extra
+            .unwrap_first()
+            .iter();
+        let mut heights = self.computer.indexes.dateindex_to_first_height.iter();
+
+        let mut entries = Vec::with_capacity(total / self.step + 1);
+        let mut i = self.start_di.to_usize();
+
+        while i <= self.end_di.to_usize() {
+            let di = DateIndex::from(i);
+            if let (Some(ts), Some(h)) = (timestamps.get(di), heights.get(di))
+                && let Some(entry) = transform(di, ts, h)
+            {
+                entries.push(entry);
+            }
+            i += self.step;
+        }
+
+        entries
+    }
+}