fix: calc change count (#556)

* fix: calc change count

* fix: len ops

.changeset/two-jokes-happen.md

@@ -0,0 +1,5 @@
+---
+"loro-crdt": patch
+---
+
+Add changeCount and opCount methods

crates/loro-internal/src/container/richtext/richtext_state.rs

@@ -1757,7 +1757,6 @@ impl RichtextState {
         self.get_index_from_cursor(right, PosType::Entity).unwrap()
     }
 
-    #[tracing::instrument(level = "trace", skip(self))]
     pub fn get_index_from_cursor(
         &self,
         cursor: generic_btree::Cursor,

crates/loro-internal/src/loro.rs

@@ -1212,7 +1212,17 @@ impl LoroDoc {
     #[inline]
     pub fn len_ops(&self) -> usize {
         let oplog = self.oplog.try_lock().unwrap();
-        oplog.vv().iter().map(|(_, ops)| *ops).sum::<i32>() as usize
+        let ans = oplog.vv().iter().map(|(_, ops)| *ops).sum::<i32>() as usize;
+        if oplog.is_shallow() {
+            let sub = oplog
+                .shallow_since_vv()
+                .iter()
+                .map(|(_, ops)| *ops)
+                .sum::<i32>() as usize;
+            ans - sub
+        } else {
+            ans
+        }
     }
 
     #[inline]

crates/loro-internal/src/oplog/change_store.rs

@@ -433,6 +433,7 @@ impl ChangeStore {
     }
 
     pub fn change_num(&self) -> usize {
+        self.ensure_block_loaded_in_range(Bound::Unbounded, Bound::Unbounded);
         let mut inner = self.inner.try_lock().unwrap();
         inner
             .mem_parsed_kv

crates/loro-wasm/src/lib.rs

@@ -1412,6 +1412,18 @@ impl LoroDoc {
         console_log!("{:#?}", oplog.diagnose_size());
     }
 
+    /// Get the number of changes in the oplog.
+    pub fn changeCount(&self) -> usize {
+        let borrow_mut = &self.0;
+        let oplog = borrow_mut.oplog().try_lock().unwrap();
+        oplog.len_changes()
+    }
+
+    /// Get the number of ops in the oplog.
+    pub fn opCount(&self) -> usize {
+        self.0.len_ops()
+    }
+
     /// Get all of changes in the oplog.
     ///
     /// Note: this method is expensive when the oplog is large. O(n)

crates/loro/tests/loro_rust_test.rs

@@ -2238,3 +2238,21 @@ fn is_deleted() {
     let container_after = doc.get_map(&container_before.id());
     assert!(container_after.is_deleted());
 }
+
+#[test]
+fn change_count() {
+    let doc = LoroDoc::new();
+    let n = 1024 * 5;
+    for i in 0..n {
+        doc.get_text("text").insert(0, "H").unwrap();
+        doc.set_next_commit_message(&format!("{}", i));
+        doc.commit();
+    }
+
+    doc.compact_change_store();
+    assert_eq!(doc.len_changes(), n);
+    let bytes = doc.export(loro::ExportMode::Snapshot);
+    let new_doc = LoroDoc::new();
+    new_doc.import(&bytes.unwrap()).unwrap();
+    assert_eq!(new_doc.len_changes(), n);
+}