From ccee20164132ea4c3e6fe07e00f05438df61a8ed Mon Sep 17 00:00:00 2001
From: Zixuan Chen <remch183@outlook.com>
Date: Sat, 5 Aug 2023 12:44:31 +0800
Subject: [PATCH] refactor: better interface

---
 crates/loro-internal/src/change.rs  | 28 ++++++++++++---------
 crates/loro-internal/src/handler.rs | 38 +++++++++++++++++++++++++----
 crates/loro-internal/src/oplog.rs   |  4 +++
 3 files changed, 53 insertions(+), 17 deletions(-)

diff --git a/crates/loro-internal/src/change.rs b/crates/loro-internal/src/change.rs
index af7df3a8..c822a309 100644
--- a/crates/loro-internal/src/change.rs
+++ b/crates/loro-internal/src/change.rs
@@ -50,6 +50,22 @@ impl<O> Change<O> {
             timestamp,
         }
     }
+
+    pub fn ops(&self) -> &RleVec<[O; 1]> {
+        &self.ops
+    }
+
+    pub fn lamport(&self) -> Lamport {
+        self.lamport
+    }
+
+    pub fn timestamp(&self) -> Timestamp {
+        self.timestamp
+    }
+
+    pub fn id(&self) -> ID {
+        self.id
+    }
 }
 
 impl<O: Mergable + HasLength + HasIndex + Debug> HasIndex for Change<O> {
@@ -119,18 +135,6 @@ impl DagNode for Change {
 }
 
 impl Change {
-    pub fn lamport(&self) -> Lamport {
-        self.lamport
-    }
-
-    pub fn timestamp(&self) -> Timestamp {
-        self.timestamp
-    }
-
-    pub fn id(&self) -> ID {
-        self.id
-    }
-
     pub fn can_merge_right(&self, other: &Self) -> bool {
         other.id.peer == self.id.peer
             && other.id.counter == self.id.counter + self.content_len() as Counter
diff --git a/crates/loro-internal/src/handler.rs b/crates/loro-internal/src/handler.rs
index 95a6a423..f97c6907 100644
--- a/crates/loro-internal/src/handler.rs
+++ b/crates/loro-internal/src/handler.rs
@@ -21,19 +21,37 @@ pub struct TextHandler {
     state: Weak<Mutex<DocState>>,
 }
 
+impl std::fmt::Debug for TextHandler {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("TextHandler")
+    }
+}
+
 #[derive(Clone)]
 pub struct MapHandler {
     container_idx: ContainerIdx,
     state: Weak<Mutex<DocState>>,
 }
 
+impl std::fmt::Debug for MapHandler {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("MapHandler")
+    }
+}
+
 #[derive(Clone)]
 pub struct ListHandler {
     container_idx: ContainerIdx,
     state: Weak<Mutex<DocState>>,
 }
 
-#[derive(Clone, EnumAsInner)]
+impl std::fmt::Debug for ListHandler {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("ListHandler")
+    }
+}
+
+#[derive(Clone, EnumAsInner, Debug)]
 pub enum Handler {
     Text(TextHandler),
     Map(MapHandler),
@@ -322,6 +340,11 @@ impl ListHandler {
         )
     }
 
+    pub fn push(&self, txn: &mut Transaction, v: LoroValue) -> LoroResult<()> {
+        let pos = self.len();
+        self.insert(txn, pos, v)
+    }
+
     pub fn insert_container(
         &self,
         txn: &mut Transaction,
@@ -435,9 +458,9 @@ impl ListHandler {
             })
     }
 
-    pub fn for_each<I>(&self, f: I)
+    pub fn for_each<I>(&self, mut f: I)
     where
-        I: Fn(&LoroValue),
+        I: FnMut(&LoroValue),
     {
         self.state
             .upgrade()
@@ -468,6 +491,11 @@ impl MapHandler {
             return Ok(());
         }
 
+        if self.get(key).map(|x| x == value).unwrap_or(false) {
+            // skip if the value is already set
+            return Ok(());
+        }
+
         txn.apply_local_op(
             self.container_idx,
             crate::op::RawOpContent::Map(crate::container::map::MapSet {
@@ -514,9 +542,9 @@ impl MapHandler {
         )
     }
 
-    pub fn for_each<I>(&self, f: I)
+    pub fn for_each<I>(&self, mut f: I)
     where
-        I: Fn(&str, &MapValue),
+        I: FnMut(&str, &MapValue),
     {
         self.state
             .upgrade()
diff --git a/crates/loro-internal/src/oplog.rs b/crates/loro-internal/src/oplog.rs
index 99cdd163..fe8186ed 100644
--- a/crates/loro-internal/src/oplog.rs
+++ b/crates/loro-internal/src/oplog.rs
@@ -228,6 +228,10 @@ impl OpLog {
         ID::new(peer, cnt)
     }
 
+    pub fn get_peer_changes(&self, peer: PeerID) -> Option<&RleVec<[Change; 0]>> {
+        self.changes.get(&peer)
+    }
+
     pub(crate) fn vv(&self) -> &VersionVector {
         &self.dag.vv
     }