From 08e4ed9d407128debe616cfb9d3865e1e69b338e Mon Sep 17 00:00:00 2001
From: Zixuan Chen <remch183@outlook.com>
Date: Wed, 8 Nov 2023 16:15:11 +0800
Subject: [PATCH] feat: add `from_checkout` mark to event (#164)

---
 crates/loro-internal/src/event.rs  | 20 +++++++++++++++++++-
 crates/loro-internal/src/loro.rs   |  2 ++
 crates/loro-internal/src/state.rs  |  3 +++
 crates/loro-internal/src/txn.rs    |  1 +
 crates/loro-internal/tests/test.rs | 24 +++++++++++++++++++++++-
 5 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/crates/loro-internal/src/event.rs b/crates/loro-internal/src/event.rs
index 3482a0ce..66f7bbb2 100644
--- a/crates/loro-internal/src/event.rs
+++ b/crates/loro-internal/src/event.rs
@@ -1,4 +1,5 @@
 use enum_as_inner::EnumAsInner;
+use fxhash::FxHasher64;
 use serde::{Deserialize, Serialize};
 use smallvec::SmallVec;
 
@@ -10,7 +11,10 @@ use crate::{
     InternalString, LoroValue,
 };
 
-use std::borrow::Cow;
+use std::{
+    borrow::Cow,
+    hash::{Hash, Hasher},
+};
 
 use loro_common::{ContainerID, TreeID};
 
@@ -43,9 +47,21 @@ pub struct DocDiff {
     pub to: Frontiers,
     pub origin: InternalString,
     pub local: bool,
+    /// Whether the diff is created from the checkout operation.
+    pub from_checkout: bool,
     pub diff: Vec<ContainerDiff>,
 }
 
+impl DocDiff {
+    /// Get the unique id of the diff.
+    pub fn id(&self) -> u64 {
+        let mut hasher = FxHasher64::default();
+        self.from.hash(&mut hasher);
+        self.to.hash(&mut hasher);
+        hasher.finish()
+    }
+}
+
 #[derive(Debug, Clone)]
 pub(crate) struct InternalContainerDiff {
     pub(crate) idx: ContainerIdx,
@@ -71,6 +87,7 @@ pub(crate) enum DiffVariant {
 pub(crate) struct InternalDocDiff<'a> {
     pub(crate) origin: InternalString,
     pub(crate) local: bool,
+    pub(crate) from_checkout: bool,
     pub(crate) diff: Cow<'a, [InternalContainerDiff]>,
     pub(crate) new_version: Cow<'a, Frontiers>,
 }
@@ -80,6 +97,7 @@ impl<'a> InternalDocDiff<'a> {
         InternalDocDiff {
             origin: self.origin,
             local: self.local,
+            from_checkout: self.from_checkout,
             diff: Cow::Owned((*self.diff).to_owned()),
             new_version: Cow::Owned((*self.new_version).to_owned()),
         }
diff --git a/crates/loro-internal/src/loro.rs b/crates/loro-internal/src/loro.rs
index f8f70a13..e4a72640 100644
--- a/crates/loro-internal/src/loro.rs
+++ b/crates/loro-internal/src/loro.rs
@@ -404,6 +404,7 @@ impl LoroDoc {
                         origin,
                         local: false,
                         diff: (diff).into(),
+                        from_checkout: false,
                         new_version: Cow::Owned(oplog.frontiers().clone()),
                     });
                 }
@@ -627,6 +628,7 @@ impl LoroDoc {
             origin: "checkout".into(),
             local: true,
             diff: Cow::Owned(diff),
+            from_checkout: true,
             new_version: Cow::Owned(frontiers.clone()),
         });
         let events = state.take_events();
diff --git a/crates/loro-internal/src/state.rs b/crates/loro-internal/src/state.rs
index 05a12446..a3939122 100644
--- a/crates/loro-internal/src/state.rs
+++ b/crates/loro-internal/src/state.rs
@@ -429,6 +429,7 @@ impl DocState {
             self.record_diff(InternalDocDiff {
                 origin: Default::default(),
                 local: false,
+                from_checkout: false,
                 diff,
                 new_version: Cow::Borrowed(&frontiers),
             });
@@ -664,6 +665,7 @@ impl DocState {
         let to = (*diffs.last().unwrap().new_version).to_owned();
         let origin = diffs[0].origin.clone();
         let local = diffs[0].local;
+        let from_checkout = diffs[0].from_checkout;
         for diff in diffs {
             #[allow(clippy::unnecessary_to_owned)]
             for container_diff in diff.diff.into_owned() {
@@ -714,6 +716,7 @@ impl DocState {
             from,
             to,
             origin,
+            from_checkout,
             local,
             diff,
         }
diff --git a/crates/loro-internal/src/txn.rs b/crates/loro-internal/src/txn.rs
index f2d70a24..f4f01cd5 100644
--- a/crates/loro-internal/src/txn.rs
+++ b/crates/loro-internal/src/txn.rs
@@ -321,6 +321,7 @@ impl Transaction {
                         })
                         .collect(),
                 ),
+                from_checkout: false,
                 new_version: Cow::Borrowed(oplog.frontiers()),
             }),
         );
diff --git a/crates/loro-internal/tests/test.rs b/crates/loro-internal/tests/test.rs
index 2268a181..befadcb6 100644
--- a/crates/loro-internal/tests/test.rs
+++ b/crates/loro-internal/tests/test.rs
@@ -1,4 +1,4 @@
-use std::sync::{Arc, Mutex};
+use std::sync::{atomic::AtomicBool, Arc, Mutex};
 
 use loro_common::{ContainerID, ContainerType, LoroValue, ID};
 use loro_internal::{
@@ -6,6 +6,28 @@ use loro_internal::{
 };
 use serde_json::json;
 
+#[test]
+fn event_from_checkout() {
+    let mut a = LoroDoc::new_auto_commit();
+    let sub_id = a.subscribe_root(Arc::new(|event| {
+        assert!(!event.doc.from_checkout);
+    }));
+    a.get_text("text").insert_(0, "hello").unwrap();
+    a.commit_then_renew();
+    let version = a.oplog_frontiers();
+    a.get_text("text").insert_(0, "hello").unwrap();
+    a.commit_then_renew();
+    a.unsubscribe(sub_id);
+    let ran = Arc::new(AtomicBool::new(false));
+    let ran_cloned = ran.clone();
+    a.subscribe_root(Arc::new(move |event| {
+        assert!(event.doc.from_checkout);
+        ran.store(true, std::sync::atomic::Ordering::Relaxed);
+    }));
+    a.checkout(&version).unwrap();
+    assert!(ran_cloned.load(std::sync::atomic::Ordering::Relaxed));
+}
+
 #[test]
 fn out_of_bound_test() {
     let a = LoroDoc::new_auto_commit();