From 0fc73089320a4e7698bd44ed2a83093881dd7673 Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Sat, 23 Jul 2022 09:27:21 +0200
Subject: [PATCH] Allow grouping local transactions even if remote peer edits
 in between

---
 crates/language/src/proto.rs |  2 --
 crates/rpc/proto/zed.proto   |  1 -
 crates/text/src/tests.rs     |  2 ++
 crates/text/src/text.rs      | 21 ++++-----------------
 4 files changed, 6 insertions(+), 20 deletions(-)

diff --git a/crates/language/src/proto.rs b/crates/language/src/proto.rs
index c7c22c55c9..4dca2f855d 100644
--- a/crates/language/src/proto.rs
+++ b/crates/language/src/proto.rs
@@ -450,7 +450,6 @@ pub fn serialize_transaction(transaction: &Transaction) -> proto::Transaction {
             .map(serialize_local_timestamp)
             .collect(),
         start: serialize_version(&transaction.start),
-        end: serialize_version(&transaction.end),
     }
 }
 
@@ -467,7 +466,6 @@ pub fn deserialize_transaction(transaction: proto::Transaction) -> Result<Transa
             .map(deserialize_local_timestamp)
             .collect(),
         start: deserialize_version(transaction.start.into()),
-        end: deserialize_version(transaction.end),
     })
 }
 
diff --git a/crates/rpc/proto/zed.proto b/crates/rpc/proto/zed.proto
index f3eaf0038d..35f3049edb 100644
--- a/crates/rpc/proto/zed.proto
+++ b/crates/rpc/proto/zed.proto
@@ -534,7 +534,6 @@ message Transaction {
     LocalTimestamp id = 1;
     repeated LocalTimestamp edit_ids = 2;
     repeated VectorClockEntry start = 3;
-    repeated VectorClockEntry end = 4;
 }
 
 message LocalTimestamp {
diff --git a/crates/text/src/tests.rs b/crates/text/src/tests.rs
index 3594f72984..2f67579f47 100644
--- a/crates/text/src/tests.rs
+++ b/crates/text/src/tests.rs
@@ -564,7 +564,9 @@ fn test_history() {
     assert_eq!(buffer.text(), "12cde6");
 
     // Redo stack gets cleared after performing an edit.
+    buffer.start_transaction_at(now);
     buffer.edit([(0..0, "X")]);
+    buffer.end_transaction_at(now);
     assert_eq!(buffer.text(), "X12cde6");
     buffer.redo();
     assert_eq!(buffer.text(), "X12cde6");
diff --git a/crates/text/src/text.rs b/crates/text/src/text.rs
index 266cb402a0..60ae833650 100644
--- a/crates/text/src/text.rs
+++ b/crates/text/src/text.rs
@@ -92,7 +92,6 @@ pub struct Transaction {
     pub id: TransactionId,
     pub edit_ids: Vec<clock::Local>,
     pub start: clock::Global,
-    pub end: clock::Global,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -105,15 +104,6 @@ impl HistoryEntry {
     pub fn transaction_id(&self) -> TransactionId {
         self.transaction.id
     }
-
-    fn push_edit(&mut self, edit_operation: &EditOperation) {
-        self.transaction
-            .edit_ids
-            .push(edit_operation.timestamp.local());
-        self.transaction
-            .end
-            .observe(edit_operation.timestamp.local());
-    }
 }
 
 struct History {
@@ -162,8 +152,7 @@ impl History {
             self.undo_stack.push(HistoryEntry {
                 transaction: Transaction {
                     id,
-                    start: start.clone(),
-                    end: start,
+                    start,
                     edit_ids: Default::default(),
                 },
                 first_edit_at: now,
@@ -209,7 +198,6 @@ impl History {
             while let Some(prev_entry) = entries.next_back() {
                 if !prev_entry.suppress_grouping
                     && entry.first_edit_at - prev_entry.last_edit_at <= self.group_interval
-                    && entry.transaction.start == prev_entry.transaction.end
                 {
                     entry = prev_entry;
                     new_len -= 1;
@@ -223,13 +211,12 @@ impl History {
         if let Some(last_entry) = entries_to_keep.last_mut() {
             for entry in &*entries_to_merge {
                 for edit_id in &entry.transaction.edit_ids {
-                    last_entry.push_edit(self.operations[edit_id].as_edit().unwrap());
+                    last_entry.transaction.edit_ids.push(*edit_id);
                 }
             }
 
             if let Some(entry) = entries_to_merge.last_mut() {
                 last_entry.last_edit_at = entry.last_edit_at;
-                last_entry.transaction.end = entry.transaction.end.clone();
             }
         }
 
@@ -257,9 +244,9 @@ impl History {
 
     fn push_undo(&mut self, op_id: clock::Local) {
         assert_ne!(self.transaction_depth, 0);
-        if let Some(Operation::Edit(edit)) = self.operations.get(&op_id) {
+        if let Some(Operation::Edit(_)) = self.operations.get(&op_id) {
             let last_transaction = self.undo_stack.last_mut().unwrap();
-            last_transaction.push_edit(&edit);
+            last_transaction.transaction.edit_ids.push(op_id);
         }
     }