copies: return early from CopiesTreeDiffStream::poll_next() on Pendin…

…g/None
jj-vcs · Aug 21, 2024 · 48a2a76 · 48a2a76
1 parent e9a052e
commit 48a2a76
Showing 1 changed file with 22 additions and 24 deletions.
diff --git a/lib/src/copies.rs b/lib/src/copies.rs
@@ -18,7 +18,7 @@ use std::collections::HashMap;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
-use futures::Stream;
+use futures::{ready, Stream};
 
 use crate::backend::{BackendResult, CopyRecord};
 use crate::merge::MergedTreeValue;
@@ -121,28 +121,26 @@ impl Stream for CopiesTreeDiffStream<'_> {
     type Item = CopiesTreeDiffEntry;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        self.inner.as_mut().poll_next(cx).map(|option| {
-            option.map(|diff_entry| {
-                let Some(CopyRecord { source, .. }) =
-                    self.copy_records.for_target(&diff_entry.path)
-                else {
-                    return CopiesTreeDiffEntry {
-                        source: diff_entry.path.clone(),
-                        target: diff_entry.path,
-                        value: diff_entry.value,
-                    };
-                };
-
-                CopiesTreeDiffEntry {
-                    source: source.clone(),
-                    target: diff_entry.path,
-                    value: diff_entry.value.and_then(|(_, target_value)| {
-                        self.source_tree
-                            .path_value(source)
-                            .map(|source_value| (source_value, target_value))
-                    }),
-                }
-            })
-        })
+        let Some(diff_entry) = ready!(self.inner.as_mut().poll_next(cx)) else {
+            return Poll::Ready(None);
+        };
+
+        let Some(CopyRecord { source, .. }) = self.copy_records.for_target(&diff_entry.path) else {
+            return Poll::Ready(Some(CopiesTreeDiffEntry {
+                source: diff_entry.path.clone(),
+                target: diff_entry.path,
+                value: diff_entry.value,
+            }));
+        };
+
+        Poll::Ready(Some(CopiesTreeDiffEntry {
+            source: source.clone(),
+            target: diff_entry.path,
+            value: diff_entry.value.and_then(|(_, target_value)| {
+                self.source_tree
+                    .path_value(source)
+                    .map(|source_value| (source_value, target_value))
+            }),
+        }))
     }
 }