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fix: keep TOC reload insertion on the fast path #63

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Merged
pathscale merged 1 commit into from
Aug 8, 2026
Merged

fix: keep TOC reload insertion on the fast path #63

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10 changes: 4 additions & 6 deletions src/persistence/space/index/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -246,7 +246,7 @@ where
self.next_page_id.fetch_add(1, Ordering::Relaxed).into()
};
self.table_of_contents
.insert((node_id.key.clone(), node_id.value), page_id);
.insert((node_id.key.clone(), node_id.value), page_id)?;
self.table_of_contents.persist(&mut self.index_file).await?;
self.add_new_index_page(node_id, page_id).await?;

Expand Down Expand Up @@ -279,7 +279,7 @@ where
self.table_of_contents.insert(
(splitted_page.node_id.key.clone(), splitted_page.node_id.link),
new_page_id,
);
)?;
self.table_of_contents.persist(&mut self.index_file).await?;

self.add_index_page(splitted_page, new_page_id).await?;
Expand Down Expand Up @@ -437,7 +437,7 @@ where
self.next_page_id.fetch_add(1, Ordering::Relaxed).into()
};
self.table_of_contents
.insert((max_value.key.clone(), max_value.value), page_id);
.insert((max_value.key.clone(), max_value.value), page_id)?;

let size = get_index_page_size_from_data_length::<T>(INNER_PAGE_SIZE as usize);
let mut page = IndexPage::new(max_value.clone().into(), size);
Expand All @@ -451,8 +451,6 @@ where
let header = GeneralHeader::new(page_id, PageType::Index, self.space_id);
let general_page = GeneralPage { inner: page, header };
pages.insert(page_id, general_page);
self.table_of_contents
.insert((max_value.key.clone(), max_value.value), page_id)
}
ChangeEvent::RemoveNode { event_id: _, max_value } => {
self.table_of_contents.remove(&(max_value.key.clone(), max_value.value));
Expand Down Expand Up @@ -494,7 +492,7 @@ where
self.table_of_contents.insert(
(splitted_page.node_id.key.clone(), splitted_page.node_id.link),
new_page_id,
);
)?;
let header = GeneralHeader::new(new_page_id, PageType::Index, self.space_id);
let general_page = GeneralPage {
inner: splitted_page,
Expand Down
90 changes: 59 additions & 31 deletions src/persistence/space/index/table_of_contents.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -54,35 +54,30 @@ where
&mut self.pages[self.current_page]
}

pub fn insert(&mut self, node_id: T, page_id: PageId)
pub fn insert(&mut self, node_id: T, page_id: PageId) -> eyre::Result<()>
where
T: Clone + SizeMeasurable,
{
// Replacing an existing identity must not leave duplicate mappings in
// separate TOC segments or inflate the page's estimated size.
let mut first_existing = None;
for index in 0..self.pages.len() {
if self.pages[index].inner.contains(&node_id) {
self.pages[index].inner.remove_without_record(&node_id);
first_existing.get_or_insert(index);
}
}
if let Some(first) = first_existing {
self.current_page = first;
}

let next_page_id = self.next_page_id.clone();
let entry_size = (node_id.clone(), page_id).aligned_size();

loop {
let page = self.get_current_page_mut();
page.inner.insert(node_id.clone(), page_id);
if page.inner.estimated_size() <= DATA_LENGTH as usize {
return;
let page = &mut self.pages[self.current_page];
if page.inner.estimated_size() + entry_size <= DATA_LENGTH as usize {
page.inner.insert(node_id, page_id);
return Ok(());
}
page.inner.remove_without_record(&node_id);

if !page.header.next_id.is_empty() {
self.current_page += 1;
let next = self.current_page + 1;
if next >= self.pages.len() {
return Err(eyre::eyre!(
"table-of-contents segment {} links past the loaded chain of {} segments",
self.current_page,
self.pages.len()
));
}
self.current_page = next;
continue;
}

Expand All @@ -98,7 +93,7 @@ where
next_page.inner.insert(node_id, page_id);
self.pages.push(next_page);
self.current_page = self.pages.len() - 1;
return;
return Ok(());
}
}

Expand Down Expand Up @@ -246,7 +241,7 @@ mod tests {
fn insert_to_empty() {
let mut toc = IndexTableOfContents::<u8, 128>::new(0.into(), Arc::new(AtomicU32::new(0)));
let key = 1;
toc.insert(key, 1.into());
toc.insert(key, 1.into()).unwrap();

let page = toc.pages[toc.current_page].clone();
assert!(
Expand All @@ -264,7 +259,7 @@ mod tests {
#[test]
fn checked_update_reports_a_missing_identity_without_mutating_the_toc() {
let mut toc = IndexTableOfContents::<u8, 128>::new(0.into(), Arc::new(AtomicU32::new(1)));
toc.insert(7, 2.into());
toc.insert(7, 2.into()).unwrap();

assert!(!toc.try_update_key(&8, 9));
assert_eq!(toc.get(&7), Some(2.into()));
Expand All @@ -276,7 +271,7 @@ mod tests {
let mut toc = IndexTableOfContents::<u8, 20>::new(0.into(), Arc::new(AtomicU32::new(0)));
let mut keys = vec![];
for key in 0..10 {
toc.insert(key, 1.into());
toc.insert(key, 1.into()).unwrap();
keys.push(key);
}

Expand All @@ -301,25 +296,51 @@ mod tests {
fn insert_reaches_existing_tail_after_reload_resets_cursor() {
let mut toc = IndexTableOfContents::<u8, 20>::new(0.into(), Arc::new(AtomicU32::new(0)));
for key in 0..10 {
toc.insert(key, u32::from(key).into());
toc.insert(key, u32::from(key).into()).unwrap();
}
assert!(toc.pages.len() > 1, "fixture must span TOC pages");

// `parse_from_file` starts at the first TOC segment. When that segment
// is already full and has a successor, a new page identity must carry
// forward until an existing or newly-created tail can accept it.
toc.current_page = 0;
toc.insert(200, PageId::from(200));
let before_sizes: Vec<_> = toc.pages.iter().map(|page| page.inner.estimated_size()).collect();
toc.insert(200, PageId::from(200)).unwrap();

assert_eq!(toc.get(&200), Some(PageId::from(200)));
for (page, before_size) in toc.pages.iter().zip(before_sizes) {
if page.inner.contains(&200) {
continue;
}
assert_eq!(
page.inner.estimated_size(),
before_size,
"probing a full TOC segment must not change its persisted size"
);
}
}

#[test]
fn insert_reports_a_truncated_segment_chain() {
let mut toc = IndexTableOfContents::<u8, 20>::new(0.into(), Arc::new(AtomicU32::new(0)));
for key in 0..10 {
toc.insert(key, u32::from(key).into()).unwrap();
}
assert!(!toc.pages[0].header.next_id.is_empty());
toc.pages.truncate(1);
toc.current_page = 0;

let error = toc.insert(200, PageId::from(200)).unwrap_err();

assert!(error.to_string().contains("links past the loaded chain"));
}

#[test]
fn reinsert_on_empty_space() {
let mut toc = IndexTableOfContents::<u8, 20>::new(0.into(), Arc::new(AtomicU32::new(0)));
let mut keys = vec![];
for key in 0..10 {
toc.insert(key, 1.into());
toc.insert(key, 1.into()).unwrap();
keys.push(key);
}

Expand All @@ -346,11 +367,18 @@ mod tests {

let new_key = keys.last().unwrap() + 1;
let id = toc.pop_empty_page_id().unwrap();
toc.insert(new_key, id);
let before_insert_segments = toc.pages.len();
toc.insert(new_key, id).unwrap();
assert_eq!(toc.get(&new_key), Some(id), "reused page id was not recorded");
assert!(
toc.current_page >= before_remove_current_page,
"`current_page` did not advance to a segment that could hold the identity"
assert_eq!(
toc.pages.len(),
before_insert_segments + 1,
"the fixture's full successor chain should append one segment"
);
assert_eq!(
toc.current_page,
toc.pages.len() - 1,
"the cursor should name the segment that accepted the identity"
);
assert_eq!(
toc.pages[after_remove_current_page].inner.clone().pop_empty_page(),
Expand Down
10 changes: 4 additions & 6 deletions src/persistence/space/index/unsized_.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -135,7 +135,7 @@ where
self.next_page_id.fetch_add(1, Ordering::Relaxed).into()
};
self.table_of_contents
.insert((node_id.key.clone(), node_id.value), page_id);
.insert((node_id.key.clone(), node_id.value), page_id)?;
self.table_of_contents.persist(&mut self.index_file).await?;
self.add_new_index_page(node_id, page_id).await?;

Expand Down Expand Up @@ -307,7 +307,7 @@ where
self.table_of_contents.insert(
(splitted_page.node_id.key.clone(), splitted_page.node_id.link),
new_page_id,
);
)?;
self.table_of_contents.persist(&mut self.index_file).await?;

self.add_index_page(splitted_page, new_page_id).await?;
Expand Down Expand Up @@ -489,14 +489,12 @@ where
self.next_page_id.fetch_add(1, Ordering::Relaxed).into()
};
self.table_of_contents
.insert((max_value.key.clone(), max_value.value), page_id);
.insert((max_value.key.clone(), max_value.value), page_id)?;

let page = UnsizedIndexPage::<T, INNER_PAGE_SIZE>::new(max_value.clone().into())?;
let header = GeneralHeader::new(page_id, PageType::IndexUnsized, self.space_id);
let general_page = GeneralPage { inner: page, header };
pages.insert(page_id, general_page);
self.table_of_contents
.insert((max_value.key.clone(), max_value.value), page_id)
}
ChangeEvent::RemoveNode { event_id: _, max_value } => {
self.table_of_contents.remove(&(max_value.key.clone(), max_value.value));
Expand Down Expand Up @@ -561,7 +559,7 @@ where
));
}
let right_page_key = (splitted_page.node_id.key.clone(), splitted_page.node_id.link);
self.table_of_contents.insert(right_page_key.clone(), new_page_id);
self.table_of_contents.insert(right_page_key.clone(), new_page_id)?;
if self.table_of_contents.get(&right_page_key) != Some(new_page_id) {
return Err(eyre!(
"unsized index split identity did not become canonical (page={new_page_id:?})"
Expand Down
6 changes: 4 additions & 2 deletions src/persistence/space/index/util.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,8 @@ where
let mut toc = IndexTableOfContents::new(0.into(), next_page_id.clone());
for page in pages {
let page_id = next_page_id.fetch_add(1, Ordering::Relaxed);
toc.insert((page.node_id.key.clone(), page.node_id.link), page_id.into());
toc.insert((page.node_id.key.clone(), page.node_id.link), page_id.into())
.expect("new in-memory TOC chain should remain internally consistent");
let header = GeneralHeader::new(page_id.into(), PageType::Index, 0.into());
let index_page = GeneralPage { inner: page, header };
general_index_pages.push(index_page)
Expand All @@ -45,7 +46,8 @@ where
let mut toc = IndexTableOfContents::new(0.into(), next_page_id.clone());
for page in pages {
let page_id = next_page_id.fetch_add(1, Ordering::Relaxed);
toc.insert((page.node_id.key.clone(), page.node_id.link), page_id.into());
toc.insert((page.node_id.key.clone(), page.node_id.link), page_id.into())
.expect("new in-memory TOC chain should remain internally consistent");
let header = GeneralHeader::new(page_id.into(), PageType::IndexUnsized, 0.into());
let index_page = GeneralPage { inner: page, header };
general_index_pages.push(index_page)
Expand Down
2 changes: 1 addition & 1 deletion tests/persistence/toc/write.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@ async fn test_persist_index_table_of_contents() {
remove_file_if_exists("tests/data/persist_index_table_of_contents.wt.idx".to_string()).await;

let mut toc = IndexTableOfContents::<u32, { INNER_PAGE_SIZE as u32 }>::new(0.into(), Arc::new(AtomicU32::new(1)));
toc.insert(13, 1.into());
toc.insert(13, 1.into()).unwrap();
let mut file = File::create("tests/data/persist_index_table_of_contents.wt.idx")
.await
.unwrap();
Expand Down
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