B fixes a real correctness bug (timestamp-based feed cutoffs failing under same-millisecond posts and clock rollback) and closes a permission-leak edge case for private rooms, backed by substantial integration tests exercising these exact scenarios. A refines pair-selection heuristics for a ranking algorithm with good test coverage, but it's an optimization/tuning change rather than a bugfix, and its value is more speculative/UX-quality than correctness-critical.
constitution · epochs · watch · epoch 3
comparison
c_2722a3195825 (tommy-mor) vs c_0a9a8eab32ba (tommy-mor)
download prompt · raw event · cmp_294842c3dee606
council reasoning
B fixes real correctness and permission bugs by anchoring catch-up to durable ingest index (not timestamps), so concurrent/same-ms and clock-rollback posts are not missed, and private-room visibility/revocation cannot leak or skip content; it also adds room on FeedPost and solid multi-user integration tests. A is a solid ranking heuristic refinement (attach-isolate before isolate-isolate, then zip adjacent ranks) with unit tests, but it optimizes pair suggestion quality rather than closing feed reliability/security gaps.
Side B fixes a correctness issue in feed catch-up by anchoring implicit pagination to durable ingest order instead of timestamps, preserving behavior across same-millisecond posts and clock rollback, while also enforcing permission-aware visibility and exposing room metadata. It refactors duplicated feed-building into a shared helper and adds comprehensive integration tests for multi-user, private-room, and permission-revocation scenarios, whereas Side A mainly improves pair-selection heuristics and ordering for ranking refinement with supporting tests.
sides
A — c_2722a3195825 (tommy-mor)
message
[5db58b98] Improve vote pair selection for spanning trees and rank refinement. Prefer attaching unranked items to established components before comparing isolates, then zip down adjacent rank-centrality pairs once the pool is fully connected, skipping pairs that already have votes. Co-authored-by: Cursor <cursoragent@cursor.com>
diff preview
diff --git a/server/src/pair.rs b/server/src/pair.rs
index 54b5d2417e9dba04ed8df422156e274c2b2f76b2..c14de4b0502c8b5a17cddf3746077739d56e03e0 100644
--- a/server/src/pair.rs
+++ b/server/src/pair.rs
@@ -3,13 +3,21 @@
//! Pair selection prefers **bridge** votes — comparisons between items in
//! different connected components of the voted-pairs graph — so the pool
//! merges into one ranking group before refining within it.
+//!
+//! Among unvoted bridges, prefer merging established voted components, then
+//! attaching a never-voted child to an established component, and only then
+//! comparing two never-voted children (so the voted graph grows as one tree).
+//!
+//! Once every pool child sits in one voted component, refinement **zips** down
+//! the rank-centrality order: prefer 1 vs 2, then 2 vs 3, and so on, skipping
+//! pairs that already have a vote.
use rand::seq::SliceRandom;
use std::collections::{HashMap, HashSet};
use crate::{
path_types::ItemId,
- ranking::connected_components_from_voted_pairs,
+ ranking::{connected_components_from_voted_pairs, ranked_items},
reducer::{GlobalTree, GroupState},
};
@@ -28,36 +36,77 @@ fn pair_is_voted(group: &GroupState, a: &ItemId, b: &ItemId) -> bool {
group.voted_pairs.contains(&(i, j))
}
-/// Component id per pool item: voted-pairs graph components plus one id per
-/// never-voted child.
-fn component_ids(group: &GroupState, pool: &[ItemId]) -> HashMap<ItemId, usize> {
+/// Voted-pairs layout for pool items: component id per item plus which ids are
+/// multi-node voted components (ranked groups in the UI).
+struct ComponentLayout {
+ ids: HashMap<ItemId, usize>,
+ established: HashSet<usize>,
+}
+
+fn component_layout(group: &GroupState, pool: &[ItemId]) -> ComponentLayout {
let n = group.idx_to_item.len();
let (comps, isolates) =
connected_components_from_voted_pairs(n, group.voted_pairs.iter().copied());
- let mut out: HashMap<ItemId, usize> = HashMap::new();
+ let mut established = HashSet::new();
+ let mut ids: HashMap<ItemId, usize> = HashMap::new();
for (comp_idx, comp) in comps.iter().enumerate() {
+ if comp.len() >= 2 {
+ established.insert(comp_idx);
+ }
for &idx in comp {
if idx < n {
- out.insert(group.idx_to_item[idx].clone(), comp_idx);
+ ids.insert(group.idx_to_item[idx].clone(), comp_idx);
}
}
}
let mut next = comps.len();
for &idx in &isolates {
if idx < n {
- out.insert(group.idx_to_item[idx].clone(), next);
+ ids.insert(group.idx_to_item[idx].clone(), next);
next += 1;
}
}
for item in pool {
- out.entry(item.clone()).or_insert_with(|| {
+ ids.entry(item.clone()).or_insert_with(|| {
let id = next;
next += 1;
id
});
}
- out
+ ComponentLayout { ids, established }
+}
+
+/// Every pool child shares one multi-node voted component (spanning tree phase done).
+fn pool_fully_connected(layout: &ComponentLayout, pool: &[ItemId]) -> bool {
+ if pool.len() < 2 {
+ return false;
+ }
+ let mut comp_id = None;
+ for item in pool {
+ let Some(id) = layout.ids.get(item) else {
+ return false;
+ };
+ if !layout.established.contains(id) {
+ return false;
+ }
+ match comp_id {
+ None => comp_id = Some(*id),
+ Some(expected) if expected == *id => {}
+ _ => return false,
+ }
+ }
+ comp_id.is_some()
+}
+
+/// Pool children that appear in `group`, sorted best rank first.
+fn ranked_pool_order(group: &GroupState, pool: &[ItemId]) -> Vec<ItemId> {
+ let pool_set: HashSet<_> = pool.iter().collect();
+ ranked_items(group)
+ .into_iter()
+ .map(|r| r.item)
+ .filter(|id| pool_set.contains(id))
+ .collect()
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
@@ -72,19 +121,108 @@ enum PairPriority {
WithinVoted = 3,
}
-fn pair_priority(
+/// Tie-break among unvoted bridge pairs.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+enum BridgeSubPriority {
+ /// Both endpoints lie in established (multi-node) voted components.
+ MergeEstablished = 0,
+ /// One established component member and one never-voted child.
+ AttachIsolate = 1,
+ /// Two never-voted children (separate singleton components).
+ IsolatePair = 2,
+}
+
+/// Tie-break among within-component pairs once the pool is one connected group.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+struct WithinSubPriority {
+ /// 1 = adjacent ranks (i vs i+1); larger = farther apart in the order.
+ rank_gap: usize,
+ /// min rank index of the two — zip from the top (1 vs 2 before 2 vs 3).
+ zip_index: usize,
+}
+
+const WITHIN_SUB_WORST: WithinSubPriority = WithinSubPriority {
+ rank_gap: usize::MAX,
+ zip_index: usize::MAX,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+struct PairSortKey {
+ priority: PairPriority,
+ bridge_sub: BridgeSubPriority,
+ within_sub: WithinSubPriority,
+}
+
+fn item_in_established(layout: &ComponentLayout, item: &ItemId) -> bool {
+ layout
+ .ids
+ .get(item)
+ .is_some_and(|id| layout.established.contains(id))
+}
+
+fn bridge_sub_priority(layout: &ComponentLayout, a: &ItemId, b: &ItemId) -> BridgeSubPriority {
+ let a_est = item_in_established(layout, a);
+ let b_est = item_in_established(layout, b);
+ match (a_est, b_est) {
+ (true, true) => BridgeSubPriority::MergeEstablished,
+ (true, false) | (false, true) => BridgeSubPriority::AttachIsolate,
+ (false, false) => BridgeSubPriority::IsolatePair,
+ }
+}
+
+fn within_sub_priority(
+ group: &GroupState,
+ pool: &[ItemId],
+ layout: &ComponentLayout,
+ a: &ItemId,
+ b: &ItemId,
+) -> WithinSubPriority {
+ if !pool_fully_connected(layout, pool) {
+ return WITHIN_SUB_WORST;
+ }
+ let order = ranked_pool_order(group, pool);
+ let (Some(i), Some(j)) = (order.iter().position(|x| x == a), order.iter().position(|x| x == b))
+ else {
+ return WITHIN_SUB_WORST;
+ };
+ WithinSubPriority {
+ rank_gap: i.abs_diff(j),
+ zip_index: i.min(j),
+ }
+}
+
+fn pair_sort_key(
group: &GroupState,
- components: &HashMap<ItemId, usize>,
+ pool: &[ItemId],
+ layout: &ComponentLayout,
a: &ItemId,
b: &ItemId,
-) -> PairPriority {
+) -> PairSortKey {
let voted = pair_is_voted(group, a, b);
- let bridge = components.get(a) != components.get(b);
- match (bridge, voted) {
+ let bridge = layout.ids.get(a) != layout.ids.get(b);
+ let priority = match (bridge, voted) {
(true, false) => PairPriority::BridgeUnvoted,
(false, false) => PairPriority::WithinUnvoted,
(true, true) => PairPriority::BridgeVoted,
(false, true) => PairPriority::WithinVoted,
+ };
+ let bridge_sub = if priority == PairPriority::BridgeUnvoted {
+ bridge_sub_priority(layout, a, b)
+ } else {
+ BridgeSubPriority::MergeEstablished
+ };
+ let within_sub = if matches!(
+ priority,
+ PairPriority::WithinUnvoted | PairPriority::WithinVoted
+ ) {
+ within_sub_priority(group, pool, layout, a, b)
+ } else {
+ WITHIN_SUB_WORST
+ };
+ PairSortKey {
+ priority,
+ bridge_sub,
+ within_sub,
}
}
@@ -109,9 +247,12 @@ fn candidate_pairs(pool: &[ItemId], exclude: Option<(&ItemId, &ItemId)>) -> Vec<
/// Pick the next pair to vote on within `pool`.
///
-/// 1. Prefer unvoted **bridge** pairs (connect separate ranking components).
-/// 2. Then unvoted within-component pairs (refinement).
-/// 3. Then already-voted pairs (re-compare).
+/// 1. Prefer unvoted **bridge** pairs (connect separate ranking components),
+/// with sub-priority: merge established components, attach an isolate to
+/// established, then compare two isolates.
+/// 2. Then unvoted within-component pairs; when the pool is one connected group,
+/// prefer adjacent ranks (1 vs 2, 2 vs 3, …) in order, skipping voted pairs.
+/// 3. Then already-voted pairs (re-compare), with the same zip ordering.
pub fn suggest_next_pair_in_pool(
group: &GroupState,
pool: &[ItemId],
@@ -121,15 +262,15 @@ pub fn suggest_next_pair_in_pool(
if candidates.is_empty() {
return None;
}
- let components = component_ids(group, pool);
+ let layout = component_layout(group, pool);
let best = candidates
.iter()
- .map(|(a, b)| (pair_priority(group, &components, a, b), (a, b)))
- .min_by_key(|(p, _)| *p)?
+ .map(|(a, b)| (pair_sort_key(group, pool, &layout, a, b), (a, b)))
+ .min_by_key(|(k, _)| *k)?
.0;
let best_pairs: Vec<(ItemId, ItemId)> = candidates
.into_iter()
- .filter(|(a, b)| pair_priority(group, &components, a, b) == best)
+ .filter(|(a, b)| pair_sort_key(group, pool, &layout, a, b) == best)
.collect();
best_pairs.choose(&mut rand::thread_rng()).cloned()
}
@@ -303,6 +444,38 @@ mod tests {
assert!(from_ab && from_cd, "expected bridge pair, got {:?}", chosen);
}
+ #[test]
+ fn suggest_prefers_attach_over_isolate_pair_among_many_unranked() {
+ let parent = ItemId::parse("reddit.com/r/rust").unwrap();
+ let mut tree = seed_children(
+ &parent,
+ &[
+ "reddit.com/r/rust/a",
+ "reddit.com/r/rust/b",
+ "reddit.com/r/rust/c",
+ "reddit.com/r/rust/d",
+ "reddit.com/r/rust/e",
+ ],
+ );
+ let ab =
+ VoteData::from_recorded(1, "reddit.com/r/rust/a", "reddit.com/r/rust/b", 2, 1).unwrap();
+ tree.apply_vote(&parent, ab);
+ let group = tree.get(&parent).unwrap().local_ranking.clone();
+ let pool = children_of(&tree, &parent);
+ let pair = suggest_next_pair_in_pool(&group, &pool, None).unwrap();
+ let chosen = pair_set(&pair);
+ let from_ab =
+ chosen.contains("reddit.com/r/rust/a") || chosen.contains("reddit.com/r/rust/b");
+ let from_cde = chosen.contains("reddit.com/r/rust/c")
+ || chosen.contains("reddit.com/r/rust/d")
+ || chosen.contains("reddit.com/r/rust/e");
+ assert!(
+ from_ab && from_cde,
+ "expected ranked+unranked attach, got {:?}",
+ chosen
+ );
+ }
+
#[test]
fn suggest_connects_isolate_to_existing_component() {
let parent = ItemId::parse("reddit.com/r/rust").unwrap();
@@ -325,6 +498,65 @@ mod tests {
assert!(chosen.contains("reddit.com/r/rust/a") || chosen.contains("reddit.com/r/rust/b"));
}
+ #[test]
+ fn suggest_zips_adjacent_ranks_when_tree_complete() {
+ let parent = ItemId::parse("reddit.com/r/rust").unwrap();
+ let mut tree = seed_children(
+ &parent,
+ &[
+ "reddit.com/r/rust/a",
+ "reddit.com/r/rust/b",
+ "reddit.com/r/rust/c",
+ ],
+ );
+ // Star at a connects all three; b-c is the only unvoted adjacent pair left.
+ for (a, b, l, r) in [
+ ("reddit.com/r/rust/a", "reddit.com/r/rust/b", 3, 1),
+ ("reddit.com/r/rust/a", "reddit.com/r/rust/c", 2, 1),
+ ] {
+ let v = VoteData::from_recorded(1, a, b, l, r).unwrap();
+ tree.apply_vote(&parent, v);
+ }
+ let group = tree.get(&parent).unwrap().local_ranking.clone();
+ let pool = children_of(&tree, &parent);
+ let pair = suggest_next_pair_in_pool(&group, &pool, None).unwrap();
+ let chosen = pair_set(&pair);
+ // a-b and a-c voted;
… preview truncated; 1,687 characters omittedB — c_0a9a8eab32ba (tommy-mor)
message
[c94456ff] Make feed catch-up stable and permission-aware Anchor implicit feeds to durable ingest order and cover multi-user private-room visibility so concurrent posts are not missed or leaked. Co-authored-by: Cursor <cursoragent@cursor.com>
diff preview
diff --git a/cli/src/main.rs b/cli/src/main.rs
index abb5a55b49f60fe28fbfd4ec02715cb94ea0b4ec..c4f1494df3aedbd8b883aea6249579aa8336abfe 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -878,6 +878,30 @@ mod tests {
"graph: 4 items, 3/6 pairs (50.0% density), 1 component, connected"
);
}
+
+ #[test]
+ fn feed_without_since_uses_logged_in_delegate_from_env() {
+ let key = "SLUG_DELEGATE";
+ let previous = std::env::var_os(key);
+ let expected = "00000000-0000-0000-0000-0000000000ee:test:local/model";
+ std::env::set_var(key, expected);
+
+ let cli = Cli::try_parse_from(["slugsocial", "feed"]).expect("parse feed");
+
+ match previous {
+ Some(value) => std::env::set_var(key, value),
+ None => std::env::remove_var(key),
+ }
+ match cli.cmd {
+ Some(Command::Feed {
+ delegate, since, ..
+ }) => {
+ assert_eq!(delegate.as_deref(), Some(expected));
+ assert!(since.is_none());
+ }
+ _ => panic!("expected feed command"),
+ }
+ }
}
async fn run_scoped(base: &str, room: &str, sub: ScopedCmd) -> Result<()> {
@@ -1626,7 +1650,15 @@ async fn run() -> Result<()> {
} else {
for p in &resp.posts {
let ago = slug_types::timeago::timeago(now_ms, p.ts);
- println!("<post id=\"{}\" ts=\"{}\">", p.id, ago);
+ let thread_attr = p
+ .thread
+ .as_deref()
+ .map(|thread| format!(" thread=\"{thread}\""))
+ .unwrap_or_default();
+ println!(
+ "<post id=\"{}\" ts=\"{}\" room=\"{}\"{}>",
+ p.id, ago, p.room, thread_attr
+ );
print!("{}", p.body);
if !p.body.ends_with('\n') { println!(); }
println!("</post>");
diff --git a/server/src/api/rpc.rs b/server/src/api/rpc.rs
index afc4f95bef160c1e38ecff2c096d6440cd94e2b3..46d748f918d9b225acc4ecedfe5a1793089407b5 100644
--- a/server/src/api/rpc.rs
+++ b/server/src/api/rpc.rs
@@ -72,6 +72,80 @@ fn can_view_scope(reduced: &ReducerState, scope: &ScopeId, principal: Option<&st
}
}
+/// Build a feed in durable ingest order.
+///
+/// An implicit feed boundary is an ingest position, not only its millisecond timestamp. Two users
+/// can post in the same millisecond, and wall-clock timestamps can move backwards during replay.
+/// Explicit `since` remains a timestamp query for API compatibility, but scans the whole ordered
+/// ledger rather than assuming timestamps are monotonic.
+fn rpc_feed(
+ reduced: &ReducerState,
+ viewer: &str,
+ delegate: Option<String>,
+ requested_since: Option<i64>,
+ implicit_anchor: Option<(usize, i64)>,
+ limit: usize,
+) -> FeedResponse {
+ let since = requested_since.or_else(|| implicit_anchor.map(|(_, ts)| ts));
+ let implicit_anchor_index = requested_since
+ .is_none()
+ .then(|| implicit_anchor.map(|(index, _)| index))
+ .flatten();
+
+ let matching: Vec<&str> = reduced
+ .ingests_ordered
+ .iter()
+ .enumerate()
+ .rev()
+ .filter(|(index, id)| {
+ reduced.ingests_by_id.get(id.as_str()).is_some_and(|ing| {
+ match requested_since {
+ Some(cutoff) => ing.ts > cutoff,
+ None => implicit_anchor_index.is_none_or(|anchor| *index > anchor),
+ }
+ })
+ })
+ .map(|(_, id)| id.as_str())
+ .filter(|id| {
+ reduced.ingests_by_id.get(*id).is_some_and(|ing| {
+ let scope = scope_from_room_wire(&ing.room_id);
+ can_view_scope(reduced, &scope, Some(viewer))
+ })
+ })
+ .filter(|id| !reduced.redacted_posts.contains(*id))
+ .collect();
+
+ let total = matching.len();
+ let posts = matching
+ .into_iter()
+ .take(limit)
+ .filter_map(|id| reduced.ingests_by_id.get(id))
+ .map(|ing| {
+ let scope = scope_from_room_wire(&ing.room_id);
+ let thread_post_index = reduced.try_thread_post_index_chronological(
+ &scope,
+ &ing.thread_tag,
+ &ing.id,
+ );
+ FeedPost {
+ ts: ing.ts,
+ id: ing.id.clone(),
+ room: ing.room_id.clone(),
+ thread: Some(ing.thread_tag.clone()),
+ thread_post_index,
+ body: ing.raw.clone(),
+ }
+ })
+ .collect();
+
+ FeedResponse {
+ delegate,
+ since,
+ posts,
+ total,
+ }
+}
+
fn principal_from_optional_bearer(headers: &HeaderMap, reduced: &ReducerState) -> Result<Option<String>, RpcErr> {
if headers.contains_key(axum::http::header::AUTHORIZATION) {
verify_bearer_principal(headers, reduced)
@@ -1506,60 +1580,27 @@ pub async fn handle_rpc_batch(
Some("this delegate is not bound to your signed-in account".into()),
)
} else {
- let since_default = reduced
+ let implicit_anchor = reduced
.ingests_ordered
.iter()
+ .enumerate()
.rev()
- .filter_map(|id| reduced.ingests_by_id.get(id))
- .find(|ing| {
- if ing.delegate.as_deref() != Some(delegate_stored.as_str()) {
- return false;
- }
- let scope = scope_from_room_wire(&ing.room_id);
- can_view_scope(&reduced, &scope, Some(viewer.as_str()))
- })
- .map(|ing| ing.ts);
- let since = since.or(since_default);
- let cutoff = since.unwrap_or(0);
- let limit = limit.unwrap_or(DEFAULT_LIMIT).min(MAX_LIMIT);
- let matching: Vec<&str> = reduced.ingests_ordered.iter().rev()
- .map(|id| id.as_str())
- .take_while(|id| reduced.ingests_by_id.get(*id).is_some_and(|ing| ing.ts > cutoff))
- .filter(|id| {
- reduced.ingests_by_id.get(*id).is_some_and(|ing| {
- let scope = scope_from_room_wire(&ing.room_id);
- can_view_scope(&reduced, &scope, Some(viewer.as_str()))
+ .find_map(|(index, id)| {
+ reduced.ingests_by_id.get(id).and_then(|ing| {
+ (ing.delegate.as_deref()
+ == Some(delegate_stored.as_str()))
+ .then_some((index, ing.ts))
})
- })
- .filter(|id| !reduced.redacted_posts.contains(*id))
- .collect();
- let total = matching.len();
- let posts: Vec<FeedPost> = matching.into_iter()
- .take(limit)
- .filter_map(|id| reduced.ingests_by_id.get(id))
- .map(|ing| {
- let scope = scope_from_room_wire(&ing.room_id);
- let thread_post_index = reduced
- .try_thread_post_index_chronological(
- &scope,
- &ing.thread_tag,
- &ing.id,
- );
- FeedPost {
- ts: ing.ts,
- id: ing.id.clone(),
- thread: Some(ing.thread_tag.clone()),
- thread_post_index,
- body: ing.raw.clone(),
- }
- })
- .collect();
- line_ok(RpcResult::Feed(FeedResponse {
- delegate: Some(delegate_stored),
+ });
+ let limit = limit.unwrap_or(DEFAULT_LIMIT).min(MAX_LIMIT);
+ line_ok(RpcResult::Feed(rpc_feed(
+ &reduced,
+ &viewer,
+ Some(delegate_stored),
since,
- posts,
- total,
- }))
+ implicit_anchor,
+ limit,
+ )))
};
drop(reduced);
line
@@ -1567,60 +1608,25 @@ pub async fn handle_rpc_batch(
None => {
// Session catch-up: last time *you* posted anything (delegate or not), so revisiting
// an old chat with only a token still gets a sane cutoff.
- let since_default = reduced
+ let implicit_anchor = reduced
.ingests_ordered
.iter()
+ .enumerate()
.rev()
- .filter_map(|id| reduced.ingests_by_id.get(id))
- .find(|ing| {
- if ing.principal != viewer {
- return false;
- }
- let scope = scope_from_room_wire(&ing.room_id);
- can_view_scope(&reduced, &scope, Some(viewer.as_str()))
- })
- .map(|ing| ing.ts);
- let since = since.or(since_default);
- let cutoff = since.unwrap_or(0);
- let limit = limit.unwrap_or(DEFAULT_LIMIT).min(MAX_LIMIT);
- let matching: Vec<&str> = reduced.ingests_ordered.iter().rev()
- .map(|id| id.as_str())
- .take_while(|id| reduced.inges
… preview truncated; 14,758 characters omittedHardlinks — judgments / attempts / prompt
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