From f8baf2a2a9f5a026435ccb65826f676865858cd3 Mon Sep 17 00:00:00 2001 From: Arik Sosman Date: Tue, 27 Jun 2023 15:58:12 -0400 Subject: [PATCH] Send reminders for stale-ish channels. --- src/config.rs | 4 ++ src/lib.rs | 2 +- src/lookup.rs | 89 +++++++++++++++++++++++++++++++++++++++----- src/serialization.rs | 28 +++++++++++++- 4 files changed, 111 insertions(+), 12 deletions(-) diff --git a/src/config.rs b/src/config.rs index bf5a171..acf7ac9 100644 --- a/src/config.rs +++ b/src/config.rs @@ -16,6 +16,10 @@ use tokio_postgres::Config; pub(crate) const SCHEMA_VERSION: i32 = 8; pub(crate) const SNAPSHOT_CALCULATION_INTERVAL: u32 = 3600 * 24; // every 24 hours, in seconds +/// If the last update in either direction was more than six days ago, we send a reminder +/// That reminder may be either in the form of a channel announcement, or in the form of empty +/// updates in both directions. +pub(crate) const CHANNEL_REMINDER_AGE: u32 = 6 * 24 * 3600; pub(crate) const DOWNLOAD_NEW_GOSSIP: bool = true; pub(crate) fn network() -> Network { diff --git a/src/lib.rs b/src/lib.rs index cd91a4e..c6f266d 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -213,7 +213,7 @@ async fn serialize_delta(network_graph: Arc>, last_sync UpdateSerializationMechanism::Full => { update_count_full += 1; } - UpdateSerializationMechanism::Incremental(_) => { + UpdateSerializationMechanism::Incremental(_) | UpdateSerializationMechanism::Reminder => { update_count_incremental += 1; } }; diff --git a/src/lookup.rs b/src/lookup.rs index fbd89fa..ce3f40c 100644 --- a/src/lookup.rs +++ b/src/lookup.rs @@ -31,17 +31,25 @@ pub(super) struct DirectedUpdateDelta { pub(super) last_update_before_seen: Option, pub(super) mutated_properties: MutatedProperties, pub(super) latest_update_after_seen: Option, + pub(super) serialization_update_flags: Option, } pub(super) struct ChannelDelta { pub(super) announcement: Option, pub(super) updates: (Option, Option), - pub(super) first_update_seen: Option, + pub(super) first_bidirectional_updates_seen: Option, + /// The seen timestamp of the older of the two latest directional updates + pub(super) requires_reminder: bool, } impl Default for ChannelDelta { fn default() -> Self { - Self { announcement: None, updates: (None, None), first_update_seen: None } + Self { + announcement: None, + updates: (None, None), + first_bidirectional_updates_seen: None, + requires_reminder: false, + } } } @@ -51,6 +59,7 @@ impl Default for DirectedUpdateDelta { last_update_before_seen: None, mutated_properties: MutatedProperties::default(), latest_update_after_seen: None, + serialization_update_flags: None } } } @@ -63,9 +72,8 @@ pub(super) async fn connect_to_db() -> (Client, Connection) /// Fetch all the channel announcements that are presently in the network graph, regardless of /// whether they had been seen before. /// Also include all announcements for which the first update was announced -/// after `last_syc_timestamp` +/// after `last_sync_timestamp` pub(super) async fn fetch_channel_announcements(delta_set: &mut DeltaSet, network_graph: Arc>, client: &Client, last_sync_timestamp: u32) { - let last_sync_timestamp_object = SystemTime::UNIX_EPOCH.add(Duration::from_secs(last_sync_timestamp as u64)); println!("Obtaining channel ids from network graph"); let channel_ids = { let read_only_graph = network_graph.read_only(); @@ -124,13 +132,76 @@ pub(super) async fn fetch_channel_announcements(delta_set: &mut DeltaSet, networ let current_seen_timestamp_object: SystemTime = current_row.get("seen"); let current_seen_timestamp: u32 = current_seen_timestamp_object.duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs() as u32; - if (current_seen_timestamp > last_sync_timestamp) { + if current_seen_timestamp > last_sync_timestamp { // the newer of the two oldest seen directional updates came after last sync timestamp let current_channel_delta = delta_set.entry(scid).or_insert(ChannelDelta::default()); // first time a channel was seen in both directions (*current_channel_delta).first_bidirectional_updates_seen = Some(current_seen_timestamp); } } + + println!("Annotating channel announcements whose latest channel update in a given direction occurred more than six days ago"); + /// Steps: + /// — Obtain all updates, distinct by (scid, direction), ordered by seen DESC + /// — From those updates, select distinct by (scid), ordered by seen ASC (to obtain the older one per direction) + let current_timestamp = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs() as u32; + let reminder_threshold_timestamp = current_timestamp.saturating_sub(config::CHANNEL_REMINDER_AGE); + let mut channels_requiring_reminders: Vec = vec![]; + + let older_latest_directional_updates = client.query(" + SELECT DISTINCT ON (short_channel_id) * + FROM ( + SELECT DISTINCT ON (short_channel_id, direction) * + FROM channel_updates + WHERE short_channel_id = any($1) + ORDER BY short_channel_id ASC, direction ASC, seen DESC + ) AS directional_last_seens + ORDER BY short_channel_id ASC, seen ASC + ", &[&channel_ids]).await.unwrap(); + + for current_row in older_latest_directional_updates { + let blob: Vec = current_row.get("blob_signed"); + let mut readable = Cursor::new(blob); + let unsigned_update = ChannelUpdate::read(&mut readable).unwrap().contents; + let scid = unsigned_update.short_channel_id; + let current_seen_timestamp_object: SystemTime = current_row.get("seen"); + let current_seen_timestamp: u32 = current_seen_timestamp_object.duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs() as u32; + + if current_seen_timestamp <= reminder_threshold_timestamp { + // annotate this channel as requiring that reminders be sent to the client + let current_channel_delta = delta_set.entry(scid).or_insert(ChannelDelta::default()); + + // way might be able to get away with not using this + (*current_channel_delta).requires_reminder = true; + + // get the latest seen update in both directions for this channel + channels_requiring_reminders.push(scid as i64); + } + } + + println!("Fetching latest update data for channels requiring reminders"); + let latest_reminder_updates = client.query(" + SELECT DISTINCT ON (short_channel_id, direction) * + FROM channel_updates + WHERE short_channel_id = any($1) + ORDER BY short_channel_id ASC, direction ASC, seen DESC + ", &[&channels_requiring_reminders]).await.unwrap(); + + for current_update in latest_reminder_updates { + let blob: Vec = current_update.get("blob_signed"); + let mut readable = Cursor::new(blob); + let unsigned_update = ChannelUpdate::read(&mut readable).unwrap().contents; + let scid = unsigned_update.short_channel_id; + let direction: bool = current_update.get("direction"); + + let current_channel_delta = delta_set.entry(scid).or_insert(ChannelDelta::default()); + let update_delta = if !direction { + (*current_channel_delta).updates.0.get_or_insert(DirectedUpdateDelta::default()) + } else { + (*current_channel_delta).updates.1.get_or_insert(DirectedUpdateDelta::default()) + }; + update_delta.serialization_update_flags = Some(unsigned_update.flags); + } } pub(super) async fn fetch_channel_updates(delta_set: &mut DeltaSet, client: &Client, last_sync_timestamp: u32, consider_intermediate_updates: bool) { @@ -233,7 +304,7 @@ pub(super) async fn fetch_channel_updates(delta_set: &mut DeltaSet, client: &Cli } // determine mutations - if let Some(last_seen_update) = update_delta.last_update_before_seen.as_ref(){ + if let Some(last_seen_update) = update_delta.last_update_before_seen.as_ref() { if unsigned_channel_update.flags != last_seen_update.flags { update_delta.mutated_properties.flags = true; } @@ -253,7 +324,6 @@ pub(super) async fn fetch_channel_updates(delta_set: &mut DeltaSet, client: &Cli update_delta.mutated_properties.htlc_maximum_msat = true; } } - } println!("Processed intermediate rows ({}) (delta size: {}): {:?}", intermediate_update_count, delta_set.len(), start.elapsed()); } @@ -276,13 +346,14 @@ pub(super) fn filter_delta_set(delta_set: &mut DeltaSet) { let update_reference = update.as_ref().unwrap(); // update_reference.latest_update_after_seen.is_some() && !update_reference.intermediate_updates.is_empty() // if there has been an update after the channel was first seen - update_reference.latest_update_after_seen.is_some() + + v.requires_reminder || update_reference.latest_update_after_seen.is_some() }; let direction_a_meets_criteria = update_meets_criteria(&v.updates.0); let direction_b_meets_criteria = update_meets_criteria(&v.updates.1); - if !direction_a_meets_criteria && !direction_b_meets_criteria { + if !v.requires_reminder && !direction_a_meets_criteria && !direction_b_meets_criteria { delta_set.remove(&k); } } diff --git a/src/serialization.rs b/src/serialization.rs index f7db29d..1ab410a 100644 --- a/src/serialization.rs +++ b/src/serialization.rs @@ -79,6 +79,7 @@ impl MutatedProperties { pub(super) enum UpdateSerializationMechanism { Full, Incremental(MutatedProperties), + Reminder, } struct FullUpdateValueHistograms { @@ -127,7 +128,7 @@ pub(super) fn serialize_delta_set(delta_set: DeltaSet, last_sync_timestamp: u32) let current_announcement_seen = channel_announcement_delta.seen; let is_new_announcement = current_announcement_seen >= last_sync_timestamp; - let is_newly_updated_announcement = if let Some(first_update_seen) = channel_delta.first_update_seen { + let is_newly_updated_announcement = if let Some(first_update_seen) = channel_delta.first_bidirectional_updates_seen { first_update_seen >= last_sync_timestamp } else { false @@ -176,8 +177,26 @@ pub(super) fn serialize_delta_set(delta_set: DeltaSet, last_sync_timestamp: u32) mechanism: UpdateSerializationMechanism::Full, }); } + } else if let Some(flags) = updates.serialization_update_flags { + // we need to insert a fake channel update where the only information + let fake_update = UnsignedChannelUpdate { + flags, + chain_hash: BlockHash::all_zeros(), + short_channel_id: 0, + cltv_expiry_delta: 0, + fee_base_msat: 0, + fee_proportional_millionths: 0, + htlc_maximum_msat: 0, + htlc_minimum_msat: 0, + timestamp: 0, + excess_data: Vec::with_capacity(0), + }; + serialization_set.updates.push(UpdateSerialization { + update: fake_update, + mechanism: UpdateSerializationMechanism::Reminder + }) } - }; + } }; categorize_directed_update_serialization(direction_a_updates); @@ -282,6 +301,11 @@ pub(super) fn serialize_stripped_channel_update(update: &UpdateSerialization, de serialized_flags |= 0b_0000_0100; latest_update.htlc_maximum_msat.write(&mut delta_serialization).unwrap(); } + }, + + UpdateSerializationMechanism::Reminder => { + // indicate that this update is incremental + serialized_flags |= 0b_1000_0000; } } let scid_delta = BigSize(latest_update.short_channel_id - previous_scid); -- 2.30.2