From 72de632cb51ab1b7bde5b80dbebcd76361027f07 Mon Sep 17 00:00:00 2001
From: Brooks Prumo <brooks@solana.com>
Date: Mon, 4 Oct 2021 19:59:01 -0500
Subject: [PATCH] Add get_incremental_snapshot_hash_for_node() to gossip

Fixes #20377
---
 gossip/src/cluster_info.rs | 16 ++++++++++++++--
 gossip/src/crds_entry.rs   | 11 ++++++++++-
 gossip/src/crds_value.rs   |  8 ++++----
 3 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/gossip/src/cluster_info.rs b/gossip/src/cluster_info.rs
index 778f8319a93faf..00f930e8a171d2 100644
--- a/gossip/src/cluster_info.rs
+++ b/gossip/src/cluster_info.rs
@@ -23,8 +23,8 @@ use {
         crds_gossip_error::CrdsGossipError,
         crds_gossip_pull::{CrdsFilter, ProcessPullStats, CRDS_GOSSIP_PULL_CRDS_TIMEOUT_MS},
         crds_value::{
-            self, CrdsData, CrdsValue, CrdsValueLabel, EpochSlotsIndex, LowestSlot, NodeInstance,
-            SnapshotHashes, Version, Vote, MAX_WALLCLOCK,
+            self, CrdsData, CrdsValue, CrdsValueLabel, EpochSlotsIndex, IncrementalSnapshotHashes,
+            LowestSlot, NodeInstance, SnapshotHashes, Version, Vote, MAX_WALLCLOCK,
         },
         epoch_slots::EpochSlots,
         gossip_error::GossipError,
@@ -1115,6 +1115,18 @@ impl ClusterInfo {
         Some(map(hashes))
     }
 
+    pub fn get_incremental_snapshot_hash_for_node<F, Y>(&self, pubkey: &Pubkey, map: F) -> Option<Y>
+    where
+        F: FnOnce((&(Slot, Hash), &Vec<(Slot, Hash)>)) -> Y,
+    {
+        let gossip_crds = self.gossip.crds.read().unwrap();
+        let incremental_snapshot_hash = gossip_crds.get::<&IncrementalSnapshotHashes>(*pubkey)?;
+        Some(map((
+            &incremental_snapshot_hash.base,
+            &incremental_snapshot_hash.hashes,
+        )))
+    }
+
     /// Returns epoch-slots inserted since the given cursor.
     /// Excludes entries from nodes with unkown or different shred version.
     pub fn get_epoch_slots(&self, cursor: &mut Cursor) -> Vec<EpochSlots> {
diff --git a/gossip/src/crds_entry.rs b/gossip/src/crds_entry.rs
index 38b826b52aeaed..a3541ef3f3ecd5 100644
--- a/gossip/src/crds_entry.rs
+++ b/gossip/src/crds_entry.rs
@@ -3,7 +3,8 @@ use {
         contact_info::ContactInfo,
         crds::VersionedCrdsValue,
         crds_value::{
-            CrdsData, CrdsValue, CrdsValueLabel, LegacyVersion, LowestSlot, SnapshotHashes, Version,
+            CrdsData, CrdsValue, CrdsValueLabel, IncrementalSnapshotHashes, LegacyVersion,
+            LowestSlot, SnapshotHashes, Version,
         },
     },
     indexmap::IndexMap,
@@ -56,6 +57,11 @@ impl_crds_entry!(ContactInfo, CrdsData::ContactInfo(node), node);
 impl_crds_entry!(LegacyVersion, CrdsData::LegacyVersion(version), version);
 impl_crds_entry!(LowestSlot, CrdsData::LowestSlot(_, slot), slot);
 impl_crds_entry!(Version, CrdsData::Version(version), version);
+impl_crds_entry!(
+    IncrementalSnapshotHashes,
+    CrdsData::IncrementalSnapshotHashes(incremental_snapshot_hashes),
+    incremental_snapshot_hashes
+);
 
 impl<'a, 'b> CrdsEntry<'a, 'b> for &'a SnapshotHashes {
     type Key = Pubkey;
@@ -114,6 +120,9 @@ mod tests {
                 CrdsData::SnapshotHashes(hash) => {
                     assert_eq!(crds.get::<&SnapshotHashes>(key), Some(hash))
                 }
+                CrdsData::IncrementalSnapshotHashes(hash) => {
+                    assert_eq!(crds.get::<&IncrementalSnapshotHashes>(key), Some(hash))
+                }
                 _ => (),
             }
         }
diff --git a/gossip/src/crds_value.rs b/gossip/src/crds_value.rs
index d862572bc2bdab..85bae36d240ce1 100644
--- a/gossip/src/crds_value.rs
+++ b/gossip/src/crds_value.rs
@@ -209,10 +209,10 @@ impl SnapshotHashes {
 
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, AbiExample)]
 pub struct IncrementalSnapshotHashes {
-    from: Pubkey,
-    base: (Slot, Hash),
-    hashes: Vec<(Slot, Hash)>,
-    wallclock: u64,
+    pub(crate) from: Pubkey,
+    pub(crate) base: (Slot, Hash),
+    pub(crate) hashes: Vec<(Slot, Hash)>,
+    pub(crate) wallclock: u64,
 }
 
 impl Sanitize for IncrementalSnapshotHashes {