defines alias for Fn(&ContactInfo) -> R trait

anza-xyz#4391
adds type parameter to ContactInfo.cache but we don't want to expose
that to outside of gossip crate.

In order to encapsulate that change in gossip crate, this commit adds an
alias for:
    Fn(&ContactInfo) -> R
which can be used outside of gossip crate.

core/src/banking_simulation.rs

@@ -19,7 +19,7 @@ use {
     solana_client::connection_cache::ConnectionCache,
     solana_gossip::{
         cluster_info::{ClusterInfo, Node},
-        contact_info::ContactInfo,
+        contact_info::ContactInfoQuery,
     },
     solana_ledger::{
         blockstore::{Blockstore, PurgeType},
@@ -250,7 +250,7 @@ impl LikeClusterInfo for Arc<DummyClusterInfo> {
 
     fn lookup_contact_info<F, Y>(&self, _id: &Pubkey, _map: F) -> Option<Y>
     where
-        F: FnOnce(&ContactInfo) -> Y,
+        F: ContactInfoQuery<Y>,
     {
         None
     }

core/src/banking_stage.rs

@@ -31,7 +31,7 @@ use {
     crossbeam_channel::{unbounded, Receiver, RecvTimeoutError, Sender},
     histogram::Histogram,
     solana_client::connection_cache::ConnectionCache,
-    solana_gossip::{cluster_info::ClusterInfo, contact_info::ContactInfo},
+    solana_gossip::{cluster_info::ClusterInfo, contact_info::ContactInfoQuery},
     solana_ledger::blockstore_processor::TransactionStatusSender,
     solana_measure::measure_us,
     solana_perf::{data_budget::DataBudget, packet::PACKETS_PER_BATCH},
@@ -330,7 +330,7 @@ pub trait LikeClusterInfo: Send + Sync + 'static + Clone {
 
     fn lookup_contact_info<F, Y>(&self, id: &Pubkey, map: F) -> Option<Y>
     where
-        F: FnOnce(&ContactInfo) -> Y;
+        F: ContactInfoQuery<Y>;
 }
 
 impl LikeClusterInfo for Arc<ClusterInfo> {
@@ -340,7 +340,7 @@ impl LikeClusterInfo for Arc<ClusterInfo> {
 
     fn lookup_contact_info<F, Y>(&self, id: &Pubkey, map: F) -> Option<Y>
     where
-        F: FnOnce(&ContactInfo) -> Y,
+        F: ContactInfoQuery<Y>,
     {
         self.deref().lookup_contact_info(id, map)
     }

core/src/next_leader.rs

@@ -3,7 +3,7 @@ use {
     itertools::Itertools,
     solana_gossip::{
         cluster_info::ClusterInfo,
-        contact_info::{ContactInfo, Protocol},
+        contact_info::{ContactInfoQuery, Protocol},
     },
     solana_poh::poh_recorder::PohRecorder,
     solana_sdk::{clock::FORWARD_TRANSACTIONS_TO_LEADER_AT_SLOT_OFFSET, pubkey::Pubkey},
@@ -45,14 +45,11 @@ pub(crate) fn next_leader_tpu_vote(
     })
 }
 
-pub(crate) fn next_leader<F>(
+pub(crate) fn next_leader(
     cluster_info: &impl LikeClusterInfo,
     poh_recorder: &RwLock<PohRecorder>,
-    port_selector: F,
-) -> Option<(Pubkey, SocketAddr)>
-where
-    F: FnOnce(&ContactInfo) -> Option<SocketAddr>,
-{
+    port_selector: impl ContactInfoQuery<Option<SocketAddr>>,
+) -> Option<(Pubkey, SocketAddr)> {
     let leader_pubkey = poh_recorder
         .read()
         .unwrap()

core/src/warm_quic_cache_service.rs

@@ -5,7 +5,7 @@ use {
     rand::{thread_rng, Rng},
     solana_client::connection_cache::{ConnectionCache, Protocol},
     solana_connection_cache::client_connection::ClientConnection as TpuConnection,
-    solana_gossip::{cluster_info::ClusterInfo, contact_info::ContactInfo},
+    solana_gossip::{cluster_info::ClusterInfo, contact_info::ContactInfoQuery},
     solana_poh::poh_recorder::PohRecorder,
     solana_pubkey::Pubkey,
     std::{
@@ -32,7 +32,7 @@ impl WarmQuicCacheService {
         cache: Option<&ConnectionCache>,
         cluster_info: &ClusterInfo,
         leader_pubkey: &Pubkey,
-        contact_info_selector: impl Fn(&ContactInfo) -> Option<SocketAddr>,
+        contact_info_selector: impl ContactInfoQuery<Option<SocketAddr>>,
         log_context: &str,
     ) {
         if let Some(connection_cache) = cache {

gossip/src/cluster_info.rs

@@ -18,7 +18,7 @@ use {
         cluster_info_metrics::{
             submit_gossip_stats, Counter, GossipStats, ScopedTimer, TimedGuard,
         },
-        contact_info::{self, ContactInfo, Error as ContactInfoError},
+        contact_info::{self, ContactInfo, ContactInfoQuery, Error as ContactInfoError},
         crds::{Crds, Cursor, GossipRoute},
         crds_data::{
             self, CrdsData, EpochSlotsIndex, LowestSlot, NodeInstance, SnapshotHashes, Version,
@@ -466,7 +466,7 @@ impl ClusterInfo {
 
     pub fn lookup_contact_info<F, Y>(&self, id: &Pubkey, map: F) -> Option<Y>
     where
-        F: FnOnce(&ContactInfo) -> Y,
+        F: ContactInfoQuery<Y>,
     {
         let gossip_crds = self.gossip.crds.read().unwrap();
         gossip_crds.get(*id).map(map)
@@ -1112,7 +1112,7 @@ impl ClusterInfo {
     }
 
     /// all validators that have a valid tvu port and are on the same `shred_version`.
-    pub fn tvu_peers<R>(&self, query: impl Fn(&ContactInfo) -> R) -> Vec<R> {
+    pub fn tvu_peers<R>(&self, query: impl ContactInfoQuery<R>) -> Vec<R> {
         let self_pubkey = self.id();
         let self_shred_version = self.my_shred_version();
         self.time_gossip_read_lock("tvu_peers", &self.stats.tvu_peers)

gossip/src/contact_info.rs

@@ -42,6 +42,11 @@ const SOCKET_TAG_TVU_QUIC: u8 = 11;
 const_assert_eq!(SOCKET_CACHE_SIZE, 13);
 const SOCKET_CACHE_SIZE: usize = SOCKET_TAG_TPU_VOTE_QUIC as usize + 1usize;
 
+// An alias for a function that reads data from a ContactInfo entry stored in
+// the gossip CRDS table.
+pub trait ContactInfoQuery<R>: Fn(&ContactInfo) -> R {}
+impl<R, F: Fn(&ContactInfo) -> R> ContactInfoQuery<R> for F {}
+
 #[derive(Copy, Clone, Debug, Eq, Error, PartialEq)]
 pub enum Error {
     #[error("Duplicate IP address: {0}")]