Replace HashMap and IndexMap with indexmap_amortized

This will hopefully get down latency.

aquatic_common/Cargo.toml

@@ -11,11 +11,12 @@ repository = "https://github.com/greatest-ape/aquatic"
 name = "aquatic_common"
 
 [dependencies]
+ahash = "0.7"
 anyhow = "1"
 arc-swap = "1"
 hashbrown = "0.11.2"
 hex = "0.4"
-indexmap = "1"
+indexmap-amortized = "1"
 log = "0.4"
 privdrop = "0.5"
 rand = { version = "0.8", features = ["small_rng"] }

aquatic_common/src/lib.rs

@@ -1,13 +1,15 @@
 use std::net::IpAddr;
 use std::time::{Duration, Instant};
 
-use indexmap::IndexMap;
+use ahash::RandomState;
 use rand::Rng;
 
 pub mod access_list;
 pub mod cpu_pinning;
 pub mod privileges;
 
+pub type AHashIndexMap<K, V> = indexmap_amortized::IndexMap<K, V, RandomState>;
+
 /// Peer or connection valid until this instant
 ///
 /// Used instead of "last seen" or similar to hopefully prevent arithmetic
@@ -32,7 +34,7 @@ impl ValidUntil {
 #[inline]
 pub fn extract_response_peers<K, V, R, F>(
     rng: &mut impl Rng,
-    peer_map: &IndexMap<K, V>,
+    peer_map: &AHashIndexMap<K, V>,
     max_num_peers_to_take: usize,
     sender_peer_map_key: K,
     peer_conversion_function: F,