accounts-db: Use NoHashHasher in AccountStorageMap

`DashMap` uses SipHash by default. `AccountStorageMap` uses `Slot` as a
key and therefore it doesn't have any chance of collisions. We can skip
hashing the key entirely.

accounts-db/src/account_storage.rs

@@ -4,6 +4,7 @@ use {
     crate::accounts_db::{AccountStorageEntry, AccountsFileId},
     dashmap::DashMap,
     solana_clock::Slot,
+    solana_nohash_hasher::BuildNoHashHasher,
     std::sync::Arc,
 };
 
@@ -18,7 +19,7 @@ pub struct AccountStorageReference {
     pub id: AccountsFileId,
 }
 
-pub type AccountStorageMap = DashMap<Slot, AccountStorageReference>;
+pub type AccountStorageMap = DashMap<Slot, AccountStorageReference, BuildNoHashHasher<Slot>>;
 
 #[derive(Default, Debug)]
 pub struct AccountStorage {
@@ -27,7 +28,7 @@ pub struct AccountStorage {
     /// while shrink is operating on a slot, there can be 2 append vecs active for that slot
     /// Once the index has been updated to only refer to the new append vec, the single entry for the slot in 'map' can be updated.
     /// Entries in 'shrink_in_progress_map' can be found by 'get_account_storage_entry'
-    shrink_in_progress_map: DashMap<Slot, Arc<AccountStorageEntry>>,
+    shrink_in_progress_map: DashMap<Slot, Arc<AccountStorageEntry>, BuildNoHashHasher<Slot>>,
 }
 
 impl AccountStorage {
@@ -227,7 +228,7 @@ impl AccountStorage {
 
 /// iterate contents of AccountStorage without exposing internals
 pub struct AccountStorageIter<'a> {
-    iter: dashmap::iter::Iter<'a, Slot, AccountStorageReference>,
+    iter: dashmap::iter::Iter<'a, Slot, AccountStorageReference, BuildNoHashHasher<Slot>>,
 }
 
 impl<'a> AccountStorageIter<'a> {

runtime/src/bank/serde_snapshot.rs

@@ -21,6 +21,7 @@ mod tests {
             },
             stakes::{SerdeStakesToStakeFormat, Stakes, StakesEnum},
         },
+        ahash::RandomState as AHashRandomState,
         solana_accounts_db::{
             account_storage::{AccountStorageMap, AccountStorageReference},
             accounts_db::{
@@ -53,7 +54,10 @@ mod tests {
         storage_access: StorageAccess,
     ) -> Result<StorageAndNextAccountsFileId, AccountsFileError> {
         let storage_entries = accounts_db.get_storages(RangeFull).0;
-        let storage: AccountStorageMap = AccountStorageMap::with_capacity(storage_entries.len());
+        let storage: AccountStorageMap = AccountStorageMap::with_capacity_and_hasher(
+            storage_entries.len(),
+            AHashRandomState::new(),
+        );
         let mut next_append_vec_id = 0;
         for storage_entry in storage_entries.into_iter() {
             // Copy file to new directory

runtime/src/serde_snapshot/tests.rs

@@ -9,6 +9,7 @@ mod serde_snapshot_tests {
             },
             snapshot_utils::{get_storages_to_serialize, StorageAndNextAccountsFileId},
         },
+        ahash::RandomState as AHashRandomState,
         bincode::{serialize_into, Error},
         log::info,
         rand::{thread_rng, Rng},
@@ -133,7 +134,10 @@ mod serde_snapshot_tests {
         storage_access: StorageAccess,
     ) -> Result<StorageAndNextAccountsFileId, AccountsFileError> {
         let storage_entries = accounts_db.get_storages(RangeFull).0;
-        let storage: AccountStorageMap = AccountStorageMap::with_capacity(storage_entries.len());
+        let storage: AccountStorageMap = AccountStorageMap::with_capacity_and_hasher(
+            storage_entries.len(),
+            AHashRandomState::new(),
+        );
         let mut next_append_vec_id = 0;
         for storage_entry in storage_entries.into_iter() {
             // Copy file to new directory

runtime/src/snapshot_utils/snapshot_storage_rebuilder.rs

@@ -6,6 +6,7 @@ use {
         self, reconstruct_single_storage, remap_and_reconstruct_single_storage,
         snapshot_storage_lengths_from_fields, SerializedAccountsFileId,
     },
+    ahash::RandomState as AHashRandomState,
     crossbeam_channel::{select, unbounded, Receiver, Sender},
     dashmap::DashMap,
     log::*,
@@ -118,7 +119,10 @@ impl SnapshotStorageRebuilder {
         snapshot_from: SnapshotFrom,
         storage_access: StorageAccess,
     ) -> Self {
-        let storage = DashMap::with_capacity(snapshot_storage_lengths.len());
+        let storage = DashMap::with_capacity_and_hasher(
+            snapshot_storage_lengths.len(),
+            AHashRandomState::new(),
+        );
         let storage_paths: DashMap<_, _> = snapshot_storage_lengths
             .iter()
             .map(|(slot, storage_lengths)| {