From 52de97e28072cdb02958efe4cc0b2f0104f54ba9 Mon Sep 17 00:00:00 2001
From: Brooks Prumo <brooks@solana.com>
Date: Tue, 21 Sep 2021 15:09:04 -0500
Subject: [PATCH] Add type alias for Uid (#20075)

---
 bucket_map/src/bucket.rs         |  4 ++--
 bucket_map/src/bucket_storage.rs | 20 +++++++++++---------
 bucket_map/src/index_entry.rs    |  4 ++--
 3 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/bucket_map/src/bucket.rs b/bucket_map/src/bucket.rs
index 5a91bcf8f..bb646fb29 100644
--- a/bucket_map/src/bucket.rs
+++ b/bucket_map/src/bucket.rs
@@ -1,7 +1,7 @@
 use crate::bucket_item::BucketItem;
 use crate::bucket_map::BucketMapError;
 use crate::bucket_stats::BucketMapStats;
-use crate::bucket_storage::{BucketStorage, UID_UNLOCKED};
+use crate::bucket_storage::{BucketStorage, Uid, UID_UNLOCKED};
 use crate::index_entry::IndexEntry;
 use crate::{MaxSearch, RefCount};
 use rand::thread_rng;
@@ -141,7 +141,7 @@ impl<T: Clone + Copy> Bucket<T> {
     fn bucket_create_key(
         index: &BucketStorage,
         key: &Pubkey,
-        elem_uid: u64,
+        elem_uid: Uid,
         random: u64,
         ref_count: u64,
     ) -> Result<u64, BucketMapError> {
diff --git a/bucket_map/src/bucket_storage.rs b/bucket_map/src/bucket_storage.rs
index 59bd3e534..2a68cdb5c 100644
--- a/bucket_map/src/bucket_storage.rs
+++ b/bucket_map/src/bucket_storage.rs
@@ -31,25 +31,27 @@ use std::sync::Arc;
 */
 const DEFAULT_CAPACITY_POW2: u8 = 5;
 
+/// A Header UID of 0 indicates that the header is unlocked
+pub(crate) const UID_UNLOCKED: Uid = 0;
+
+pub(crate) type Uid = u64;
+
 #[repr(C)]
 struct Header {
     lock: AtomicU64,
 }
 
-/// A Header UID of 0 indicates that the header is unlocked
-pub(crate) const UID_UNLOCKED: u64 = 0;
-
 impl Header {
-    fn try_lock(&self, uid: u64) -> bool {
+    fn try_lock(&self, uid: Uid) -> bool {
         Ok(UID_UNLOCKED)
             == self
                 .lock
                 .compare_exchange(UID_UNLOCKED, uid, Ordering::Acquire, Ordering::Relaxed)
     }
-    fn unlock(&self) -> u64 {
+    fn unlock(&self) -> Uid {
         self.lock.swap(UID_UNLOCKED, Ordering::Release)
     }
-    fn uid(&self) -> u64 {
+    fn uid(&self) -> Uid {
         self.lock.load(Ordering::Relaxed)
     }
 }
@@ -120,7 +122,7 @@ impl BucketStorage {
         )
     }
 
-    pub fn uid(&self, ix: u64) -> u64 {
+    pub fn uid(&self, ix: u64) -> Uid {
         if ix >= self.num_cells() {
             panic!("bad index size");
         }
@@ -132,7 +134,7 @@ impl BucketStorage {
         }
     }
 
-    pub fn allocate(&self, ix: u64, uid: u64) -> Result<(), BucketStorageError> {
+    pub fn allocate(&self, ix: u64, uid: Uid) -> Result<(), BucketStorageError> {
         if ix >= self.num_cells() {
             panic!("allocate: bad index size");
         }
@@ -153,7 +155,7 @@ impl BucketStorage {
         e
     }
 
-    pub fn free(&self, ix: u64, uid: u64) {
+    pub fn free(&self, ix: u64, uid: Uid) {
         if ix >= self.num_cells() {
             panic!("free: bad index size");
         }
diff --git a/bucket_map/src/index_entry.rs b/bucket_map/src/index_entry.rs
index fd9ac23f0..492eff100 100644
--- a/bucket_map/src/index_entry.rs
+++ b/bucket_map/src/index_entry.rs
@@ -1,5 +1,5 @@
 use crate::bucket::Bucket;
-use crate::bucket_storage::BucketStorage;
+use crate::bucket_storage::{BucketStorage, Uid};
 use crate::RefCount;
 use solana_sdk::clock::Slot;
 use solana_sdk::pubkey::Pubkey;
@@ -54,7 +54,7 @@ impl IndexEntry {
         };
         Some((slice, self.ref_count))
     }
-    pub fn key_uid(key: &Pubkey) -> u64 {
+    pub fn key_uid(key: &Pubkey) -> Uid {
         let mut s = DefaultHasher::new();
         key.hash(&mut s);
         s.finish().max(1u64)