hashing: give hash values a name

This will make it easier and safer to try out different hashing schemes.

This is a mostly mechanical replacement of `uint32_t` with `HashValue`.

The latter is currently a type alias but will change to a wrapper struct
for better type safety and to avoid some useless overhashing.

PiperOrigin-RevId: 502360037
Change-Id: I093133abef810713009f6fb34a085b65a7ba0ce1

1 files changed, 4 insertions, 3 deletions

diff --git a/equality_cache.h b/equality_cache.h
index 377efa6..dcd5ef2 100644
--- a/equality_cache.h
+++ b/equality_cache.h
@@ -26,6 +26,7 @@
 
 #include "equality.h"
 #include "graph.h"
+#include "hashing.h"
 #include "metrics.h"
 
 namespace stg {
@@ -43,8 +44,8 @@ namespace stg {
 // Node hashes such as those generated by the Fingerprint function object may be
 // supplied to avoid equality testing when hashes differ.
 struct EqualityCache {
-  EqualityCache(const std::unordered_map<Id, uint32_t>& hashes,
-                    Metrics& metrics)
+  EqualityCache(const std::unordered_map<Id, HashValue>& hashes,
+                Metrics& metrics)
       : hashes(hashes),
         query_count(metrics, "cache.query_count"),
         query_equal_ids(metrics, "cache.query_equal_ids"),
@@ -200,7 +201,7 @@ struct EqualityCache {
     }
   }
 
-  const std::unordered_map<Id, uint32_t>& hashes;
+  const std::unordered_map<Id, HashValue>& hashes;
   std::unordered_map<Id, Id> mapping;
   std::unordered_map<Id, size_t> rank;
   std::unordered_map<Id, std::unordered_set<Id>> inequalities;