Enable usage of wider/custom keys

crocdialer · Sep 29, 2024 · 52b6704 · 52b6704
1 parent 9269f30
commit 52b6704
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Showing 2 changed files with 28 additions and 7 deletions.
diff --git a/include/vierkant/linear_hashmap.hpp b/include/vierkant/linear_hashmap.hpp
@@ -49,7 +49,7 @@ class linear_hashmap
     inline void clear()
     {
         storage_item_t *ptr = m_storage.get(), *end = ptr + m_capacity;
-        for(; ptr != end; ++ptr) { ptr->key = 0; }
+        for(; ptr != end; ++ptr) { ptr->key = key_t(); }
     }
 
     value_t &put(const key_t &key, value_t value)
@@ -68,10 +68,10 @@ class linear_hashmap
             if(probed_key != key)
             {
                 // hit another entry, keep searching
-                if(probed_key != 0) { continue; }
+                if(probed_key != key_t()) { continue; }
 
                 item.key.compare_exchange_strong(probed_key, key, std::memory_order_relaxed, std::memory_order_relaxed);
-                if(probed_key && probed_key != key)
+                if((probed_key != key_t()) && (probed_key != key))
                 {
                     // another thread just stole it
                     continue;
@@ -91,7 +91,7 @@ class linear_hashmap
         {
             idx &= m_capacity - 1;
             auto &item = m_storage[idx];
-            if(!item.key) { return {}; }
+            if(item.key == key_t()) { return {}; }
             else if(key == item.key) { return item.value; }
         }
     }
@@ -124,7 +124,7 @@ class linear_hashmap
     }
 
 private:
-    struct alignas(16) storage_item_t
+    struct storage_item_t
     {
         std::atomic<key_t> key;
         value_t value{};

diff --git a/tests/TestLinearHashmap.cpp b/tests/TestLinearHashmap.cpp
@@ -36,9 +36,30 @@ TEST(linear_hashmap, basic)
     EXPECT_EQ(hashmap.get(69), 99);
     EXPECT_TRUE(hashmap.contains(13));
     EXPECT_EQ(hashmap.get(13), 12);
+}
+
+TEST(linear_hashmap, custom_key)
+{
+    // custom 32-byte key
+    struct custom_key_t
+    {
+        int v[8]{};
+        constexpr bool operator==(const custom_key_t &other) const
+        {
+            for(uint32_t i = 0; i < 8; ++i)
+            {
+                if(v[i] != other.v[i]) { return false; }
+            }
+            return true;
+        }
+    };
+    constexpr uint32_t test_capacity = 100;
+    auto hashmap = vierkant::linear_hashmap<custom_key_t, uint64_t>(test_capacity);
 
-    vierkant::linear_hashmap<uint64_t, uint64_t> other_map;
-    other_map = vierkant::linear_hashmap<uint64_t, uint64_t>(19);
+    custom_key_t k1{{1, 2, 3, 4, 5, 6, 7, 8}};
+    hashmap.put(k1, 69);
+    EXPECT_TRUE(hashmap.contains(k1));
+    EXPECT_FALSE(hashmap.contains(custom_key_t()));
 }
 
 TEST(linear_hashmap, resize)