Merge 5cce4d293e into merged_master (Bitcoin PR bitcoin/bitcoin#27334)

src/bench/prevector.cpp

@@ -80,6 +80,30 @@ static void PrevectorDeserialize(benchmark::Bench& bench)
     });
 }
 
+template <typename T>
+static void PrevectorFillVectorDirect(benchmark::Bench& bench)
+{
+    bench.run([&] {
+        std::vector<prevector<28, T>> vec;
+        for (size_t i = 0; i < 260; ++i) {
+            vec.emplace_back();
+        }
+    });
+}
+
+
+template <typename T>
+static void PrevectorFillVectorIndirect(benchmark::Bench& bench)
+{
+    bench.run([&] {
+        std::vector<prevector<28, T>> vec;
+        for (size_t i = 0; i < 260; ++i) {
+            // force allocation
+            vec.emplace_back(29, T{});
+        }
+    });
+}
+
 #define PREVECTOR_TEST(name)                                         \
     static void Prevector##name##Nontrivial(benchmark::Bench& bench) \
     {                                                                \
@@ -96,3 +120,5 @@ PREVECTOR_TEST(Clear)
 PREVECTOR_TEST(Destructor)
 PREVECTOR_TEST(Resize)
 PREVECTOR_TEST(Deserialize)
+PREVECTOR_TEST(FillVectorDirect)
+PREVECTOR_TEST(FillVectorIndirect)

src/prevector.h

@@ -264,8 +264,10 @@ public:
         fill(item_ptr(0), other.begin(),  other.end());
     }
 
-    prevector(prevector<N, T, Size, Diff>&& other) {
-        swap(other);
+    prevector(prevector<N, T, Size, Diff>&& other) noexcept
+        : _union(std::move(other._union)), _size(other._size)
+    {
+        other._size = 0;
     }
 
     prevector& operator=(const prevector<N, T, Size, Diff>& other) {
@@ -276,8 +278,13 @@ public:
         return *this;
     }
 
-    prevector& operator=(prevector<N, T, Size, Diff>&& other) {
-        swap(other);
+    prevector& operator=(prevector<N, T, Size, Diff>&& other) noexcept {
+        if (!is_direct()) {
+            free(_union.indirect_contents.indirect);
+        }
+        _union = std::move(other._union);
+        _size = other._size;
+        other._size = 0;
         return *this;
     }
 

src/validation.h

@@ -44,6 +44,7 @@
 #include <stdint.h>
 #include <string>
 #include <thread>
+#include <type_traits>
 #include <utility>
 #include <vector>
 
@@ -339,6 +340,11 @@ public:
     ScriptError GetScriptError() const { return error; }
 };
 
+// CScriptCheck is used a lot in std::vector, make sure that's efficient
+static_assert(std::is_nothrow_move_assignable_v<CScriptCheck>);
+static_assert(std::is_nothrow_move_constructible_v<CScriptCheck>);
+static_assert(std::is_nothrow_destructible_v<CScriptCheck>);
+
 /** Initializes the script-execution cache */
 [[nodiscard]] bool InitScriptExecutionCache(size_t max_size_bytes);