From a72f1753af9d16476871e624a11fdbe26dbc1c74 Mon Sep 17 00:00:00 2001
From: Jelmer van der Linde <jelmer@ikhoefgeen.nl>
Date: Mon, 3 Jul 2023 16:22:11 +0100
Subject: [PATCH 1/2] Add `Reserve()` method to `AutoProbing`

An implementation that's not re-allocating in a while loop is left as an exercise to the reader
---
 util/probing_hash_table.hh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/util/probing_hash_table.hh b/util/probing_hash_table.hh
index c1965b4..eae3f78 100644
--- a/util/probing_hash_table.hh
+++ b/util/probing_hash_table.hh
@@ -393,10 +393,19 @@ template <class EntryT, class HashT, class EqualT = std::equal_to<typename Entry
       return backend_.RawEnd();
     }
 
+    void Reserve(size_t capacity) {
+      while (threshold_ < capacity)
+        Double();
+    }
+
   private:
     void DoubleIfNeeded() {
       if (UTIL_LIKELY(Size() < threshold_))
         return;
+      Double();
+    }
+
+    void Double() {
       HugeRealloc(backend_.DoubleTo(), KeyIsRawZero(backend_.invalid_), mem_);
       allocated_ = backend_.DoubleTo();
       backend_.Double(mem_.get(), !KeyIsRawZero(backend_.invalid_));

From c7f11998ec051fbdcdc3e3e1f0fcbb58d3edc39d Mon Sep 17 00:00:00 2001
From: Jelmer van der Linde <jelmer@ikhoefgeen.nl>
Date: Mon, 3 Jul 2023 16:23:10 +0100
Subject: [PATCH 2/2] Make `AutoProbing` move-assignable

---
 util/mmap.hh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/util/mmap.hh b/util/mmap.hh
index cd35eff..a8f8f43 100644
--- a/util/mmap.hh
+++ b/util/mmap.hh
@@ -82,6 +82,14 @@ class scoped_memory {
       : data_(from.data_), size_(from.size_), source_(from.source_) {
       from.steal();
     }
+
+    scoped_memory &operator=(scoped_memory &&from) noexcept {
+      reset();
+      size_ = from.size_;
+      source_ = from.source_;
+      data_ = from.steal();
+      return *this;
+    }
 #endif
 
     ~scoped_memory() { reset(); }