Add bulkFirstGeq benchmark

Bench.cpp

@@ -1,4 +1,5 @@
 #include "Facade.h"
+#include "Internal.h"
 
 #include <nanobench.h>
 
@@ -55,8 +56,49 @@ void monotonicallyIncreasing() {
   });
 
   bench.run("end", [&] { facade.versioned.end(v); });
-
-  // TODO benchmark reads
 }
 
-int main() { monotonicallyIncreasing(); }
+void bulkFirstGeq() {
+  constexpr int kNumKeys = 100000;
+  constexpr int kNumQueries = 100;
+  ankerl::nanobench::Bench bench;
+  bench.batch(kNumQueries);
+
+  // Initialize `versionedMap`
+  weaselab::VersionedMap versionedMap{0};
+  for (int64_t i = 0; i < kNumKeys; ++i) {
+    const auto bigEndian = __builtin_bswap64(i);
+    weaselab::VersionedMap::Mutation m;
+    m.param1 = (const uint8_t *)&bigEndian;
+    m.param1Len = sizeof(bigEndian);
+    m.param2 = (const uint8_t *)&bigEndian;
+    m.param2Len = sizeof(bigEndian);
+    m.type = weaselab::VersionedMap::Set;
+    versionedMap.addMutations(&m, 1, i + 1);
+  }
+
+  // Prepare queries
+  Arena arena;
+  auto *keys = new (arena) weaselab::VersionedMap::Key[kNumQueries];
+  auto *versions = new (arena) int64_t[kNumQueries];
+  for (int64_t i = 0; i < kNumQueries; ++i) {
+    int64_t version = i * kNumKeys / kNumQueries;
+    versions[i] = version;
+    const auto bigEndian = __builtin_bswap64(version);
+    uint8_t *k = new (arena) uint8_t[sizeof(bigEndian)];
+    memcpy(k, &bigEndian, sizeof(bigEndian));
+    keys[i].p = k;
+    keys[i].len = sizeof(bigEndian);
+  }
+
+  // Bench
+  bench.run("bulkFirstGeq", [&] {
+    weaselab::VersionedMap::Iterator iterators[kNumQueries];
+    versionedMap.firstGeq(keys, versions, iterators, kNumQueries);
+  });
+}
+
+int main() {
+  monotonicallyIncreasing();
+  bulkFirstGeq();
+}