From 76d0785b331aedbeacb8565832c2b87c89c2a7e4 Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Tue, 25 Jun 2024 20:46:48 -0700
Subject: [PATCH] Add worst-case benchmark for radix tree

Closes #27
---
 Bench.cpp | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 72 insertions(+), 1 deletion(-)

diff --git a/Bench.cpp b/Bench.cpp
index 0f8e81a..3ab5b5f 100644
--- a/Bench.cpp
+++ b/Bench.cpp
@@ -258,4 +258,75 @@ void benchConflictSet() {
   }
 }
 
-int main(void) { benchConflictSet(); }
+void benchWorstCaseForRadixRangeRead() {
+  ankerl::nanobench::Bench bench;
+  ConflictSet cs{0};
+
+  int64_t version = 0;
+
+  constexpr int kKeyLength = 50;
+
+  for (int i = 0; i < kKeyLength; ++i) {
+    for (int j = 0; j < 256; ++j) {
+      auto b = std::vector<uint8_t>(i, 0);
+      b.push_back(j);
+      auto e = std::vector<uint8_t>(i, 255);
+      e.push_back(j);
+      weaselab::ConflictSet::WriteRange w[] = {{
+                                                   {b.data(), int(b.size())},
+                                                   {nullptr, 0},
+                                               },
+                                               {
+                                                   {e.data(), int(e.size())},
+                                                   {nullptr, 0},
+                                               }};
+      cs.addWrites(w, sizeof(w) / sizeof(w[0]), version);
+    }
+  }
+
+  // Defeat short-circuiting on the left
+  {
+    auto k = std::vector<uint8_t>(kKeyLength, 0);
+    weaselab::ConflictSet::WriteRange w[] = {
+        {
+            {k.data(), int(k.size())},
+            {nullptr, 0},
+        },
+    };
+    cs.addWrites(w, sizeof(w) / sizeof(w[0]), 2);
+  }
+
+  // Defeat short-circuiting on the right
+  {
+    auto k = std::vector<uint8_t>(kKeyLength, 255);
+    weaselab::ConflictSet::WriteRange w[] = {
+        {
+            {k.data(), int(k.size())},
+            {nullptr, 0},
+        },
+    };
+    cs.addWrites(w, sizeof(w) / sizeof(w[0]), 2);
+  }
+
+  auto begin = std::vector<uint8_t>(kKeyLength - 1, 0);
+  begin.push_back(1);
+  auto end = std::vector<uint8_t>(kKeyLength - 1, 255);
+  end.push_back(254);
+
+  weaselab::ConflictSet::Result result;
+  weaselab::ConflictSet::ReadRange r{
+      {begin.data(), int(begin.size())}, {end.data(), int(end.size())}, 1};
+
+  bench.run("worst case for radix tree", [&]() {
+    result = weaselab::ConflictSet::TooOld;
+    cs.check(&r, &result, 1);
+    if (result != weaselab::ConflictSet::Commit) {
+      abort();
+    }
+  });
+}
+
+int main(void) {
+  benchConflictSet();
+  benchWorstCaseForRadixRangeRead();
+}