From 403d70a1d3d59ceb94f3ebf35e59206b203a44ec Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Thu, 15 Aug 2024 11:33:16 -0700
Subject: [PATCH] Prefer not copying node in eraseBetween

If numChildren + entryPresent is enough, we don't have to copy even if
it would fit in a smaller node.

If we have to copy, we might as well use the smallest acceptable node
type.
---
 ConflictSet.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index ef73503..46aa484 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -1827,7 +1827,7 @@ void eraseBetween(Node **inTree, Node16 *n, int begin, int end,
     n->index[i] = n->index[i + count];
   }
 
-  if (n->numChildren > Node3::kMaxNodes) {
+  if (n->numChildren + n->entryPresent >= kMinChildrenNode16) {
     // nop
   } else if (n->numChildren > 0) {
     auto *newNode = tls->allocate<Node3>(n->partialKeyLen);
@@ -1867,7 +1867,7 @@ void eraseBetween(Node **inTree, Node48 *n, int begin, int end,
     --n->numChildren;
   }
 
-  if (n->numChildren > Node16::kMaxNodes) {
+  if (n->numChildren + n->entryPresent >= kMinChildrenNode48) {
     // nop
   } else if (n->numChildren > Node3::kMaxNodes) {
     auto *newNode = tls->allocate<Node16>(n->partialKeyLen);
@@ -1896,7 +1896,7 @@ void eraseBetween(Node **inTree, Node256 *n, int begin, int end,
     n->bitSet.reset(i);
     --n->numChildren;
   }
-  if (n->numChildren > Node48::kMaxNodes) {
+  if (n->numChildren + n->entryPresent >= kMinChildrenNode256) {
     // nop
   } else if (n->numChildren > Node16::kMaxNodes) {
     auto *newNode = tls->allocate<Node48>(n->partialKeyLen);