From 68239cd80b7c70b1bf9038d23d8313b46a236304 Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Tue, 6 Feb 2024 12:37:02 -0800
Subject: [PATCH] Maintain nextSib in firstGeq

This is slower, but I think it's closer to what we want for our eventual bespoke
"fused-check-and-search" implementation.
---
 ConflictSet.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index 79705e6..0b94be9 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -657,6 +657,7 @@ std::string getSearchPath(Node *n) {
 
 Iterator firstGeq(Node *n, const std::span<const uint8_t> key) {
   auto remaining = key;
+  Node *nextSib = nullptr;
   for (;;) {
     if (n->partialKeyLen > 0) {
       int commonLen = std::min<int>(n->partialKeyLen, remaining.size());
@@ -668,7 +669,7 @@ Iterator firstGeq(Node *n, const std::span<const uint8_t> key) {
         if (c > 0) {
           goto downLeftSpine;
         } else {
-          n = nextSibling(n);
+          n = nextSib;
           goto downLeftSpine;
         }
       }
@@ -691,6 +692,10 @@ Iterator firstGeq(Node *n, const std::span<const uint8_t> key) {
       goto downLeftSpine;
     } else {
       int c = getChildGeq(n, remaining[0]);
+      int c2 = getChildGeq(n, int(remaining[0]) + 1);
+      if (c2 >= 0) {
+        nextSib = getChildExists(n, c2);
+      }
       if (c == remaining[0]) {
         n = getChildExists(n, c);
         remaining = remaining.subspan(1, remaining.size() - 1);
@@ -699,7 +704,7 @@ Iterator firstGeq(Node *n, const std::span<const uint8_t> key) {
           n = getChildExists(n, c);
           goto downLeftSpine;
         } else {
-          n = nextSibling(n);
+          n = nextSib;
           goto downLeftSpine;
         }
       }