Share search of common prefix

ConflictSet.cpp

@@ -1061,6 +1061,31 @@ bool checkRangeRead(Node *n, std::span<const uint8_t> begin,
   int lcp = longestCommonPrefix(begin.data(), end.data(),
                                 std::min(begin.size(), end.size()));
 
+  SearchStepWise search{n, begin.subspan(0, lcp)};
+  Arena arena;
+  for (;;) {
+    assert(getSearchPath(arena, search.n) <=>
+               begin.subspan(0, lcp - search.remaining.size()) ==
+           0);
+    if (search.n->maxVersion <= readVersion) {
+      return true;
+    }
+    if (search.step()) {
+      break;
+    }
+  }
+  assert(getSearchPath(arena, search.n) <=>
+             begin.subspan(0, lcp - search.remaining.size()) ==
+         0);
+
+  const int consumed = lcp - search.remaining.size();
+  assert(consumed >= 0);
+
+  begin = begin.subspan(consumed, int(begin.size()) - consumed);
+  end = end.subspan(consumed, int(end.size()) - consumed);
+  n = search.n;
+  lcp -= consumed;
+
   if (lcp == int(begin.size())) {
     for (int i = lcp; i < int(end.size()); ++i) {
       if (!checkPointRead(n, end.subspan(0, i), readVersion)) {