Add short-circuiting back to checkRangeRead

ConflictSet.cpp

@@ -547,6 +547,46 @@ Node *nextSibling(Node *node, Vector<uint8_t> &searchPath) {
   }
 }
 
+// Performs a physical search for remaining
+struct SearchStepWise {
+  Node *n;
+  std::span<const uint8_t> remaining;
+
+  SearchStepWise() {}
+  SearchStepWise(Node *n, std::span<const uint8_t> remaining)
+      : n(n), remaining(remaining) {
+    assert(n->partialKeyLen == 0);
+  }
+
+  bool step() {
+    if (remaining.size() == 0) {
+      return true;
+    } else {
+      int c = getChildGeq(n, remaining[0]);
+      if (c == remaining[0]) {
+        auto *child = getChildExists(n, c);
+        int i = 0;
+        for (; i < child->partialKeyLen; ++i) {
+          if (!(i + 1 < int(remaining.size()) &&
+                remaining[i + 1] == child->partialKey[i])) {
+            break;
+          }
+        }
+        if (i != child->partialKeyLen) {
+          return true;
+        }
+        n = child;
+        remaining =
+            remaining.subspan(1 + child->partialKeyLen,
+                              remaining.size() - (1 + child->partialKeyLen));
+      } else {
+        return true;
+      }
+    }
+    return false;
+  }
+};
+
 struct FirstGeqStepwise {
   Node *n;
   std::span<const uint8_t> remaining;
@@ -894,6 +934,26 @@ bytes:
 bool checkRangeRead(Node *n, const std::span<const uint8_t> begin,
                     const std::span<const uint8_t> end, int64_t readVersion,
                     Arena &arena) {
+
+  int cl = std::min(begin.size(), end.size());
+  int lcp = longestCommonPrefix(begin.data(), end.data(), cl);
+
+  SearchStepWise search{n, begin.subspan(0, lcp)};
+  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);
+
   auto left = firstGeq(n, begin);
 
 #if DEBUG_VERBOSE && !defined(NDEBUG)