Save a few instructions in addWriteRange

ConflictSet.cpp

@@ -285,6 +285,27 @@ Node *&getChildExists(Node *self, uint8_t index) {
   __builtin_unreachable(); // GCOVR_EXCL_LINE
 }
 
+Node *getChild(Node *self, uint8_t index) {
+  if (self->type <= Type::Node16) {
+    auto *self16 = static_cast<Node16 *>(self);
+    int i = getNodeIndex(self16, index);
+    if (i >= 0) {
+      return self16->children[i];
+    }
+    return nullptr;
+  } else if (self->type == Type::Node48) {
+    auto *self48 = static_cast<Node48 *>(self);
+    int secondIndex = self48->index[index];
+    if (secondIndex >= 0) {
+      return self48->children[secondIndex];
+    }
+    return nullptr;
+  } else {
+    auto *self256 = static_cast<Node256 *>(self);
+    return self256->children[index];
+  }
+}
+
 int getChildGeq(Node *self, int child) {
   if (child > 255) {
     return -1;
@@ -1466,21 +1487,17 @@ void addWriteRange(Node *&root, int64_t oldestVersion,
   auto *n = root;
 
   for (;;) {
-    if (int(remaining.size()) < n->partialKeyLen + 1) {
+    if (int(remaining.size()) <= n->partialKeyLen) {
       break;
     }
-    int i = 0;
-    for (; i < n->partialKeyLen; ++i) {
-      if (remaining[i] != n->partialKey[i]) {
-        break;
-      }
-    }
+    int i = longestCommonPrefixPartialKey(n->partialKey, remaining.data(),
+                                          n->partialKeyLen);
     if (i != n->partialKeyLen) {
       break;
     }
 
-    int c = getChildGeq(n, remaining[n->partialKeyLen]);
-    if (c != remaining[n->partialKeyLen]) {
+    auto *child = getChild(n, remaining[n->partialKeyLen]);
+    if (child == nullptr) {
       break;
     }
 
@@ -1488,7 +1505,7 @@ void addWriteRange(Node *&root, int64_t oldestVersion,
 
     remaining = remaining.subspan(n->partialKeyLen + 1,
                                   remaining.size() - (n->partialKeyLen + 1));
-    n = getChildExists(n, c);
+    n = child;
   }
 
   Node **useAsRoot = n->parent == nullptr