From 9015b555de9ddd1045990c4034c848794b61cf01 Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Tue, 29 Oct 2024 17:24:10 -0700
Subject: [PATCH] Allow passing two roots to addWriteRange

---
 ConflictSet.cpp | 44 ++++++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index ab79da1..610de73 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -3108,26 +3108,13 @@ void fixupMaxVersion(Node *node, WriteContext *writeContext) {
   setMaxVersion(node, max);
 }
 
-void addWriteRange(TaggedNodePointer &root, std::span<const uint8_t> begin,
-                   std::span<const uint8_t> end, InternalVersionT writeVersion,
-                   WriteContext *writeContext, ConflictSet::Impl *impl) {
-
-  int lcp = longestCommonPrefix(begin.data(), end.data(),
-                                std::min(begin.size(), end.size()));
-  if (lcp == int(begin.size()) && end.size() == begin.size() + 1 &&
-      end.back() == 0) {
-    return addPointWrite(root, begin, writeVersion, writeContext);
-  }
+void addWriteRange(TaggedNodePointer &beginRoot, std::span<const uint8_t> begin,
+                   TaggedNodePointer &endRoot, std::span<const uint8_t> end,
+                   InternalVersionT writeVersion, WriteContext *writeContext,
+                   ConflictSet::Impl *impl, bool beginIsPrefix) {
   ++writeContext->accum.range_writes;
-  const bool beginIsPrefix = lcp == int(begin.size());
 
-  auto useAsRoot =
-      insert(&root, begin.subspan(0, lcp), writeVersion, writeContext);
-
-  begin = begin.subspan(lcp, begin.size() - lcp);
-  end = end.subspan(lcp, end.size() - lcp);
-
-  Node *beginNode = *insert(useAsRoot, begin, writeVersion, writeContext);
+  Node *beginNode = *insert(&beginRoot, begin, writeVersion, writeContext);
   addKey(beginNode);
   if (!beginNode->entryPresent) {
     ++writeContext->accum.entries_inserted;
@@ -3139,7 +3126,7 @@ void addWriteRange(TaggedNodePointer &root, std::span<const uint8_t> begin,
   }
   beginNode->entry.pointVersion = writeVersion;
 
-  Node *endNode = *insert(useAsRoot, end, writeVersion, writeContext);
+  Node *endNode = *insert(&endRoot, end, writeVersion, writeContext);
   addKey(endNode);
   if (!endNode->entryPresent) {
     ++writeContext->accum.entries_inserted;
@@ -3149,7 +3136,7 @@ void addWriteRange(TaggedNodePointer &root, std::span<const uint8_t> begin,
                      : std::max(p->entry.rangeVersion, writeContext->zero);
     if (beginIsPrefix) {
       // beginNode may have been invalidated when inserting end
-      beginNode = *useAsRoot;
+      beginNode = beginRoot;
       assert(beginNode->entryPresent);
     }
     endNode->entryPresent = true;
@@ -3173,6 +3160,23 @@ void addWriteRange(TaggedNodePointer &root, std::span<const uint8_t> begin,
   fixupMaxVersion(iter, writeContext);
 }
 
+void addWriteRange(TaggedNodePointer &root, std::span<const uint8_t> begin,
+                   std::span<const uint8_t> end, InternalVersionT writeVersion,
+                   WriteContext *writeContext, ConflictSet::Impl *impl) {
+  int lcp = longestCommonPrefix(begin.data(), end.data(),
+                                std::min(begin.size(), end.size()));
+  if (lcp == int(begin.size()) && end.size() == begin.size() + 1 &&
+      end.back() == 0) {
+    return addPointWrite(root, begin, writeVersion, writeContext);
+  }
+  auto useAsRoot =
+      insert(&root, begin.subspan(0, lcp), writeVersion, writeContext);
+
+  addWriteRange(*useAsRoot, begin.subspan(lcp, begin.size() - lcp), *useAsRoot,
+                end.subspan(lcp, end.size() - lcp), writeVersion, writeContext,
+                impl, int(begin.size()) == lcp);
+}
+
 Node *firstGeqPhysical(Node *n, const std::span<const uint8_t> key) {
   auto remaining = key;
   for (;;) {