From 2dba0d5be32025992d8509cdbc06a78e5b321926 Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Fri, 9 Aug 2024 13:58:31 -0700
Subject: [PATCH] Have insert return a pointer to the in-tree pointer

---
 ConflictSet.cpp | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index 5fa8624..61327ad 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -2922,14 +2922,14 @@ void consumePartialKey(Node *&self, std::span<const uint8_t> &key,
   key = key.subspan(partialKeyIndex, key.size() - partialKeyIndex);
 }
 
-// Returns a pointer to the newly inserted node.  Caller must set
-// `entryPresent`, and `entry` fields.  All nodes along the search path of the
-// result will have `maxVersion` set to `writeVersion` as a postcondition. Nodes
-// along the search path may be invalidated.
+// Returns a pointer the pointer to the newly inserted node in the tree.  Caller
+// must set `entryPresent`, and `entry` fields.  All nodes along the search path
+// of the result will have `maxVersion` set to `writeVersion` as a
+// postcondition. Nodes along the search path may be invalidated.
 [[nodiscard]]
-Node *insert(Node **self, std::span<const uint8_t> key,
-             InternalVersionT writeVersion, WriteContext *tls,
-             ConflictSet::Impl *impl) {
+Node **insert(Node **self, std::span<const uint8_t> key,
+              InternalVersionT writeVersion, WriteContext *tls,
+              ConflictSet::Impl *impl) {
 
   if ((*self)->partialKeyLen > 0) {
     consumePartialKey(*self, key, writeVersion, tls);
@@ -2940,7 +2940,7 @@ Node *insert(Node **self, std::span<const uint8_t> key,
   for (;; ++tls->accum.insert_iterations) {
 
     if (key.size() == 0) {
-      return *self;
+      return self;
     }
 
     auto &child = getOrCreateChild(*self, key.front(), writeVersion, tls);
@@ -2953,7 +2953,7 @@ Node *insert(Node **self, std::span<const uint8_t> key,
       child->parentsIndex = key.front();
       setMaxVersion(child, impl, writeVersion);
       memcpy(child->partialKey(), key.data() + 1, child->partialKeyLen);
-      return child;
+      return &child;
     }
 
     self = &child;
@@ -2996,7 +2996,7 @@ void addPointWrite(Node *&root, std::span<const uint8_t> key,
                    InternalVersionT writeVersion, WriteContext *tls,
                    ConflictSet::Impl *impl) {
   ++tls->accum.point_writes;
-  auto *n = insert(&root, key, writeVersion, tls, impl);
+  auto *n = *insert(&root, key, writeVersion, tls, impl);
   if (!n->entryPresent) {
     ++tls->accum.entries_inserted;
     auto *p = nextLogical(n);
@@ -3097,7 +3097,7 @@ void addWriteRange(Node *&root, std::span<const uint8_t> begin,
   begin = begin.subspan(consumed, begin.size() - consumed);
   end = end.subspan(consumed, end.size() - consumed);
 
-  auto *beginNode = insert(useAsRoot, begin, writeVersion, tls, impl);
+  auto *beginNode = *insert(useAsRoot, begin, writeVersion, tls, impl);
 
   const bool insertedBegin = !beginNode->entryPresent;
 
@@ -3114,7 +3114,7 @@ void addWriteRange(Node *&root, std::span<const uint8_t> begin,
   assert(writeVersion >= beginNode->entry.pointVersion);
   beginNode->entry.pointVersion = writeVersion;
 
-  auto *endNode = insert(useAsRoot, end, writeVersion, tls, impl);
+  auto *endNode = *insert(useAsRoot, end, writeVersion, tls, impl);
 
   const bool insertedEnd = !endNode->entryPresent;
 
@@ -3132,7 +3132,7 @@ void addWriteRange(Node *&root, std::span<const uint8_t> begin,
   if (beginIsPrefix && insertedEnd) {
     // beginNode may have been invalidated when inserting end. TODO can we do
     // better?
-    beginNode = insert(useAsRoot, begin, writeVersion, tls, impl);
+    beginNode = *insert(useAsRoot, begin, writeVersion, tls, impl);
     assert(beginNode->entryPresent);
   }