From b169dad1e5083eae333ba9a7e11fed74a05385de Mon Sep 17 00:00:00 2001
From: Jordan Gillard <jordan@blackcicada.info>
Date: Tue, 9 May 2023 14:33:35 -0400
Subject: [PATCH] Improve and refactor cellseqs_v2 in Nim standard library
 (#21796)

* Refactor and optimize cellseqs_v2 in Nim standard library

* Extract resizing logic into a separate 'resize' procedure for better readability and separation of concerns
* Implement realloc for non-threaded cases to improve memory operations efficiency
* Use ',' instead of ';' between parameters in 'add' procedure for consistency with other Nim code

* Respond to Araq's feedback: Refactor resize function to use reallocShared

This commit replaces the usage of allocShared and deallocShared with reallocShared to optimize memory allocation and deallocation while resizing the CellSeq.
---
 lib/system/cellseqs_v2.nim | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/lib/system/cellseqs_v2.nim b/lib/system/cellseqs_v2.nim
index 27be48d78e..c6c7b1a8e2 100644
--- a/lib/system/cellseqs_v2.nim
+++ b/lib/system/cellseqs_v2.nim
@@ -16,20 +16,17 @@ type
     len, cap: int
     d: CellArray[T]
 
-proc add[T](s: var CellSeq[T], c: T; t: PNimTypeV2) {.inline.} =
+proc resize[T](s: var CellSeq[T]) =
+  s.cap = s.cap * 3 div 2
+  var newSize = s.cap * sizeof(CellTuple[T])
+  when compileOption("threads"):
+    s.d = cast[CellArray[T]](reallocShared(s.d, newSize))
+  else:
+    s.d = cast[CellArray[T]](realloc(s.d, newSize))
+
+proc add[T](s: var CellSeq[T], c: T, t: PNimTypeV2) {.inline.} =
   if s.len >= s.cap:
-    s.cap = s.cap * 3 div 2
-    when compileOption("threads"):
-      var d = cast[CellArray[T]](allocShared(uint(s.cap * sizeof(CellTuple[T]))))
-    else:
-      var d = cast[CellArray[T]](alloc(s.cap * sizeof(CellTuple[T])))
-    copyMem(d, s.d, s.len * sizeof(CellTuple[T]))
-    when compileOption("threads"):
-      deallocShared(s.d)
-    else:
-      dealloc(s.d)
-    s.d = d
-    # XXX: realloc?
+    s.resize()
   s.d[s.len] = (c, t)
   inc(s.len)