Tweaks to array/list comparers (#1932)

Following dotnet/efcore#25344
npgsql · Jul 29, 2021 · 482c1ac · 482c1ac
1 parent dc03707
commit 482c1ac
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Showing 2 changed files with 77 additions and 5 deletions.
diff --git a/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlArrayArrayTypeMapping.cs b/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlArrayArrayTypeMapping.cs
@@ -137,34 +137,50 @@ private static bool Compare(TElem[]? a, TElem[]? b, ValueComparer<TElem> element
  return false;
  }
 
+ if (ReferenceEquals(a, b))
+ {
+ return true;
+ }
+
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  for (var i = 0; i < a.Length; i++)
+ {
  if (!elementComparer.Equals(a[i], b[i]))
+ {
  return false;
+ }
+ }
 
  return true;
  }
 
  private static int GetHashCode(TElem[] source, ValueComparer<TElem> elementComparer)
  {
  var hash = new HashCode();
+
  foreach (var el in source)
+ {
  hash.Add(el, elementComparer);
+ }
+
  return hash.ToHashCode();
  }
 
  [return: NotNullIfNotNull("source")]
  private static TElem[]? Snapshot(TElem[]? source, ValueComparer<TElem> elementComparer)
  {
- if (source == null)
+ if (source is null)
  return null;
 
  var snapshot = new TElem[source.Length];
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  for (var i = 0; i < source.Length; i++)
+ {
  snapshot[i] = elementComparer.Snapshot(source[i])!; // TODO: https://github.com/dotnet/efcore/pull/24410
+ }
+
  return snapshot;
  }
  }
@@ -191,6 +207,11 @@ private static bool Compare(TElem?[]? a, TElem?[]? b, ValueComparer<TElem> eleme
  return false;
  }
 
+ if (ReferenceEquals(a, b))
+ {
+ return true;
+ }
+
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  for (var i = 0; i < a.Length; i++)
@@ -199,11 +220,17 @@ private static bool Compare(TElem?[]? a, TElem?[]? b, ValueComparer<TElem> eleme
  if (el1 is null)
  {
  if (el2 is null)
+ {
  continue;
+ }
+
  return false;
  }
+
  if (el2 is null || !elementComparer.Equals(el1, el2))
+ {
  return false;
+ }
  }
 
  return true;
@@ -213,22 +240,31 @@ private static int GetHashCode(TElem?[] source, ValueComparer<TElem> elementComp
  {
  var nullableEqualityComparer = new NullableEqualityComparer<TElem>(elementComparer);
  var hash = new HashCode();
+
  foreach (var el in source)
+ {
  hash.Add(el, nullableEqualityComparer);
+ }
+
  return hash.ToHashCode();
  }
 
  [return: NotNullIfNotNull("source")]
  private static TElem?[]? Snapshot(TElem?[]? source, ValueComparer<TElem> elementComparer)
  {
- if (source == null)
+ if (source is null)
+ {
  return null;
+ }
 
  var snapshot = new TElem?[source.Length];
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  for (var i = 0; i < source.Length; i++)
- snapshot[i] = source[i] is { } value ? elementComparer.Snapshot(value) : (TElem?)null;
+ {
+ snapshot[i] = source[i] is { } value ? elementComparer.Snapshot(value) : null;
+ }
+
  return snapshot;
  }
  }

diff --git a/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlArrayListTypeMapping.cs b/src/EFCore.PG/Storage/Internal/Mapping/NpgsqlArrayListTypeMapping.cs
@@ -135,34 +135,51 @@ private static bool Compare(List<TElem>? a, List<TElem>? b, ValueComparer<TElem>
  return false;
  }
 
+ if (ReferenceEquals(a, b))
+ {
+ return true;
+ }
+
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  for (var i = 0; i < a.Count; i++)
+ {
  if (!elementComparer.Equals(a[i], b[i]))
+ {
  return false;
+ }
+ }
 
  return true;
  }
 
  private static int GetHashCode(List<TElem> source, ValueComparer<TElem> elementComparer)
  {
  var hash = new HashCode();
+
  foreach (var el in source)
+ {
  hash.Add(el, elementComparer);
+ }
+
  return hash.ToHashCode();
  }
 
  private static List<TElem>? Snapshot(List<TElem>? source, ValueComparer<TElem> elementComparer)
  {
- if (source == null)
+ if (source is null)
+ {
  return null;
+ }
 
  var snapshot = new List<TElem>(source.Count);
 
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  foreach (var e in source)
+ {
  snapshot.Add(elementComparer.Snapshot(e)!); // TODO: https://github.com/dotnet/efcore/pull/24410
+ }
 
  return snapshot;
  }
@@ -191,6 +208,11 @@ private static bool Compare(List<TElem?>? a, List<TElem?>? b, ValueComparer<TEle
  return false;
  }
 
+ if (ReferenceEquals(a, b))
+ {
+ return true;
+ }
+
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  for (var i = 0; i < a.Count; i++)
@@ -199,11 +221,17 @@ private static bool Compare(List<TElem?>? a, List<TElem?>? b, ValueComparer<TEle
  if (el1 is null)
  {
  if (el2 is null)
+ {
  continue;
+ }
+
  return false;
  }
+
  if (el2 is null || !elementComparer.Equals(a[i], b[i]))
+ {
  return false;
+ }
  }
 
  return true;
@@ -213,22 +241,30 @@ private static int GetHashCode(List<TElem?> source, ValueComparer<TElem> element
  {
  var nullableEqualityComparer = new NullableEqualityComparer<TElem>(elementComparer);
  var hash = new HashCode();
+
  foreach (var el in source)
+ {
  hash.Add(el, nullableEqualityComparer);
+ }
+
  return hash.ToHashCode();
  }
 
  private static List<TElem?>? Snapshot(List<TElem?>? source, ValueComparer<TElem> elementComparer)
  {
  if (source == null)
+ {
  return null;
+ }
 
  var snapshot = new List<TElem?>(source.Count);
 
  // Note: the following currently boxes every element access because ValueComparer isn't really
  // generic (see https://github.com/aspnet/EntityFrameworkCore/issues/11072)
  foreach (var e in source)
- snapshot.Add(e is { } value ? elementComparer.Snapshot(value) : (TElem?)null);
+ {
+ snapshot.Add(e is { } value ? elementComparer.Snapshot(value) : null);
+ }
 
  return snapshot;
  }