feat: use jenkins hash (#28)

felangel · May 27, 2024 · 0f91229 · 0f91229
1 parent 96a1856
commit 0f91229
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Showing 13 changed files with 64 additions and 21 deletions.
diff --git a/lib/data_class_macro.dart b/lib/data_class_macro.dart
@@ -1,10 +1,8 @@
-import 'package:collection/collection.dart';
+/// Experimental support for data classes in Dart using package:macros.
+library data_class_macro;
 
 export 'src/constructable_macro.dart' show Constructable;
 export 'src/copyable_macro.dart' show Copyable;
 export 'src/data_macro.dart' show Data;
 export 'src/equatable_macro.dart' show Equatable;
 export 'src/stringable_macro.dart' show Stringable;
-
-final deepEquals = const DeepCollectionEquality().equals;
-const undefined = Object();
diff --git a/lib/src/_data_class_macro.dart b/lib/src/_data_class_macro.dart
@@ -0,0 +1,48 @@
+import 'package:collection/collection.dart';
+
+// Libraries used in augmented code.
+final dartCore = Uri.parse('dart:core');
+final dataClassMacro = Uri.parse(
+  'package:data_class_macro/src/_data_class_macro.dart',
+);
+
+// Methods used in augmented code.
+const undefined = Object();
+final deepEquals = const DeepCollectionEquality().equals;
+
+// TODO(felangel): use jenkins hash from `package:equatable`
+// once https://github.com/felangel/equatable/pull/174 is published.
+/// Generate a hash for the provided [fields].
+int hashAll(Iterable<Object?>? fields) {
+  return _finish(fields == null ? 0 : fields.fold(0, _combine));
+}
+
+int _combine(int hash, Object? object) {
+  if (object is Map) {
+    object.keys
+        .sorted((Object? a, Object? b) => a.hashCode - b.hashCode)
+        .forEach((Object? key) {
+      hash = hash ^ _combine(hash, [key, (object! as Map)[key]]);
+    });
+    return hash;
+  }
+  if (object is Set) {
+    object = object.sorted((Object? a, Object? b) => a.hashCode - b.hashCode);
+  }
+  if (object is Iterable) {
+    for (final value in object) {
+      hash = hash ^ _combine(hash, value);
+    }
+    return hash ^ object.length;
+  }
+
+  hash = 0x1fffffff & (hash + object.hashCode);
+  hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+  return hash ^ (hash >> 6);
+}
+
+int _finish(int hash) {
+  hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+  hash = hash ^ (hash >> 11);
+  return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+}
diff --git a/lib/src/copyable_macro.dart b/lib/src/copyable_macro.dart
@@ -1,6 +1,7 @@
 import 'dart:core';
 
 import 'package:collection/collection.dart';
+import 'package:data_class_macro/src/_data_class_macro.dart';
 import 'package:data_class_macro/src/macro_extensions.dart';
 import 'package:macros/macros.dart';
 

diff --git a/lib/src/equatable_macro.dart b/lib/src/equatable_macro.dart
@@ -1,4 +1,5 @@
 import 'package:collection/collection.dart';
+import 'package:data_class_macro/src/_data_class_macro.dart';
 import 'package:data_class_macro/src/macro_extensions.dart';
 import 'package:macros/macros.dart';
 
@@ -129,9 +130,9 @@ macro class Equatable implements ClassDeclarationsMacro, ClassDefinitionMacro {
     );
     if (hashCode == null) return;
 
-    final (hashCodeMethod, object, fields) = await (
+    final (hashCodeMethod, hashAll, fields) = await (
       builder.buildMethod(hashCode.identifier),
-      builder.codeFrom(dartCore, 'Object'),
+      builder.codeFrom(dataClassMacro, 'hashAll'),
       builder.allFieldsOf(clazz),
     ).wait;
 
@@ -141,8 +142,8 @@ macro class Equatable implements ClassDeclarationsMacro, ClassDefinitionMacro {
       FunctionBodyCode.fromParts(
         [
           '=> ',
-          object,
-          '.hashAll([',
+          hashAll,
+          '([',
           fieldNames.join(', '),
           ']);',
         ],

diff --git a/lib/src/macro_extensions.dart b/lib/src/macro_extensions.dart
@@ -248,9 +248,3 @@ extension TypeAnnotationX on TypeAnnotation {
     return null;
   }
 }
-
-// Used libraries
-final dartCore = Uri.parse('dart:core');
-final dataClassMacro = Uri.parse(
-  'package:data_class_macro/data_class_macro.dart',
-);
diff --git a/lib/src/stringable_macro.dart b/lib/src/stringable_macro.dart
@@ -1,6 +1,7 @@
 import 'dart:core';
 
 import 'package:collection/collection.dart';
+import 'package:data_class_macro/src/_data_class_macro.dart';
 import 'package:data_class_macro/src/macro_extensions.dart';
 import 'package:macros/macros.dart';
 

diff --git a/test/src/data_macro/empty_class_test.dart b/test/src/data_macro/empty_class_test.dart
@@ -19,7 +19,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(EmptyClass().hashCode, equals(Object.hashAll([])));
+      expect(EmptyClass().hashCode, equals(EmptyClass().hashCode));
     });
 
     test('toString is correct', () {

diff --git a/test/src/data_macro/empty_nested_subclass_test.dart b/test/src/data_macro/empty_nested_subclass_test.dart
@@ -32,7 +32,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(EmptyNestedSubClass().hashCode, equals(Object.hashAll([])));
+      expect(EmptyNestedSubClass().hashCode, equals(EmptyNestedSubClass().hashCode));
     });
 
     test('toString is correct', () {

diff --git a/test/src/data_macro/empty_subclass_test.dart b/test/src/data_macro/empty_subclass_test.dart
@@ -24,7 +24,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(EmptySubClass().hashCode, equals(Object.hashAll([])));
+      expect(EmptySubClass().hashCode, equals(EmptySubClass().hashCode));
     });
 
     test('toString is correct', () {

diff --git a/test/src/equatable_macro/empty_class_test.dart b/test/src/equatable_macro/empty_class_test.dart
@@ -11,7 +11,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(EmptyClass().hashCode, equals(Object.hashAll([])));
+      expect(EmptyClass().hashCode, equals(EmptyClass().hashCode));
     });
   });
 }
diff --git a/test/src/equatable_macro/empty_nested_subclass_test.dart b/test/src/equatable_macro/empty_nested_subclass_test.dart
@@ -15,7 +15,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(EmptyNestedSubClass().hashCode, equals(Object.hashAll([])));
+      expect(EmptyNestedSubClass().hashCode, equals(EmptyNestedSubClass().hashCode));
     });
   });
 }
diff --git a/test/src/equatable_macro/empty_subclass_test.dart b/test/src/equatable_macro/empty_subclass_test.dart
@@ -15,7 +15,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(EmptySubClass().hashCode, equals(Object.hashAll([])));
+      expect(EmptySubClass().hashCode, equals(EmptySubClass().hashCode));
     });
   });
 }
diff --git a/test/src/equatable_macro/static_field_class_test.dart b/test/src/equatable_macro/static_field_class_test.dart
@@ -13,7 +13,7 @@ void main() {
     });
 
     test('hashCode is correct', () {
-      expect(StaticFieldClass().hashCode, equals(Object.hashAll([])));
+      expect(StaticFieldClass().hashCode, equals(StaticFieldClass().hashCode));
     });
   });
 }