Use jenkins hash

docs/docs/getting_started.md

@@ -8,4 +8,4 @@ permalink: /getting-started/
 # Getting started
 {% include content/getting_started.md %}
 
-Congrats, you are now ready to fully use moor and [write queries]({{site.url}}/writing-queries/).
+Congrats, you are now ready to fully use moor and [write queries]({{site.url}}/queries/).

moor/example/example.g.dart

@@ -49,7 +49,8 @@ class Category {
   }
 
   @override
-  int get hashCode => (id.hashCode) * 31 + description.hashCode;
+  int get hashCode =>
+      $moorjf($mrjf($mrjc(0, id.hashCode), description.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||
@@ -179,10 +180,10 @@ class Recipe {
   }
 
   @override
-  int get hashCode =>
-      (((id.hashCode) * 31 + title.hashCode) * 31 + instructions.hashCode) *
-          31 +
-      category.hashCode;
+  int get hashCode => $moorjf($mrjf(
+      $mrjf(
+          $mrjf($mrjc(0, id.hashCode), title.hashCode), instructions.hashCode),
+      category.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||
@@ -336,8 +337,8 @@ class Ingredient {
   }
 
   @override
-  int get hashCode =>
-      ((id.hashCode) * 31 + name.hashCode) * 31 + caloriesPer100g.hashCode;
+  int get hashCode => $moorjf($mrjf(
+      $mrjf($mrjc(0, id.hashCode), name.hashCode), caloriesPer100g.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||
@@ -481,9 +482,9 @@ class IngredientInRecipe {
   }
 
   @override
-  int get hashCode =>
-      ((recipe.hashCode) * 31 + ingredient.hashCode) * 31 +
-      amountInGrams.hashCode;
+  int get hashCode => $moorjf($mrjf(
+      $mrjf($mrjc(0, recipe.hashCode), ingredient.hashCode),
+      amountInGrams.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||

moor/lib/moor.dart

@@ -26,3 +26,4 @@ export 'package:moor/src/runtime/database.dart';
 export 'package:moor/src/types/sql_types.dart';
 export 'package:moor/src/runtime/migration.dart';
 export 'package:moor/src/runtime/exceptions.dart';
+export 'package:moor/src/utils/hash.dart';

moor/lib/src/utils/hash.dart

@@ -0,0 +1,17 @@
+// Shamelessly stolen from https://github.com/google/built_value.dart/blob/1fa5da43b5e121a1d3ec2e205f29ca80927958b0/built_value/lib/built_value.dart#L195-L209
+
+/// For use by generated code in calculating hash codes. Do not use directly.
+int $mrjc(int hash, int value) {
+  // Jenkins hash "combine".
+  hash = 0x1fffffff & (hash + value);
+  hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+  return hash ^ (hash >> 6);
+}
+
+/// For use by generated code in calculating hash codes. Do not use directly.
+int $mrjf(int hash) {
+  // Jenkins hash "finish".
+  hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+  hash = hash ^ (hash >> 11);
+  return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+}

moor/test/data/tables/todos.g.dart

@@ -78,11 +78,11 @@ class TodoEntry {
   }
 
   @override
-  int get hashCode =>
-      ((((id.hashCode) * 31 + title.hashCode) * 31 + content.hashCode) * 31 +
-              targetDate.hashCode) *
-          31 +
-      category.hashCode;
+  int get hashCode => $moorjf($mrjf(
+      $mrjf(
+          $mrjf($mrjf($mrjc(0, id.hashCode), title.hashCode), content.hashCode),
+          targetDate.hashCode),
+      category.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||
@@ -251,7 +251,8 @@ class Category {
   }
 
   @override
-  int get hashCode => (id.hashCode) * 31 + description.hashCode;
+  int get hashCode =>
+      $moorjf($mrjf($mrjc(0, id.hashCode), description.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||
@@ -397,11 +398,12 @@ class User {
   }
 
   @override
-  int get hashCode =>
-      ((((id.hashCode) * 31 + name.hashCode) * 31 + isAwesome.hashCode) * 31 +
-              profilePicture.hashCode) *
-          31 +
-      creationTime.hashCode;
+  int get hashCode => $moorjf($mrjf(
+      $mrjf(
+          $mrjf(
+              $mrjf($mrjc(0, id.hashCode), name.hashCode), isAwesome.hashCode),
+          profilePicture.hashCode),
+      creationTime.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||
@@ -565,7 +567,7 @@ class SharedTodo {
   }
 
   @override
-  int get hashCode => (todo.hashCode) * 31 + user.hashCode;
+  int get hashCode => $moorjf($mrjf($mrjc(0, todo.hashCode), user.hashCode));
   @override
   bool operator ==(other) =>
       identical(this, other) ||

moor_generator/lib/src/utils/type_utils.dart

@@ -1,9 +1,9 @@
 import 'package:analyzer/dart/element/type.dart';
 
-bool isFrommoor(DartType type) {
+bool isFromMoor(DartType type) {
   return type.element.library.location.components.first.contains('moor');
 }
 
 bool isColumn(DartType type) {
-  return isFrommoor(type) && type.name.contains('Column');
+  return isFromMoor(type) && type.name.contains('Column');
 }

moor_generator/lib/src/writer/data_class_writer.dart

@@ -1,6 +1,9 @@
 import 'package:moor_generator/src/model/specified_table.dart';
 import 'package:recase/recase.dart';
 
+const _hashCombine = '\$mrjc';
+const _hashFinish = '\$mrjf';
+
 class DataClassWriter {
   final SpecifiedTable table;
 
@@ -37,12 +40,7 @@ class DataClassWriter {
 
     buffer.write('@override\n int get hashCode => ');
 
-    if (table.columns.isEmpty) {
-      buffer.write('identityHashCode(this); \n');
-    } else {
-      final fields = table.columns.map((c) => c.dartGetterName).toList();
-      buffer..write(_calculateHashCode(fields))..write('; \n');
-    }
+    _writeHashCode(buffer);
 
     // override ==
     //    return identical(this, other) || (other is DataClass && other.id == id && ...)
@@ -184,18 +182,31 @@ class DataClassWriter {
     buffer..write("..write(')')).toString();")..write('\}\n');
   }
 
+  void _writeHashCode(StringBuffer buffer) {
+    if (table.columns.isEmpty) {
+      buffer.write('identityHashCode(this); \n');
+    } else {
+      final fields = table.columns.map((c) => c.dartGetterName).toList();
+      buffer
+        ..write('\$moorjf(')
+        ..write(_calculateHashCode(fields))
+        ..write(')')
+        ..write('; \n');
+    }
+  }
+
   /// Recursively creates the implementation for hashCode of the data class,
   /// assuming it has at least one field. When it has one field, we just return
   /// the hash code of that field. Otherwise, we multiply it with 31 and add
   /// the hash code of the next field, and so on.
   String _calculateHashCode(List<String> fields) {
     if (fields.length == 1) {
-      return '${fields.last}.hashCode';
+      return '$_hashCombine(0, ${fields.last}.hashCode)';
     } else {
       final last = fields.removeLast();
       final innerHash = _calculateHashCode(fields);
 
-      return '($innerHash) * 31 + $last.hashCode';
+      return '$_hashFinish($innerHash, $last.hashCode)';
     }
   }
 }