Canonicalize generic types in an isolate specific hash table

runtime/vm/type_table.h

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_TYPE_TABLE_H_
+#define VM_TYPE_TABLE_H_
+
+#include "platform/assert.h"
+#include "vm/hash_table.h"
+#include "vm/object.h"
+
+namespace dart {
+
+class CanonicalTypeKey {
+ public:
+  explicit CanonicalTypeKey(const Type& key) : key_(key) {
+  }
+  bool Matches(const Type& arg) const {
+    return key_.Equals(arg);
+  }
+  uword Hash() const {
+    return key_.Hash();
+  }
+  const Type& key_;
+
+ private:
+  DISALLOW_ALLOCATION();
+};
+
+
+// Traits for looking up Canonical Type based on it's hash.
+class CanonicalTypeTraits {
+ public:
+  static const char* Name() { return "CanonicalTypeTraits"; }
+  static bool ReportStats() { return false; }
+
+  // Called when growing the table.
+  static bool IsMatch(const Object& a, const Object& b) {
+    ASSERT(a.IsType() && b.IsType());
+    const Type& arg1 = Type::Cast(a);
+    const Type& arg2 = Type::Cast(b);
+    return arg1.Equals(arg2) && (arg1.Hash() == arg2.Hash());
+  }
+  static bool IsMatch(const CanonicalTypeKey& a, const Object& b) {
+    ASSERT(b.IsType());
+    return a.Matches(Type::Cast(b));
+  }
+  static uword Hash(const Object& key) {
+    ASSERT(key.IsType());
+    return Type::Cast(key).Hash();
+  }
+  static uword Hash(const CanonicalTypeKey& key) {
+    return key.Hash();
+  }
+  static RawObject* NewKey(const CanonicalTypeKey& obj) {
+    return obj.key_.raw();
+  }
+};
+typedef UnorderedHashSet <CanonicalTypeTraits> CanonicalTypeSet;
+
+
+class CanonicalTypeArgumentsKey {
+ public:
+  explicit CanonicalTypeArgumentsKey(const TypeArguments& key) : key_(key) {
+  }
+  bool Matches(const TypeArguments& arg) const {
+    return key_.Equals(arg) && (key_.Hash() == arg.Hash());
+  }
+  uword Hash() const {
+    return key_.Hash();
+  }
+  const TypeArguments& key_;
+
+ private:
+  DISALLOW_ALLOCATION();
+};
+
+
+// Traits for looking up Canonical TypeArguments based on its hash.
+class CanonicalTypeArgumentsTraits {
+ public:
+  static const char* Name() { return "CanonicalTypeArgumentsTraits"; }
+  static bool ReportStats() { return false; }
+
+  // Called when growing the table.
+  static bool IsMatch(const Object& a, const Object& b) {
+    ASSERT(a.IsTypeArguments() && b.IsTypeArguments());
+    const TypeArguments& arg1 = TypeArguments::Cast(a);
+    const TypeArguments& arg2 = TypeArguments::Cast(b);
+    return arg1.Equals(arg2) && (arg1.Hash() == arg2.Hash());
+  }
+  static bool IsMatch(const CanonicalTypeArgumentsKey& a, const Object& b) {
+    ASSERT(b.IsTypeArguments());
+    return a.Matches(TypeArguments::Cast(b));
+  }
+  static uword Hash(const Object& key) {
+    ASSERT(key.IsTypeArguments());
+    return TypeArguments::Cast(key).Hash();
+  }
+  static uword Hash(const CanonicalTypeArgumentsKey& key) {
+    return key.Hash();
+  }
+  static RawObject* NewKey(const CanonicalTypeArgumentsKey& obj) {
+    return obj.key_.raw();
+  }
+};
+typedef UnorderedHashSet<CanonicalTypeArgumentsTraits>
+    CanonicalTypeArgumentsSet;
+
+}  // namespace dart
+
+#endif  // VM_TYPE_TABLE_H_