1 files changed, 54 insertions, 0 deletions
diff --git a/deps/v8/src/compiler/refs-map.h b/deps/v8/src/compiler/refs-map.h
new file mode 100644
index 0000000000..daaf433049
--- /dev/null
+++ b/deps/v8/src/compiler/refs-map.h
@@ -0,0 +1,54 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_COMPILER_REFS_MAP_H_
+#define V8_COMPILER_REFS_MAP_H_
+
+#include "src/base/hashmap.h"
+#include "src/globals.h"
+#include "src/zone/zone.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+class ObjectData;
+
+class AddressMatcher : public base::KeyEqualityMatcher<Address> {
+ public:
+  bool operator()(uint32_t hash1, uint32_t hash2, const Address& key1,
+                  const Address& key2) const {
+    return key1 == key2;
+  }
+};
+
+// This class employs our own implementation of hash map for the purpose of
+// storing the mapping between canonical Addresses and allocated ObjectData.
+// It's used as the refs map in JSHeapBroker and as the snapshot in
+// PerIsolateCompilerCache, as we need a cheap copy between the two and
+// std::unordered_map doesn't satisfy this requirement, as it rehashes the
+// whole map and copies all entries one by one.
+class RefsMap
+    : public base::TemplateHashMapImpl<Address, ObjectData*, AddressMatcher,
+                                       ZoneAllocationPolicy>,
+      public ZoneObject {
+ public:
+  RefsMap(uint32_t capacity, AddressMatcher match, Zone* zone);
+  RefsMap(const RefsMap* other, Zone* zone);
+
+  bool IsEmpty() const { return occupancy() == 0; }
+
+  // Wrappers around methods from UnderlyingMap
+  Entry* Lookup(const Address& key) const;
+  Entry* LookupOrInsert(const Address& key, Zone* zone);
+
+ private:
+  static uint32_t Hash(Address addr);
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_REFS_MAP_H_