Separate preaload matching from MemoryCache

third_party/WebKit/Source/platform/loader/fetch/PreloadKey.h

+// Copyright 2017 The Chromium 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 PreloadKey_h
+#define PreloadKey_h
+
+#include "platform/loader/fetch/Resource.h"
+#include "platform/weborigin/KURL.h"
+#include "platform/weborigin/KURLHash.h"
+#include "platform/wtf/HashTraits.h"
+
+namespace blink {
+
+// PreloadKey is a key type of the prealods map in a fetch group (a.k.a.
+// blink::ResourceFetcher).
+struct PreloadKey final {
+ public:
+  struct Hash {
+    STATIC_ONLY(Hash);
+
+   public:
+    static unsigned GetHash(const PreloadKey& key) {
+      return KURLHash::GetHash(key.url);
+    }
+    static bool Equal(const PreloadKey& x, const PreloadKey& y) {
+      return x == y;
+    }
+    static constexpr bool safe_to_compare_to_empty_or_deleted = false;
+  };
+
+  PreloadKey() = default;
+  PreloadKey(WTF::HashTableDeletedValueType)
+      : url(WTF::kHashTableDeletedValue) {}
+  PreloadKey(const KURL& url, Resource::Type type)
+      : url(FragmentRemovedUrl(url)), type(type) {}
+
+  bool IsHashTableDeletedValue() const { return url.IsHashTableDeletedValue(); }
+
+  bool operator==(const PreloadKey& x) const {
+    return url == x.url && type == x.type;
+  }
+
+  static KURL FragmentRemovedUrl(const KURL& src) {

[Nate Chapin, 2017/05/02 00:02:16]

RemoveFragmentFromUrl() would be a little clearer.

[yhirano, 2017/05/02 10:22:17]

Done.

+    if (!src.HasFragmentIdentifier())
+      return src;
+    KURL url = src;
+    url.RemoveFragmentIdentifier();
+    return url;
+  }
+
+  KURL url;
+  Resource::Type type = Resource::kMainResource;
+};
+
+}  // namespace blink
+
+namespace WTF {
+
+template <>
+struct DefaultHash<blink::PreloadKey> {
+  using Hash = blink::PreloadKey::Hash;
+};
+
+template <>
+struct HashTraits<blink::PreloadKey>
+    : public SimpleClassHashTraits<blink::PreloadKey> {};
+
+}  // namespace WTF
+
+#endif  // PreloadKey_h