netwerk/base/nsURIHashKey.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5 #ifndef nsURIHashKey_h__
   6 #define nsURIHashKey_h__
   7
   8 #include <utility>
   9
  10 #include "PLDHashTable.h"
  11 #include "mozilla/Unused.h"
  12 #include "nsCOMPtr.h"
  13 #include "nsHashKeys.h"
  14 #include "nsIURI.h"
  15
  16 /**
  17  * Hashtable key class to use with nsTHashtable/nsBaseHashtable
  18  */
  19 class nsURIHashKey : public PLDHashEntryHdr {
  20  public:
  21   typedef nsIURI* KeyType;
  22   typedef const nsIURI* KeyTypePointer;
  23
  24   nsURIHashKey() { MOZ_COUNT_CTOR(nsURIHashKey); }
  25   explicit nsURIHashKey(const nsIURI* aKey) : mKey(const_cast<nsIURI*>(aKey)) {
  26     MOZ_COUNT_CTOR(nsURIHashKey);
  27   }
  28   nsURIHashKey(nsURIHashKey&& toMove)
  29       : PLDHashEntryHdr(std::move(toMove)), mKey(std::move(toMove.mKey)) {
  30     MOZ_COUNT_CTOR(nsURIHashKey);
  31   }
  32   MOZ_COUNTED_DTOR(nsURIHashKey)
  33
  34   nsURIHashKey& operator=(const nsURIHashKey& aOther) {
  35     mKey = aOther.mKey;
  36     return *this;
  37   }
  38
  39   nsIURI* GetKey() const { return mKey; }
  40
  41   bool KeyEquals(const nsIURI* aKey) const {
  42     bool eq;
  43     if (!mKey) {
  44       return !aKey;
  45     }
  46     if (NS_SUCCEEDED(mKey->Equals(const_cast<nsIURI*>(aKey), &eq))) {
  47       return eq;
  48     }
  49     return false;
  50   }
  51
  52   static const nsIURI* KeyToPointer(nsIURI* aKey) { return aKey; }
  53   static PLDHashNumber HashKey(const nsIURI* aKey) {
  54     if (!aKey) {
  55       // If the key is null, return hash for empty string.
  56       return mozilla::HashString(""_ns);
  57     }
  58     nsAutoCString spec;
  59     // If GetSpec() fails, ignoring the failure and proceeding with an
  60     // empty |spec| seems like the best thing to do.
  61     mozilla::Unused << const_cast<nsIURI*>(aKey)->GetSpec(spec);
  62     return mozilla::HashString(spec);
  63   }
  64
  65   enum { ALLOW_MEMMOVE = true };
  66
  67  protected:
  68   nsCOMPtr<nsIURI> mKey;
  69 };
  70
  71 #endif  // nsURIHashKey_h__