image/ImageCacheKey.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
   6 /**
   7  * ImageCacheKey is the key type for the image cache (see imgLoader.h).
   8  */
   9
  10 #ifndef mozilla_image_src_ImageCacheKey_h
  11 #define mozilla_image_src_ImageCacheKey_h
  12
  13 #include "mozilla/BasePrincipal.h"
  14 #include "mozilla/Maybe.h"
  15 #include "mozilla/RefPtr.h"
  16 #include "PLDHashTable.h"
  17
  18 class nsIURI;
  19
  20 namespace mozilla {
  21 namespace image {
  22
  23 /**
  24  * An ImageLib cache entry key.
  25  *
  26  * We key the cache on the initial URI (before any redirects), with some
  27  * canonicalization applied. See ComputeHash() for the details.
  28  * Controlled documents do not share their cache entries with
  29  * non-controlled documents, or other controlled documents.
  30  */
  31 class ImageCacheKey final {
  32  public:
  33   ImageCacheKey(nsIURI* aURI, const OriginAttributes& aAttrs,
  34                 dom::Document* aDocument);
  35
  36   ImageCacheKey(const ImageCacheKey& aOther);
  37   ImageCacheKey(ImageCacheKey&& aOther);
  38
  39   bool operator==(const ImageCacheKey& aOther) const;
  40   PLDHashNumber Hash() const {
  41     if (MOZ_UNLIKELY(mHash.isNothing())) {
  42       EnsureHash();
  43     }
  44     return mHash.value();
  45   }
  46
  47   /// A weak pointer to the URI.
  48   nsIURI* URI() const { return mURI; }
  49
  50   const OriginAttributes& OriginAttributesRef() const {
  51     return mOriginAttributes;
  52   }
  53
  54   /// Is this cache entry for a chrome image?
  55   bool IsChrome() const { return mIsChrome; }
  56
  57   /// A token indicating which service worker controlled document this entry
  58   /// belongs to, if any.
  59   void* ControlledDocument() const { return mControlledDocument; }
  60
  61  private:
  62   // For ServiceWorker we need to use the document as
  63   // token for the key. All those exceptions are handled by this method.
  64   static void* GetSpecialCaseDocumentToken(dom::Document* aDocument);
  65
  66   // For anti-tracking we need to use an isolation key. It can be the suffix of
  67   // the PatitionedPrincipal (see StoragePrincipalHelper.h) or the top-level
  68   // document's base domain. This is handled by this method.
  69   static nsCString GetIsolationKey(dom::Document* aDocument, nsIURI* aURI);
  70
  71   void EnsureHash() const;
  72
  73   nsCOMPtr<nsIURI> mURI;
  74   OriginAttributes mOriginAttributes;
  75   void* mControlledDocument;
  76   nsCString mIsolationKey;
  77   mutable Maybe<PLDHashNumber> mHash;
  78   bool mIsChrome;
  79 };
  80
  81 }  // namespace image
  82 }  // namespace mozilla
  83
  84 #endif  // mozilla_image_src_ImageCacheKey_h