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
  22 enum CORSMode : uint8_t;
  23
  24 namespace image {
  25
  26 /**
  27  * An ImageLib cache entry key.
  28  *
  29  * We key the cache on the initial URI (before any redirects), with some
  30  * canonicalization applied. See ComputeHash() for the details.
  31  * Controlled documents do not share their cache entries with
  32  * non-controlled documents, or other controlled documents.
  33  */
  34 class ImageCacheKey final {
  35  public:
  36   ImageCacheKey(nsIURI*, CORSMode, const OriginAttributes&, dom::Document*);
  37
  38   ImageCacheKey(const ImageCacheKey& aOther);
  39   ImageCacheKey(ImageCacheKey&& aOther);
  40
  41   bool operator==(const ImageCacheKey& aOther) const;
  42   PLDHashNumber Hash() const {
  43     if (MOZ_UNLIKELY(mHash.isNothing())) {
  44       EnsureHash();
  45     }
  46     return mHash.value();
  47   }
  48
  49   /// A weak pointer to the URI.
  50   nsIURI* URI() const { return mURI; }
  51
  52   CORSMode GetCORSMode() const { return mCORSMode; }
  53
  54   const OriginAttributes& OriginAttributesRef() const {
  55     return mOriginAttributes;
  56   }
  57
  58   const nsCString& IsolationKeyRef() const { return mIsolationKey; }
  59
  60   /// A token indicating which service worker controlled document this entry
  61   /// belongs to, if any.
  62   void* ControlledDocument() const { return mControlledDocument; }
  63
  64  private:
  65   // For ServiceWorker we need to use the document as
  66   // token for the key. All those exceptions are handled by this method.
  67   static void* GetSpecialCaseDocumentToken(dom::Document* aDocument);
  68
  69   // For anti-tracking we need to use an isolation key. It can be the suffix of
  70   // the PatitionedPrincipal (see StoragePrincipalHelper.h) or the top-level
  71   // document's base domain. This is handled by this method.
  72   static nsCString GetIsolationKey(dom::Document* aDocument, nsIURI* aURI);
  73
  74   void EnsureHash() const;
  75
  76   nsCOMPtr<nsIURI> mURI;
  77   const OriginAttributes mOriginAttributes;
  78   void* mControlledDocument;
  79   nsCString mIsolationKey;
  80   mutable Maybe<PLDHashNumber> mHash;
  81   const CORSMode mCORSMode;
  82 };
  83
  84 }  // namespace image
  85 }  // namespace mozilla
  86
  87 #endif  // mozilla_image_src_ImageCacheKey_h