ImageCacheKey.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * ImageCacheKey is the key type for the image cache (see imgLoader.h).
 */

#ifndef mozilla_image_src_ImageCacheKey_h
#define mozilla_image_src_ImageCacheKey_h

#include "mozilla/BasePrincipal.h"
#include "mozilla/Maybe.h"
#include "mozilla/RefPtr.h"

class nsIDocument;
class nsIURI;

namespace mozilla {
namespace image {

class ImageURL;

/**
 * An ImageLib cache entry key.
 *
 * We key the cache on the initial URI (before any redirects), with some
 * canonicalization applied. See ComputeHash() for the details.
 * Controlled documents do not share their cache entries with
 * non-controlled documents, or other controlled documents.
 */
class ImageCacheKey final
{
public:
  ImageCacheKey(nsIURI* aURI, const OriginAttributes& aAttrs,
                nsIDocument* aDocument, nsresult& aRv);
  ImageCacheKey(ImageURL* aURI, const OriginAttributes& aAttrs,
                nsIDocument* aDocument);

  ImageCacheKey(const ImageCacheKey& aOther);
  ImageCacheKey(ImageCacheKey&& aOther);

  bool operator==(const ImageCacheKey& aOther) const;
  PLDHashNumber Hash() const { return mHash; }

  /// A weak pointer to the URI spec for this cache entry. For logging only.
  const char* Spec() const;

  /// Is this cache entry for a chrome image?
  bool IsChrome() const { return mIsChrome; }

  /// A token indicating which service worker controlled document this entry
  /// belongs to, if any.
  void* ControlledDocument() const { return mControlledDocument; }

private:
  static PLDHashNumber ComputeHash(ImageURL* aURI,
                                   const Maybe<uint64_t>& aBlobSerial,
                                   const OriginAttributes& aAttrs,
                                   void* aControlledDocument,
                                   bool aIsStyloEnabled);
  static void* GetControlledDocumentToken(nsIDocument* aDocument);

  RefPtr<ImageURL> mURI;
  Maybe<uint64_t> mBlobSerial;
  OriginAttributes mOriginAttributes;
  void* mControlledDocument;
  PLDHashNumber mHash;
  bool mIsChrome;
  // To prevent the reftests of styloVsGecko taking the same image cache after
  // refreshing, we need to store different caches of stylo and gecko. So, we
  // also consider the info of StyloEnabled() in ImageCacheKey.
  bool mIsStyloEnabled;
};

} // namespace image
} // namespace mozilla

#endif // mozilla_image_src_ImageCacheKey_h