gecko-dev/image/ImageCacheKey.h
Emilio Cobos Álvarez 96b0ee6817 Bug 1665343 - Remove blob specialness in image cache. r=tnikkel
We use it to merge blobs, but that doesn't match the spec. Per:

  https://html.spec.whatwg.org/#the-list-of-available-images

We should key off the URI, and thus a revoked image should be able to be
reused if the request is cached. This works to allow printing revoked
blob images, which other browsers allow.

I don't see any way to make that work easily while preserving the blob
image optimization. That being said, it seems other browsers also
re-decode when creating different URLs for the same blob (see the
test-case attached to the bug), so it seems we should be able to live
without it.

Differential Revision: https://phabricator.services.mozilla.com/D90544
2020-09-22 22:02:42 +00:00

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2.5 KiB
C++

/* -*- 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"
#include "PLDHashTable.h"
class nsIURI;
namespace mozilla {
namespace image {
/**
* 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,
dom::Document* aDocument);
ImageCacheKey(const ImageCacheKey& aOther);
ImageCacheKey(ImageCacheKey&& aOther);
bool operator==(const ImageCacheKey& aOther) const;
PLDHashNumber Hash() const {
if (MOZ_UNLIKELY(mHash.isNothing())) {
EnsureHash();
}
return mHash.value();
}
/// A weak pointer to the URI.
nsIURI* URI() const { return mURI; }
const OriginAttributes& OriginAttributesRef() const {
return mOriginAttributes;
}
/// 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:
// For ServiceWorker we need to use the document as
// token for the key. All those exceptions are handled by this method.
static void* GetSpecialCaseDocumentToken(dom::Document* aDocument);
// For anti-tracking we need to use an isolation key. It can be the suffix of
// the PatitionedPrincipal (see StoragePrincipalHelper.h) or the top-level
// document's base domain. This is handled by this method.
static nsCString GetIsolationKey(dom::Document* aDocument, nsIURI* aURI);
void EnsureHash() const;
nsCOMPtr<nsIURI> mURI;
OriginAttributes mOriginAttributes;
void* mControlledDocument;
nsCString mIsolationKey;
mutable Maybe<PLDHashNumber> mHash;
bool mIsChrome;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_src_ImageCacheKey_h