image/imgLoader.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_image_imgLoader_h
   8 #define mozilla_image_imgLoader_h
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/CORSMode.h"
  12 #include "mozilla/Mutex.h"
  13 #include "mozilla/EnumSet.h"
  14 #include "mozilla/UniquePtr.h"
  15
  16 #include "imgILoader.h"
  17 #include "imgICache.h"
  18 #include "nsWeakReference.h"
  19 #include "nsIContentSniffer.h"
  20 #include "nsRefPtrHashtable.h"
  21 #include "nsTHashSet.h"
  22 #include "nsExpirationTracker.h"
  23 #include "ImageCacheKey.h"
  24 #include "imgRequest.h"
  25 #include "nsIProgressEventSink.h"
  26 #include "nsIChannel.h"
  27 #include "nsIThreadRetargetableStreamListener.h"
  28 #include "imgIRequest.h"
  29
  30 class imgLoader;
  31 class imgRequestProxy;
  32 class imgINotificationObserver;
  33 class nsILoadGroup;
  34 class imgCacheExpirationTracker;
  35 class imgMemoryReporter;
  36
  37 namespace mozilla {
  38 namespace dom {
  39 class Document;
  40 }
  41 }  // namespace mozilla
  42
  43 class imgCacheEntry {
  44  public:
  45   NS_INLINE_DECL_REFCOUNTING(imgCacheEntry)
  46
  47   imgCacheEntry(imgLoader* loader, imgRequest* request,
  48                 bool aForcePrincipalCheck);
  49
  50   uint32_t GetDataSize() const { return mDataSize; }
  51   void SetDataSize(uint32_t aDataSize) {
  52     int32_t oldsize = mDataSize;
  53     mDataSize = aDataSize;
  54     UpdateCache(mDataSize - oldsize);
  55   }
  56
  57   int32_t GetTouchedTime() const { return mTouchedTime; }
  58   void SetTouchedTime(int32_t time) {
  59     mTouchedTime = time;
  60     Touch(/* updateTime = */ false);
  61   }
  62
  63   uint32_t GetLoadTime() const { return mLoadTime; }
  64
  65   void UpdateLoadTime();
  66
  67   uint32_t GetExpiryTime() const { return mExpiryTime; }
  68   void SetExpiryTime(uint32_t aExpiryTime) {
  69     mExpiryTime = aExpiryTime;
  70     Touch();
  71   }
  72
  73   bool GetMustValidate() const { return mMustValidate; }
  74   void SetMustValidate(bool aValidate) {
  75     mMustValidate = aValidate;
  76     Touch();
  77   }
  78
  79   already_AddRefed<imgRequest> GetRequest() const {
  80     RefPtr<imgRequest> req = mRequest;
  81     return req.forget();
  82   }
  83
  84   bool Evicted() const { return mEvicted; }
  85
  86   nsExpirationState* GetExpirationState() { return &mExpirationState; }
  87
  88   bool HasNoProxies() const { return mHasNoProxies; }
  89
  90   bool ForcePrincipalCheck() const { return mForcePrincipalCheck; }
  91
  92   bool HasNotified() const { return mHasNotified; }
  93   void SetHasNotified() {
  94     MOZ_ASSERT(!mHasNotified);
  95     mHasNotified = true;
  96   }
  97
  98   imgLoader* Loader() const { return mLoader; }
  99
 100  private:  // methods
 101   friend class imgLoader;
 102   friend class imgCacheQueue;
 103   void Touch(bool updateTime = true);
 104   void UpdateCache(int32_t diff = 0);
 105   void SetEvicted(bool evict) { mEvicted = evict; }
 106   void SetHasNoProxies(bool hasNoProxies);
 107
 108   // Private, unimplemented copy constructor.
 109   imgCacheEntry(const imgCacheEntry&);
 110   ~imgCacheEntry();
 111
 112  private:  // data
 113   imgLoader* mLoader;
 114   RefPtr<imgRequest> mRequest;
 115   uint32_t mDataSize;
 116   int32_t mTouchedTime;
 117   uint32_t mLoadTime;
 118   uint32_t mExpiryTime;
 119   nsExpirationState mExpirationState;
 120   bool mMustValidate : 1;
 121   bool mEvicted : 1;
 122   bool mHasNoProxies : 1;
 123   bool mForcePrincipalCheck : 1;
 124   bool mHasNotified : 1;
 125 };
 126
 127 #include <vector>
 128
 129 #define NS_IMGLOADER_CID                             \
 130   { /* c1354898-e3fe-4602-88a7-c4520c21cb4e */       \
 131     0xc1354898, 0xe3fe, 0x4602, {                    \
 132       0x88, 0xa7, 0xc4, 0x52, 0x0c, 0x21, 0xcb, 0x4e \
 133     }                                                \
 134   }
 135
 136 class imgCacheQueue {
 137  public:
 138   imgCacheQueue();
 139   void Remove(imgCacheEntry*);
 140   void Push(imgCacheEntry*);
 141   void MarkDirty();
 142   bool IsDirty();
 143   already_AddRefed<imgCacheEntry> Pop();
 144   void Refresh();
 145   uint32_t GetSize() const;
 146   void UpdateSize(int32_t diff);
 147   uint32_t GetNumElements() const;
 148   bool Contains(imgCacheEntry* aEntry) const;
 149   typedef nsTArray<RefPtr<imgCacheEntry>> queueContainer;
 150   typedef queueContainer::iterator iterator;
 151   typedef queueContainer::const_iterator const_iterator;
 152
 153   iterator begin();
 154   const_iterator begin() const;
 155   iterator end();
 156   const_iterator end() const;
 157
 158  private:
 159   queueContainer mQueue;
 160   bool mDirty;
 161   uint32_t mSize;
 162 };
 163
 164 enum class AcceptedMimeTypes : uint8_t {
 165   IMAGES,
 166   IMAGES_AND_DOCUMENTS,
 167 };
 168
 169 class imgLoader final : public imgILoader,
 170                         public nsIContentSniffer,
 171                         public imgICache,
 172                         public nsSupportsWeakReference,
 173                         public nsIObserver {
 174   virtual ~imgLoader();
 175
 176  public:
 177   using ImageCacheKey = mozilla::image::ImageCacheKey;
 178   using imgCacheTable =
 179       nsRefPtrHashtable<nsGenericHashKey<ImageCacheKey>, imgCacheEntry>;
 180   using imgSet = nsTHashSet<imgRequest*>;
 181   using Mutex = mozilla::Mutex;
 182
 183   NS_DECL_ISUPPORTS
 184   NS_DECL_IMGILOADER
 185   NS_DECL_NSICONTENTSNIFFER
 186   NS_DECL_IMGICACHE
 187   NS_DECL_NSIOBSERVER
 188
 189   /**
 190    * Get the normal image loader instance that is used by gecko code, creating
 191    * it if necessary.
 192    */
 193   static imgLoader* NormalLoader();
 194
 195   /**
 196    * Get the Private Browsing image loader instance that is used by gecko code,
 197    * creating it if necessary.
 198    */
 199   static imgLoader* PrivateBrowsingLoader();
 200
 201   /**
 202    * Gecko code should use NormalLoader() or PrivateBrowsingLoader() to get the
 203    * appropriate image loader.
 204    *
 205    * This constructor is public because the XPCOM module code that creates
 206    * instances of "@mozilla.org/image/loader;1" / "@mozilla.org/image/cache;1"
 207    * for nsIComponentManager.createInstance()/nsIServiceManager.getService()
 208    * calls (now only made by add-ons) needs access to it.
 209    *
 210    * XXX We would like to get rid of the nsIServiceManager.getService (and
 211    * nsIComponentManager.createInstance) method of creating imgLoader objects,
 212    * but there are add-ons that are still using it.  These add-ons don't
 213    * actually do anything useful with the loaders that they create since nobody
 214    * who creates an imgLoader using this method actually QIs to imgILoader and
 215    * loads images.  They all just QI to imgICache and either call clearCache()
 216    * or findEntryProperties().  Since they're doing this on an imgLoader that
 217    * has never loaded images, these calls are useless.  It seems likely that
 218    * the code that is doing this is just legacy code left over from a time when
 219    * there was only one imgLoader instance for the entire process.  (Nowadays
 220    * the correct method to get an imgILoader/imgICache is to call
 221    * imgITools::getImgCacheForDocument/imgITools::getImgLoaderForDocument.)
 222    * All the same, even though what these add-ons are doing is a no-op,
 223    * removing the nsIServiceManager.getService method of creating/getting an
 224    * imgLoader objects would cause an exception in these add-ons that could
 225    * break things.
 226    */
 227   imgLoader();
 228   nsresult Init();
 229
 230   bool IsImageAvailable(nsIURI*, nsIPrincipal* aTriggeringPrincipal,
 231                         mozilla::CORSMode, mozilla::dom::Document*);
 232
 233   [[nodiscard]] nsresult LoadImage(
 234       nsIURI* aURI, nsIURI* aInitialDocumentURI, nsIReferrerInfo* aReferrerInfo,
 235       nsIPrincipal* aLoadingPrincipal, uint64_t aRequestContextID,
 236       nsILoadGroup* aLoadGroup, imgINotificationObserver* aObserver,
 237       nsINode* aContext, mozilla::dom::Document* aLoadingDocument,
 238       nsLoadFlags aLoadFlags, nsISupports* aCacheKey,
 239       nsContentPolicyType aContentPolicyType, const nsAString& initiatorType,
 240       bool aUseUrgentStartForChannel, bool aLinkPreload,
 241       uint64_t aEarlyHintPreloaderId, imgRequestProxy** _retval);
 242
 243   [[nodiscard]] nsresult LoadImageWithChannel(
 244       nsIChannel* channel, imgINotificationObserver* aObserver,
 245       mozilla::dom::Document* aLoadingDocument, nsIStreamListener** listener,
 246       imgRequestProxy** _retval);
 247
 248   static nsresult GetMimeTypeFromContent(const char* aContents,
 249                                          uint32_t aLength,
 250                                          nsACString& aContentType);
 251
 252   /**
 253    * Returns true if the given mime type may be interpreted as an image.
 254    *
 255    * Some MIME types may be interpreted as both images and documents. (At the
 256    * moment only "image/svg+xml" falls into this category, but there may be more
 257    * in the future.) Callers which want this function to return true for such
 258    * MIME types should pass AcceptedMimeTypes::IMAGES_AND_DOCUMENTS for
 259    * @aAccept.
 260    *
 261    * @param aMimeType The MIME type to evaluate.
 262    * @param aAcceptedMimeTypes Which kinds of MIME types to treat as images.
 263    */
 264   static bool SupportImageWithMimeType(
 265       const nsACString&, AcceptedMimeTypes aAccept = AcceptedMimeTypes::IMAGES);
 266
 267   static void GlobalInit();  // for use by the factory
 268   static void Shutdown();    // for use by the factory
 269   static void ShutdownMemoryReporter();
 270
 271   enum class ClearOption {
 272     ChromeOnly,
 273     UnusedOnly,
 274   };
 275   using ClearOptions = mozilla::EnumSet<ClearOption>;
 276   nsresult ClearImageCache(ClearOptions = {});
 277   void MinimizeCache() { ClearImageCache({ClearOption::UnusedOnly}); }
 278
 279   nsresult InitCache();
 280
 281   bool RemoveFromCache(const ImageCacheKey& aKey);
 282
 283   // Enumeration describing if a given entry is in the cache queue or not.
 284   // There are some cases we know the entry is definitely not in the queue.
 285   enum class QueueState { MaybeExists, AlreadyRemoved };
 286
 287   bool RemoveFromCache(imgCacheEntry* entry,
 288                        QueueState aQueueState = QueueState::MaybeExists);
 289
 290   bool PutIntoCache(const ImageCacheKey& aKey, imgCacheEntry* aEntry);
 291
 292   void AddToUncachedImages(imgRequest* aRequest);
 293   void RemoveFromUncachedImages(imgRequest* aRequest);
 294
 295   // Returns true if we should prefer evicting cache entry |two| over cache
 296   // entry |one|.
 297   // This mixes units in the worst way, but provides reasonable results.
 298   inline static bool CompareCacheEntries(const RefPtr<imgCacheEntry>& one,
 299                                          const RefPtr<imgCacheEntry>& two) {
 300     if (!one) {
 301       return false;
 302     }
 303     if (!two) {
 304       return true;
 305     }
 306
 307     const double sizeweight = 1.0 - sCacheTimeWeight;
 308
 309     // We want large, old images to be evicted first (depending on their
 310     // relative weights). Since a larger time is actually newer, we subtract
 311     // time's weight, so an older image has a larger weight.
 312     double oneweight = double(one->GetDataSize()) * sizeweight -
 313                        double(one->GetTouchedTime()) * sCacheTimeWeight;
 314     double twoweight = double(two->GetDataSize()) * sizeweight -
 315                        double(two->GetTouchedTime()) * sCacheTimeWeight;
 316
 317     return oneweight < twoweight;
 318   }
 319
 320   void VerifyCacheSizes();
 321
 322   nsresult RemoveEntriesInternal(nsIPrincipal* aPrincipal,
 323                                  const nsACString* aBaseDomain);
 324
 325   // The image loader maintains a hash table of all imgCacheEntries. However,
 326   // only some of them will be evicted from the cache: those who have no
 327   // imgRequestProxies watching their imgRequests.
 328   //
 329   // Once an imgRequest has no imgRequestProxies, it should notify us by
 330   // calling HasNoObservers(), and null out its cache entry pointer.
 331   //
 332   // Upon having a proxy start observing again, it should notify us by calling
 333   // HasObservers(). The request's cache entry will be re-set before this
 334   // happens, by calling imgRequest::SetCacheEntry() when an entry with no
 335   // observers is re-requested.
 336   bool SetHasNoProxies(imgRequest* aRequest, imgCacheEntry* aEntry);
 337   bool SetHasProxies(imgRequest* aRequest);
 338
 339  private:  // methods
 340   static already_AddRefed<imgLoader> CreateImageLoader();
 341
 342   bool ValidateEntry(imgCacheEntry* aEntry, nsIURI* aURI,
 343                      nsIURI* aInitialDocumentURI,
 344                      nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 345                      imgINotificationObserver* aObserver,
 346                      mozilla::dom::Document* aLoadingDocument,
 347                      nsLoadFlags aLoadFlags,
 348                      nsContentPolicyType aLoadPolicyType,
 349                      bool aCanMakeNewChannel, bool* aNewChannelCreated,
 350                      imgRequestProxy** aProxyRequest,
 351                      nsIPrincipal* aTriggeringPrincipal, mozilla::CORSMode,
 352                      bool aLinkPreload, uint64_t aEarlyHintPreloaderId);
 353
 354   bool ValidateRequestWithNewChannel(
 355       imgRequest* request, nsIURI* aURI, nsIURI* aInitialDocumentURI,
 356       nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 357       imgINotificationObserver* aObserver,
 358       mozilla::dom::Document* aLoadingDocument, uint64_t aInnerWindowId,
 359       nsLoadFlags aLoadFlags, nsContentPolicyType aContentPolicyType,
 360       imgRequestProxy** aProxyRequest, nsIPrincipal* aLoadingPrincipal,
 361       mozilla::CORSMode, bool aLinkPreload, uint64_t aEarlyHintPreloaderId,
 362       bool* aNewChannelCreated);
 363
 364   void NotifyObserversForCachedImage(imgCacheEntry* aEntry, imgRequest* request,
 365                                      nsIURI* aURI,
 366                                      nsIReferrerInfo* aReferrerInfo,
 367                                      mozilla::dom::Document* aLoadingDocument,
 368                                      nsIPrincipal* aLoadingPrincipal,
 369                                      mozilla::CORSMode,
 370                                      uint64_t aEarlyHintPreloaderId);
 371   // aURI may be different from imgRequest's URI in the case of blob URIs, as we
 372   // can share requests with different URIs.
 373   nsresult CreateNewProxyForRequest(imgRequest* aRequest, nsIURI* aURI,
 374                                     nsILoadGroup* aLoadGroup,
 375                                     mozilla::dom::Document* aLoadingDocument,
 376                                     imgINotificationObserver* aObserver,
 377                                     nsLoadFlags aLoadFlags,
 378                                     imgRequestProxy** _retval);
 379
 380   nsresult EvictEntries(bool aChromeOnly);
 381
 382   void CacheEntriesChanged(int32_t aSizeDiff);
 383   void CheckCacheLimits();
 384
 385  private:  // data
 386   friend class imgCacheEntry;
 387   friend class imgMemoryReporter;
 388
 389   imgCacheTable mCache;
 390   imgCacheQueue mCacheQueue;
 391
 392   // Hash set of every imgRequest for this loader that isn't in mCache or
 393   // mChromeCache. The union over all imgLoader's of mCache, mChromeCache, and
 394   // mUncachedImages should be every imgRequest that is alive. These are weak
 395   // pointers so we rely on the imgRequest destructor to remove itself.
 396   imgSet mUncachedImages MOZ_GUARDED_BY(mUncachedImagesMutex);
 397   // The imgRequest can have refs to them held on non-main thread, so we need
 398   // a mutex because we modify the uncached images set from the imgRequest
 399   // destructor.
 400   Mutex mUncachedImagesMutex;
 401
 402   static double sCacheTimeWeight;
 403   static uint32_t sCacheMaxSize;
 404   static imgMemoryReporter* sMemReporter;
 405
 406   mozilla::UniquePtr<imgCacheExpirationTracker> mCacheTracker;
 407   bool mRespectPrivacy;
 408 };
 409
 410 /**
 411  * proxy stream listener class used to handle multipart/x-mixed-replace
 412  */
 413
 414 #include "nsCOMPtr.h"
 415 #include "nsIStreamListener.h"
 416 #include "nsIThreadRetargetableStreamListener.h"
 417
 418 class ProxyListener : public nsIStreamListener,
 419                       public nsIThreadRetargetableStreamListener {
 420  public:
 421   explicit ProxyListener(nsIStreamListener* dest);
 422
 423   /* additional members */
 424   NS_DECL_THREADSAFE_ISUPPORTS
 425   NS_DECL_NSISTREAMLISTENER
 426   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 427   NS_DECL_NSIREQUESTOBSERVER
 428
 429  private:
 430   virtual ~ProxyListener();
 431
 432   nsCOMPtr<nsIStreamListener> mDestListener;
 433 };
 434
 435 /**
 436  * A class that implements nsIProgressEventSink and forwards all calls to it to
 437  * the original notification callbacks of the channel. Also implements
 438  * nsIInterfaceRequestor and gives out itself for nsIProgressEventSink calls,
 439  * and forwards everything else to the channel's notification callbacks.
 440  */
 441 class nsProgressNotificationProxy final : public nsIProgressEventSink,
 442                                           public nsIChannelEventSink,
 443                                           public nsIInterfaceRequestor {
 444  public:
 445   nsProgressNotificationProxy(nsIChannel* channel, imgIRequest* proxy)
 446       : mImageRequest(proxy) {
 447     channel->GetNotificationCallbacks(getter_AddRefs(mOriginalCallbacks));
 448   }
 449
 450   NS_DECL_ISUPPORTS
 451   NS_DECL_NSIPROGRESSEVENTSINK
 452   NS_DECL_NSICHANNELEVENTSINK
 453   NS_DECL_NSIINTERFACEREQUESTOR
 454  private:
 455   ~nsProgressNotificationProxy() = default;
 456
 457   nsCOMPtr<nsIInterfaceRequestor> mOriginalCallbacks;
 458   nsCOMPtr<nsIRequest> mImageRequest;
 459 };
 460
 461 /**
 462  * validate checker
 463  */
 464
 465 #include "nsCOMArray.h"
 466
 467 class imgCacheValidator : public nsIStreamListener,
 468                           public nsIThreadRetargetableStreamListener,
 469                           public nsIChannelEventSink,
 470                           public nsIInterfaceRequestor,
 471                           public nsIAsyncVerifyRedirectCallback {
 472  public:
 473   imgCacheValidator(nsProgressNotificationProxy* progress, imgLoader* loader,
 474                     imgRequest* aRequest, mozilla::dom::Document* aDocument,
 475                     uint64_t aInnerWindowId,
 476                     bool forcePrincipalCheckForCacheEntry);
 477
 478   void AddProxy(imgRequestProxy* aProxy);
 479   void RemoveProxy(imgRequestProxy* aProxy);
 480
 481   NS_DECL_THREADSAFE_ISUPPORTS
 482   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 483   NS_DECL_NSISTREAMLISTENER
 484   NS_DECL_NSIREQUESTOBSERVER
 485   NS_DECL_NSICHANNELEVENTSINK
 486   NS_DECL_NSIINTERFACEREQUESTOR
 487   NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
 488
 489  private:
 490   void UpdateProxies(bool aCancelRequest, bool aSyncNotify);
 491   virtual ~imgCacheValidator();
 492
 493   nsCOMPtr<nsIStreamListener> mDestListener;
 494   RefPtr<nsProgressNotificationProxy> mProgressProxy;
 495   nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
 496   nsCOMPtr<nsIChannel> mRedirectChannel;
 497
 498   RefPtr<imgRequest> mRequest;
 499   AutoTArray<RefPtr<imgRequestProxy>, 4> mProxies;
 500
 501   RefPtr<imgRequest> mNewRequest;
 502   RefPtr<imgCacheEntry> mNewEntry;
 503
 504   RefPtr<mozilla::dom::Document> mDocument;
 505   uint64_t mInnerWindowId;
 506
 507   imgLoader* mImgLoader;
 508
 509   bool mHadInsecureRedirect;
 510 };
 511
 512 #endif  // mozilla_image_imgLoader_h