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/UniquePtr.h"
  14
  15 #include "imgILoader.h"
  16 #include "imgICache.h"
  17 #include "nsWeakReference.h"
  18 #include "nsIContentSniffer.h"
  19 #include "nsRefPtrHashtable.h"
  20 #include "nsTHashSet.h"
  21 #include "nsExpirationTracker.h"
  22 #include "ImageCacheKey.h"
  23 #include "imgRequest.h"
  24 #include "nsIProgressEventSink.h"
  25 #include "nsIChannel.h"
  26 #include "nsIThreadRetargetableStreamListener.h"
  27 #include "imgIRequest.h"
  28
  29 class imgLoader;
  30 class imgRequestProxy;
  31 class imgINotificationObserver;
  32 class nsILoadGroup;
  33 class imgCacheExpirationTracker;
  34 class imgMemoryReporter;
  35
  36 namespace mozilla {
  37 namespace dom {
  38 class Document;
  39 }
  40 }  // namespace mozilla
  41
  42 class imgCacheEntry {
  43  public:
  44   imgCacheEntry(imgLoader* loader, imgRequest* request,
  45                 bool aForcePrincipalCheck);
  46   ~imgCacheEntry();
  47
  48   nsrefcnt AddRef() {
  49     MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");
  50     NS_ASSERT_OWNINGTHREAD(imgCacheEntry);
  51     ++mRefCnt;
  52     NS_LOG_ADDREF(this, mRefCnt, "imgCacheEntry", sizeof(*this));
  53     return mRefCnt;
  54   }
  55
  56   nsrefcnt Release() {
  57     MOZ_ASSERT(0 != mRefCnt, "dup release");
  58     NS_ASSERT_OWNINGTHREAD(imgCacheEntry);
  59     --mRefCnt;
  60     NS_LOG_RELEASE(this, mRefCnt, "imgCacheEntry");
  61     if (mRefCnt == 0) {
  62       mRefCnt = 1; /* stabilize */
  63       delete this;
  64       return 0;
  65     }
  66     return mRefCnt;
  67   }
  68
  69   uint32_t GetDataSize() const { return mDataSize; }
  70   void SetDataSize(uint32_t aDataSize) {
  71     int32_t oldsize = mDataSize;
  72     mDataSize = aDataSize;
  73     UpdateCache(mDataSize - oldsize);
  74   }
  75
  76   int32_t GetTouchedTime() const { return mTouchedTime; }
  77   void SetTouchedTime(int32_t time) {
  78     mTouchedTime = time;
  79     Touch(/* updateTime = */ false);
  80   }
  81
  82   uint32_t GetLoadTime() const { return mLoadTime; }
  83
  84   void UpdateLoadTime();
  85
  86   uint32_t GetExpiryTime() const { return mExpiryTime; }
  87   void SetExpiryTime(uint32_t aExpiryTime) {
  88     mExpiryTime = aExpiryTime;
  89     Touch();
  90   }
  91
  92   bool GetMustValidate() const { return mMustValidate; }
  93   void SetMustValidate(bool aValidate) {
  94     mMustValidate = aValidate;
  95     Touch();
  96   }
  97
  98   already_AddRefed<imgRequest> GetRequest() const {
  99     RefPtr<imgRequest> req = mRequest;
 100     return req.forget();
 101   }
 102
 103   bool Evicted() const { return mEvicted; }
 104
 105   nsExpirationState* GetExpirationState() { return &mExpirationState; }
 106
 107   bool HasNoProxies() const { return mHasNoProxies; }
 108
 109   bool ForcePrincipalCheck() const { return mForcePrincipalCheck; }
 110
 111   imgLoader* Loader() const { return mLoader; }
 112
 113  private:  // methods
 114   friend class imgLoader;
 115   friend class imgCacheQueue;
 116   void Touch(bool updateTime = true);
 117   void UpdateCache(int32_t diff = 0);
 118   void SetEvicted(bool evict) { mEvicted = evict; }
 119   void SetHasNoProxies(bool hasNoProxies);
 120
 121   // Private, unimplemented copy constructor.
 122   imgCacheEntry(const imgCacheEntry&);
 123
 124  private:  // data
 125   nsAutoRefCnt mRefCnt;
 126   NS_DECL_OWNINGTHREAD
 127
 128   imgLoader* mLoader;
 129   RefPtr<imgRequest> mRequest;
 130   uint32_t mDataSize;
 131   int32_t mTouchedTime;
 132   uint32_t mLoadTime;
 133   uint32_t mExpiryTime;
 134   nsExpirationState mExpirationState;
 135   bool mMustValidate : 1;
 136   bool mEvicted : 1;
 137   bool mHasNoProxies : 1;
 138   bool mForcePrincipalCheck : 1;
 139 };
 140
 141 #include <vector>
 142
 143 #define NS_IMGLOADER_CID                             \
 144   { /* c1354898-e3fe-4602-88a7-c4520c21cb4e */       \
 145     0xc1354898, 0xe3fe, 0x4602, {                    \
 146       0x88, 0xa7, 0xc4, 0x52, 0x0c, 0x21, 0xcb, 0x4e \
 147     }                                                \
 148   }
 149
 150 class imgCacheQueue {
 151  public:
 152   imgCacheQueue();
 153   void Remove(imgCacheEntry*);
 154   void Push(imgCacheEntry*);
 155   void MarkDirty();
 156   bool IsDirty();
 157   already_AddRefed<imgCacheEntry> Pop();
 158   void Refresh();
 159   uint32_t GetSize() const;
 160   void UpdateSize(int32_t diff);
 161   uint32_t GetNumElements() const;
 162   bool Contains(imgCacheEntry* aEntry) const;
 163   typedef nsTArray<RefPtr<imgCacheEntry>> queueContainer;
 164   typedef queueContainer::iterator iterator;
 165   typedef queueContainer::const_iterator const_iterator;
 166
 167   iterator begin();
 168   const_iterator begin() const;
 169   iterator end();
 170   const_iterator end() const;
 171
 172  private:
 173   queueContainer mQueue;
 174   bool mDirty;
 175   uint32_t mSize;
 176 };
 177
 178 enum class AcceptedMimeTypes : uint8_t {
 179   IMAGES,
 180   IMAGES_AND_DOCUMENTS,
 181 };
 182
 183 class imgLoader final : public imgILoader,
 184                         public nsIContentSniffer,
 185                         public imgICache,
 186                         public nsSupportsWeakReference,
 187                         public nsIObserver {
 188   virtual ~imgLoader();
 189
 190  public:
 191   using ImageCacheKey = mozilla::image::ImageCacheKey;
 192   using imgCacheTable =
 193       nsRefPtrHashtable<nsGenericHashKey<ImageCacheKey>, imgCacheEntry>;
 194   using imgSet = nsTHashSet<imgRequest*>;
 195   using Mutex = mozilla::Mutex;
 196
 197   NS_DECL_ISUPPORTS
 198   NS_DECL_IMGILOADER
 199   NS_DECL_NSICONTENTSNIFFER
 200   NS_DECL_IMGICACHE
 201   NS_DECL_NSIOBSERVER
 202
 203   /**
 204    * Get the normal image loader instance that is used by gecko code, creating
 205    * it if necessary.
 206    */
 207   static imgLoader* NormalLoader();
 208
 209   /**
 210    * Get the Private Browsing image loader instance that is used by gecko code,
 211    * creating it if necessary.
 212    */
 213   static imgLoader* PrivateBrowsingLoader();
 214
 215   /**
 216    * Gecko code should use NormalLoader() or PrivateBrowsingLoader() to get the
 217    * appropriate image loader.
 218    *
 219    * This constructor is public because the XPCOM module code that creates
 220    * instances of "@mozilla.org/image/loader;1" / "@mozilla.org/image/cache;1"
 221    * for nsIComponentManager.createInstance()/nsIServiceManager.getService()
 222    * calls (now only made by add-ons) needs access to it.
 223    *
 224    * XXX We would like to get rid of the nsIServiceManager.getService (and
 225    * nsIComponentManager.createInstance) method of creating imgLoader objects,
 226    * but there are add-ons that are still using it.  These add-ons don't
 227    * actually do anything useful with the loaders that they create since nobody
 228    * who creates an imgLoader using this method actually QIs to imgILoader and
 229    * loads images.  They all just QI to imgICache and either call clearCache()
 230    * or findEntryProperties().  Since they're doing this on an imgLoader that
 231    * has never loaded images, these calls are useless.  It seems likely that
 232    * the code that is doing this is just legacy code left over from a time when
 233    * there was only one imgLoader instance for the entire process.  (Nowadays
 234    * the correct method to get an imgILoader/imgICache is to call
 235    * imgITools::getImgCacheForDocument/imgITools::getImgLoaderForDocument.)
 236    * All the same, even though what these add-ons are doing is a no-op,
 237    * removing the nsIServiceManager.getService method of creating/getting an
 238    * imgLoader objects would cause an exception in these add-ons that could
 239    * break things.
 240    */
 241   imgLoader();
 242   nsresult Init();
 243
 244   bool IsImageAvailable(nsIURI*, nsIPrincipal* aTriggeringPrincipal,
 245                         mozilla::CORSMode, mozilla::dom::Document*);
 246
 247   [[nodiscard]] nsresult LoadImage(
 248       nsIURI* aURI, nsIURI* aInitialDocumentURI, nsIReferrerInfo* aReferrerInfo,
 249       nsIPrincipal* aLoadingPrincipal, uint64_t aRequestContextID,
 250       nsILoadGroup* aLoadGroup, imgINotificationObserver* aObserver,
 251       nsINode* aContext, mozilla::dom::Document* aLoadingDocument,
 252       nsLoadFlags aLoadFlags, nsISupports* aCacheKey,
 253       nsContentPolicyType aContentPolicyType, const nsAString& initiatorType,
 254       bool aUseUrgentStartForChannel, bool aLinkPreload,
 255       imgRequestProxy** _retval);
 256
 257   [[nodiscard]] nsresult LoadImageWithChannel(
 258       nsIChannel* channel, imgINotificationObserver* aObserver,
 259       mozilla::dom::Document* aLoadingDocument, nsIStreamListener** listener,
 260       imgRequestProxy** _retval);
 261
 262   static nsresult GetMimeTypeFromContent(const char* aContents,
 263                                          uint32_t aLength,
 264                                          nsACString& aContentType);
 265
 266   /**
 267    * Returns true if the given mime type may be interpreted as an image.
 268    *
 269    * Some MIME types may be interpreted as both images and documents. (At the
 270    * moment only "image/svg+xml" falls into this category, but there may be more
 271    * in the future.) Callers which want this function to return true for such
 272    * MIME types should pass AcceptedMimeTypes::IMAGES_AND_DOCUMENTS for
 273    * @aAccept.
 274    *
 275    * @param aMimeType The MIME type to evaluate.
 276    * @param aAcceptedMimeTypes Which kinds of MIME types to treat as images.
 277    */
 278   static bool SupportImageWithMimeType(
 279       const nsACString&, AcceptedMimeTypes aAccept = AcceptedMimeTypes::IMAGES);
 280
 281   static void GlobalInit();  // for use by the factory
 282   static void Shutdown();    // for use by the factory
 283   static void ShutdownMemoryReporter();
 284
 285   nsresult ClearChromeImageCache();
 286   nsresult ClearImageCache();
 287   void MinimizeCaches();
 288
 289   nsresult InitCache();
 290
 291   bool RemoveFromCache(const ImageCacheKey& aKey);
 292
 293   // Enumeration describing if a given entry is in the cache queue or not.
 294   // There are some cases we know the entry is definitely not in the queue.
 295   enum class QueueState { MaybeExists, AlreadyRemoved };
 296
 297   bool RemoveFromCache(imgCacheEntry* entry,
 298                        QueueState aQueueState = QueueState::MaybeExists);
 299
 300   bool PutIntoCache(const ImageCacheKey& aKey, imgCacheEntry* aEntry);
 301
 302   void AddToUncachedImages(imgRequest* aRequest);
 303   void RemoveFromUncachedImages(imgRequest* aRequest);
 304
 305   // Returns true if we should prefer evicting cache entry |two| over cache
 306   // entry |one|.
 307   // This mixes units in the worst way, but provides reasonable results.
 308   inline static bool CompareCacheEntries(const RefPtr<imgCacheEntry>& one,
 309                                          const RefPtr<imgCacheEntry>& two) {
 310     if (!one) {
 311       return false;
 312     }
 313     if (!two) {
 314       return true;
 315     }
 316
 317     const double sizeweight = 1.0 - sCacheTimeWeight;
 318
 319     // We want large, old images to be evicted first (depending on their
 320     // relative weights). Since a larger time is actually newer, we subtract
 321     // time's weight, so an older image has a larger weight.
 322     double oneweight = double(one->GetDataSize()) * sizeweight -
 323                        double(one->GetTouchedTime()) * sCacheTimeWeight;
 324     double twoweight = double(two->GetDataSize()) * sizeweight -
 325                        double(two->GetTouchedTime()) * sCacheTimeWeight;
 326
 327     return oneweight < twoweight;
 328   }
 329
 330   void VerifyCacheSizes();
 331
 332   nsresult RemoveEntriesInternal(nsIPrincipal* aPrincipal,
 333                                  const nsACString* aBaseDomain);
 334
 335   // The image loader maintains a hash table of all imgCacheEntries. However,
 336   // only some of them will be evicted from the cache: those who have no
 337   // imgRequestProxies watching their imgRequests.
 338   //
 339   // Once an imgRequest has no imgRequestProxies, it should notify us by
 340   // calling HasNoObservers(), and null out its cache entry pointer.
 341   //
 342   // Upon having a proxy start observing again, it should notify us by calling
 343   // HasObservers(). The request's cache entry will be re-set before this
 344   // happens, by calling imgRequest::SetCacheEntry() when an entry with no
 345   // observers is re-requested.
 346   bool SetHasNoProxies(imgRequest* aRequest, imgCacheEntry* aEntry);
 347   bool SetHasProxies(imgRequest* aRequest);
 348
 349  private:  // methods
 350   static already_AddRefed<imgLoader> CreateImageLoader();
 351
 352   bool ValidateEntry(
 353       imgCacheEntry* aEntry, nsIURI* aURI, nsIURI* aInitialDocumentURI,
 354       nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 355       imgINotificationObserver* aObserver,
 356       mozilla::dom::Document* aLoadingDocument, nsLoadFlags aLoadFlags,
 357       nsContentPolicyType aLoadPolicyType, bool aCanMakeNewChannel,
 358       bool* aNewChannelCreated, imgRequestProxy** aProxyRequest,
 359       nsIPrincipal* aTriggeringPrincipal, mozilla::CORSMode, bool aLinkPreload);
 360
 361   bool ValidateRequestWithNewChannel(
 362       imgRequest* request, nsIURI* aURI, nsIURI* aInitialDocumentURI,
 363       nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 364       imgINotificationObserver* aObserver,
 365       mozilla::dom::Document* aLoadingDocument, uint64_t aInnerWindowId,
 366       nsLoadFlags aLoadFlags, nsContentPolicyType aContentPolicyType,
 367       imgRequestProxy** aProxyRequest, nsIPrincipal* aLoadingPrincipal,
 368       mozilla::CORSMode, bool aLinkPreload, bool* aNewChannelCreated);
 369
 370   void NotifyObserversForCachedImage(imgCacheEntry* aEntry, imgRequest* request,
 371                                      nsIURI* aURI,
 372                                      nsIReferrerInfo* aReferrerInfo,
 373                                      mozilla::dom::Document* aLoadingDocument,
 374                                      nsIPrincipal* aLoadingPrincipal,
 375                                      mozilla::CORSMode);
 376   // aURI may be different from imgRequest's URI in the case of blob URIs, as we
 377   // can share requests with different URIs.
 378   nsresult CreateNewProxyForRequest(imgRequest* aRequest, nsIURI* aURI,
 379                                     nsILoadGroup* aLoadGroup,
 380                                     mozilla::dom::Document* aLoadingDocument,
 381                                     imgINotificationObserver* aObserver,
 382                                     nsLoadFlags aLoadFlags,
 383                                     imgRequestProxy** _retval);
 384
 385   nsresult EvictEntries(imgCacheTable& aCacheToClear);
 386   nsresult EvictEntries(imgCacheQueue& aQueueToClear);
 387
 388   imgCacheTable& GetCache(bool aForChrome);
 389   imgCacheTable& GetCache(const ImageCacheKey& aKey);
 390   imgCacheQueue& GetCacheQueue(bool aForChrome);
 391   imgCacheQueue& GetCacheQueue(const ImageCacheKey& aKey);
 392   void CacheEntriesChanged(bool aForChrome, int32_t aSizeDiff = 0);
 393   void CheckCacheLimits(imgCacheTable& cache, imgCacheQueue& queue);
 394
 395  private:  // data
 396   friend class imgCacheEntry;
 397   friend class imgMemoryReporter;
 398
 399   imgCacheTable mCache;
 400   imgCacheQueue mCacheQueue;
 401
 402   imgCacheTable mChromeCache;
 403   imgCacheQueue mChromeCacheQueue;
 404
 405   // Hash set of every imgRequest for this loader that isn't in mCache or
 406   // mChromeCache. The union over all imgLoader's of mCache, mChromeCache, and
 407   // mUncachedImages should be every imgRequest that is alive. These are weak
 408   // pointers so we rely on the imgRequest destructor to remove itself.
 409   imgSet mUncachedImages;
 410   // The imgRequest can have refs to them held on non-main thread, so we need
 411   // a mutex because we modify the uncached images set from the imgRequest
 412   // destructor.
 413   Mutex mUncachedImagesMutex;
 414
 415   static double sCacheTimeWeight;
 416   static uint32_t sCacheMaxSize;
 417   static imgMemoryReporter* sMemReporter;
 418
 419   mozilla::UniquePtr<imgCacheExpirationTracker> mCacheTracker;
 420   bool mRespectPrivacy;
 421 };
 422
 423 /**
 424  * proxy stream listener class used to handle multipart/x-mixed-replace
 425  */
 426
 427 #include "nsCOMPtr.h"
 428 #include "nsIStreamListener.h"
 429 #include "nsIThreadRetargetableStreamListener.h"
 430
 431 class ProxyListener : public nsIStreamListener,
 432                       public nsIThreadRetargetableStreamListener {
 433  public:
 434   explicit ProxyListener(nsIStreamListener* dest);
 435
 436   /* additional members */
 437   NS_DECL_THREADSAFE_ISUPPORTS
 438   NS_DECL_NSISTREAMLISTENER
 439   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 440   NS_DECL_NSIREQUESTOBSERVER
 441
 442  private:
 443   virtual ~ProxyListener();
 444
 445   nsCOMPtr<nsIStreamListener> mDestListener;
 446 };
 447
 448 /**
 449  * A class that implements nsIProgressEventSink and forwards all calls to it to
 450  * the original notification callbacks of the channel. Also implements
 451  * nsIInterfaceRequestor and gives out itself for nsIProgressEventSink calls,
 452  * and forwards everything else to the channel's notification callbacks.
 453  */
 454 class nsProgressNotificationProxy final : public nsIProgressEventSink,
 455                                           public nsIChannelEventSink,
 456                                           public nsIInterfaceRequestor {
 457  public:
 458   nsProgressNotificationProxy(nsIChannel* channel, imgIRequest* proxy)
 459       : mImageRequest(proxy) {
 460     channel->GetNotificationCallbacks(getter_AddRefs(mOriginalCallbacks));
 461   }
 462
 463   NS_DECL_ISUPPORTS
 464   NS_DECL_NSIPROGRESSEVENTSINK
 465   NS_DECL_NSICHANNELEVENTSINK
 466   NS_DECL_NSIINTERFACEREQUESTOR
 467  private:
 468   ~nsProgressNotificationProxy() = default;
 469
 470   nsCOMPtr<nsIInterfaceRequestor> mOriginalCallbacks;
 471   nsCOMPtr<nsIRequest> mImageRequest;
 472 };
 473
 474 /**
 475  * validate checker
 476  */
 477
 478 #include "nsCOMArray.h"
 479
 480 class imgCacheValidator : public nsIStreamListener,
 481                           public nsIThreadRetargetableStreamListener,
 482                           public nsIChannelEventSink,
 483                           public nsIInterfaceRequestor,
 484                           public nsIAsyncVerifyRedirectCallback {
 485  public:
 486   imgCacheValidator(nsProgressNotificationProxy* progress, imgLoader* loader,
 487                     imgRequest* aRequest, mozilla::dom::Document* aDocument,
 488                     uint64_t aInnerWindowId,
 489                     bool forcePrincipalCheckForCacheEntry);
 490
 491   void AddProxy(imgRequestProxy* aProxy);
 492   void RemoveProxy(imgRequestProxy* aProxy);
 493
 494   NS_DECL_THREADSAFE_ISUPPORTS
 495   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 496   NS_DECL_NSISTREAMLISTENER
 497   NS_DECL_NSIREQUESTOBSERVER
 498   NS_DECL_NSICHANNELEVENTSINK
 499   NS_DECL_NSIINTERFACEREQUESTOR
 500   NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
 501
 502  private:
 503   void UpdateProxies(bool aCancelRequest, bool aSyncNotify);
 504   virtual ~imgCacheValidator();
 505
 506   nsCOMPtr<nsIStreamListener> mDestListener;
 507   RefPtr<nsProgressNotificationProxy> mProgressProxy;
 508   nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
 509   nsCOMPtr<nsIChannel> mRedirectChannel;
 510
 511   RefPtr<imgRequest> mRequest;
 512   AutoTArray<RefPtr<imgRequestProxy>, 4> mProxies;
 513
 514   RefPtr<imgRequest> mNewRequest;
 515   RefPtr<imgCacheEntry> mNewEntry;
 516
 517   RefPtr<mozilla::dom::Document> mDocument;
 518   uint64_t mInnerWindowId;
 519
 520   imgLoader* mImgLoader;
 521
 522   bool mHadInsecureRedirect;
 523 };
 524
 525 #endif  // mozilla_image_imgLoader_h