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/dom/Document.h"
  13 #include "mozilla/Mutex.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 "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 image {}  // namespace image
  38 }  // namespace mozilla
  39
  40 class imgCacheEntry {
  41  public:
  42   static uint32_t SecondsFromPRTime(PRTime prTime);
  43
  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   int32_t GetExpiryTime() const { return mExpiryTime; }
  87   void SetExpiryTime(int32_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   int32_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   typedef mozilla::image::ImageCacheKey ImageCacheKey;
 192   typedef nsRefPtrHashtable<nsGenericHashKey<ImageCacheKey>, imgCacheEntry>
 193       imgCacheTable;
 194   typedef nsTHashtable<nsPtrHashKey<imgRequest>> imgSet;
 195   typedef mozilla::Mutex 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   [[nodiscard]] nsresult LoadImage(
 245       nsIURI* aURI, nsIURI* aInitialDocumentURI, nsIReferrerInfo* aReferrerInfo,
 246       nsIPrincipal* aLoadingPrincipal, uint64_t aRequestContextID,
 247       nsILoadGroup* aLoadGroup, imgINotificationObserver* aObserver,
 248       nsINode* aContext, mozilla::dom::Document* aLoadingDocument,
 249       nsLoadFlags aLoadFlags, nsISupports* aCacheKey,
 250       nsContentPolicyType aContentPolicyType, const nsAString& initiatorType,
 251       bool aUseUrgentStartForChannel, bool aLinkPreload,
 252       imgRequestProxy** _retval);
 253
 254   [[nodiscard]] nsresult LoadImageWithChannel(
 255       nsIChannel* channel, imgINotificationObserver* aObserver,
 256       mozilla::dom::Document* aLoadingDocument, nsIStreamListener** listener,
 257       imgRequestProxy** _retval);
 258
 259   static nsresult GetMimeTypeFromContent(const char* aContents,
 260                                          uint32_t aLength,
 261                                          nsACString& aContentType);
 262
 263   /**
 264    * Returns true if the given mime type may be interpreted as an image.
 265    *
 266    * Some MIME types may be interpreted as both images and documents. (At the
 267    * moment only "image/svg+xml" falls into this category, but there may be more
 268    * in the future.) Callers which want this function to return true for such
 269    * MIME types should pass AcceptedMimeTypes::IMAGES_AND_DOCUMENTS for
 270    * @aAccept.
 271    *
 272    * @param aMimeType The MIME type to evaluate.
 273    * @param aAcceptedMimeTypes Which kinds of MIME types to treat as images.
 274    */
 275   static bool SupportImageWithMimeType(
 276       const char* aMimeType,
 277       AcceptedMimeTypes aAccept = AcceptedMimeTypes::IMAGES);
 278
 279   static void GlobalInit();  // for use by the factory
 280   static void Shutdown();    // for use by the factory
 281   static void ShutdownMemoryReporter();
 282
 283   nsresult ClearChromeImageCache();
 284   nsresult ClearImageCache();
 285   void MinimizeCaches();
 286
 287   nsresult InitCache();
 288
 289   bool RemoveFromCache(const ImageCacheKey& aKey);
 290
 291   // Enumeration describing if a given entry is in the cache queue or not.
 292   // There are some cases we know the entry is definitely not in the queue.
 293   enum class QueueState { MaybeExists, AlreadyRemoved };
 294
 295   bool RemoveFromCache(imgCacheEntry* entry,
 296                        QueueState aQueueState = QueueState::MaybeExists);
 297
 298   bool PutIntoCache(const ImageCacheKey& aKey, imgCacheEntry* aEntry);
 299
 300   void AddToUncachedImages(imgRequest* aRequest);
 301   void RemoveFromUncachedImages(imgRequest* aRequest);
 302
 303   // Returns true if we should prefer evicting cache entry |two| over cache
 304   // entry |one|.
 305   // This mixes units in the worst way, but provides reasonable results.
 306   inline static bool CompareCacheEntries(const RefPtr<imgCacheEntry>& one,
 307                                          const RefPtr<imgCacheEntry>& two) {
 308     if (!one) {
 309       return false;
 310     }
 311     if (!two) {
 312       return true;
 313     }
 314
 315     const double sizeweight = 1.0 - sCacheTimeWeight;
 316
 317     // We want large, old images to be evicted first (depending on their
 318     // relative weights). Since a larger time is actually newer, we subtract
 319     // time's weight, so an older image has a larger weight.
 320     double oneweight = double(one->GetDataSize()) * sizeweight -
 321                        double(one->GetTouchedTime()) * sCacheTimeWeight;
 322     double twoweight = double(two->GetDataSize()) * sizeweight -
 323                        double(two->GetTouchedTime()) * sCacheTimeWeight;
 324
 325     return oneweight < twoweight;
 326   }
 327
 328   void VerifyCacheSizes();
 329
 330   // The image loader maintains a hash table of all imgCacheEntries. However,
 331   // only some of them will be evicted from the cache: those who have no
 332   // imgRequestProxies watching their imgRequests.
 333   //
 334   // Once an imgRequest has no imgRequestProxies, it should notify us by
 335   // calling HasNoObservers(), and null out its cache entry pointer.
 336   //
 337   // Upon having a proxy start observing again, it should notify us by calling
 338   // HasObservers(). The request's cache entry will be re-set before this
 339   // happens, by calling imgRequest::SetCacheEntry() when an entry with no
 340   // observers is re-requested.
 341   bool SetHasNoProxies(imgRequest* aRequest, imgCacheEntry* aEntry);
 342   bool SetHasProxies(imgRequest* aRequest);
 343
 344   // This method converts imgIRequest::CORS_* values to mozilla::CORSMode
 345   // values.
 346   static mozilla::CORSMode ConvertToCORSMode(uint32_t aImgCORS);
 347
 348  private:  // methods
 349   static already_AddRefed<imgLoader> CreateImageLoader();
 350
 351   bool PreferLoadFromCache(nsIURI* aURI) const;
 352
 353   bool ValidateEntry(
 354       imgCacheEntry* aEntry, nsIURI* aURI, nsIURI* aInitialDocumentURI,
 355       nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 356       imgINotificationObserver* aObserver,
 357       mozilla::dom::Document* aLoadingDocument, nsLoadFlags aLoadFlags,
 358       nsContentPolicyType aLoadPolicyType, bool aCanMakeNewChannel,
 359       bool* aNewChannelCreated, imgRequestProxy** aProxyRequest,
 360       nsIPrincipal* aTriggeringPrincipal, int32_t aCORSMode, bool aLinkPreload);
 361
 362   bool ValidateRequestWithNewChannel(
 363       imgRequest* request, nsIURI* aURI, nsIURI* aInitialDocumentURI,
 364       nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 365       imgINotificationObserver* aObserver,
 366       mozilla::dom::Document* aLoadingDocument, uint64_t aInnerWindowId,
 367       nsLoadFlags aLoadFlags, nsContentPolicyType aContentPolicyType,
 368       imgRequestProxy** aProxyRequest, nsIPrincipal* aLoadingPrincipal,
 369       int32_t aCORSMode, bool aLinkPreload, bool* aNewChannelCreated);
 370
 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(imgCacheTable& aCacheToClear);
 381   nsresult EvictEntries(imgCacheQueue& aQueueToClear);
 382
 383   imgCacheTable& GetCache(bool aForChrome);
 384   imgCacheTable& GetCache(const ImageCacheKey& aKey);
 385   imgCacheQueue& GetCacheQueue(bool aForChrome);
 386   imgCacheQueue& GetCacheQueue(const ImageCacheKey& aKey);
 387   void CacheEntriesChanged(bool aForChrome, int32_t aSizeDiff = 0);
 388   void CheckCacheLimits(imgCacheTable& cache, imgCacheQueue& queue);
 389
 390  private:  // data
 391   friend class imgCacheEntry;
 392   friend class imgMemoryReporter;
 393
 394   imgCacheTable mCache;
 395   imgCacheQueue mCacheQueue;
 396
 397   imgCacheTable mChromeCache;
 398   imgCacheQueue mChromeCacheQueue;
 399
 400   // Hash set of every imgRequest for this loader that isn't in mCache or
 401   // mChromeCache. The union over all imgLoader's of mCache, mChromeCache, and
 402   // mUncachedImages should be every imgRequest that is alive. These are weak
 403   // pointers so we rely on the imgRequest destructor to remove itself.
 404   imgSet mUncachedImages;
 405   // The imgRequest can have refs to them held on non-main thread, so we need
 406   // a mutex because we modify the uncached images set from the imgRequest
 407   // destructor.
 408   Mutex mUncachedImagesMutex;
 409
 410   static double sCacheTimeWeight;
 411   static uint32_t sCacheMaxSize;
 412   static imgMemoryReporter* sMemReporter;
 413
 414   mozilla::UniquePtr<imgCacheExpirationTracker> mCacheTracker;
 415   bool mRespectPrivacy;
 416 };
 417
 418 /**
 419  * proxy stream listener class used to handle multipart/x-mixed-replace
 420  */
 421
 422 #include "nsCOMPtr.h"
 423 #include "nsIStreamListener.h"
 424 #include "nsIThreadRetargetableStreamListener.h"
 425
 426 class ProxyListener : public nsIStreamListener,
 427                       public nsIThreadRetargetableStreamListener {
 428  public:
 429   explicit ProxyListener(nsIStreamListener* dest);
 430
 431   /* additional members */
 432   NS_DECL_THREADSAFE_ISUPPORTS
 433   NS_DECL_NSISTREAMLISTENER
 434   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 435   NS_DECL_NSIREQUESTOBSERVER
 436
 437  private:
 438   virtual ~ProxyListener();
 439
 440   nsCOMPtr<nsIStreamListener> mDestListener;
 441 };
 442
 443 /**
 444  * A class that implements nsIProgressEventSink and forwards all calls to it to
 445  * the original notification callbacks of the channel. Also implements
 446  * nsIInterfaceRequestor and gives out itself for nsIProgressEventSink calls,
 447  * and forwards everything else to the channel's notification callbacks.
 448  */
 449 class nsProgressNotificationProxy final : public nsIProgressEventSink,
 450                                           public nsIChannelEventSink,
 451                                           public nsIInterfaceRequestor {
 452  public:
 453   nsProgressNotificationProxy(nsIChannel* channel, imgIRequest* proxy)
 454       : mImageRequest(proxy) {
 455     channel->GetNotificationCallbacks(getter_AddRefs(mOriginalCallbacks));
 456   }
 457
 458   NS_DECL_ISUPPORTS
 459   NS_DECL_NSIPROGRESSEVENTSINK
 460   NS_DECL_NSICHANNELEVENTSINK
 461   NS_DECL_NSIINTERFACEREQUESTOR
 462  private:
 463   ~nsProgressNotificationProxy() = default;
 464
 465   nsCOMPtr<nsIInterfaceRequestor> mOriginalCallbacks;
 466   nsCOMPtr<nsIRequest> mImageRequest;
 467 };
 468
 469 /**
 470  * validate checker
 471  */
 472
 473 #include "nsCOMArray.h"
 474
 475 class imgCacheValidator : public nsIStreamListener,
 476                           public nsIThreadRetargetableStreamListener,
 477                           public nsIChannelEventSink,
 478                           public nsIInterfaceRequestor,
 479                           public nsIAsyncVerifyRedirectCallback {
 480  public:
 481   imgCacheValidator(nsProgressNotificationProxy* progress, imgLoader* loader,
 482                     imgRequest* aRequest, mozilla::dom::Document* aDocument,
 483                     uint64_t aInnerWindowId,
 484                     bool forcePrincipalCheckForCacheEntry);
 485
 486   void AddProxy(imgRequestProxy* aProxy);
 487   void RemoveProxy(imgRequestProxy* aProxy);
 488
 489   void PrioritizeAsPreload();
 490
 491   NS_DECL_THREADSAFE_ISUPPORTS
 492   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 493   NS_DECL_NSISTREAMLISTENER
 494   NS_DECL_NSIREQUESTOBSERVER
 495   NS_DECL_NSICHANNELEVENTSINK
 496   NS_DECL_NSIINTERFACEREQUESTOR
 497   NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
 498
 499  private:
 500   void UpdateProxies(bool aCancelRequest, bool aSyncNotify);
 501   virtual ~imgCacheValidator();
 502
 503   nsCOMPtr<nsIStreamListener> mDestListener;
 504   RefPtr<nsProgressNotificationProxy> mProgressProxy;
 505   nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
 506   nsCOMPtr<nsIChannel> mRedirectChannel;
 507
 508   RefPtr<imgRequest> mRequest;
 509   AutoTArray<RefPtr<imgRequestProxy>, 4> mProxies;
 510
 511   RefPtr<imgRequest> mNewRequest;
 512   RefPtr<imgCacheEntry> mNewEntry;
 513
 514   RefPtr<mozilla::dom::Document> mDocument;
 515   uint64_t mInnerWindowId;
 516
 517   imgLoader* mImgLoader;
 518
 519   bool mHadInsecureRedirect;
 520 };
 521
 522 #endif  // mozilla_image_imgLoader_h