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/Mutex.h"
  12 #include "mozilla/UniquePtr.h"
  13
  14 #include "imgILoader.h"
  15 #include "imgICache.h"
  16 #include "nsWeakReference.h"
  17 #include "nsIContentSniffer.h"
  18 #include "nsRefPtrHashtable.h"
  19 #include "nsExpirationTracker.h"
  20 #include "ImageCacheKey.h"
  21 #include "imgRequest.h"
  22 #include "nsIProgressEventSink.h"
  23 #include "nsIChannel.h"
  24 #include "nsIThreadRetargetableStreamListener.h"
  25 #include "imgIRequest.h"
  26
  27 class imgLoader;
  28 class imgRequestProxy;
  29 class imgINotificationObserver;
  30 class nsILoadGroup;
  31 class imgCacheExpirationTracker;
  32 class imgMemoryReporter;
  33
  34 namespace mozilla {
  35 namespace image {}  // namespace image
  36 }  // namespace mozilla
  37
  38 class imgCacheEntry {
  39  public:
  40   static uint32_t SecondsFromPRTime(PRTime prTime);
  41
  42   imgCacheEntry(imgLoader* loader, imgRequest* request,
  43                 bool aForcePrincipalCheck);
  44   ~imgCacheEntry();
  45
  46   nsrefcnt AddRef() {
  47     MOZ_ASSERT(int32_t(mRefCnt) >= 0, "illegal refcnt");
  48     NS_ASSERT_OWNINGTHREAD(imgCacheEntry);
  49     ++mRefCnt;
  50     NS_LOG_ADDREF(this, mRefCnt, "imgCacheEntry", sizeof(*this));
  51     return mRefCnt;
  52   }
  53
  54   nsrefcnt Release() {
  55     MOZ_ASSERT(0 != mRefCnt, "dup release");
  56     NS_ASSERT_OWNINGTHREAD(imgCacheEntry);
  57     --mRefCnt;
  58     NS_LOG_RELEASE(this, mRefCnt, "imgCacheEntry");
  59     if (mRefCnt == 0) {
  60       mRefCnt = 1; /* stabilize */
  61       delete this;
  62       return 0;
  63     }
  64     return mRefCnt;
  65   }
  66
  67   uint32_t GetDataSize() const { return mDataSize; }
  68   void SetDataSize(uint32_t aDataSize) {
  69     int32_t oldsize = mDataSize;
  70     mDataSize = aDataSize;
  71     UpdateCache(mDataSize - oldsize);
  72   }
  73
  74   int32_t GetTouchedTime() const { return mTouchedTime; }
  75   void SetTouchedTime(int32_t time) {
  76     mTouchedTime = time;
  77     Touch(/* updateTime = */ false);
  78   }
  79
  80   uint32_t GetLoadTime() const { return mLoadTime; }
  81
  82   void UpdateLoadTime();
  83
  84   int32_t GetExpiryTime() const { return mExpiryTime; }
  85   void SetExpiryTime(int32_t aExpiryTime) {
  86     mExpiryTime = aExpiryTime;
  87     Touch();
  88   }
  89
  90   bool GetMustValidate() const { return mMustValidate; }
  91   void SetMustValidate(bool aValidate) {
  92     mMustValidate = aValidate;
  93     Touch();
  94   }
  95
  96   already_AddRefed<imgRequest> GetRequest() const {
  97     RefPtr<imgRequest> req = mRequest;
  98     return req.forget();
  99   }
 100
 101   bool Evicted() const { return mEvicted; }
 102
 103   nsExpirationState* GetExpirationState() { return &mExpirationState; }
 104
 105   bool HasNoProxies() const { return mHasNoProxies; }
 106
 107   bool ForcePrincipalCheck() const { return mForcePrincipalCheck; }
 108
 109   imgLoader* Loader() const { return mLoader; }
 110
 111  private:  // methods
 112   friend class imgLoader;
 113   friend class imgCacheQueue;
 114   void Touch(bool updateTime = true);
 115   void UpdateCache(int32_t diff = 0);
 116   void SetEvicted(bool evict) { mEvicted = evict; }
 117   void SetHasNoProxies(bool hasNoProxies);
 118
 119   // Private, unimplemented copy constructor.
 120   imgCacheEntry(const imgCacheEntry&);
 121
 122  private:  // data
 123   nsAutoRefCnt mRefCnt;
 124   NS_DECL_OWNINGTHREAD
 125
 126   imgLoader* mLoader;
 127   RefPtr<imgRequest> mRequest;
 128   uint32_t mDataSize;
 129   int32_t mTouchedTime;
 130   uint32_t mLoadTime;
 131   int32_t mExpiryTime;
 132   nsExpirationState mExpirationState;
 133   bool mMustValidate : 1;
 134   bool mEvicted : 1;
 135   bool mHasNoProxies : 1;
 136   bool mForcePrincipalCheck : 1;
 137 };
 138
 139 #include <vector>
 140
 141 #define NS_IMGLOADER_CID                             \
 142   { /* c1354898-e3fe-4602-88a7-c4520c21cb4e */       \
 143     0xc1354898, 0xe3fe, 0x4602, {                    \
 144       0x88, 0xa7, 0xc4, 0x52, 0x0c, 0x21, 0xcb, 0x4e \
 145     }                                                \
 146   }
 147
 148 class imgCacheQueue {
 149  public:
 150   imgCacheQueue();
 151   void Remove(imgCacheEntry*);
 152   void Push(imgCacheEntry*);
 153   void MarkDirty();
 154   bool IsDirty();
 155   already_AddRefed<imgCacheEntry> Pop();
 156   void Refresh();
 157   uint32_t GetSize() const;
 158   void UpdateSize(int32_t diff);
 159   uint32_t GetNumElements() const;
 160   bool Contains(imgCacheEntry* aEntry) const;
 161   typedef nsTArray<RefPtr<imgCacheEntry>> queueContainer;
 162   typedef queueContainer::iterator iterator;
 163   typedef queueContainer::const_iterator const_iterator;
 164
 165   iterator begin();
 166   const_iterator begin() const;
 167   iterator end();
 168   const_iterator end() const;
 169
 170  private:
 171   queueContainer mQueue;
 172   bool mDirty;
 173   uint32_t mSize;
 174 };
 175
 176 enum class AcceptedMimeTypes : uint8_t {
 177   IMAGES,
 178   IMAGES_AND_DOCUMENTS,
 179 };
 180
 181 class imgLoader final : public imgILoader,
 182                         public nsIContentSniffer,
 183                         public imgICache,
 184                         public nsSupportsWeakReference,
 185                         public nsIObserver {
 186   virtual ~imgLoader();
 187
 188  public:
 189   typedef mozilla::image::ImageCacheKey ImageCacheKey;
 190   typedef nsRefPtrHashtable<nsGenericHashKey<ImageCacheKey>, imgCacheEntry>
 191       imgCacheTable;
 192   typedef nsTHashtable<nsPtrHashKey<imgRequest>> imgSet;
 193   typedef mozilla::Mutex Mutex;
 194
 195   NS_DECL_ISUPPORTS
 196   NS_DECL_IMGILOADER
 197   NS_DECL_NSICONTENTSNIFFER
 198   NS_DECL_IMGICACHE
 199   NS_DECL_NSIOBSERVER
 200
 201   /**
 202    * Get the normal image loader instance that is used by gecko code, creating
 203    * it if necessary.
 204    */
 205   static imgLoader* NormalLoader();
 206
 207   /**
 208    * Get the Private Browsing image loader instance that is used by gecko code,
 209    * creating it if necessary.
 210    */
 211   static imgLoader* PrivateBrowsingLoader();
 212
 213   /**
 214    * Gecko code should use NormalLoader() or PrivateBrowsingLoader() to get the
 215    * appropriate image loader.
 216    *
 217    * This constructor is public because the XPCOM module code that creates
 218    * instances of "@mozilla.org/image/loader;1" / "@mozilla.org/image/cache;1"
 219    * for nsIComponentManager.createInstance()/nsIServiceManager.getService()
 220    * calls (now only made by add-ons) needs access to it.
 221    *
 222    * XXX We would like to get rid of the nsIServiceManager.getService (and
 223    * nsIComponentManager.createInstance) method of creating imgLoader objects,
 224    * but there are add-ons that are still using it.  These add-ons don't
 225    * actually do anything useful with the loaders that they create since nobody
 226    * who creates an imgLoader using this method actually QIs to imgILoader and
 227    * loads images.  They all just QI to imgICache and either call clearCache()
 228    * or findEntryProperties().  Since they're doing this on an imgLoader that
 229    * has never loaded images, these calls are useless.  It seems likely that
 230    * the code that is doing this is just legacy code left over from a time when
 231    * there was only one imgLoader instance for the entire process.  (Nowadays
 232    * the correct method to get an imgILoader/imgICache is to call
 233    * imgITools::getImgCacheForDocument/imgITools::getImgLoaderForDocument.)
 234    * All the same, even though what these add-ons are doing is a no-op,
 235    * removing the nsIServiceManager.getService method of creating/getting an
 236    * imgLoader objects would cause an exception in these add-ons that could
 237    * break things.
 238    */
 239   imgLoader();
 240   nsresult Init();
 241
 242   MOZ_MUST_USE nsresult LoadImage(
 243       nsIURI* aURI, nsIURI* aInitialDocumentURI, nsIReferrerInfo* aReferrerInfo,
 244       nsIPrincipal* aLoadingPrincipal, uint64_t aRequestContextID,
 245       nsILoadGroup* aLoadGroup, imgINotificationObserver* aObserver,
 246       nsINode* aContext, mozilla::dom::Document* aLoadingDocument,
 247       nsLoadFlags aLoadFlags, nsISupports* aCacheKey,
 248       nsContentPolicyType aContentPolicyType, const nsAString& initiatorType,
 249       bool aUseUrgentStartForChannel, imgRequestProxy** _retval);
 250
 251   MOZ_MUST_USE nsresult
 252   LoadImageWithChannel(nsIChannel* channel, imgINotificationObserver* aObserver,
 253                        nsISupports* aCX, nsIStreamListener** listener,
 254                        imgRequestProxy** _retval);
 255
 256   static nsresult GetMimeTypeFromContent(const char* aContents,
 257                                          uint32_t aLength,
 258                                          nsACString& aContentType);
 259
 260   /**
 261    * Returns true if the given mime type may be interpreted as an image.
 262    *
 263    * Some MIME types may be interpreted as both images and documents. (At the
 264    * moment only "image/svg+xml" falls into this category, but there may be more
 265    * in the future.) Callers which want this function to return true for such
 266    * MIME types should pass AcceptedMimeTypes::IMAGES_AND_DOCUMENTS for
 267    * @aAccept.
 268    *
 269    * @param aMimeType The MIME type to evaluate.
 270    * @param aAcceptedMimeTypes Which kinds of MIME types to treat as images.
 271    */
 272   static bool SupportImageWithMimeType(
 273       const char* aMimeType,
 274       AcceptedMimeTypes aAccept = AcceptedMimeTypes::IMAGES);
 275
 276   static void GlobalInit();  // for use by the factory
 277   static void Shutdown();    // for use by the factory
 278   static void ShutdownMemoryReporter();
 279
 280   nsresult ClearChromeImageCache();
 281   nsresult ClearImageCache();
 282   void MinimizeCaches();
 283
 284   nsresult InitCache();
 285
 286   bool RemoveFromCache(const ImageCacheKey& aKey);
 287
 288   // Enumeration describing if a given entry is in the cache queue or not.
 289   // There are some cases we know the entry is definitely not in the queue.
 290   enum class QueueState { MaybeExists, AlreadyRemoved };
 291
 292   bool RemoveFromCache(imgCacheEntry* entry,
 293                        QueueState aQueueState = QueueState::MaybeExists);
 294
 295   bool PutIntoCache(const ImageCacheKey& aKey, imgCacheEntry* aEntry);
 296
 297   void AddToUncachedImages(imgRequest* aRequest);
 298   void RemoveFromUncachedImages(imgRequest* aRequest);
 299
 300   // Returns true if we should prefer evicting cache entry |two| over cache
 301   // entry |one|.
 302   // This mixes units in the worst way, but provides reasonable results.
 303   inline static bool CompareCacheEntries(const RefPtr<imgCacheEntry>& one,
 304                                          const RefPtr<imgCacheEntry>& two) {
 305     if (!one) {
 306       return false;
 307     }
 308     if (!two) {
 309       return true;
 310     }
 311
 312     const double sizeweight = 1.0 - sCacheTimeWeight;
 313
 314     // We want large, old images to be evicted first (depending on their
 315     // relative weights). Since a larger time is actually newer, we subtract
 316     // time's weight, so an older image has a larger weight.
 317     double oneweight = double(one->GetDataSize()) * sizeweight -
 318                        double(one->GetTouchedTime()) * sCacheTimeWeight;
 319     double twoweight = double(two->GetDataSize()) * sizeweight -
 320                        double(two->GetTouchedTime()) * sCacheTimeWeight;
 321
 322     return oneweight < twoweight;
 323   }
 324
 325   void VerifyCacheSizes();
 326
 327   // The image loader maintains a hash table of all imgCacheEntries. However,
 328   // only some of them will be evicted from the cache: those who have no
 329   // imgRequestProxies watching their imgRequests.
 330   //
 331   // Once an imgRequest has no imgRequestProxies, it should notify us by
 332   // calling HasNoObservers(), and null out its cache entry pointer.
 333   //
 334   // Upon having a proxy start observing again, it should notify us by calling
 335   // HasObservers(). The request's cache entry will be re-set before this
 336   // happens, by calling imgRequest::SetCacheEntry() when an entry with no
 337   // observers is re-requested.
 338   bool SetHasNoProxies(imgRequest* aRequest, imgCacheEntry* aEntry);
 339   bool SetHasProxies(imgRequest* aRequest);
 340
 341  private:  // methods
 342   static already_AddRefed<imgLoader> CreateImageLoader();
 343
 344   bool PreferLoadFromCache(nsIURI* aURI) const;
 345
 346   bool ValidateEntry(imgCacheEntry* aEntry, nsIURI* aKey,
 347                      nsIURI* aInitialDocumentURI,
 348                      nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 349                      imgINotificationObserver* aObserver, nsISupports* aCX,
 350                      mozilla::dom::Document* aLoadingDocument,
 351                      nsLoadFlags aLoadFlags,
 352                      nsContentPolicyType aContentPolicyType,
 353                      bool aCanMakeNewChannel, bool* aNewChannelCreated,
 354                      imgRequestProxy** aProxyRequest,
 355                      nsIPrincipal* aLoadingPrincipal, int32_t aCORSMode);
 356
 357   bool ValidateRequestWithNewChannel(
 358       imgRequest* request, nsIURI* aURI, nsIURI* aInitialDocumentURI,
 359       nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
 360       imgINotificationObserver* aObserver, nsISupports* aCX,
 361       mozilla::dom::Document* aLoadingDocument, uint64_t aInnerWindowId,
 362       nsLoadFlags aLoadFlags, nsContentPolicyType aContentPolicyType,
 363       imgRequestProxy** aProxyRequest, nsIPrincipal* aLoadingPrincipal,
 364       int32_t aCORSMode, bool* aNewChannelCreated);
 365
 366   nsresult CreateNewProxyForRequest(imgRequest* aRequest,
 367                                     nsILoadGroup* aLoadGroup,
 368                                     mozilla::dom::Document* aLoadingDocument,
 369                                     imgINotificationObserver* aObserver,
 370                                     nsLoadFlags aLoadFlags,
 371                                     imgRequestProxy** _retval);
 372
 373   void ReadAcceptHeaderPref();
 374
 375   nsresult EvictEntries(imgCacheTable& aCacheToClear);
 376   nsresult EvictEntries(imgCacheQueue& aQueueToClear);
 377
 378   imgCacheTable& GetCache(bool aForChrome);
 379   imgCacheTable& GetCache(const ImageCacheKey& aKey);
 380   imgCacheQueue& GetCacheQueue(bool aForChrome);
 381   imgCacheQueue& GetCacheQueue(const ImageCacheKey& aKey);
 382   void CacheEntriesChanged(bool aForChrome, int32_t aSizeDiff = 0);
 383   void CheckCacheLimits(imgCacheTable& cache, imgCacheQueue& queue);
 384
 385  private:  // data
 386   friend class imgCacheEntry;
 387   friend class imgMemoryReporter;
 388
 389   imgCacheTable mCache;
 390   imgCacheQueue mCacheQueue;
 391
 392   imgCacheTable mChromeCache;
 393   imgCacheQueue mChromeCacheQueue;
 394
 395   // Hash set of every imgRequest for this loader that isn't in mCache or
 396   // mChromeCache. The union over all imgLoader's of mCache, mChromeCache, and
 397   // mUncachedImages should be every imgRequest that is alive. These are weak
 398   // pointers so we rely on the imgRequest destructor to remove itself.
 399   imgSet mUncachedImages;
 400   // The imgRequest can have refs to them held on non-main thread, so we need
 401   // a mutex because we modify the uncached images set from the imgRequest
 402   // destructor.
 403   Mutex mUncachedImagesMutex;
 404
 405   static double sCacheTimeWeight;
 406   static uint32_t sCacheMaxSize;
 407   static imgMemoryReporter* sMemReporter;
 408
 409   nsCString mAcceptHeader;
 410
 411   mozilla::UniquePtr<imgCacheExpirationTracker> mCacheTracker;
 412   bool mRespectPrivacy;
 413 };
 414
 415 /**
 416  * proxy stream listener class used to handle multipart/x-mixed-replace
 417  */
 418
 419 #include "nsCOMPtr.h"
 420 #include "nsIStreamListener.h"
 421 #include "nsIThreadRetargetableStreamListener.h"
 422
 423 class ProxyListener : public nsIStreamListener,
 424                       public nsIThreadRetargetableStreamListener {
 425  public:
 426   explicit ProxyListener(nsIStreamListener* dest);
 427
 428   /* additional members */
 429   NS_DECL_THREADSAFE_ISUPPORTS
 430   NS_DECL_NSISTREAMLISTENER
 431   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 432   NS_DECL_NSIREQUESTOBSERVER
 433
 434  private:
 435   virtual ~ProxyListener();
 436
 437   nsCOMPtr<nsIStreamListener> mDestListener;
 438 };
 439
 440 /**
 441  * A class that implements nsIProgressEventSink and forwards all calls to it to
 442  * the original notification callbacks of the channel. Also implements
 443  * nsIInterfaceRequestor and gives out itself for nsIProgressEventSink calls,
 444  * and forwards everything else to the channel's notification callbacks.
 445  */
 446 class nsProgressNotificationProxy final : public nsIProgressEventSink,
 447                                           public nsIChannelEventSink,
 448                                           public nsIInterfaceRequestor {
 449  public:
 450   nsProgressNotificationProxy(nsIChannel* channel, imgIRequest* proxy)
 451       : mImageRequest(proxy) {
 452     channel->GetNotificationCallbacks(getter_AddRefs(mOriginalCallbacks));
 453   }
 454
 455   NS_DECL_ISUPPORTS
 456   NS_DECL_NSIPROGRESSEVENTSINK
 457   NS_DECL_NSICHANNELEVENTSINK
 458   NS_DECL_NSIINTERFACEREQUESTOR
 459  private:
 460   ~nsProgressNotificationProxy() {}
 461
 462   nsCOMPtr<nsIInterfaceRequestor> mOriginalCallbacks;
 463   nsCOMPtr<nsIRequest> mImageRequest;
 464 };
 465
 466 /**
 467  * validate checker
 468  */
 469
 470 #include "nsCOMArray.h"
 471
 472 class imgCacheValidator : public nsIStreamListener,
 473                           public nsIThreadRetargetableStreamListener,
 474                           public nsIChannelEventSink,
 475                           public nsIInterfaceRequestor,
 476                           public nsIAsyncVerifyRedirectCallback {
 477  public:
 478   imgCacheValidator(nsProgressNotificationProxy* progress, imgLoader* loader,
 479                     imgRequest* aRequest, nsISupports* aContext,
 480                     uint64_t aInnerWindowId,
 481                     bool forcePrincipalCheckForCacheEntry);
 482
 483   void AddProxy(imgRequestProxy* aProxy);
 484   void RemoveProxy(imgRequestProxy* aProxy);
 485
 486   NS_DECL_THREADSAFE_ISUPPORTS
 487   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 488   NS_DECL_NSISTREAMLISTENER
 489   NS_DECL_NSIREQUESTOBSERVER
 490   NS_DECL_NSICHANNELEVENTSINK
 491   NS_DECL_NSIINTERFACEREQUESTOR
 492   NS_DECL_NSIASYNCVERIFYREDIRECTCALLBACK
 493
 494  private:
 495   void UpdateProxies(bool aCancelRequest, bool aSyncNotify);
 496   virtual ~imgCacheValidator();
 497
 498   nsCOMPtr<nsIStreamListener> mDestListener;
 499   RefPtr<nsProgressNotificationProxy> mProgressProxy;
 500   nsCOMPtr<nsIAsyncVerifyRedirectCallback> mRedirectCallback;
 501   nsCOMPtr<nsIChannel> mRedirectChannel;
 502
 503   RefPtr<imgRequest> mRequest;
 504   AutoTArray<RefPtr<imgRequestProxy>, 4> mProxies;
 505
 506   RefPtr<imgRequest> mNewRequest;
 507   RefPtr<imgCacheEntry> mNewEntry;
 508
 509   nsCOMPtr<nsISupports> mContext;
 510   uint64_t mInnerWindowId;
 511
 512   imgLoader* mImgLoader;
 513
 514   bool mHadInsecureRedirect;
 515 };
 516
 517 #endif  // mozilla_image_imgLoader_h