Source/WebCore/loader/cache/CachedResource.cpp

   1 /*
   2     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
   3     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
   4     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
   5     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
   6     Copyright (C) 2004-2011, 2014 Apple Inc. All rights reserved.
   7
   8     This library is free software; you can redistribute it and/or
   9     modify it under the terms of the GNU Library General Public
  10     License as published by the Free Software Foundation; either
  11     version 2 of the License, or (at your option) any later version.
  12
  13     This library is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16     Library General Public License for more details.
  17
  18     You should have received a copy of the GNU Library General Public License
  19     along with this library; see the file COPYING.LIB.  If not, write to
  20     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21     Boston, MA 02110-1301, USA.
  22 */
  23
  24 #include "config.h"
  25 #include "CachedResource.h"
  26
  27 #include "CachedResourceClient.h"
  28 #include "CachedResourceClientWalker.h"
  29 #include "CachedResourceHandle.h"
  30 #include "CachedResourceLoader.h"
  31 #include "CrossOriginAccessControl.h"
  32 #include "DiagnosticLoggingClient.h"
  33 #include "DiagnosticLoggingKeys.h"
  34 #include "Document.h"
  35 #include "DocumentLoader.h"
  36 #include "FrameLoader.h"
  37 #include "FrameLoaderClient.h"
  38 #include "HTTPHeaderNames.h"
  39 #include "InspectorInstrumentation.h"
  40 #include "URL.h"
  41 #include "LoaderStrategy.h"
  42 #include "Logging.h"
  43 #include "MainFrame.h"
  44 #include "MemoryCache.h"
  45 #include "PlatformStrategies.h"
  46 #include "ResourceHandle.h"
  47 #include "SchemeRegistry.h"
  48 #include "SecurityOrigin.h"
  49 #include "SubresourceLoader.h"
  50 #include <wtf/CurrentTime.h>
  51 #include <wtf/MathExtras.h>
  52 #include <wtf/RefCountedLeakCounter.h>
  53 #include <wtf/StdLibExtras.h>
  54 #include <wtf/text/CString.h>
  55 #include <wtf/Vector.h>
  56
  57 #if USE(QUICK_LOOK)
  58 #include "QuickLook.h"
  59 #endif
  60
  61 using namespace WTF;
  62
  63 #define RELEASE_LOG_IF_ALLOWED(fmt, ...) RELEASE_LOG_IF(cachedResourceLoader.isAlwaysOnLoggingAllowed(), Network, "%p - CachedResource::" fmt, this, ##__VA_ARGS__)
  64
  65 namespace WebCore {
  66
  67 ResourceLoadPriority CachedResource::defaultPriorityForResourceType(Type type)
  68 {
  69     switch (type) {
  70     case CachedResource::MainResource:
  71         return ResourceLoadPriority::VeryHigh;
  72     case CachedResource::CSSStyleSheet:
  73     case CachedResource::Script:
  74         return ResourceLoadPriority::High;
  75 #if ENABLE(SVG_FONTS)
  76     case CachedResource::SVGFontResource:
  77 #endif
  78     case CachedResource::MediaResource:
  79     case CachedResource::FontResource:
  80     case CachedResource::RawResource:
  81     case CachedResource::Icon:
  82         return ResourceLoadPriority::Medium;
  83     case CachedResource::ImageResource:
  84         return ResourceLoadPriority::Low;
  85 #if ENABLE(XSLT)
  86     case CachedResource::XSLStyleSheet:
  87         return ResourceLoadPriority::High;
  88 #endif
  89     case CachedResource::SVGDocumentResource:
  90         return ResourceLoadPriority::Low;
  91     case CachedResource::Beacon:
  92         return ResourceLoadPriority::VeryLow;
  93 #if ENABLE(LINK_PREFETCH)
  94     case CachedResource::LinkPrefetch:
  95         return ResourceLoadPriority::VeryLow;
  96     case CachedResource::LinkSubresource:
  97         return ResourceLoadPriority::VeryLow;
  98 #endif
  99 #if ENABLE(VIDEO_TRACK)
 100     case CachedResource::TextTrackResource:
 101         return ResourceLoadPriority::Low;
 102 #endif
 103     }
 104     ASSERT_NOT_REACHED();
 105     return ResourceLoadPriority::Low;
 106 }
 107
 108 static Seconds deadDecodedDataDeletionIntervalForResourceType(CachedResource::Type type)
 109 {
 110     if (type == CachedResource::Script)
 111         return 0_s;
 112
 113     return MemoryCache::singleton().deadDecodedDataDeletionInterval();
 114 }
 115
 116 DEFINE_DEBUG_ONLY_GLOBAL(RefCountedLeakCounter, cachedResourceLeakCounter, ("CachedResource"));
 117
 118 CachedResource::CachedResource(CachedResourceRequest&& request, Type type, PAL::SessionID sessionID)
 119     : m_resourceRequest(request.releaseResourceRequest())
 120     , m_options(request.options())
 121     , m_decodedDataDeletionTimer(*this, &CachedResource::destroyDecodedData, deadDecodedDataDeletionIntervalForResourceType(type))
 122     , m_sessionID(sessionID)
 123     , m_loadPriority(defaultPriorityForResourceType(type))
 124     , m_responseTimestamp(std::chrono::system_clock::now())
 125     , m_fragmentIdentifierForRequest(request.releaseFragmentIdentifier())
 126     , m_origin(request.releaseOrigin())
 127     , m_initiatorName(request.initiatorName())
 128     , m_isLinkPreload(request.isLinkPreload())
 129     , m_hasUnknownEncoding(request.isLinkPreload())
 130     , m_type(type)
 131     , m_ignoreForRequestCount(request.ignoreForRequestCount())
 132 {
 133     ASSERT(sessionID.isValid());
 134
 135     setLoadPriority(request.priority());
 136 #ifndef NDEBUG
 137     cachedResourceLeakCounter.increment();
 138 #endif
 139
 140     // FIXME: We should have a better way of checking for Navigation loads, maybe FetchMode::Options::Navigate.
 141     ASSERT(m_origin || m_type == CachedResource::MainResource);
 142
 143     if (isRequestCrossOrigin(m_origin.get(), m_resourceRequest.url(), m_options))
 144         setCrossOrigin();
 145 }
 146
 147 // FIXME: For this constructor, we should probably mandate that the URL has no fragment identifier.
 148 CachedResource::CachedResource(const URL& url, Type type, PAL::SessionID sessionID)
 149     : m_resourceRequest(url)
 150     , m_decodedDataDeletionTimer(*this, &CachedResource::destroyDecodedData, deadDecodedDataDeletionIntervalForResourceType(type))
 151     , m_sessionID(sessionID)
 152     , m_responseTimestamp(std::chrono::system_clock::now())
 153     , m_fragmentIdentifierForRequest(CachedResourceRequest::splitFragmentIdentifierFromRequestURL(m_resourceRequest))
 154     , m_type(type)
 155     , m_status(Cached)
 156 {
 157     ASSERT(sessionID.isValid());
 158 #ifndef NDEBUG
 159     cachedResourceLeakCounter.increment();
 160 #endif
 161 }
 162
 163 CachedResource::~CachedResource()
 164 {
 165     ASSERT(!m_resourceToRevalidate); // Should be true because canDelete() checks this.
 166     ASSERT(canDelete());
 167     ASSERT(!inCache());
 168     ASSERT(!m_deleted);
 169     ASSERT(url().isNull() || !allowsCaching() || MemoryCache::singleton().resourceForRequest(resourceRequest(), sessionID()) != this);
 170
 171 #ifndef NDEBUG
 172     m_deleted = true;
 173     cachedResourceLeakCounter.decrement();
 174 #endif
 175
 176     if (m_owningCachedResourceLoader)
 177         m_owningCachedResourceLoader->removeCachedResource(*this);
 178 }
 179
 180 void CachedResource::failBeforeStarting()
 181 {
 182     // FIXME: What if resources in other frames were waiting for this revalidation?
 183     LOG(ResourceLoading, "Cannot start loading '%s'", url().string().latin1().data());
 184     if (allowsCaching() && m_resourceToRevalidate)
 185         MemoryCache::singleton().revalidationFailed(*this);
 186     error(CachedResource::LoadError);
 187 }
 188
 189 void CachedResource::load(CachedResourceLoader& cachedResourceLoader)
 190 {
 191     if (!cachedResourceLoader.frame()) {
 192         RELEASE_LOG_IF_ALLOWED("load: No associated frame");
 193         failBeforeStarting();
 194         return;
 195     }
 196     Frame& frame = *cachedResourceLoader.frame();
 197
 198     // Prevent new loads if we are in the PageCache or being added to the PageCache.
 199     // We query the top document because new frames may be created in pagehide event handlers
 200     // and their pageCacheState will not reflect the fact that they are about to enter page
 201     // cache.
 202     if (auto* topDocument = frame.mainFrame().document()) {
 203         if (topDocument->pageCacheState() != Document::NotInPageCache) {
 204             RELEASE_LOG_IF_ALLOWED("load: Already in page cache or being added to it (frame = %p)", &frame);
 205             failBeforeStarting();
 206             return;
 207         }
 208     }
 209
 210     FrameLoader& frameLoader = frame.loader();
 211     if (m_options.securityCheck == DoSecurityCheck && (frameLoader.state() == FrameStateProvisional || !frameLoader.activeDocumentLoader() || frameLoader.activeDocumentLoader()->isStopping())) {
 212         if (frameLoader.state() == FrameStateProvisional)
 213             RELEASE_LOG_IF_ALLOWED("load: Failed security check -- state is provisional (frame = %p)", &frame);
 214         else if (!frameLoader.activeDocumentLoader())
 215             RELEASE_LOG_IF_ALLOWED("load: Failed security check -- not active document (frame = %p)", &frame);
 216         else if (frameLoader.activeDocumentLoader()->isStopping())
 217             RELEASE_LOG_IF_ALLOWED("load: Failed security check -- active loader is stopping (frame = %p)", &frame);
 218         failBeforeStarting();
 219         return;
 220     }
 221
 222     m_loading = true;
 223
 224     if (isCacheValidator()) {
 225         CachedResource* resourceToRevalidate = m_resourceToRevalidate;
 226         ASSERT(resourceToRevalidate->canUseCacheValidator());
 227         ASSERT(resourceToRevalidate->isLoaded());
 228         const String& lastModified = resourceToRevalidate->response().httpHeaderField(HTTPHeaderName::LastModified);
 229         const String& eTag = resourceToRevalidate->response().httpHeaderField(HTTPHeaderName::ETag);
 230         if (!lastModified.isEmpty() || !eTag.isEmpty()) {
 231             ASSERT(cachedResourceLoader.cachePolicy(type(), url()) != CachePolicyReload);
 232             if (cachedResourceLoader.cachePolicy(type(), url()) == CachePolicyRevalidate)
 233                 m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::CacheControl, "max-age=0");
 234             if (!lastModified.isEmpty())
 235                 m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::IfModifiedSince, lastModified);
 236             if (!eTag.isEmpty())
 237                 m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::IfNoneMatch, eTag);
 238         }
 239     }
 240
 241 #if ENABLE(LINK_PREFETCH)
 242     if (type() == CachedResource::LinkPrefetch || type() == CachedResource::LinkSubresource)
 243         m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::Purpose, "prefetch");
 244 #endif
 245     m_resourceRequest.setPriority(loadPriority());
 246
 247     // Navigation algorithm is setting up the request before sending it to CachedResourceLoader?CachedResource.
 248     // So no need for extra fields for MainResource.
 249     if (type() != CachedResource::MainResource)
 250         frameLoader.addExtraFieldsToSubresourceRequest(m_resourceRequest);
 251
 252
 253     // FIXME: It's unfortunate that the cache layer and below get to know anything about fragment identifiers.
 254     // We should look into removing the expectation of that knowledge from the platform network stacks.
 255     ResourceRequest request(m_resourceRequest);
 256     if (!m_fragmentIdentifierForRequest.isNull()) {
 257         URL url = request.url();
 258         url.setFragmentIdentifier(m_fragmentIdentifierForRequest);
 259         request.setURL(url);
 260         m_fragmentIdentifierForRequest = String();
 261     }
 262
 263     if (m_options.keepAlive) {
 264         if (!cachedResourceLoader.keepaliveRequestTracker().tryRegisterRequest(*this)) {
 265             setResourceError({ errorDomainWebKitInternal, 0, request.url(), ASCIILiteral("Reached maximum amount of queued data of 64Kb for keepalive requests") });
 266             failBeforeStarting();
 267             return;
 268         }
 269         // FIXME: We should not special-case Beacon here.
 270         if (shouldUsePingLoad(type())) {
 271         ASSERT(m_origin);
 272             // Beacon is not exposed to workers so it is safe to rely on the document here.
 273             auto* document = cachedResourceLoader.document();
 274             auto* contentSecurityPolicy = document && !document->shouldBypassMainWorldContentSecurityPolicy() ? document->contentSecurityPolicy() : nullptr;
 275             ASSERT(m_originalRequestHeaders);
 276             platformStrategies()->loaderStrategy()->createPingHandle(frame.loader().networkingContext(), request, *m_originalRequestHeaders, *m_origin, contentSecurityPolicy, m_options);
 277             // FIXME: We currently do not get notified when ping loads finish so we treat them as finishing right away.
 278             finishLoading(nullptr);
 279             return;
 280         }
 281     }
 282
 283     m_loader = platformStrategies()->loaderStrategy()->loadResource(frame, *this, request, m_options);
 284     if (!m_loader) {
 285         RELEASE_LOG_IF_ALLOWED("load: Unable to create SubresourceLoader (frame = %p)", &frame);
 286         failBeforeStarting();
 287         return;
 288     }
 289
 290     m_status = Pending;
 291 }
 292
 293 void CachedResource::loadFrom(const CachedResource& resource)
 294 {
 295     ASSERT(url() == resource.url());
 296     ASSERT(type() == resource.type());
 297     ASSERT(resource.status() == Status::Cached);
 298
 299     if (isCrossOrigin() && m_options.mode == FetchOptions::Mode::Cors) {
 300         ASSERT(m_origin);
 301         String errorMessage;
 302         if (!WebCore::passesAccessControlCheck(resource.response(), m_options.allowCredentials, *m_origin, errorMessage)) {
 303             setResourceError(ResourceError(String(), 0, url(), errorMessage, ResourceError::Type::AccessControl));
 304             return;
 305         }
 306     }
 307
 308     setBodyDataFrom(resource);
 309     setStatus(Status::Cached);
 310     setLoading(false);
 311 }
 312
 313 void CachedResource::setBodyDataFrom(const CachedResource& resource)
 314 {
 315     m_data = resource.m_data;
 316     m_response = resource.m_response;
 317     m_response.setTainting(m_responseTainting);
 318     setDecodedSize(resource.decodedSize());
 319     setEncodedSize(resource.encodedSize());
 320 }
 321
 322 void CachedResource::checkNotify()
 323 {
 324     if (isLoading() || stillNeedsLoad())
 325         return;
 326
 327     CachedResourceClientWalker<CachedResourceClient> walker(m_clients);
 328     while (CachedResourceClient* client = walker.next())
 329         client->notifyFinished(*this);
 330 }
 331
 332 void CachedResource::addDataBuffer(SharedBuffer&)
 333 {
 334     ASSERT(dataBufferingPolicy() == BufferData);
 335 }
 336
 337 void CachedResource::addData(const char*, unsigned)
 338 {
 339     ASSERT(dataBufferingPolicy() == DoNotBufferData);
 340 }
 341
 342 void CachedResource::finishLoading(SharedBuffer*)
 343 {
 344     setLoading(false);
 345     checkNotify();
 346 }
 347
 348 void CachedResource::error(CachedResource::Status status)
 349 {
 350     setStatus(status);
 351     ASSERT(errorOccurred());
 352     m_data = nullptr;
 353
 354     setLoading(false);
 355     checkNotify();
 356 }
 357
 358 void CachedResource::cancelLoad()
 359 {
 360     if (!isLoading() && !stillNeedsLoad())
 361         return;
 362
 363     setStatus(LoadError);
 364     setLoading(false);
 365     checkNotify();
 366 }
 367
 368 void CachedResource::finish()
 369 {
 370     if (!errorOccurred())
 371         m_status = Cached;
 372 }
 373
 374 void CachedResource::setCrossOrigin()
 375 {
 376     ASSERT(m_options.mode != FetchOptions::Mode::SameOrigin);
 377     m_responseTainting = (m_options.mode == FetchOptions::Mode::Cors) ? ResourceResponse::Tainting::Cors : ResourceResponse::Tainting::Opaque;
 378 }
 379
 380 bool CachedResource::isCrossOrigin() const
 381 {
 382     return m_responseTainting != ResourceResponse::Tainting::Basic;
 383 }
 384
 385 bool CachedResource::isCORSSameOrigin() const
 386 {
 387     // Following resource types do not use CORS
 388     ASSERT(type() != CachedResource::Type::FontResource);
 389 #if ENABLE(SVG_FONTS)
 390     ASSERT(type() != CachedResource::Type::SVGFontResource);
 391 #endif
 392 #if ENABLE(XSLT)
 393     ASSERT(type() != CachedResource::XSLStyleSheet);
 394 #endif
 395
 396     // https://html.spec.whatwg.org/multipage/infrastructure.html#cors-same-origin
 397     return !loadFailedOrCanceled() && m_responseTainting != ResourceResponse::Tainting::Opaque;
 398 }
 399
 400 bool CachedResource::isExpired() const
 401 {
 402     if (m_response.isNull())
 403         return false;
 404
 405     return computeCurrentAge(m_response, m_responseTimestamp) > freshnessLifetime(m_response);
 406 }
 407
 408 static inline bool shouldCacheSchemeIndefinitely(StringView scheme)
 409 {
 410 #if PLATFORM(COCOA)
 411     if (equalLettersIgnoringASCIICase(scheme, "applewebdata"))
 412         return true;
 413 #endif
 414 #if USE(SOUP)
 415     if (equalLettersIgnoringASCIICase(scheme, "resource"))
 416         return true;
 417 #endif
 418     return equalLettersIgnoringASCIICase(scheme, "data");
 419 }
 420
 421 std::chrono::microseconds CachedResource::freshnessLifetime(const ResourceResponse& response) const
 422 {
 423     using namespace std::literals::chrono_literals;
 424
 425     if (!response.url().protocolIsInHTTPFamily()) {
 426         StringView protocol = response.url().protocol();
 427         if (!shouldCacheSchemeIndefinitely(protocol)) {
 428             // Don't cache non-HTTP main resources since we can't check for freshness.
 429             // FIXME: We should not cache subresources either, but when we tried this
 430             // it caused performance and flakiness issues in our test infrastructure.
 431             if (m_type == MainResource || SchemeRegistry::shouldAlwaysRevalidateURLScheme(protocol.toStringWithoutCopying()))
 432                 return 0us;
 433         }
 434
 435         return std::chrono::microseconds::max();
 436     }
 437
 438     return computeFreshnessLifetimeForHTTPFamily(response, m_responseTimestamp);
 439 }
 440
 441 void CachedResource::redirectReceived(ResourceRequest&, const ResourceResponse& response)
 442 {
 443     m_requestedFromNetworkingLayer = true;
 444     if (response.isNull())
 445         return;
 446
 447     updateRedirectChainStatus(m_redirectChainCacheStatus, response);
 448 }
 449
 450 void CachedResource::setResponse(const ResourceResponse& response)
 451 {
 452     ASSERT(m_response.type() == ResourceResponse::Type::Default);
 453     m_response = response;
 454     m_response.setRedirected(m_redirectChainCacheStatus.status != RedirectChainCacheStatus::NoRedirection);
 455     if (m_response.tainting() == ResourceResponse::Tainting::Basic || m_response.tainting() == ResourceResponse::Tainting::Cors)
 456         m_response.setTainting(m_responseTainting);
 457
 458     m_varyingHeaderValues = collectVaryingRequestHeaders(m_resourceRequest, m_response, m_sessionID);
 459 }
 460
 461 void CachedResource::responseReceived(const ResourceResponse& response)
 462 {
 463     setResponse(response);
 464     m_responseTimestamp = std::chrono::system_clock::now();
 465     String encoding = response.textEncodingName();
 466     if (!encoding.isNull())
 467         setEncoding(encoding);
 468 }
 469
 470 void CachedResource::clearLoader()
 471 {
 472     ASSERT(m_loader);
 473     m_identifierForLoadWithoutResourceLoader = m_loader->identifier();
 474     m_loader = nullptr;
 475     deleteIfPossible();
 476 }
 477
 478 void CachedResource::addClient(CachedResourceClient& client)
 479 {
 480     if (addClientToSet(client))
 481         didAddClient(client);
 482 }
 483
 484 void CachedResource::didAddClient(CachedResourceClient& client)
 485 {
 486     if (m_decodedDataDeletionTimer.isActive())
 487         m_decodedDataDeletionTimer.stop();
 488
 489     if (m_clientsAwaitingCallback.remove(&client))
 490         m_clients.add(&client);
 491     if (!isLoading() && !stillNeedsLoad())
 492         client.notifyFinished(*this);
 493 }
 494
 495 bool CachedResource::addClientToSet(CachedResourceClient& client)
 496 {
 497     if (m_preloadResult == PreloadNotReferenced && client.shouldMarkAsReferenced()) {
 498         if (isLoaded())
 499             m_preloadResult = PreloadReferencedWhileComplete;
 500         else if (m_requestedFromNetworkingLayer)
 501             m_preloadResult = PreloadReferencedWhileLoading;
 502         else
 503             m_preloadResult = PreloadReferenced;
 504     }
 505     if (allowsCaching() && !hasClients() && inCache())
 506         MemoryCache::singleton().addToLiveResourcesSize(*this);
 507
 508     if ((m_type == RawResource || m_type == MainResource) && !m_response.isNull() && !m_proxyResource) {
 509         // Certain resources (especially XHRs and main resources) do crazy things if an asynchronous load returns
 510         // synchronously (e.g., scripts may not have set all the state they need to handle the load).
 511         // Therefore, rather than immediately sending callbacks on a cache hit like other CachedResources,
 512         // we schedule the callbacks and ensure we never finish synchronously.
 513         ASSERT(!m_clientsAwaitingCallback.contains(&client));
 514         m_clientsAwaitingCallback.add(&client, std::make_unique<Callback>(*this, client));
 515         return false;
 516     }
 517
 518     m_clients.add(&client);
 519     return true;
 520 }
 521
 522 void CachedResource::removeClient(CachedResourceClient& client)
 523 {
 524     auto callback = m_clientsAwaitingCallback.take(&client);
 525     if (callback) {
 526         ASSERT(!m_clients.contains(&client));
 527         callback->cancel();
 528         callback = nullptr;
 529     } else {
 530         ASSERT(m_clients.contains(&client));
 531         m_clients.remove(&client);
 532         didRemoveClient(client);
 533     }
 534
 535     if (deleteIfPossible()) {
 536         // `this` object is dead here.
 537         return;
 538     }
 539
 540     if (hasClients())
 541         return;
 542
 543     auto& memoryCache = MemoryCache::singleton();
 544     if (allowsCaching() && inCache()) {
 545         memoryCache.removeFromLiveResourcesSize(*this);
 546         memoryCache.removeFromLiveDecodedResourcesList(*this);
 547     }
 548     if (!m_switchingClientsToRevalidatedResource)
 549         allClientsRemoved();
 550     destroyDecodedDataIfNeeded();
 551
 552     if (!allowsCaching())
 553         return;
 554
 555     if (response().cacheControlContainsNoStore() && url().protocolIs("https")) {
 556         // RFC2616 14.9.2:
 557         // "no-store: ... MUST make a best-effort attempt to remove the information from volatile storage as promptly as possible"
 558         // "... History buffers MAY store such responses as part of their normal operation."
 559         // We allow non-secure content to be reused in history, but we do not allow secure content to be reused.
 560         memoryCache.remove(*this);
 561     }
 562     memoryCache.pruneSoon();
 563 }
 564
 565 void CachedResource::destroyDecodedDataIfNeeded()
 566 {
 567     if (!m_decodedSize)
 568         return;
 569     if (!MemoryCache::singleton().deadDecodedDataDeletionInterval())
 570         return;
 571     m_decodedDataDeletionTimer.restart();
 572 }
 573
 574 void CachedResource::decodedDataDeletionTimerFired()
 575 {
 576     destroyDecodedData();
 577 }
 578
 579 bool CachedResource::deleteIfPossible()
 580 {
 581     if (canDelete()) {
 582         if (!inCache()) {
 583             InspectorInstrumentation::willDestroyCachedResource(*this);
 584             delete this;
 585             return true;
 586         }
 587         if (m_data)
 588             m_data->hintMemoryNotNeededSoon();
 589     }
 590     return false;
 591 }
 592
 593 void CachedResource::setDecodedSize(unsigned size)
 594 {
 595     if (size == m_decodedSize)
 596         return;
 597
 598     long long delta = static_cast<long long>(size) - m_decodedSize;
 599
 600     // The object must be moved to a different queue, since its size has been changed.
 601     // Remove before updating m_decodedSize, so we find the resource in the correct LRU list.
 602     if (allowsCaching() && inCache())
 603         MemoryCache::singleton().removeFromLRUList(*this);
 604
 605     m_decodedSize = size;
 606
 607     if (allowsCaching() && inCache()) {
 608         auto& memoryCache = MemoryCache::singleton();
 609         // Now insert into the new LRU list.
 610         memoryCache.insertInLRUList(*this);
 611
 612         // Insert into or remove from the live decoded list if necessary.
 613         // When inserting into the LiveDecodedResourcesList it is possible
 614         // that the m_lastDecodedAccessTime is still zero or smaller than
 615         // the m_lastDecodedAccessTime of the current list head. This is a
 616         // violation of the invariant that the list is to be kept sorted
 617         // by access time. The weakening of the invariant does not pose
 618         // a problem. For more details please see: https://bugs.webkit.org/show_bug.cgi?id=30209
 619         bool inLiveDecodedResourcesList = memoryCache.inLiveDecodedResourcesList(*this);
 620         if (m_decodedSize && !inLiveDecodedResourcesList && hasClients())
 621             memoryCache.insertInLiveDecodedResourcesList(*this);
 622         else if (!m_decodedSize && inLiveDecodedResourcesList)
 623             memoryCache.removeFromLiveDecodedResourcesList(*this);
 624
 625         // Update the cache's size totals.
 626         memoryCache.adjustSize(hasClients(), delta);
 627     }
 628 }
 629
 630 void CachedResource::setEncodedSize(unsigned size)
 631 {
 632     if (size == m_encodedSize)
 633         return;
 634
 635     long long delta = static_cast<long long>(size) - m_encodedSize;
 636
 637     // The object must be moved to a different queue, since its size has been changed.
 638     // Remove before updating m_encodedSize, so we find the resource in the correct LRU list.
 639     if (allowsCaching() && inCache())
 640         MemoryCache::singleton().removeFromLRUList(*this);
 641
 642     m_encodedSize = size;
 643
 644     if (allowsCaching() && inCache()) {
 645         auto& memoryCache = MemoryCache::singleton();
 646         memoryCache.insertInLRUList(*this);
 647         memoryCache.adjustSize(hasClients(), delta);
 648     }
 649 }
 650
 651 void CachedResource::didAccessDecodedData(double timeStamp)
 652 {
 653     m_lastDecodedAccessTime = timeStamp;
 654
 655     if (allowsCaching() && inCache()) {
 656         auto& memoryCache = MemoryCache::singleton();
 657         if (memoryCache.inLiveDecodedResourcesList(*this)) {
 658             memoryCache.removeFromLiveDecodedResourcesList(*this);
 659             memoryCache.insertInLiveDecodedResourcesList(*this);
 660         }
 661         memoryCache.pruneSoon();
 662     }
 663 }
 664
 665 void CachedResource::setResourceToRevalidate(CachedResource* resource)
 666 {
 667     ASSERT(resource);
 668     ASSERT(!m_resourceToRevalidate);
 669     ASSERT(resource != this);
 670     ASSERT(m_handlesToRevalidate.isEmpty());
 671     ASSERT(resource->type() == type());
 672     ASSERT(!resource->m_proxyResource);
 673
 674     LOG(ResourceLoading, "CachedResource %p setResourceToRevalidate %p", this, resource);
 675
 676     resource->m_proxyResource = this;
 677     m_resourceToRevalidate = resource;
 678 }
 679
 680 void CachedResource::clearResourceToRevalidate()
 681 {
 682     ASSERT(m_resourceToRevalidate);
 683     ASSERT(m_resourceToRevalidate->m_proxyResource == this);
 684
 685     if (m_switchingClientsToRevalidatedResource)
 686         return;
 687
 688     m_resourceToRevalidate->m_proxyResource = nullptr;
 689     m_resourceToRevalidate->deleteIfPossible();
 690
 691     m_handlesToRevalidate.clear();
 692     m_resourceToRevalidate = nullptr;
 693     deleteIfPossible();
 694 }
 695
 696 void CachedResource::switchClientsToRevalidatedResource()
 697 {
 698     ASSERT(m_resourceToRevalidate);
 699     ASSERT(m_resourceToRevalidate->inCache());
 700     ASSERT(!inCache());
 701
 702     LOG(ResourceLoading, "CachedResource %p switchClientsToRevalidatedResource %p", this, m_resourceToRevalidate);
 703
 704     m_switchingClientsToRevalidatedResource = true;
 705     for (auto& handle : m_handlesToRevalidate) {
 706         handle->m_resource = m_resourceToRevalidate;
 707         m_resourceToRevalidate->registerHandle(handle);
 708         --m_handleCount;
 709     }
 710     ASSERT(!m_handleCount);
 711     m_handlesToRevalidate.clear();
 712
 713     Vector<CachedResourceClient*> clientsToMove;
 714     for (auto& entry : m_clients) {
 715         CachedResourceClient* client = entry.key;
 716         unsigned count = entry.value;
 717         while (count) {
 718             clientsToMove.append(client);
 719             --count;
 720         }
 721     }
 722
 723     for (auto& client : clientsToMove)
 724         removeClient(*client);
 725     ASSERT(m_clients.isEmpty());
 726
 727     for (auto& client : clientsToMove)
 728         m_resourceToRevalidate->addClientToSet(*client);
 729     for (auto& client : clientsToMove) {
 730         // Calling didAddClient may do anything, including trying to cancel revalidation.
 731         // Assert that it didn't succeed.
 732         ASSERT(m_resourceToRevalidate);
 733         // Calling didAddClient for a client may end up removing another client. In that case it won't be in the set anymore.
 734         if (m_resourceToRevalidate->m_clients.contains(client))
 735             m_resourceToRevalidate->didAddClient(*client);
 736     }
 737     m_switchingClientsToRevalidatedResource = false;
 738 }
 739
 740 void CachedResource::updateResponseAfterRevalidation(const ResourceResponse& validatingResponse)
 741 {
 742     m_responseTimestamp = std::chrono::system_clock::now();
 743
 744     updateResponseHeadersAfterRevalidation(m_response, validatingResponse);
 745 }
 746
 747 void CachedResource::registerHandle(CachedResourceHandleBase* h)
 748 {
 749     ++m_handleCount;
 750     if (m_resourceToRevalidate)
 751         m_handlesToRevalidate.add(h);
 752 }
 753
 754 void CachedResource::unregisterHandle(CachedResourceHandleBase* h)
 755 {
 756     ASSERT(m_handleCount > 0);
 757     --m_handleCount;
 758
 759     if (m_resourceToRevalidate)
 760          m_handlesToRevalidate.remove(h);
 761
 762     if (!m_handleCount)
 763         deleteIfPossible();
 764 }
 765
 766 bool CachedResource::canUseCacheValidator() const
 767 {
 768     if (m_loading || errorOccurred())
 769         return false;
 770
 771     if (m_response.cacheControlContainsNoStore())
 772         return false;
 773     return m_response.hasCacheValidatorFields();
 774 }
 775
 776 CachedResource::RevalidationDecision CachedResource::makeRevalidationDecision(CachePolicy cachePolicy) const
 777 {
 778     switch (cachePolicy) {
 779     case CachePolicyHistoryBuffer:
 780         return RevalidationDecision::No;
 781
 782     case CachePolicyReload:
 783         return RevalidationDecision::YesDueToCachePolicy;
 784
 785     case CachePolicyRevalidate:
 786         if (m_response.cacheControlContainsImmutable() && m_response.url().protocolIs("https")) {
 787             if (isExpired())
 788                 return RevalidationDecision::YesDueToExpired;
 789             return RevalidationDecision::No;
 790         }
 791         return RevalidationDecision::YesDueToCachePolicy;
 792
 793     case CachePolicyVerify:
 794         if (m_response.cacheControlContainsNoCache())
 795             return RevalidationDecision::YesDueToNoCache;
 796         // FIXME: Cache-Control:no-store should prevent storing, not reuse.
 797         if (m_response.cacheControlContainsNoStore())
 798             return RevalidationDecision::YesDueToNoStore;
 799
 800         if (isExpired())
 801             return RevalidationDecision::YesDueToExpired;
 802
 803         return RevalidationDecision::No;
 804     };
 805     ASSERT_NOT_REACHED();
 806     return RevalidationDecision::No;
 807 }
 808
 809 bool CachedResource::redirectChainAllowsReuse(ReuseExpiredRedirectionOrNot reuseExpiredRedirection) const
 810 {
 811     return WebCore::redirectChainAllowsReuse(m_redirectChainCacheStatus, reuseExpiredRedirection);
 812 }
 813
 814 bool CachedResource::varyHeaderValuesMatch(const ResourceRequest& request)
 815 {
 816     if (m_varyingHeaderValues.isEmpty())
 817         return true;
 818
 819     return verifyVaryingRequestHeaders(m_varyingHeaderValues, request, m_sessionID);
 820 }
 821
 822 unsigned CachedResource::overheadSize() const
 823 {
 824     static const int kAverageClientsHashMapSize = 384;
 825     return sizeof(CachedResource) + m_response.memoryUsage() + kAverageClientsHashMapSize + m_resourceRequest.url().string().length() * 2;
 826 }
 827
 828 bool CachedResource::areAllClientsXMLHttpRequests() const
 829 {
 830     if (type() != RawResource)
 831         return false;
 832
 833     for (auto& client : m_clients) {
 834         if (!client.key->isXMLHttpRequest())
 835             return false;
 836     }
 837     return true;
 838 }
 839
 840 void CachedResource::setLoadPriority(const std::optional<ResourceLoadPriority>& loadPriority)
 841 {
 842     if (loadPriority)
 843         m_loadPriority = loadPriority.value();
 844     else
 845         m_loadPriority = defaultPriorityForResourceType(type());
 846 }
 847
 848 inline CachedResource::Callback::Callback(CachedResource& resource, CachedResourceClient& client)
 849     : m_resource(resource)
 850     , m_client(client)
 851     , m_timer(*this, &Callback::timerFired)
 852 {
 853     m_timer.startOneShot(0_s);
 854 }
 855
 856 inline void CachedResource::Callback::cancel()
 857 {
 858     if (m_timer.isActive())
 859         m_timer.stop();
 860 }
 861
 862 void CachedResource::Callback::timerFired()
 863 {
 864     m_resource.didAddClient(m_client);
 865 }
 866
 867 #if USE(FOUNDATION) || USE(SOUP)
 868
 869 void CachedResource::tryReplaceEncodedData(SharedBuffer& newBuffer)
 870 {
 871     if (!m_data)
 872         return;
 873
 874     if (!mayTryReplaceEncodedData())
 875         return;
 876
 877     // We have to do the memcmp because we can't tell if the replacement file backed data is for the
 878     // same resource or if we made a second request with the same URL which gave us a different
 879     // resource. We have seen this happen for cached POST resources.
 880     if (m_data->size() != newBuffer.size() || memcmp(m_data->data(), newBuffer.data(), m_data->size()))
 881         return;
 882
 883     m_data->clear();
 884     m_data->append(newBuffer);
 885     didReplaceSharedBufferContents();
 886 }
 887
 888 #endif
 889
 890 }