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 "LoaderStrategy.h"
  41 #include "Logging.h"
  42 #include "MainFrame.h"
  43 #include "MemoryCache.h"
  44 #include "PlatformStrategies.h"
  45 #include "ProgressTracker.h"
  46 #include "ResourceHandle.h"
  47 #include "SchemeRegistry.h"
  48 #include "SecurityOrigin.h"
  49 #include "SubresourceLoader.h"
  50 #include "URL.h"
  51 #include <wtf/CurrentTime.h>
  52 #include <wtf/MathExtras.h>
  53 #include <wtf/RefCountedLeakCounter.h>
  54 #include <wtf/StdLibExtras.h>
  55 #include <wtf/Vector.h>
  56 #include <wtf/text/CString.h>
  57
  58 #if USE(QUICK_LOOK)
  59 #include "QuickLook.h"
  60 #endif
  61
  62 using namespace WTF;
  63
  64 #define RELEASE_LOG_IF_ALLOWED(fmt, ...) RELEASE_LOG_IF(cachedResourceLoader.isAlwaysOnLoggingAllowed(), Network, "%p - CachedResource::" fmt, this, ##__VA_ARGS__)
  65
  66 namespace WebCore {
  67
  68 ResourceLoadPriority CachedResource::defaultPriorityForResourceType(Type type)
  69 {
  70     switch (type) {
  71     case CachedResource::MainResource:
  72         return ResourceLoadPriority::VeryHigh;
  73     case CachedResource::CSSStyleSheet:
  74     case CachedResource::Script:
  75         return ResourceLoadPriority::High;
  76 #if ENABLE(SVG_FONTS)
  77     case CachedResource::SVGFontResource:
  78 #endif
  79     case CachedResource::MediaResource:
  80     case CachedResource::FontResource:
  81     case CachedResource::RawResource:
  82     case CachedResource::Icon:
  83         return ResourceLoadPriority::Medium;
  84     case CachedResource::ImageResource:
  85         return ResourceLoadPriority::Low;
  86 #if ENABLE(XSLT)
  87     case CachedResource::XSLStyleSheet:
  88         return ResourceLoadPriority::High;
  89 #endif
  90     case CachedResource::SVGDocumentResource:
  91         return ResourceLoadPriority::Low;
  92     case CachedResource::Beacon:
  93         return ResourceLoadPriority::VeryLow;
  94 #if ENABLE(LINK_PREFETCH)
  95     case CachedResource::LinkPrefetch:
  96         return ResourceLoadPriority::VeryLow;
  97     case CachedResource::LinkSubresource:
  98         return ResourceLoadPriority::VeryLow;
  99 #endif
 100 #if ENABLE(VIDEO_TRACK)
 101     case CachedResource::TextTrackResource:
 102         return ResourceLoadPriority::Low;
 103 #endif
 104     }
 105     ASSERT_NOT_REACHED();
 106     return ResourceLoadPriority::Low;
 107 }
 108
 109 static Seconds deadDecodedDataDeletionIntervalForResourceType(CachedResource::Type type)
 110 {
 111     if (type == CachedResource::Script)
 112         return 0_s;
 113
 114     return MemoryCache::singleton().deadDecodedDataDeletionInterval();
 115 }
 116
 117 DEFINE_DEBUG_ONLY_GLOBAL(RefCountedLeakCounter, cachedResourceLeakCounter, ("CachedResource"));
 118
 119 CachedResource::CachedResource(CachedResourceRequest&& request, Type type, PAL::SessionID sessionID)
 120     : m_resourceRequest(request.releaseResourceRequest())
 121     , m_options(request.options())
 122     , m_decodedDataDeletionTimer(*this, &CachedResource::destroyDecodedData, deadDecodedDataDeletionIntervalForResourceType(type))
 123     , m_sessionID(sessionID)
 124     , m_loadPriority(defaultPriorityForResourceType(type))
 125     , m_responseTimestamp(std::chrono::system_clock::now())
 126     , m_fragmentIdentifierForRequest(request.releaseFragmentIdentifier())
 127     , m_origin(request.releaseOrigin())
 128     , m_initiatorName(request.initiatorName())
 129     , m_isLinkPreload(request.isLinkPreload())
 130     , m_hasUnknownEncoding(request.isLinkPreload())
 131     , m_type(type)
 132     , m_ignoreForRequestCount(request.ignoreForRequestCount())
 133 {
 134     ASSERT(sessionID.isValid());
 135
 136     setLoadPriority(request.priority());
 137 #ifndef NDEBUG
 138     cachedResourceLeakCounter.increment();
 139 #endif
 140
 141     // FIXME: We should have a better way of checking for Navigation loads, maybe FetchMode::Options::Navigate.
 142     ASSERT(m_origin || m_type == CachedResource::MainResource);
 143
 144     if (isRequestCrossOrigin(m_origin.get(), m_resourceRequest.url(), m_options))
 145         setCrossOrigin();
 146 }
 147
 148 // FIXME: For this constructor, we should probably mandate that the URL has no fragment identifier.
 149 CachedResource::CachedResource(const URL& url, Type type, PAL::SessionID sessionID)
 150     : m_resourceRequest(url)
 151     , m_decodedDataDeletionTimer(*this, &CachedResource::destroyDecodedData, deadDecodedDataDeletionIntervalForResourceType(type))
 152     , m_sessionID(sessionID)
 153     , m_responseTimestamp(std::chrono::system_clock::now())
 154     , m_fragmentIdentifierForRequest(CachedResourceRequest::splitFragmentIdentifierFromRequestURL(m_resourceRequest))
 155     , m_type(type)
 156     , m_status(Cached)
 157 {
 158     ASSERT(sessionID.isValid());
 159 #ifndef NDEBUG
 160     cachedResourceLeakCounter.increment();
 161 #endif
 162 }
 163
 164 CachedResource::~CachedResource()
 165 {
 166     ASSERT(!m_resourceToRevalidate); // Should be true because canDelete() checks this.
 167     ASSERT(canDelete());
 168     ASSERT(!inCache());
 169     ASSERT(!m_deleted);
 170     ASSERT(url().isNull() || !allowsCaching() || MemoryCache::singleton().resourceForRequest(resourceRequest(), sessionID()) != this);
 171
 172 #ifndef NDEBUG
 173     m_deleted = true;
 174     cachedResourceLeakCounter.decrement();
 175 #endif
 176
 177     if (m_owningCachedResourceLoader)
 178         m_owningCachedResourceLoader->removeCachedResource(*this);
 179 }
 180
 181 void CachedResource::failBeforeStarting()
 182 {
 183     // FIXME: What if resources in other frames were waiting for this revalidation?
 184     LOG(ResourceLoading, "Cannot start loading '%s'", url().string().latin1().data());
 185     if (allowsCaching() && m_resourceToRevalidate)
 186         MemoryCache::singleton().revalidationFailed(*this);
 187     error(CachedResource::LoadError);
 188 }
 189
 190 void CachedResource::load(CachedResourceLoader& cachedResourceLoader)
 191 {
 192     if (!cachedResourceLoader.frame()) {
 193         RELEASE_LOG_IF_ALLOWED("load: No associated frame");
 194         failBeforeStarting();
 195         return;
 196     }
 197     Frame& frame = *cachedResourceLoader.frame();
 198
 199     // Prevent new loads if we are in the PageCache or being added to the PageCache.
 200     // We query the top document because new frames may be created in pagehide event handlers
 201     // and their pageCacheState will not reflect the fact that they are about to enter page
 202     // cache.
 203     if (auto* topDocument = frame.mainFrame().document()) {
 204         if (topDocument->pageCacheState() != Document::NotInPageCache) {
 205             RELEASE_LOG_IF_ALLOWED("load: Already in page cache or being added to it (frame = %p)", &frame);
 206             failBeforeStarting();
 207             return;
 208         }
 209     }
 210
 211     FrameLoader& frameLoader = frame.loader();
 212     if (m_options.securityCheck == DoSecurityCheck && (frameLoader.state() == FrameStateProvisional || !frameLoader.activeDocumentLoader() || frameLoader.activeDocumentLoader()->isStopping())) {
 213         if (frameLoader.state() == FrameStateProvisional)
 214             RELEASE_LOG_IF_ALLOWED("load: Failed security check -- state is provisional (frame = %p)", &frame);
 215         else if (!frameLoader.activeDocumentLoader())
 216             RELEASE_LOG_IF_ALLOWED("load: Failed security check -- not active document (frame = %p)", &frame);
 217         else if (frameLoader.activeDocumentLoader()->isStopping())
 218             RELEASE_LOG_IF_ALLOWED("load: Failed security check -- active loader is stopping (frame = %p)", &frame);
 219         failBeforeStarting();
 220         return;
 221     }
 222
 223     m_loading = true;
 224
 225     if (isCacheValidator()) {
 226         CachedResource* resourceToRevalidate = m_resourceToRevalidate;
 227         ASSERT(resourceToRevalidate->canUseCacheValidator());
 228         ASSERT(resourceToRevalidate->isLoaded());
 229         const String& lastModified = resourceToRevalidate->response().httpHeaderField(HTTPHeaderName::LastModified);
 230         const String& eTag = resourceToRevalidate->response().httpHeaderField(HTTPHeaderName::ETag);
 231         if (!lastModified.isEmpty() || !eTag.isEmpty()) {
 232             ASSERT(cachedResourceLoader.cachePolicy(type(), url()) != CachePolicyReload);
 233             if (cachedResourceLoader.cachePolicy(type(), url()) == CachePolicyRevalidate)
 234                 m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::CacheControl, "max-age=0");
 235             if (!lastModified.isEmpty())
 236                 m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::IfModifiedSince, lastModified);
 237             if (!eTag.isEmpty())
 238                 m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::IfNoneMatch, eTag);
 239         }
 240     }
 241
 242 #if ENABLE(LINK_PREFETCH)
 243     if (type() == CachedResource::LinkPrefetch || type() == CachedResource::LinkSubresource)
 244         m_resourceRequest.setHTTPHeaderField(HTTPHeaderName::Purpose, "prefetch");
 245 #endif
 246     m_resourceRequest.setPriority(loadPriority());
 247
 248     // Navigation algorithm is setting up the request before sending it to CachedResourceLoader?CachedResource.
 249     // So no need for extra fields for MainResource.
 250     if (type() != CachedResource::MainResource)
 251         frameLoader.addExtraFieldsToSubresourceRequest(m_resourceRequest);
 252
 253
 254     // FIXME: It's unfortunate that the cache layer and below get to know anything about fragment identifiers.
 255     // We should look into removing the expectation of that knowledge from the platform network stacks.
 256     ResourceRequest request(m_resourceRequest);
 257     if (!m_fragmentIdentifierForRequest.isNull()) {
 258         URL url = request.url();
 259         url.setFragmentIdentifier(m_fragmentIdentifierForRequest);
 260         request.setURL(url);
 261         m_fragmentIdentifierForRequest = String();
 262     }
 263
 264     if (m_options.keepAlive) {
 265         if (!cachedResourceLoader.keepaliveRequestTracker().tryRegisterRequest(*this)) {
 266             setResourceError({ errorDomainWebKitInternal, 0, request.url(), ASCIILiteral("Reached maximum amount of queued data of 64Kb for keepalive requests") });
 267             failBeforeStarting();
 268             return;
 269         }
 270         // FIXME: We should not special-case Beacon here.
 271         if (shouldUsePingLoad(type())) {
 272             ASSERT(m_originalRequestHeaders);
 273             CachedResourceHandle<CachedResource> protectedThis(this);
 274
 275             // FIXME: Move beacon loads to normal subresource loading to get normal inspector request instrumentation hooks.
 276             unsigned long identifier = frame.page()->progress().createUniqueIdentifier();
 277             InspectorInstrumentation::willSendRequestOfType(&frame, identifier, frameLoader.activeDocumentLoader(), request, InspectorInstrumentation::LoadType::Beacon);
 278
 279             platformStrategies()->loaderStrategy()->startPingLoad(frame, request, *m_originalRequestHeaders, m_options, [this, protectedThis = WTFMove(protectedThis), protectedFrame = makeRef(frame), identifier] (const ResourceError& error, const ResourceResponse& response) {
 280                 if (!response.isNull())
 281                     InspectorInstrumentation::didReceiveResourceResponse(protectedFrame, identifier, protectedFrame->loader().activeDocumentLoader(), response, nullptr);
 282                 if (error.isNull()) {
 283                     finishLoading(nullptr);
 284                     NetworkLoadMetrics emptyMetrics;
 285                     InspectorInstrumentation::didFinishLoading(protectedFrame.ptr(), protectedFrame->loader().activeDocumentLoader(), identifier, emptyMetrics, nullptr);
 286                 } else {
 287                     setResourceError(error);
 288                     this->error(LoadError);
 289                     InspectorInstrumentation::didFailLoading(protectedFrame.ptr(), protectedFrame->loader().activeDocumentLoader(), identifier, error);
 290                 }
 291             });
 292             return;
 293         }
 294     }
 295
 296     m_loader = platformStrategies()->loaderStrategy()->loadResource(frame, *this, request, m_options);
 297     if (!m_loader) {
 298         RELEASE_LOG_IF_ALLOWED("load: Unable to create SubresourceLoader (frame = %p)", &frame);
 299         failBeforeStarting();
 300         return;
 301     }
 302
 303     m_status = Pending;
 304 }
 305
 306 void CachedResource::loadFrom(const CachedResource& resource)
 307 {
 308     ASSERT(url() == resource.url());
 309     ASSERT(type() == resource.type());
 310     ASSERT(resource.status() == Status::Cached);
 311
 312     if (isCrossOrigin() && m_options.mode == FetchOptions::Mode::Cors) {
 313         ASSERT(m_origin);
 314         String errorMessage;
 315         if (!WebCore::passesAccessControlCheck(resource.response(), m_options.storedCredentialsPolicy, *m_origin, errorMessage)) {
 316             setResourceError(ResourceError(String(), 0, url(), errorMessage, ResourceError::Type::AccessControl));
 317             return;
 318         }
 319     }
 320
 321     setBodyDataFrom(resource);
 322     setStatus(Status::Cached);
 323     setLoading(false);
 324 }
 325
 326 void CachedResource::setBodyDataFrom(const CachedResource& resource)
 327 {
 328     m_data = resource.m_data;
 329     m_response = resource.m_response;
 330     m_response.setTainting(m_responseTainting);
 331     setDecodedSize(resource.decodedSize());
 332     setEncodedSize(resource.encodedSize());
 333 }
 334
 335 void CachedResource::checkNotify()
 336 {
 337     if (isLoading() || stillNeedsLoad())
 338         return;
 339
 340     CachedResourceClientWalker<CachedResourceClient> walker(m_clients);
 341     while (CachedResourceClient* client = walker.next())
 342         client->notifyFinished(*this);
 343 }
 344
 345 void CachedResource::addDataBuffer(SharedBuffer&)
 346 {
 347     ASSERT(dataBufferingPolicy() == BufferData);
 348 }
 349
 350 void CachedResource::addData(const char*, unsigned)
 351 {
 352     ASSERT(dataBufferingPolicy() == DoNotBufferData);
 353 }
 354
 355 void CachedResource::finishLoading(SharedBuffer*)
 356 {
 357     setLoading(false);
 358     checkNotify();
 359 }
 360
 361 void CachedResource::error(CachedResource::Status status)
 362 {
 363     setStatus(status);
 364     ASSERT(errorOccurred());
 365     m_data = nullptr;
 366
 367     setLoading(false);
 368     checkNotify();
 369 }
 370
 371 void CachedResource::cancelLoad()
 372 {
 373     if (!isLoading() && !stillNeedsLoad())
 374         return;
 375
 376     setStatus(LoadError);
 377     setLoading(false);
 378     checkNotify();
 379 }
 380
 381 void CachedResource::finish()
 382 {
 383     if (!errorOccurred())
 384         m_status = Cached;
 385 }
 386
 387 void CachedResource::setCrossOrigin()
 388 {
 389     ASSERT(m_options.mode != FetchOptions::Mode::SameOrigin);
 390     m_responseTainting = (m_options.mode == FetchOptions::Mode::Cors) ? ResourceResponse::Tainting::Cors : ResourceResponse::Tainting::Opaque;
 391 }
 392
 393 bool CachedResource::isCrossOrigin() const
 394 {
 395     return m_responseTainting != ResourceResponse::Tainting::Basic;
 396 }
 397
 398 bool CachedResource::isCORSSameOrigin() const
 399 {
 400     // Following resource types do not use CORS
 401     ASSERT(type() != CachedResource::Type::FontResource);
 402 #if ENABLE(SVG_FONTS)
 403     ASSERT(type() != CachedResource::Type::SVGFontResource);
 404 #endif
 405 #if ENABLE(XSLT)
 406     ASSERT(type() != CachedResource::XSLStyleSheet);
 407 #endif
 408
 409     // https://html.spec.whatwg.org/multipage/infrastructure.html#cors-same-origin
 410     return !loadFailedOrCanceled() && m_responseTainting != ResourceResponse::Tainting::Opaque;
 411 }
 412
 413 bool CachedResource::isExpired() const
 414 {
 415     if (m_response.isNull())
 416         return false;
 417
 418     return computeCurrentAge(m_response, m_responseTimestamp) > freshnessLifetime(m_response);
 419 }
 420
 421 static inline bool shouldCacheSchemeIndefinitely(StringView scheme)
 422 {
 423 #if PLATFORM(COCOA)
 424     if (equalLettersIgnoringASCIICase(scheme, "applewebdata"))
 425         return true;
 426 #endif
 427 #if USE(SOUP)
 428     if (equalLettersIgnoringASCIICase(scheme, "resource"))
 429         return true;
 430 #endif
 431     return equalLettersIgnoringASCIICase(scheme, "data");
 432 }
 433
 434 std::chrono::microseconds CachedResource::freshnessLifetime(const ResourceResponse& response) const
 435 {
 436     using namespace std::literals::chrono_literals;
 437
 438     if (!response.url().protocolIsInHTTPFamily()) {
 439         StringView protocol = response.url().protocol();
 440         if (!shouldCacheSchemeIndefinitely(protocol)) {
 441             // Don't cache non-HTTP main resources since we can't check for freshness.
 442             // FIXME: We should not cache subresources either, but when we tried this
 443             // it caused performance and flakiness issues in our test infrastructure.
 444             if (m_type == MainResource || SchemeRegistry::shouldAlwaysRevalidateURLScheme(protocol.toStringWithoutCopying()))
 445                 return 0us;
 446         }
 447
 448         return std::chrono::microseconds::max();
 449     }
 450
 451     return computeFreshnessLifetimeForHTTPFamily(response, m_responseTimestamp);
 452 }
 453
 454 void CachedResource::redirectReceived(ResourceRequest&, const ResourceResponse& response)
 455 {
 456     m_requestedFromNetworkingLayer = true;
 457     if (response.isNull())
 458         return;
 459
 460     updateRedirectChainStatus(m_redirectChainCacheStatus, response);
 461 }
 462
 463 void CachedResource::setResponse(const ResourceResponse& response)
 464 {
 465     ASSERT(m_response.type() == ResourceResponse::Type::Default);
 466     m_response = response;
 467     m_response.setRedirected(m_redirectChainCacheStatus.status != RedirectChainCacheStatus::NoRedirection);
 468     if (m_response.tainting() == ResourceResponse::Tainting::Basic || m_response.tainting() == ResourceResponse::Tainting::Cors)
 469         m_response.setTainting(m_responseTainting);
 470
 471     m_varyingHeaderValues = collectVaryingRequestHeaders(m_resourceRequest, m_response, m_sessionID);
 472 }
 473
 474 void CachedResource::responseReceived(const ResourceResponse& response)
 475 {
 476     setResponse(response);
 477     m_responseTimestamp = std::chrono::system_clock::now();
 478     String encoding = response.textEncodingName();
 479     if (!encoding.isNull())
 480         setEncoding(encoding);
 481 }
 482
 483 void CachedResource::clearLoader()
 484 {
 485     ASSERT(m_loader);
 486     m_identifierForLoadWithoutResourceLoader = m_loader->identifier();
 487     m_loader = nullptr;
 488     deleteIfPossible();
 489 }
 490
 491 void CachedResource::addClient(CachedResourceClient& client)
 492 {
 493     if (addClientToSet(client))
 494         didAddClient(client);
 495 }
 496
 497 void CachedResource::didAddClient(CachedResourceClient& client)
 498 {
 499     if (m_decodedDataDeletionTimer.isActive())
 500         m_decodedDataDeletionTimer.stop();
 501
 502     if (m_clientsAwaitingCallback.remove(&client))
 503         m_clients.add(&client);
 504     if (!isLoading() && !stillNeedsLoad())
 505         client.notifyFinished(*this);
 506 }
 507
 508 bool CachedResource::addClientToSet(CachedResourceClient& client)
 509 {
 510     if (m_preloadResult == PreloadNotReferenced && client.shouldMarkAsReferenced()) {
 511         if (isLoaded())
 512             m_preloadResult = PreloadReferencedWhileComplete;
 513         else if (m_requestedFromNetworkingLayer)
 514             m_preloadResult = PreloadReferencedWhileLoading;
 515         else
 516             m_preloadResult = PreloadReferenced;
 517     }
 518     if (allowsCaching() && !hasClients() && inCache())
 519         MemoryCache::singleton().addToLiveResourcesSize(*this);
 520
 521     if ((m_type == RawResource || m_type == MainResource) && !m_response.isNull() && !m_proxyResource) {
 522         // Certain resources (especially XHRs and main resources) do crazy things if an asynchronous load returns
 523         // synchronously (e.g., scripts may not have set all the state they need to handle the load).
 524         // Therefore, rather than immediately sending callbacks on a cache hit like other CachedResources,
 525         // we schedule the callbacks and ensure we never finish synchronously.
 526         ASSERT(!m_clientsAwaitingCallback.contains(&client));
 527         m_clientsAwaitingCallback.add(&client, std::make_unique<Callback>(*this, client));
 528         return false;
 529     }
 530
 531     m_clients.add(&client);
 532     return true;
 533 }
 534
 535 void CachedResource::removeClient(CachedResourceClient& client)
 536 {
 537     auto callback = m_clientsAwaitingCallback.take(&client);
 538     if (callback) {
 539         ASSERT(!m_clients.contains(&client));
 540         callback->cancel();
 541         callback = nullptr;
 542     } else {
 543         ASSERT(m_clients.contains(&client));
 544         m_clients.remove(&client);
 545         didRemoveClient(client);
 546     }
 547
 548     if (deleteIfPossible()) {
 549         // `this` object is dead here.
 550         return;
 551     }
 552
 553     if (hasClients())
 554         return;
 555
 556     auto& memoryCache = MemoryCache::singleton();
 557     if (allowsCaching() && inCache()) {
 558         memoryCache.removeFromLiveResourcesSize(*this);
 559         memoryCache.removeFromLiveDecodedResourcesList(*this);
 560     }
 561     if (!m_switchingClientsToRevalidatedResource)
 562         allClientsRemoved();
 563     destroyDecodedDataIfNeeded();
 564
 565     if (!allowsCaching())
 566         return;
 567
 568     if (response().cacheControlContainsNoStore() && url().protocolIs("https")) {
 569         // RFC2616 14.9.2:
 570         // "no-store: ... MUST make a best-effort attempt to remove the information from volatile storage as promptly as possible"
 571         // "... History buffers MAY store such responses as part of their normal operation."
 572         // We allow non-secure content to be reused in history, but we do not allow secure content to be reused.
 573         memoryCache.remove(*this);
 574     }
 575     memoryCache.pruneSoon();
 576 }
 577
 578 void CachedResource::destroyDecodedDataIfNeeded()
 579 {
 580     if (!m_decodedSize)
 581         return;
 582     if (!MemoryCache::singleton().deadDecodedDataDeletionInterval())
 583         return;
 584     m_decodedDataDeletionTimer.restart();
 585 }
 586
 587 void CachedResource::decodedDataDeletionTimerFired()
 588 {
 589     destroyDecodedData();
 590 }
 591
 592 bool CachedResource::deleteIfPossible()
 593 {
 594     if (canDelete()) {
 595         if (!inCache()) {
 596             InspectorInstrumentation::willDestroyCachedResource(*this);
 597             delete this;
 598             return true;
 599         }
 600         if (m_data)
 601             m_data->hintMemoryNotNeededSoon();
 602     }
 603     return false;
 604 }
 605
 606 void CachedResource::setDecodedSize(unsigned size)
 607 {
 608     if (size == m_decodedSize)
 609         return;
 610
 611     long long delta = static_cast<long long>(size) - m_decodedSize;
 612
 613     // The object must be moved to a different queue, since its size has been changed.
 614     // Remove before updating m_decodedSize, so we find the resource in the correct LRU list.
 615     if (allowsCaching() && inCache())
 616         MemoryCache::singleton().removeFromLRUList(*this);
 617
 618     m_decodedSize = size;
 619
 620     if (allowsCaching() && inCache()) {
 621         auto& memoryCache = MemoryCache::singleton();
 622         // Now insert into the new LRU list.
 623         memoryCache.insertInLRUList(*this);
 624
 625         // Insert into or remove from the live decoded list if necessary.
 626         // When inserting into the LiveDecodedResourcesList it is possible
 627         // that the m_lastDecodedAccessTime is still zero or smaller than
 628         // the m_lastDecodedAccessTime of the current list head. This is a
 629         // violation of the invariant that the list is to be kept sorted
 630         // by access time. The weakening of the invariant does not pose
 631         // a problem. For more details please see: https://bugs.webkit.org/show_bug.cgi?id=30209
 632         bool inLiveDecodedResourcesList = memoryCache.inLiveDecodedResourcesList(*this);
 633         if (m_decodedSize && !inLiveDecodedResourcesList && hasClients())
 634             memoryCache.insertInLiveDecodedResourcesList(*this);
 635         else if (!m_decodedSize && inLiveDecodedResourcesList)
 636             memoryCache.removeFromLiveDecodedResourcesList(*this);
 637
 638         // Update the cache's size totals.
 639         memoryCache.adjustSize(hasClients(), delta);
 640     }
 641 }
 642
 643 void CachedResource::setEncodedSize(unsigned size)
 644 {
 645     if (size == m_encodedSize)
 646         return;
 647
 648     long long delta = static_cast<long long>(size) - m_encodedSize;
 649
 650     // The object must be moved to a different queue, since its size has been changed.
 651     // Remove before updating m_encodedSize, so we find the resource in the correct LRU list.
 652     if (allowsCaching() && inCache())
 653         MemoryCache::singleton().removeFromLRUList(*this);
 654
 655     m_encodedSize = size;
 656
 657     if (allowsCaching() && inCache()) {
 658         auto& memoryCache = MemoryCache::singleton();
 659         memoryCache.insertInLRUList(*this);
 660         memoryCache.adjustSize(hasClients(), delta);
 661     }
 662 }
 663
 664 void CachedResource::didAccessDecodedData(double timeStamp)
 665 {
 666     m_lastDecodedAccessTime = timeStamp;
 667
 668     if (allowsCaching() && inCache()) {
 669         auto& memoryCache = MemoryCache::singleton();
 670         if (memoryCache.inLiveDecodedResourcesList(*this)) {
 671             memoryCache.removeFromLiveDecodedResourcesList(*this);
 672             memoryCache.insertInLiveDecodedResourcesList(*this);
 673         }
 674         memoryCache.pruneSoon();
 675     }
 676 }
 677
 678 void CachedResource::setResourceToRevalidate(CachedResource* resource)
 679 {
 680     ASSERT(resource);
 681     ASSERT(!m_resourceToRevalidate);
 682     ASSERT(resource != this);
 683     ASSERT(m_handlesToRevalidate.isEmpty());
 684     ASSERT(resource->type() == type());
 685     ASSERT(!resource->m_proxyResource);
 686
 687     LOG(ResourceLoading, "CachedResource %p setResourceToRevalidate %p", this, resource);
 688
 689     resource->m_proxyResource = this;
 690     m_resourceToRevalidate = resource;
 691 }
 692
 693 void CachedResource::clearResourceToRevalidate()
 694 {
 695     ASSERT(m_resourceToRevalidate);
 696     ASSERT(m_resourceToRevalidate->m_proxyResource == this);
 697
 698     if (m_switchingClientsToRevalidatedResource)
 699         return;
 700
 701     m_resourceToRevalidate->m_proxyResource = nullptr;
 702     m_resourceToRevalidate->deleteIfPossible();
 703
 704     m_handlesToRevalidate.clear();
 705     m_resourceToRevalidate = nullptr;
 706     deleteIfPossible();
 707 }
 708
 709 void CachedResource::switchClientsToRevalidatedResource()
 710 {
 711     ASSERT(m_resourceToRevalidate);
 712     ASSERT(m_resourceToRevalidate->inCache());
 713     ASSERT(!inCache());
 714
 715     LOG(ResourceLoading, "CachedResource %p switchClientsToRevalidatedResource %p", this, m_resourceToRevalidate);
 716
 717     m_switchingClientsToRevalidatedResource = true;
 718     for (auto& handle : m_handlesToRevalidate) {
 719         handle->m_resource = m_resourceToRevalidate;
 720         m_resourceToRevalidate->registerHandle(handle);
 721         --m_handleCount;
 722     }
 723     ASSERT(!m_handleCount);
 724     m_handlesToRevalidate.clear();
 725
 726     Vector<CachedResourceClient*> clientsToMove;
 727     for (auto& entry : m_clients) {
 728         CachedResourceClient* client = entry.key;
 729         unsigned count = entry.value;
 730         while (count) {
 731             clientsToMove.append(client);
 732             --count;
 733         }
 734     }
 735
 736     for (auto& client : clientsToMove)
 737         removeClient(*client);
 738     ASSERT(m_clients.isEmpty());
 739
 740     for (auto& client : clientsToMove)
 741         m_resourceToRevalidate->addClientToSet(*client);
 742     for (auto& client : clientsToMove) {
 743         // Calling didAddClient may do anything, including trying to cancel revalidation.
 744         // Assert that it didn't succeed.
 745         ASSERT(m_resourceToRevalidate);
 746         // Calling didAddClient for a client may end up removing another client. In that case it won't be in the set anymore.
 747         if (m_resourceToRevalidate->m_clients.contains(client))
 748             m_resourceToRevalidate->didAddClient(*client);
 749     }
 750     m_switchingClientsToRevalidatedResource = false;
 751 }
 752
 753 void CachedResource::updateResponseAfterRevalidation(const ResourceResponse& validatingResponse)
 754 {
 755     m_responseTimestamp = std::chrono::system_clock::now();
 756
 757     updateResponseHeadersAfterRevalidation(m_response, validatingResponse);
 758 }
 759
 760 void CachedResource::registerHandle(CachedResourceHandleBase* h)
 761 {
 762     ++m_handleCount;
 763     if (m_resourceToRevalidate)
 764         m_handlesToRevalidate.add(h);
 765 }
 766
 767 void CachedResource::unregisterHandle(CachedResourceHandleBase* h)
 768 {
 769     ASSERT(m_handleCount > 0);
 770     --m_handleCount;
 771
 772     if (m_resourceToRevalidate)
 773          m_handlesToRevalidate.remove(h);
 774
 775     if (!m_handleCount)
 776         deleteIfPossible();
 777 }
 778
 779 bool CachedResource::canUseCacheValidator() const
 780 {
 781     if (m_loading || errorOccurred())
 782         return false;
 783
 784     if (m_response.cacheControlContainsNoStore())
 785         return false;
 786     return m_response.hasCacheValidatorFields();
 787 }
 788
 789 CachedResource::RevalidationDecision CachedResource::makeRevalidationDecision(CachePolicy cachePolicy) const
 790 {
 791     switch (cachePolicy) {
 792     case CachePolicyHistoryBuffer:
 793         return RevalidationDecision::No;
 794
 795     case CachePolicyReload:
 796         return RevalidationDecision::YesDueToCachePolicy;
 797
 798     case CachePolicyRevalidate:
 799         if (m_response.cacheControlContainsImmutable() && m_response.url().protocolIs("https")) {
 800             if (isExpired())
 801                 return RevalidationDecision::YesDueToExpired;
 802             return RevalidationDecision::No;
 803         }
 804         return RevalidationDecision::YesDueToCachePolicy;
 805
 806     case CachePolicyVerify:
 807         if (m_response.cacheControlContainsNoCache())
 808             return RevalidationDecision::YesDueToNoCache;
 809         // FIXME: Cache-Control:no-store should prevent storing, not reuse.
 810         if (m_response.cacheControlContainsNoStore())
 811             return RevalidationDecision::YesDueToNoStore;
 812
 813         if (isExpired())
 814             return RevalidationDecision::YesDueToExpired;
 815
 816         return RevalidationDecision::No;
 817     };
 818     ASSERT_NOT_REACHED();
 819     return RevalidationDecision::No;
 820 }
 821
 822 bool CachedResource::redirectChainAllowsReuse(ReuseExpiredRedirectionOrNot reuseExpiredRedirection) const
 823 {
 824     return WebCore::redirectChainAllowsReuse(m_redirectChainCacheStatus, reuseExpiredRedirection);
 825 }
 826
 827 bool CachedResource::varyHeaderValuesMatch(const ResourceRequest& request)
 828 {
 829     if (m_varyingHeaderValues.isEmpty())
 830         return true;
 831
 832     return verifyVaryingRequestHeaders(m_varyingHeaderValues, request, m_sessionID);
 833 }
 834
 835 unsigned CachedResource::overheadSize() const
 836 {
 837     static const int kAverageClientsHashMapSize = 384;
 838     return sizeof(CachedResource) + m_response.memoryUsage() + kAverageClientsHashMapSize + m_resourceRequest.url().string().length() * 2;
 839 }
 840
 841 bool CachedResource::areAllClientsXMLHttpRequests() const
 842 {
 843     if (type() != RawResource)
 844         return false;
 845
 846     for (auto& client : m_clients) {
 847         if (!client.key->isXMLHttpRequest())
 848             return false;
 849     }
 850     return true;
 851 }
 852
 853 void CachedResource::setLoadPriority(const std::optional<ResourceLoadPriority>& loadPriority)
 854 {
 855     if (loadPriority)
 856         m_loadPriority = loadPriority.value();
 857     else
 858         m_loadPriority = defaultPriorityForResourceType(type());
 859 }
 860
 861 inline CachedResource::Callback::Callback(CachedResource& resource, CachedResourceClient& client)
 862     : m_resource(resource)
 863     , m_client(client)
 864     , m_timer(*this, &Callback::timerFired)
 865 {
 866     m_timer.startOneShot(0_s);
 867 }
 868
 869 inline void CachedResource::Callback::cancel()
 870 {
 871     if (m_timer.isActive())
 872         m_timer.stop();
 873 }
 874
 875 void CachedResource::Callback::timerFired()
 876 {
 877     m_resource.didAddClient(m_client);
 878 }
 879
 880 #if USE(FOUNDATION) || USE(SOUP)
 881
 882 void CachedResource::tryReplaceEncodedData(SharedBuffer& newBuffer)
 883 {
 884     if (!m_data)
 885         return;
 886
 887     if (!mayTryReplaceEncodedData())
 888         return;
 889
 890     // We have to do the memcmp because we can't tell if the replacement file backed data is for the
 891     // same resource or if we made a second request with the same URL which gave us a different
 892     // resource. We have seen this happen for cached POST resources.
 893     if (m_data->size() != newBuffer.size() || memcmp(m_data->data(), newBuffer.data(), m_data->size()))
 894         return;
 895
 896     m_data->clear();
 897     m_data->append(newBuffer);
 898     didReplaceSharedBufferContents();
 899 }
 900
 901 #endif
 902
 903 }