1 files changed, 371 insertions, 0 deletions
diff --git a/uriloader/preload/PreloadService.cpp b/uriloader/preload/PreloadService.cpp
new file mode 100644
index 0000000000..5fc59760f0
--- /dev/null
+++ b/uriloader/preload/PreloadService.cpp
@@ -0,0 +1,371 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "PreloadService.h"
+
+#include "FetchPreloader.h"
+#include "PreloaderBase.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/AsyncEventDispatcher.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/dom/FetchPriority.h"
+#include "mozilla/dom/HTMLLinkElement.h"
+#include "mozilla/dom/ScriptLoader.h"
+#include "mozilla/dom/ReferrerInfo.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/FontPreloader.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "nsGenericHTMLElement.h"
+#include "nsNetUtil.h"
+
+namespace mozilla {
+
+using namespace dom;
+
+static LazyLogModule sPreloadServiceLog{"PreloadService"};
+
+PreloadService::PreloadService(dom::Document* aDoc) : mDocument(aDoc) {}
+PreloadService::~PreloadService() = default;
+
+bool PreloadService::RegisterPreload(const PreloadHashKey& aKey,
+                                     PreloaderBase* aPreload) {
+  return mPreloads.WithEntryHandle(aKey, [&](auto&& lookup) {
+    if (lookup) {
+      lookup.Data() = aPreload;
+      return true;
+    }
+    lookup.Insert(aPreload);
+    return false;
+  });
+}
+
+void PreloadService::DeregisterPreload(const PreloadHashKey& aKey) {
+  mPreloads.Remove(aKey);
+}
+
+void PreloadService::ClearAllPreloads() { mPreloads.Clear(); }
+
+bool PreloadService::PreloadExists(const PreloadHashKey& aKey) {
+  return mPreloads.Contains(aKey);
+}
+
+already_AddRefed<PreloaderBase> PreloadService::LookupPreload(
+    const PreloadHashKey& aKey) const {
+  return mPreloads.Get(aKey);
+}
+
+already_AddRefed<nsIURI> PreloadService::GetPreloadURI(const nsAString& aURL) {
+  nsIURI* base = BaseURIForPreload();
+  auto encoding = mDocument->GetDocumentCharacterSet();
+
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), aURL, encoding, base);
+  if (NS_FAILED(rv)) {
+    return nullptr;
+  }
+
+  return uri.forget();
+}
+
+already_AddRefed<PreloaderBase> PreloadService::PreloadLinkElement(
+    dom::HTMLLinkElement* aLinkElement, nsContentPolicyType aPolicyType) {
+  if (aPolicyType == nsIContentPolicy::TYPE_INVALID) {
+    MOZ_ASSERT_UNREACHABLE("Caller should check");
+    return nullptr;
+  }
+
+  nsAutoString as, charset, crossOrigin, integrity, referrerPolicy,
+      fetchPriority, rel, srcset, sizes, type, url;
+
+  nsCOMPtr<nsIURI> uri = aLinkElement->GetURI();
+  aLinkElement->GetCharset(charset);
+  aLinkElement->GetImageSrcset(srcset);
+  aLinkElement->GetImageSizes(sizes);
+  aLinkElement->GetHref(url);
+  aLinkElement->GetCrossOrigin(crossOrigin);
+  aLinkElement->GetIntegrity(integrity);
+  aLinkElement->GetReferrerPolicy(referrerPolicy);
+  aLinkElement->GetFetchPriority(fetchPriority);
+  aLinkElement->GetRel(rel);
+
+  nsAutoString nonce;
+  if (nsString* cspNonce =
+          static_cast<nsString*>(aLinkElement->GetProperty(nsGkAtoms::nonce))) {
+    nonce = *cspNonce;
+  }
+
+  if (rel.LowerCaseEqualsASCII("modulepreload")) {
+    as = u"script"_ns;
+    type = u"module"_ns;
+  } else {
+    aLinkElement->GetAs(as);
+    aLinkElement->GetType(type);
+  }
+
+  auto result = PreloadOrCoalesce(uri, url, aPolicyType, as, type, charset,
+                                  srcset, sizes, nonce, integrity, crossOrigin,
+                                  referrerPolicy, fetchPriority,
+                                  /* aFromHeader = */ false, 0);
+
+  if (!result.mPreloader) {
+    NotifyNodeEvent(aLinkElement, result.mAlreadyComplete);
+    return nullptr;
+  }
+
+  result.mPreloader->AddLinkPreloadNode(aLinkElement);
+  return result.mPreloader.forget();
+}
+
+void PreloadService::PreloadLinkHeader(
+    nsIURI* aURI, const nsAString& aURL, nsContentPolicyType aPolicyType,
+    const nsAString& aAs, const nsAString& aType, const nsAString& aNonce,
+    const nsAString& aIntegrity, const nsAString& aSrcset,
+    const nsAString& aSizes, const nsAString& aCORS,
+    const nsAString& aReferrerPolicy, uint64_t aEarlyHintPreloaderId,
+    const nsAString& aFetchPriority) {
+  if (aPolicyType == nsIContentPolicy::TYPE_INVALID) {
+    MOZ_ASSERT_UNREACHABLE("Caller should check");
+    return;
+  }
+
+  PreloadOrCoalesce(aURI, aURL, aPolicyType, aAs, aType, u""_ns, aSrcset,
+                    aSizes, aNonce, aIntegrity, aCORS, aReferrerPolicy,
+                    aFetchPriority,
+                    /* aFromHeader = */ true, aEarlyHintPreloaderId);
+}
+
+// The mapping is specified as implementation-defined, see step 15 of
+// <https://fetch.spec.whatwg.org/#concept-fetch>. For web-compatibility,
+// Chromium's mapping described at
+// <https://web.dev/articles/fetch-priority#browser_priority_and_fetchpriority>
+// is chosen.
+class SupportsPriorityValueFor {
+ public:
+  static int32_t LinkRelPreloadFont(const FetchPriority aFetchPriority) {
+    if (!StaticPrefs::network_fetchpriority_enabled()) {
+      return nsISupportsPriority::PRIORITY_HIGH;
+    }
+
+    switch (aFetchPriority) {
+      case FetchPriority::Auto:
+        return nsISupportsPriority::PRIORITY_HIGH;
+      case FetchPriority::High:
+        return nsISupportsPriority::PRIORITY_HIGH;
+      case FetchPriority::Low:
+        return nsISupportsPriority::PRIORITY_LOW;
+    }
+
+    MOZ_ASSERT_UNREACHABLE();
+    return nsISupportsPriority::PRIORITY_HIGH;
+  }
+
+  static int32_t LinkRelPreloadFetch(const FetchPriority aFetchPriority) {
+    if (!StaticPrefs::network_fetchpriority_enabled()) {
+      return nsISupportsPriority::PRIORITY_NORMAL;
+    }
+
+    switch (aFetchPriority) {
+      case FetchPriority::Auto:
+        return nsISupportsPriority::PRIORITY_NORMAL;
+      case FetchPriority::High:
+        return nsISupportsPriority::PRIORITY_HIGH;
+      case FetchPriority::Low:
+        return nsISupportsPriority::PRIORITY_LOW;
+    }
+
+    MOZ_ASSERT_UNREACHABLE();
+    return nsISupportsPriority::PRIORITY_NORMAL;
+  }
+};
+
+PreloadService::PreloadOrCoalesceResult PreloadService::PreloadOrCoalesce(
+    nsIURI* aURI, const nsAString& aURL, nsContentPolicyType aPolicyType,
+    const nsAString& aAs, const nsAString& aType, const nsAString& aCharset,
+    const nsAString& aSrcset, const nsAString& aSizes, const nsAString& aNonce,
+    const nsAString& aIntegrity, const nsAString& aCORS,
+    const nsAString& aReferrerPolicy, const nsAString& aFetchPriority,
+    bool aFromHeader, uint64_t aEarlyHintPreloaderId) {
+  if (!aURI) {
+    MOZ_ASSERT_UNREACHABLE("Should not pass null nsIURI");
+    return {nullptr, false};
+  }
+
+  bool isImgSet = false;
+  PreloadHashKey preloadKey;
+  nsCOMPtr<nsIURI> uri = aURI;
+
+  if (aAs.LowerCaseEqualsASCII("script")) {
+    preloadKey = PreloadHashKey::CreateAsScript(uri, aCORS, aType);
+  } else if (aAs.LowerCaseEqualsASCII("style")) {
+    preloadKey = PreloadHashKey::CreateAsStyle(
+        uri, mDocument->NodePrincipal(), dom::Element::StringToCORSMode(aCORS),
+        css::eAuthorSheetFeatures /* see Loader::LoadSheet */);
+  } else if (aAs.LowerCaseEqualsASCII("image")) {
+    uri = mDocument->ResolvePreloadImage(BaseURIForPreload(), aURL, aSrcset,
+                                         aSizes, &isImgSet);
+    if (!uri) {
+      return {nullptr, false};
+    }
+
+    preloadKey = PreloadHashKey::CreateAsImage(
+        uri, mDocument->NodePrincipal(), dom::Element::StringToCORSMode(aCORS));
+  } else if (aAs.LowerCaseEqualsASCII("font")) {
+    preloadKey = PreloadHashKey::CreateAsFont(
+        uri, dom::Element::StringToCORSMode(aCORS));
+  } else if (aAs.LowerCaseEqualsASCII("fetch")) {
+    preloadKey = PreloadHashKey::CreateAsFetch(
+        uri, dom::Element::StringToCORSMode(aCORS));
+  } else {
+    return {nullptr, false};
+  }
+
+  if (RefPtr<PreloaderBase> preload = LookupPreload(preloadKey)) {
+    return {std::move(preload), false};
+  }
+
+  if (aAs.LowerCaseEqualsASCII("script")) {
+    PreloadScript(uri, aType, aCharset, aCORS, aReferrerPolicy, aNonce,
+                  aFetchPriority, aIntegrity, true /* isInHead - TODO */,
+                  aEarlyHintPreloaderId);
+  } else if (aAs.LowerCaseEqualsASCII("style")) {
+    auto status = mDocument->PreloadStyle(
+        aURI, Encoding::ForLabel(aCharset), aCORS,
+        PreloadReferrerPolicy(aReferrerPolicy), aNonce, aIntegrity,
+        aFromHeader ? css::StylePreloadKind::FromLinkRelPreloadHeader
+                    : css::StylePreloadKind::FromLinkRelPreloadElement,
+        aEarlyHintPreloaderId, aFetchPriority);
+    switch (status) {
+      case dom::SheetPreloadStatus::AlreadyComplete:
+        return {nullptr, /* already_complete = */ true};
+      case dom::SheetPreloadStatus::Errored:
+      case dom::SheetPreloadStatus::InProgress:
+        break;
+    }
+  } else if (aAs.LowerCaseEqualsASCII("image")) {
+    PreloadImage(uri, aCORS, aReferrerPolicy, isImgSet, aEarlyHintPreloaderId);
+  } else if (aAs.LowerCaseEqualsASCII("font")) {
+    PreloadFont(uri, aCORS, aReferrerPolicy, aEarlyHintPreloaderId,
+                aFetchPriority);
+  } else if (aAs.LowerCaseEqualsASCII("fetch")) {
+    PreloadFetch(uri, aCORS, aReferrerPolicy, aEarlyHintPreloaderId,
+                 aFetchPriority);
+  }
+
+  RefPtr<PreloaderBase> preload = LookupPreload(preloadKey);
+  if (preload && aEarlyHintPreloaderId) {
+    preload->SetForEarlyHints();
+  }
+
+  return {preload, false};
+}
+
+void PreloadService::PreloadScript(
+    nsIURI* aURI, const nsAString& aType, const nsAString& aCharset,
+    const nsAString& aCrossOrigin, const nsAString& aReferrerPolicy,
+    const nsAString& aNonce, const nsAString& aFetchPriority,
+    const nsAString& aIntegrity, bool aScriptFromHead,
+    uint64_t aEarlyHintPreloaderId) {
+  mDocument->ScriptLoader()->PreloadURI(
+      aURI, aCharset, aType, aCrossOrigin, aNonce, aFetchPriority, aIntegrity,
+      aScriptFromHead, false, false, true,
+      PreloadReferrerPolicy(aReferrerPolicy), aEarlyHintPreloaderId);
+}
+
+void PreloadService::PreloadImage(nsIURI* aURI, const nsAString& aCrossOrigin,
+                                  const nsAString& aImageReferrerPolicy,
+                                  bool aIsImgSet,
+                                  uint64_t aEarlyHintPreloaderId) {
+  mDocument->PreLoadImage(aURI, aCrossOrigin,
+                          PreloadReferrerPolicy(aImageReferrerPolicy),
+                          aIsImgSet, true, aEarlyHintPreloaderId);
+}
+
+void PreloadService::PreloadFont(nsIURI* aURI, const nsAString& aCrossOrigin,
+                                 const nsAString& aReferrerPolicy,
+                                 uint64_t aEarlyHintPreloaderId,
+                                 const nsAString& aFetchPriority) {
+  CORSMode cors = dom::Element::StringToCORSMode(aCrossOrigin);
+  auto key = PreloadHashKey::CreateAsFont(aURI, cors);
+
+  if (PreloadExists(key)) {
+    return;
+  }
+
+  const auto fetchPriority =
+      nsGenericHTMLElement::ToFetchPriority(aFetchPriority);
+  const auto supportsPriorityValue =
+      SupportsPriorityValueFor::LinkRelPreloadFont(fetchPriority);
+  LogPriorityMapping(sPreloadServiceLog, fetchPriority, supportsPriorityValue);
+
+  RefPtr<FontPreloader> preloader = new FontPreloader();
+  dom::ReferrerPolicy referrerPolicy = PreloadReferrerPolicy(aReferrerPolicy);
+  preloader->OpenChannel(key, aURI, cors, referrerPolicy, mDocument,
+                         aEarlyHintPreloaderId, supportsPriorityValue);
+}
+
+void PreloadService::PreloadFetch(nsIURI* aURI, const nsAString& aCrossOrigin,
+                                  const nsAString& aReferrerPolicy,
+                                  uint64_t aEarlyHintPreloaderId,
+                                  const nsAString& aFetchPriority) {
+  CORSMode cors = dom::Element::StringToCORSMode(aCrossOrigin);
+  auto key = PreloadHashKey::CreateAsFetch(aURI, cors);
+
+  if (PreloadExists(key)) {
+    return;
+  }
+
+  RefPtr<FetchPreloader> preloader = new FetchPreloader();
+  dom::ReferrerPolicy referrerPolicy = PreloadReferrerPolicy(aReferrerPolicy);
+
+  const auto fetchPriority =
+      nsGenericHTMLElement::ToFetchPriority(aFetchPriority);
+  const int32_t supportsPriorityValue =
+      SupportsPriorityValueFor::LinkRelPreloadFetch(fetchPriority);
+  if (supportsPriorityValue) {
+    LogPriorityMapping(sPreloadServiceLog, fetchPriority,
+                       supportsPriorityValue);
+  }
+
+  preloader->OpenChannel(key, aURI, cors, referrerPolicy, mDocument,
+                         aEarlyHintPreloaderId, supportsPriorityValue);
+}
+
+// static
+void PreloadService::NotifyNodeEvent(nsINode* aNode, bool aSuccess) {
+  if (!aNode->IsInComposedDoc()) {
+    return;
+  }
+
+  // We don't dispatch synchronously since |node| might be in a DocGroup
+  // that we're not allowed to touch. (Our network request happens in the
+  // DocGroup of one of the mSources nodes--not necessarily this one).
+
+  RefPtr<AsyncEventDispatcher> dispatcher = new AsyncEventDispatcher(
+      aNode, aSuccess ? u"load"_ns : u"error"_ns, CanBubble::eNo);
+
+  dispatcher->RequireNodeInDocument();
+  dispatcher->PostDOMEvent();
+}
+
+dom::ReferrerPolicy PreloadService::PreloadReferrerPolicy(
+    const nsAString& aReferrerPolicy) {
+  dom::ReferrerPolicy referrerPolicy =
+      dom::ReferrerInfo::ReferrerPolicyAttributeFromString(aReferrerPolicy);
+  if (referrerPolicy == dom::ReferrerPolicy::_empty) {
+    referrerPolicy = mDocument->GetPreloadReferrerInfo()->ReferrerPolicy();
+  }
+
+  return referrerPolicy;
+}
+
+nsIURI* PreloadService::BaseURIForPreload() {
+  nsIURI* documentURI = mDocument->GetDocumentURI();
+  nsIURI* documentBaseURI = mDocument->GetDocBaseURI();
+  return (documentURI == documentBaseURI)
+             ? (mSpeculationBaseURI ? mSpeculationBaseURI.get() : documentURI)
+             : documentBaseURI;
+}
+
+}  // namespace mozilla