Bug 1546334 - Add hash and equals to make ReferrerInfo becomes key of hashtable. r=heycam

Differential Revision: https://phabricator.services.mozilla.com/D37577

--HG--
extra : moz-landing-system : lando

dom/interfaces/security/nsIReferrerInfo.idl

@@ -39,6 +39,11 @@ interface nsIReferrerInfo : nsISerializable
   [must_use, noscript, nostdcall, notxpcom]
   URIRef GetComputedReferrer();
 
+  /**
+   * Returns whether the other referrerInfo is equivalent to this referrerInfo.
+   */
+  boolean equals(in nsIReferrerInfo other);
+
   /**
    * Initialize method.
    * @param aReferrerPolicy referrer policy of the created object

dom/security/ReferrerInfo.cpp

@@ -708,6 +708,42 @@ ReferrerInfo::GetSendReferrer(bool* aSendReferrer) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+ReferrerInfo::Equals(nsIReferrerInfo* aOther, bool* aResult) {
+  NS_ENSURE_TRUE(aOther, NS_ERROR_INVALID_ARG);
+  MOZ_ASSERT(mInitialized);
+  if (aOther == this) {
+    *aResult = true;
+    return NS_OK;
+  }
+
+  *aResult = false;
+  ReferrerInfo* other = static_cast<ReferrerInfo*>(aOther);
+  MOZ_ASSERT(other->mInitialized);
+
+  if (mPolicy != other->mPolicy || mSendReferrer != other->mSendReferrer ||
+      mOverridePolicyByDefault != other->mOverridePolicyByDefault ||
+      mComputedReferrer != other->mComputedReferrer) {
+    return NS_OK;
+  }
+
+  if (!mOriginalReferrer != !other->mOriginalReferrer) {
+    // One or the other has mOriginalReferrer, but not both... not equal
+    return NS_OK;
+  }
+
+  bool originalReferrerEquals;
+  if (mOriginalReferrer &&
+      (NS_FAILED(mOriginalReferrer->Equals(other->mOriginalReferrer,
+                                           &originalReferrerEquals)) ||
+       !originalReferrerEquals)) {
+    return NS_OK;
+  }
+
+  *aResult = true;
+  return NS_OK;
+}
+
 already_AddRefed<nsIURI> ReferrerInfo::GetComputedReferrer() {
   if (!mComputedReferrer.isSome() || mComputedReferrer.value().IsEmpty()) {
     return nullptr;
@@ -722,6 +758,20 @@ already_AddRefed<nsIURI> ReferrerInfo::GetComputedReferrer() {
   return result.forget();
 }
 
+PLDHashNumber ReferrerInfo::Hash() const {
+  MOZ_ASSERT(mInitialized);
+  nsAutoCString originalReferrerSpec;
+  if (mOriginalReferrer) {
+    Unused << mOriginalReferrer->GetSpec(originalReferrerSpec);
+  }
+
+  return mozilla::AddToHash(
+      mPolicy, mSendReferrer, mOverridePolicyByDefault,
+      mozilla::HashString(originalReferrerSpec),
+      mozilla::HashString(mComputedReferrer.isSome() ? mComputedReferrer.value()
+                                                     : EmptyCString()));
+}
+
 NS_IMETHODIMP
 ReferrerInfo::Init(uint32_t aReferrerPolicy, bool aSendReferrer,
                    nsIURI* aOriginalReferrer) {

dom/security/ReferrerInfo.h

@@ -13,6 +13,7 @@
 #include "mozilla/net/ReferrerPolicy.h"
 #include "nsReadableUtils.h"
 #include "mozilla/Maybe.h"
+#include "mozilla/HashFunctions.h"
 
 #define REFERRERINFOF_CONTRACTID "@mozilla.org/referrer-info;1"
 // 041a129f-10ce-4bda-a60d-e027a26d5ed0
@@ -31,6 +32,7 @@ class nsIPrincipal;
 
 namespace mozilla {
 class StyleSheet;
+class URLAndReferrerInfo;
 
 namespace net {
 class HttpBaseChannel;
@@ -187,6 +189,11 @@ class ReferrerInfo : public nsIReferrerInfo {
                                            nsIURI* aURI = nullptr,
                                            bool privateBrowsing = false);
 
+  /**
+   * Hash function for this object
+   */
+  PLDHashNumber Hash() const;
+
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSIREFERRERINFO
   NS_DECL_NSISERIALIZABLE
@@ -348,6 +355,8 @@ class ReferrerInfo : public nsIReferrerInfo {
   void LogMessageToConsole(nsIHttpChannel* aChannel, const char* aMsg,
                            const nsTArray<nsString>& aParams) const;
 
+  friend class mozilla::URLAndReferrerInfo;
+
   nsCOMPtr<nsIURI> mOriginalReferrer;
 
   uint32_t mPolicy;