Backed out changeset 57d1339ad1c0 (bug 1380154)

netwerk/dns/nsEffectiveTLDService.cpp

@@ -9,10 +9,8 @@
 // http://wiki.mozilla.org/Gecko:Effective_TLD_Service
 
 #include "mozilla/ArrayUtils.h"
-#include "mozilla/HashFunctions.h"
 #include "mozilla/MemoryReporting.h"
 
-#include "MainThreadUtils.h"
 #include "nsEffectiveTLDService.h"
 #include "nsIIDNService.h"
 #include "nsNetUtil.h"
@@ -212,20 +210,6 @@ nsEffectiveTLDService::GetBaseDomainInternal(nsCString  &aHostname,
   if (result == PR_SUCCESS)
     return NS_ERROR_HOST_IS_IP_ADDRESS;
 
-  // Lookup in the cache if this is a normal query.
-  TLDCacheEntry* entry = nullptr;
-  if (aAdditionalParts == 1) {
-    if (LookupForAdd(aHostname, &entry)) {
-      // There was a match, just return the cached value.
-      aBaseDomain = entry->mBaseDomain;
-      if (trailingDot) {
-        aBaseDomain.Append('.');
-      }
-
-      return NS_OK;
-    }
-  }
-
   // Walk up the domain tree, most specific to least specific,
   // looking for matches at each level.  Note that a given level may
   // have multiple attributes (e.g. IsWild() and IsNormal()).
@@ -306,13 +290,6 @@ nsEffectiveTLDService::GetBaseDomainInternal(nsCString  &aHostname,
     return NS_ERROR_INSUFFICIENT_DOMAIN_LEVELS;
 
   aBaseDomain = Substring(iter, end);
-
-  // Update the MRU table if in use.
-  if (entry) {
-    entry->mHost = aHostname;
-    entry->mBaseDomain = aBaseDomain;
-  }
-
   // add on the trailing dot, if applicable
   if (trailingDot)
     aBaseDomain.Append('.');
@@ -335,13 +312,3 @@ nsEffectiveTLDService::NormalizeHostname(nsCString &aHostname)
   ToLowerCase(aHostname);
   return NS_OK;
 }
-
-bool
-nsEffectiveTLDService::LookupForAdd(const nsACString& aHost, TLDCacheEntry** aEntry)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-
-  const uint32_t hash = HashString(aHost.BeginReading(), aHost.Length());
-  *aEntry = &mMruTable[hash % kTableSize];
-  return (*aEntry)->mHost == aHost;
-}

netwerk/dns/nsEffectiveTLDService.h

@@ -37,40 +37,7 @@ private:
   ~nsEffectiveTLDService();
 
   nsCOMPtr<nsIIDNService>     mIDNService;
-
-  // The DAFSA provides a compact encoding of the rather large eTLD list.
   mozilla::Dafsa mGraph;
-
-  struct TLDCacheEntry
-  {
-    nsCString mHost;
-    nsCString mBaseDomain;
-  };
-
-  // We use a small most recently used cache to compensate for DAFSA lookups
-  // being slightly slower than a binary search on a larger table of strings.
-  //
-  // We first check the cache for a matching result and avoid a DAFSA lookup
-  // if a match is found. Otherwise we lookup the domain in the DAFSA and then
-  // cache the result. During standard browsing the same domains are repeatedly
-  // fed into |GetBaseDomainInternal| so this ends up being an effective
-  // mitigation getting about a 99% hit rate with four tabs open.
-  //
-  // A size of 31 is used rather than a more logical power-of-two such as 32
-  // since it is a prime number and provides fewer collisions when when used
-  // with our hash algorithms.
-  static const uint32_t kTableSize = 31;
-  TLDCacheEntry mMruTable[kTableSize];
-
-  /**
-   * Performs a lookup on the MRU table and provides a pointer to the hash
-   * entry that matched or should be used for adding this host.
-   *
-   * @param aHost The host to lookup.
-   * @param aEntry Out param, the entry in the MRU table to use.
-   * @return True if a match was found, false if there was a miss.
-   */
-  inline bool LookupForAdd(const nsACString& aHost, TLDCacheEntry** aEntry);
 };
 
 #endif // EffectiveTLDService_h