Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 223 insertions, 0 deletions

diff --git a/netwerk/dns/HostRecordQueue.cpp b/netwerk/dns/HostRecordQueue.cpp
new file mode 100644
index 0000000000..6e8fd5488f
--- /dev/null
+++ b/netwerk/dns/HostRecordQueue.cpp
@@ -0,0 +1,223 @@
+/* vim:set ts=4 sw=2 sts=2 et cin: */
+/* 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 "HostRecordQueue.h"
+#include "mozilla/Telemetry.h"
+#include "nsQueryObject.h"
+
+namespace mozilla {
+namespace net {
+
+void HostRecordQueue::InsertRecord(nsHostRecord* aRec,
+                                   nsIDNSService::DNSFlags aFlags,
+                                   const MutexAutoLock& aProofOfLock) {
+  if (aRec->isInList()) {
+    MOZ_DIAGNOSTIC_ASSERT(!mEvictionQ.contains(aRec),
+                          "Already in eviction queue");
+    MOZ_DIAGNOSTIC_ASSERT(!mHighQ.contains(aRec), "Already in high queue");
+    MOZ_DIAGNOSTIC_ASSERT(!mMediumQ.contains(aRec), "Already in med queue");
+    MOZ_DIAGNOSTIC_ASSERT(!mLowQ.contains(aRec), "Already in low queue");
+    MOZ_DIAGNOSTIC_ASSERT(false, "Already on some other queue?");
+  }
+
+  switch (AddrHostRecord::GetPriority(aFlags)) {
+    case AddrHostRecord::DNS_PRIORITY_HIGH:
+      mHighQ.insertBack(aRec);
+      break;
+
+    case AddrHostRecord::DNS_PRIORITY_MEDIUM:
+      mMediumQ.insertBack(aRec);
+      break;
+
+    case AddrHostRecord::DNS_PRIORITY_LOW:
+      mLowQ.insertBack(aRec);
+      break;
+  }
+  mPendingCount++;
+}
+
+void HostRecordQueue::AddToEvictionQ(
+    nsHostRecord* aRec, uint32_t aMaxCacheEntries,
+    nsRefPtrHashtable<nsGenericHashKey<nsHostKey>, nsHostRecord>& aDB,
+    const MutexAutoLock& aProofOfLock) {
+  if (aRec->isInList()) {
+    bool inEvictionQ = mEvictionQ.contains(aRec);
+    MOZ_DIAGNOSTIC_ASSERT(!inEvictionQ, "Already in eviction queue");
+    bool inHighQ = mHighQ.contains(aRec);
+    MOZ_DIAGNOSTIC_ASSERT(!inHighQ, "Already in high queue");
+    bool inMediumQ = mMediumQ.contains(aRec);
+    MOZ_DIAGNOSTIC_ASSERT(!inMediumQ, "Already in med queue");
+    bool inLowQ = mLowQ.contains(aRec);
+    MOZ_DIAGNOSTIC_ASSERT(!inLowQ, "Already in low queue");
+    MOZ_DIAGNOSTIC_ASSERT(false, "Already on some other queue?");
+
+    // Bug 1678117 - it's not clear why this can happen, but let's fix it
+    // for release users.
+    aRec->remove();
+    if (inEvictionQ) {
+      MOZ_DIAGNOSTIC_ASSERT(mEvictionQSize > 0);
+      mEvictionQSize--;
+    } else if (inHighQ || inMediumQ || inLowQ) {
+      MOZ_DIAGNOSTIC_ASSERT(mPendingCount > 0);
+      mPendingCount--;
+    }
+  }
+  mEvictionQ.insertBack(aRec);
+  if (mEvictionQSize < aMaxCacheEntries) {
+    mEvictionQSize++;
+  } else {
+    // remove first element on mEvictionQ
+    RefPtr<nsHostRecord> head = mEvictionQ.popFirst();
+    aDB.Remove(*static_cast<nsHostKey*>(head.get()));
+
+    if (!head->negative) {
+      // record the age of the entry upon eviction.
+      TimeDuration age = TimeStamp::NowLoRes() - head->mValidStart;
+      if (aRec->IsAddrRecord()) {
+        Telemetry::Accumulate(Telemetry::DNS_CLEANUP_AGE,
+                              static_cast<uint32_t>(age.ToSeconds() / 60));
+      } else {
+        Telemetry::Accumulate(Telemetry::DNS_BY_TYPE_CLEANUP_AGE,
+                              static_cast<uint32_t>(age.ToSeconds() / 60));
+      }
+      if (head->CheckExpiration(TimeStamp::Now()) !=
+          nsHostRecord::EXP_EXPIRED) {
+        if (aRec->IsAddrRecord()) {
+          Telemetry::Accumulate(Telemetry::DNS_PREMATURE_EVICTION,
+                                static_cast<uint32_t>(age.ToSeconds() / 60));
+        } else {
+          Telemetry::Accumulate(Telemetry::DNS_BY_TYPE_PREMATURE_EVICTION,
+                                static_cast<uint32_t>(age.ToSeconds() / 60));
+        }
+      }
+    }
+  }
+}
+
+void HostRecordQueue::MaybeRenewHostRecord(nsHostRecord* aRec,
+                                           const MutexAutoLock& aProofOfLock) {
+  if (!aRec->isInList()) {
+    return;
+  }
+
+  bool inEvictionQ = mEvictionQ.contains(aRec);
+  MOZ_DIAGNOSTIC_ASSERT(inEvictionQ, "Should be in eviction queue");
+  bool inHighQ = mHighQ.contains(aRec);
+  MOZ_DIAGNOSTIC_ASSERT(!inHighQ, "Already in high queue");
+  bool inMediumQ = mMediumQ.contains(aRec);
+  MOZ_DIAGNOSTIC_ASSERT(!inMediumQ, "Already in med queue");
+  bool inLowQ = mLowQ.contains(aRec);
+  MOZ_DIAGNOSTIC_ASSERT(!inLowQ, "Already in low queue");
+
+  // we're already on the eviction queue. This is a renewal
+  aRec->remove();
+  if (inEvictionQ) {
+    MOZ_DIAGNOSTIC_ASSERT(mEvictionQSize > 0);
+    mEvictionQSize--;
+  } else if (inHighQ || inMediumQ || inLowQ) {
+    MOZ_DIAGNOSTIC_ASSERT(mPendingCount > 0);
+    mPendingCount--;
+  }
+}
+
+void HostRecordQueue::FlushEvictionQ(
+    nsRefPtrHashtable<nsGenericHashKey<nsHostKey>, nsHostRecord>& aDB,
+    const MutexAutoLock& aProofOfLock) {
+  mEvictionQSize = 0;
+
+  // Clear the evictionQ and remove all its corresponding entries from
+  // the cache first
+  if (!mEvictionQ.isEmpty()) {
+    for (const RefPtr<nsHostRecord>& rec : mEvictionQ) {
+      rec->Cancel();
+      aDB.Remove(*static_cast<nsHostKey*>(rec));
+    }
+    mEvictionQ.clear();
+  }
+}
+
+void HostRecordQueue::MaybeRemoveFromQ(nsHostRecord* aRec,
+                                       const MutexAutoLock& aProofOfLock) {
+  if (!aRec->isInList()) {
+    return;
+  }
+
+  if (mHighQ.contains(aRec) || mMediumQ.contains(aRec) ||
+      mLowQ.contains(aRec)) {
+    mPendingCount--;
+  } else if (mEvictionQ.contains(aRec)) {
+    mEvictionQSize--;
+  } else {
+    MOZ_ASSERT(false, "record is in other queue");
+  }
+
+  aRec->remove();
+}
+
+void HostRecordQueue::MoveToAnotherPendingQ(nsHostRecord* aRec,
+                                            nsIDNSService::DNSFlags aFlags,
+                                            const MutexAutoLock& aProofOfLock) {
+  if (!(mHighQ.contains(aRec) || mMediumQ.contains(aRec) ||
+        mLowQ.contains(aRec))) {
+    MOZ_ASSERT(false, "record is not in the pending queue");
+    return;
+  }
+
+  aRec->remove();
+  InsertRecord(aRec, aFlags, aProofOfLock);
+}
+
+already_AddRefed<nsHostRecord> HostRecordQueue::Dequeue(
+    bool aHighQOnly, const MutexAutoLock& aProofOfLock) {
+  RefPtr<nsHostRecord> rec;
+  if (!mHighQ.isEmpty()) {
+    rec = mHighQ.popFirst();
+  } else if (!mMediumQ.isEmpty() && !aHighQOnly) {
+    rec = mMediumQ.popFirst();
+  } else if (!mLowQ.isEmpty() && !aHighQOnly) {
+    rec = mLowQ.popFirst();
+  }
+
+  if (rec) {
+    mPendingCount--;
+  }
+
+  return rec.forget();
+}
+
+void HostRecordQueue::ClearAll(
+    const std::function<void(nsHostRecord*)>& aCallback,
+    const MutexAutoLock& aProofOfLock) {
+  mPendingCount = 0;
+
+  auto clearPendingQ = [&](LinkedList<RefPtr<nsHostRecord>>& aPendingQ) {
+    if (aPendingQ.isEmpty()) {
+      return;
+    }
+
+    // loop through pending queue, erroring out pending lookups.
+    for (const RefPtr<nsHostRecord>& rec : aPendingQ) {
+      rec->Cancel();
+      aCallback(rec);
+    }
+    aPendingQ.clear();
+  };
+
+  clearPendingQ(mHighQ);
+  clearPendingQ(mMediumQ);
+  clearPendingQ(mLowQ);
+
+  mEvictionQSize = 0;
+  if (!mEvictionQ.isEmpty()) {
+    for (const RefPtr<nsHostRecord>& rec : mEvictionQ) {
+      rec->Cancel();
+    }
+  }
+
+  mEvictionQ.clear();
+}
+
+}  // namespace net
+}  // namespace mozilla