Add m-esr52 at 52.6.0

1 files changed, 4274 insertions, 0 deletions

diff --git a/netwerk/cache2/CacheFileIOManager.cpp b/netwerk/cache2/CacheFileIOManager.cpp
new file mode 100644
index 000000000..1d0d57635
--- /dev/null
+++ b/netwerk/cache2/CacheFileIOManager.cpp
@@ -0,0 +1,4274 @@
+/* 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 "CacheLog.h"
+#include "CacheFileIOManager.h"
+
+#include "../cache/nsCacheUtils.h"
+#include "CacheHashUtils.h"
+#include "CacheStorageService.h"
+#include "CacheIndex.h"
+#include "CacheFileUtils.h"
+#include "nsThreadUtils.h"
+#include "CacheFile.h"
+#include "CacheObserver.h"
+#include "nsIFile.h"
+#include "CacheFileContextEvictor.h"
+#include "nsITimer.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIDirectoryEnumerator.h"
+#include "nsIObserverService.h"
+#include "nsICacheStorageVisitor.h"
+#include "nsISizeOf.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Services.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "private/pprio.h"
+#include "mozilla/Preferences.h"
+#include "nsNetUtil.h"
+
+// include files for ftruncate (or equivalent)
+#if defined(XP_UNIX)
+#include <unistd.h>
+#elif defined(XP_WIN)
+#include <windows.h>
+#undef CreateFile
+#undef CREATE_NEW
+#else
+// XXX add necessary include file for ftruncate (or equivalent)
+#endif
+
+
+namespace mozilla {
+namespace net {
+
+#define kOpenHandlesLimit        128
+#define kMetadataWriteDelay      5000
+#define kRemoveTrashStartDelay   60000 // in milliseconds
+#define kSmartSizeUpdateInterval 60000 // in milliseconds
+
+#ifdef ANDROID
+const uint32_t kMaxCacheSizeKB = 200*1024; // 200 MB
+#else
+const uint32_t kMaxCacheSizeKB = 350*1024; // 350 MB
+#endif
+
+bool
+CacheFileHandle::DispatchRelease()
+{
+  if (CacheFileIOManager::IsOnIOThreadOrCeased()) {
+    return false;
+  }
+
+  nsCOMPtr<nsIEventTarget> ioTarget = CacheFileIOManager::IOTarget();
+  if (!ioTarget) {
+    return false;
+  }
+
+  nsresult rv =
+    ioTarget->Dispatch(NewNonOwningRunnableMethod(this,
+						  &CacheFileHandle::Release),
+		       nsIEventTarget::DISPATCH_NORMAL);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  return true;
+}
+
+NS_IMPL_ADDREF(CacheFileHandle)
+NS_IMETHODIMP_(MozExternalRefCountType)
+CacheFileHandle::Release()
+{
+  nsrefcnt count = mRefCnt - 1;
+  if (DispatchRelease()) {
+    // Redispatched to the IO thread.
+    return count;
+  }
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  LOG(("CacheFileHandle::Release() [this=%p, refcnt=%d]", this, mRefCnt.get()));
+  NS_PRECONDITION(0 != mRefCnt, "dup release");
+  count = --mRefCnt;
+  NS_LOG_RELEASE(this, count, "CacheFileHandle");
+
+  if (0 == count) {
+    mRefCnt = 1;
+    delete (this);
+    return 0;
+  }
+
+  return count;
+}
+
+NS_INTERFACE_MAP_BEGIN(CacheFileHandle)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+CacheFileHandle::CacheFileHandle(const SHA1Sum::Hash *aHash, bool aPriority, PinningStatus aPinning)
+  : mHash(aHash)
+  , mIsDoomed(false)
+  , mClosed(false)
+  , mPriority(aPriority)
+  , mSpecialFile(false)
+  , mInvalid(false)
+  , mFileExists(false)
+  , mDoomWhenFoundPinned(false)
+  , mDoomWhenFoundNonPinned(false)
+  , mKilled(false)
+  , mPinning(aPinning)
+  , mFileSize(-1)
+  , mFD(nullptr)
+{
+  // If we initialize mDoomed in the initialization list, that initialization is
+  // not guaranteeded to be atomic.  Whereas this assignment here is guaranteed
+  // to be atomic.  TSan will see this (atomic) assignment and be satisfied
+  // that cross-thread accesses to mIsDoomed are properly synchronized.
+  mIsDoomed = false;
+  LOG(("CacheFileHandle::CacheFileHandle() [this=%p, hash=%08x%08x%08x%08x%08x]"
+       , this, LOGSHA1(aHash)));
+}
+
+CacheFileHandle::CacheFileHandle(const nsACString &aKey, bool aPriority, PinningStatus aPinning)
+  : mHash(nullptr)
+  , mIsDoomed(false)
+  , mClosed(false)
+  , mPriority(aPriority)
+  , mSpecialFile(true)
+  , mInvalid(false)
+  , mFileExists(false)
+  , mDoomWhenFoundPinned(false)
+  , mDoomWhenFoundNonPinned(false)
+  , mKilled(false)
+  , mPinning(aPinning)
+  , mFileSize(-1)
+  , mFD(nullptr)
+  , mKey(aKey)
+{
+  // See comment above about the initialization of mIsDoomed.
+  mIsDoomed = false;
+  LOG(("CacheFileHandle::CacheFileHandle() [this=%p, key=%s]", this,
+       PromiseFlatCString(aKey).get()));
+}
+
+CacheFileHandle::~CacheFileHandle()
+{
+  LOG(("CacheFileHandle::~CacheFileHandle() [this=%p]", this));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  RefPtr<CacheFileIOManager> ioMan = CacheFileIOManager::gInstance;
+  if (!IsClosed() && ioMan) {
+    ioMan->CloseHandleInternal(this);
+  }
+}
+
+void
+CacheFileHandle::Log()
+{
+  nsAutoCString leafName;
+  if (mFile) {
+    mFile->GetNativeLeafName(leafName);
+  }
+
+  if (mSpecialFile) {
+    LOG(("CacheFileHandle::Log() - special file [this=%p, "
+         "isDoomed=%d, priority=%d, closed=%d, invalid=%d, "
+         "pinning=%d, fileExists=%d, fileSize=%lld, leafName=%s, key=%s]",
+         this,
+         bool(mIsDoomed), bool(mPriority), bool(mClosed), bool(mInvalid),
+         mPinning, bool(mFileExists), mFileSize, leafName.get(), mKey.get()));
+  } else {
+    LOG(("CacheFileHandle::Log() - entry file [this=%p, hash=%08x%08x%08x%08x%08x, "
+         "isDoomed=%d, priority=%d, closed=%d, invalid=%d, "
+         "pinning=%d, fileExists=%d, fileSize=%lld, leafName=%s, key=%s]",
+         this, LOGSHA1(mHash),
+         bool(mIsDoomed), bool(mPriority), bool(mClosed), bool(mInvalid),
+         mPinning, bool(mFileExists), mFileSize, leafName.get(), mKey.get()));
+  }
+}
+
+uint32_t
+CacheFileHandle::FileSizeInK() const
+{
+  MOZ_ASSERT(mFileSize != -1);
+  uint64_t size64 = mFileSize;
+
+  size64 += 0x3FF;
+  size64 >>= 10;
+
+  uint32_t size;
+  if (size64 >> 32) {
+    NS_WARNING("CacheFileHandle::FileSizeInK() - FileSize is too large, "
+               "truncating to PR_UINT32_MAX");
+    size = PR_UINT32_MAX;
+  } else {
+    size = static_cast<uint32_t>(size64);
+  }
+
+  return size;
+}
+
+bool
+CacheFileHandle::SetPinned(bool aPinned)
+{
+  LOG(("CacheFileHandle::SetPinned [this=%p, pinned=%d]", this, aPinned));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  mPinning = aPinned
+    ? PinningStatus::PINNED
+    : PinningStatus::NON_PINNED;
+
+  if ((MOZ_UNLIKELY(mDoomWhenFoundPinned) && aPinned) ||
+      (MOZ_UNLIKELY(mDoomWhenFoundNonPinned) && !aPinned)) {
+
+    LOG(("  dooming, when: pinned=%d, non-pinned=%d, found: pinned=%d",
+      bool(mDoomWhenFoundPinned), bool(mDoomWhenFoundNonPinned), aPinned));
+
+    mDoomWhenFoundPinned = false;
+    mDoomWhenFoundNonPinned = false;
+
+    return false;
+  }
+
+  return true;
+}
+
+// Memory reporting
+
+size_t
+CacheFileHandle::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = 0;
+  nsCOMPtr<nsISizeOf> sizeOf;
+
+  sizeOf = do_QueryInterface(mFile);
+  if (sizeOf) {
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  n += mallocSizeOf(mFD);
+  n += mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  return n;
+}
+
+size_t
+CacheFileHandle::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+/******************************************************************************
+ *  CacheFileHandles::HandleHashKey
+ *****************************************************************************/
+
+void
+CacheFileHandles::HandleHashKey::AddHandle(CacheFileHandle* aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  mHandles.InsertElementAt(0, aHandle);
+}
+
+void
+CacheFileHandles::HandleHashKey::RemoveHandle(CacheFileHandle* aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  DebugOnly<bool> found;
+  found = mHandles.RemoveElement(aHandle);
+  MOZ_ASSERT(found);
+}
+
+already_AddRefed<CacheFileHandle>
+CacheFileHandles::HandleHashKey::GetNewestHandle()
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  RefPtr<CacheFileHandle> handle;
+  if (mHandles.Length()) {
+    handle = mHandles[0];
+  }
+
+  return handle.forget();
+}
+
+void
+CacheFileHandles::HandleHashKey::GetHandles(nsTArray<RefPtr<CacheFileHandle> > &aResult)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  for (uint32_t i = 0; i < mHandles.Length(); ++i) {
+    CacheFileHandle* handle = mHandles[i];
+    aResult.AppendElement(handle);
+  }
+}
+
+#ifdef DEBUG
+
+void
+CacheFileHandles::HandleHashKey::AssertHandlesState()
+{
+  for (uint32_t i = 0; i < mHandles.Length(); ++i) {
+    CacheFileHandle* handle = mHandles[i];
+    MOZ_ASSERT(handle->IsDoomed());
+  }
+}
+
+#endif
+
+size_t
+CacheFileHandles::HandleHashKey::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  size_t n = 0;
+  n += mallocSizeOf(mHash.get());
+  for (uint32_t i = 0; i < mHandles.Length(); ++i) {
+    n += mHandles[i]->SizeOfIncludingThis(mallocSizeOf);
+  }
+
+  return n;
+}
+
+/******************************************************************************
+ *  CacheFileHandles
+ *****************************************************************************/
+
+CacheFileHandles::CacheFileHandles()
+{
+  LOG(("CacheFileHandles::CacheFileHandles() [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheFileHandles);
+}
+
+CacheFileHandles::~CacheFileHandles()
+{
+  LOG(("CacheFileHandles::~CacheFileHandles() [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileHandles);
+}
+
+nsresult
+CacheFileHandles::GetHandle(const SHA1Sum::Hash *aHash,
+                            CacheFileHandle **_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHash);
+
+#ifdef DEBUG_HANDLES
+  LOG(("CacheFileHandles::GetHandle() [hash=%08x%08x%08x%08x%08x]",
+       LOGSHA1(aHash)));
+#endif
+
+  // find hash entry for key
+  HandleHashKey *entry = mTable.GetEntry(*aHash);
+  if (!entry) {
+    LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+         "no handle entries found", LOGSHA1(aHash)));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+#ifdef DEBUG_HANDLES
+  Log(entry);
+#endif
+
+  // Check if the entry is doomed
+  RefPtr<CacheFileHandle> handle = entry->GetNewestHandle();
+  if (!handle) {
+    LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+         "no handle found %p, entry %p", LOGSHA1(aHash), handle.get(), entry));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (handle->IsDoomed()) {
+    LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+         "found doomed handle %p, entry %p", LOGSHA1(aHash), handle.get(), entry));
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  LOG(("CacheFileHandles::GetHandle() hash=%08x%08x%08x%08x%08x "
+       "found handle %p, entry %p", LOGSHA1(aHash), handle.get(), entry));
+
+  handle.forget(_retval);
+  return NS_OK;
+}
+
+
+nsresult
+CacheFileHandles::NewHandle(const SHA1Sum::Hash *aHash,
+                            bool aPriority, CacheFileHandle::PinningStatus aPinning,
+                            CacheFileHandle **_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHash);
+
+#ifdef DEBUG_HANDLES
+  LOG(("CacheFileHandles::NewHandle() [hash=%08x%08x%08x%08x%08x]", LOGSHA1(aHash)));
+#endif
+
+  // find hash entry for key
+  HandleHashKey *entry = mTable.PutEntry(*aHash);
+
+#ifdef DEBUG_HANDLES
+  Log(entry);
+#endif
+
+#ifdef DEBUG
+  entry->AssertHandlesState();
+#endif
+
+  RefPtr<CacheFileHandle> handle = new CacheFileHandle(entry->Hash(), aPriority, aPinning);
+  entry->AddHandle(handle);
+
+  LOG(("CacheFileHandles::NewHandle() hash=%08x%08x%08x%08x%08x "
+       "created new handle %p, entry=%p", LOGSHA1(aHash), handle.get(), entry));
+
+  handle.forget(_retval);
+  return NS_OK;
+}
+
+void
+CacheFileHandles::RemoveHandle(CacheFileHandle *aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHandle);
+
+  if (!aHandle) {
+    return;
+  }
+
+#ifdef DEBUG_HANDLES
+  LOG(("CacheFileHandles::RemoveHandle() [handle=%p, hash=%08x%08x%08x%08x%08x]"
+       , aHandle, LOGSHA1(aHandle->Hash())));
+#endif
+
+  // find hash entry for key
+  HandleHashKey *entry = mTable.GetEntry(*aHandle->Hash());
+  if (!entry) {
+    MOZ_ASSERT(CacheFileIOManager::IsShutdown(),
+      "Should find entry when removing a handle before shutdown");
+
+    LOG(("CacheFileHandles::RemoveHandle() hash=%08x%08x%08x%08x%08x "
+         "no entries found", LOGSHA1(aHandle->Hash())));
+    return;
+  }
+
+#ifdef DEBUG_HANDLES
+  Log(entry);
+#endif
+
+  LOG(("CacheFileHandles::RemoveHandle() hash=%08x%08x%08x%08x%08x "
+       "removing handle %p", LOGSHA1(entry->Hash()), aHandle));
+  entry->RemoveHandle(aHandle);
+
+  if (entry->IsEmpty()) {
+    LOG(("CacheFileHandles::RemoveHandle() hash=%08x%08x%08x%08x%08x "
+         "list is empty, removing entry %p", LOGSHA1(entry->Hash()), entry));
+    mTable.RemoveEntry(*entry->Hash());
+  }
+}
+
+void
+CacheFileHandles::GetAllHandles(nsTArray<RefPtr<CacheFileHandle> > *_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  for (auto iter = mTable.Iter(); !iter.Done(); iter.Next()) {
+    iter.Get()->GetHandles(*_retval);
+  }
+}
+
+void
+CacheFileHandles::GetActiveHandles(
+  nsTArray<RefPtr<CacheFileHandle> > *_retval)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  for (auto iter = mTable.Iter(); !iter.Done(); iter.Next()) {
+    RefPtr<CacheFileHandle> handle = iter.Get()->GetNewestHandle();
+    MOZ_ASSERT(handle);
+
+    if (!handle->IsDoomed()) {
+      _retval->AppendElement(handle);
+    }
+  }
+}
+
+void
+CacheFileHandles::ClearAll()
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  mTable.Clear();
+}
+
+uint32_t
+CacheFileHandles::HandleCount()
+{
+  return mTable.Count();
+}
+
+#ifdef DEBUG_HANDLES
+void
+CacheFileHandles::Log(CacheFileHandlesEntry *entry)
+{
+  LOG(("CacheFileHandles::Log() BEGIN [entry=%p]", entry));
+
+  nsTArray<RefPtr<CacheFileHandle> > array;
+  aEntry->GetHandles(array);
+
+  for (uint32_t i = 0; i < array.Length(); ++i) {
+    CacheFileHandle *handle = array[i];
+    handle->Log();
+  }
+
+  LOG(("CacheFileHandles::Log() END [entry=%p]", entry));
+}
+#endif
+
+// Memory reporting
+
+size_t
+CacheFileHandles::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  return mTable.SizeOfExcludingThis(mallocSizeOf);
+}
+
+// Events
+
+class ShutdownEvent : public Runnable {
+public:
+  ShutdownEvent()
+    : mMonitor("ShutdownEvent.mMonitor")
+    , mNotified(false)
+  {
+    MOZ_COUNT_CTOR(ShutdownEvent);
+  }
+
+protected:
+  ~ShutdownEvent()
+  {
+    MOZ_COUNT_DTOR(ShutdownEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    MonitorAutoLock mon(mMonitor);
+
+    CacheFileIOManager::gInstance->ShutdownInternal();
+
+    mNotified = true;
+    mon.Notify();
+
+    return NS_OK;
+  }
+
+  void PostAndWait()
+  {
+    MonitorAutoLock mon(mMonitor);
+
+    DebugOnly<nsresult> rv;
+    rv = CacheFileIOManager::gInstance->mIOThread->Dispatch(
+      this, CacheIOThread::WRITE); // When writes and closing of handles is done
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+    PRIntervalTime const waitTime = PR_MillisecondsToInterval(1000);
+    while (!mNotified) {
+      mon.Wait(waitTime);
+      if (!mNotified) {
+        // If there is any IO blocking on the IO thread, this will
+        // try to cancel it.  Returns no later than after two seconds.
+        MonitorAutoUnlock unmon(mMonitor); // Prevent delays
+        CacheFileIOManager::gInstance->mIOThread->CancelBlockingIO();
+      }
+    }
+  }
+
+protected:
+  mozilla::Monitor mMonitor;
+  bool             mNotified;
+};
+
+class OpenFileEvent : public Runnable {
+public:
+  OpenFileEvent(const nsACString &aKey, uint32_t aFlags,
+                CacheFileIOListener *aCallback)
+    : mFlags(aFlags)
+    , mCallback(aCallback)
+    , mKey(aKey)
+  {
+    MOZ_COUNT_CTOR(OpenFileEvent);
+    mIOMan = CacheFileIOManager::gInstance;
+  }
+
+protected:
+  ~OpenFileEvent()
+  {
+    MOZ_COUNT_DTOR(OpenFileEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv = NS_OK;
+
+    if (!(mFlags & CacheFileIOManager::SPECIAL_FILE)) {
+      SHA1Sum sum;
+      sum.update(mKey.BeginReading(), mKey.Length());
+      sum.finish(mHash);
+    }
+
+    if (!mIOMan) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      if (mFlags & CacheFileIOManager::SPECIAL_FILE) {
+        rv = mIOMan->OpenSpecialFileInternal(mKey, mFlags,
+                                             getter_AddRefs(mHandle));
+      } else {
+        rv = mIOMan->OpenFileInternal(&mHash, mKey, mFlags,
+                                      getter_AddRefs(mHandle));
+      }
+      mIOMan = nullptr;
+      if (mHandle) {
+        if (mHandle->Key().IsEmpty()) {
+          mHandle->Key() = mKey;
+        }
+      }
+    }
+
+    mCallback->OnFileOpened(mHandle, rv);
+    return NS_OK;
+  }
+
+protected:
+  SHA1Sum::Hash                 mHash;
+  uint32_t                      mFlags;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+  RefPtr<CacheFileIOManager>    mIOMan;
+  RefPtr<CacheFileHandle>       mHandle;
+  nsCString                     mKey;
+};
+
+class ReadEvent : public Runnable {
+public:
+  ReadEvent(CacheFileHandle *aHandle, int64_t aOffset, char *aBuf,
+            int32_t aCount, CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mOffset(aOffset)
+    , mBuf(aBuf)
+    , mCount(aCount)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(ReadEvent);
+  }
+
+protected:
+  ~ReadEvent()
+  {
+    MOZ_COUNT_DTOR(ReadEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed() || (mCallback && mCallback->IsKilled())) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->ReadInternal(
+        mHandle, mOffset, mBuf, mCount);
+    }
+
+    mCallback->OnDataRead(mHandle, mBuf, rv);
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  int64_t                       mOffset;
+  char                         *mBuf;
+  int32_t                       mCount;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class WriteEvent : public Runnable {
+public:
+  WriteEvent(CacheFileHandle *aHandle, int64_t aOffset, const char *aBuf,
+             int32_t aCount, bool aValidate, bool aTruncate,
+             CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mOffset(aOffset)
+    , mBuf(aBuf)
+    , mCount(aCount)
+    , mValidate(aValidate)
+    , mTruncate(aTruncate)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(WriteEvent);
+  }
+
+protected:
+  ~WriteEvent()
+  {
+    MOZ_COUNT_DTOR(WriteEvent);
+
+    if (!mCallback && mBuf) {
+      free(const_cast<char *>(mBuf));
+    }
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed() || (mCallback && mCallback->IsKilled())) {
+      // We usually get here only after the internal shutdown
+      // (i.e. mShuttingDown == true).  Pretend write has succeeded
+      // to avoid any past-shutdown file dooming.
+      rv = (CacheObserver::IsPastShutdownIOLag() ||
+            CacheFileIOManager::gInstance->mShuttingDown)
+        ? NS_OK
+        : NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->WriteInternal(
+          mHandle, mOffset, mBuf, mCount, mValidate, mTruncate);
+      if (NS_FAILED(rv) && !mCallback) {
+        // No listener is going to handle the error, doom the file
+        CacheFileIOManager::gInstance->DoomFileInternal(mHandle);
+      }
+    }
+    if (mCallback) {
+      mCallback->OnDataWritten(mHandle, mBuf, rv);
+    } else {
+      free(const_cast<char *>(mBuf));
+      mBuf = nullptr;
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  int64_t                       mOffset;
+  const char                   *mBuf;
+  int32_t                       mCount;
+  bool                          mValidate : 1;
+  bool                          mTruncate : 1;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class DoomFileEvent : public Runnable {
+public:
+  DoomFileEvent(CacheFileHandle *aHandle,
+                CacheFileIOListener *aCallback)
+    : mCallback(aCallback)
+    , mHandle(aHandle)
+  {
+    MOZ_COUNT_CTOR(DoomFileEvent);
+  }
+
+protected:
+  ~DoomFileEvent()
+  {
+    MOZ_COUNT_DTOR(DoomFileEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed()) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->DoomFileInternal(mHandle);
+    }
+
+    if (mCallback) {
+      mCallback->OnFileDoomed(mHandle, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  nsCOMPtr<CacheFileIOListener>              mCallback;
+  nsCOMPtr<nsIEventTarget>                   mTarget;
+  RefPtr<CacheFileHandle>                    mHandle;
+};
+
+class DoomFileByKeyEvent : public Runnable {
+public:
+  DoomFileByKeyEvent(const nsACString &aKey,
+                     CacheFileIOListener *aCallback)
+    : mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(DoomFileByKeyEvent);
+
+    SHA1Sum sum;
+    sum.update(aKey.BeginReading(), aKey.Length());
+    sum.finish(mHash);
+
+    mIOMan = CacheFileIOManager::gInstance;
+  }
+
+protected:
+  ~DoomFileByKeyEvent()
+  {
+    MOZ_COUNT_DTOR(DoomFileByKeyEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (!mIOMan) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = mIOMan->DoomFileByKeyInternal(&mHash);
+      mIOMan = nullptr;
+    }
+
+    if (mCallback) {
+      mCallback->OnFileDoomed(nullptr, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  SHA1Sum::Hash                 mHash;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+  RefPtr<CacheFileIOManager>    mIOMan;
+};
+
+class ReleaseNSPRHandleEvent : public Runnable {
+public:
+  explicit ReleaseNSPRHandleEvent(CacheFileHandle *aHandle)
+    : mHandle(aHandle)
+  {
+    MOZ_COUNT_CTOR(ReleaseNSPRHandleEvent);
+  }
+
+protected:
+  ~ReleaseNSPRHandleEvent()
+  {
+    MOZ_COUNT_DTOR(ReleaseNSPRHandleEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    if (!mHandle->IsClosed()) {
+      CacheFileIOManager::gInstance->MaybeReleaseNSPRHandleInternal(mHandle);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+};
+
+class TruncateSeekSetEOFEvent : public Runnable {
+public:
+  TruncateSeekSetEOFEvent(CacheFileHandle *aHandle, int64_t aTruncatePos,
+                          int64_t aEOFPos, CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mTruncatePos(aTruncatePos)
+    , mEOFPos(aEOFPos)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(TruncateSeekSetEOFEvent);
+  }
+
+protected:
+  ~TruncateSeekSetEOFEvent()
+  {
+    MOZ_COUNT_DTOR(TruncateSeekSetEOFEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed() || (mCallback && mCallback->IsKilled())) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->TruncateSeekSetEOFInternal(
+        mHandle, mTruncatePos, mEOFPos);
+    }
+
+    if (mCallback) {
+      mCallback->OnEOFSet(mHandle, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  int64_t                       mTruncatePos;
+  int64_t                       mEOFPos;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class RenameFileEvent : public Runnable {
+public:
+  RenameFileEvent(CacheFileHandle *aHandle, const nsACString &aNewName,
+                  CacheFileIOListener *aCallback)
+    : mHandle(aHandle)
+    , mNewName(aNewName)
+    , mCallback(aCallback)
+  {
+    MOZ_COUNT_CTOR(RenameFileEvent);
+  }
+
+protected:
+  ~RenameFileEvent()
+  {
+    MOZ_COUNT_DTOR(RenameFileEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    nsresult rv;
+
+    if (mHandle->IsClosed()) {
+      rv = NS_ERROR_NOT_INITIALIZED;
+    } else {
+      rv = CacheFileIOManager::gInstance->RenameFileInternal(mHandle,
+                                                             mNewName);
+    }
+
+    if (mCallback) {
+      mCallback->OnFileRenamed(mHandle, rv);
+    }
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle>       mHandle;
+  nsCString                     mNewName;
+  nsCOMPtr<CacheFileIOListener> mCallback;
+};
+
+class InitIndexEntryEvent : public Runnable {
+public:
+  InitIndexEntryEvent(CacheFileHandle *aHandle,
+                      OriginAttrsHash aOriginAttrsHash, bool aAnonymous,
+                      bool aPinning)
+    : mHandle(aHandle)
+    , mOriginAttrsHash(aOriginAttrsHash)
+    , mAnonymous(aAnonymous)
+    , mPinning(aPinning)
+  {
+    MOZ_COUNT_CTOR(InitIndexEntryEvent);
+  }
+
+protected:
+  ~InitIndexEntryEvent()
+  {
+    MOZ_COUNT_DTOR(InitIndexEntryEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    if (mHandle->IsClosed() || mHandle->IsDoomed()) {
+      return NS_OK;
+    }
+
+    CacheIndex::InitEntry(mHandle->Hash(), mOriginAttrsHash, mAnonymous,
+                          mPinning);
+
+    // We cannot set the filesize before we init the entry. If we're opening
+    // an existing entry file, frecency and expiration time will be set after
+    // parsing the entry file, but we must set the filesize here since nobody is
+    // going to set it if there is no write to the file.
+    uint32_t sizeInK = mHandle->FileSizeInK();
+    CacheIndex::UpdateEntry(mHandle->Hash(), nullptr, nullptr, &sizeInK);
+
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle> mHandle;
+  OriginAttrsHash         mOriginAttrsHash;
+  bool                    mAnonymous;
+  bool                    mPinning;
+};
+
+class UpdateIndexEntryEvent : public Runnable {
+public:
+  UpdateIndexEntryEvent(CacheFileHandle *aHandle, const uint32_t *aFrecency,
+                        const uint32_t *aExpirationTime)
+    : mHandle(aHandle)
+    , mHasFrecency(false)
+    , mHasExpirationTime(false)
+  {
+    MOZ_COUNT_CTOR(UpdateIndexEntryEvent);
+    if (aFrecency) {
+      mHasFrecency = true;
+      mFrecency = *aFrecency;
+    }
+    if (aExpirationTime) {
+      mHasExpirationTime = true;
+      mExpirationTime = *aExpirationTime;
+    }
+  }
+
+protected:
+  ~UpdateIndexEntryEvent()
+  {
+    MOZ_COUNT_DTOR(UpdateIndexEntryEvent);
+  }
+
+public:
+  NS_IMETHOD Run() override
+  {
+    if (mHandle->IsClosed() || mHandle->IsDoomed()) {
+      return NS_OK;
+    }
+
+    CacheIndex::UpdateEntry(mHandle->Hash(),
+                            mHasFrecency ? &mFrecency : nullptr,
+                            mHasExpirationTime ? &mExpirationTime : nullptr,
+                            nullptr);
+    return NS_OK;
+  }
+
+protected:
+  RefPtr<CacheFileHandle> mHandle;
+  bool                      mHasFrecency;
+  bool                      mHasExpirationTime;
+  uint32_t                  mFrecency;
+  uint32_t                  mExpirationTime;
+};
+
+class MetadataWriteScheduleEvent : public Runnable
+{
+public:
+  enum EMode {
+    SCHEDULE,
+    UNSCHEDULE,
+    SHUTDOWN
+  } mMode;
+
+  RefPtr<CacheFile> mFile;
+  RefPtr<CacheFileIOManager> mIOMan;
+
+  MetadataWriteScheduleEvent(CacheFileIOManager * aManager,
+                             CacheFile * aFile,
+                             EMode aMode)
+    : mMode(aMode)
+    , mFile(aFile)
+    , mIOMan(aManager)
+  { }
+
+  virtual ~MetadataWriteScheduleEvent() { }
+
+  NS_IMETHOD Run() override
+  {
+    RefPtr<CacheFileIOManager> ioMan = CacheFileIOManager::gInstance;
+    if (!ioMan) {
+      NS_WARNING("CacheFileIOManager already gone in MetadataWriteScheduleEvent::Run()");
+      return NS_OK;
+    }
+
+    switch (mMode)
+    {
+    case SCHEDULE:
+      ioMan->ScheduleMetadataWriteInternal(mFile);
+      break;
+    case UNSCHEDULE:
+      ioMan->UnscheduleMetadataWriteInternal(mFile);
+      break;
+    case SHUTDOWN:
+      ioMan->ShutdownMetadataWriteSchedulingInternal();
+      break;
+    }
+    return NS_OK;
+  }
+};
+
+StaticRefPtr<CacheFileIOManager> CacheFileIOManager::gInstance;
+
+NS_IMPL_ISUPPORTS(CacheFileIOManager, nsITimerCallback)
+
+CacheFileIOManager::CacheFileIOManager()
+  : mShuttingDown(false)
+  , mTreeCreated(false)
+  , mTreeCreationFailed(false)
+  , mOverLimitEvicting(false)
+  , mRemovingTrashDirs(false)
+{
+  LOG(("CacheFileIOManager::CacheFileIOManager [this=%p]", this));
+  MOZ_COUNT_CTOR(CacheFileIOManager);
+  MOZ_ASSERT(!gInstance, "multiple CacheFileIOManager instances!");
+}
+
+CacheFileIOManager::~CacheFileIOManager()
+{
+  LOG(("CacheFileIOManager::~CacheFileIOManager [this=%p]", this));
+  MOZ_COUNT_DTOR(CacheFileIOManager);
+}
+
+// static
+nsresult
+CacheFileIOManager::Init()
+{
+  LOG(("CacheFileIOManager::Init()"));
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (gInstance) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  RefPtr<CacheFileIOManager> ioMan = new CacheFileIOManager();
+
+  nsresult rv = ioMan->InitInternal();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  gInstance = ioMan.forget();
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::InitInternal()
+{
+  nsresult rv;
+
+  mIOThread = new CacheIOThread();
+
+  rv = mIOThread->Init();
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Can't create background thread");
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mStartTime = TimeStamp::NowLoRes();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::Shutdown()
+{
+  LOG(("CacheFileIOManager::Shutdown() [gInstance=%p]", gInstance.get()));
+
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!gInstance) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  Telemetry::AutoTimer<Telemetry::NETWORK_DISK_CACHE_SHUTDOWN_V2> shutdownTimer;
+
+  CacheIndex::PreShutdown();
+
+  ShutdownMetadataWriteScheduling();
+
+  RefPtr<ShutdownEvent> ev = new ShutdownEvent();
+  ev->PostAndWait();
+
+  MOZ_ASSERT(gInstance->mHandles.HandleCount() == 0);
+  MOZ_ASSERT(gInstance->mHandlesByLastUsed.Length() == 0);
+
+  if (gInstance->mIOThread) {
+    gInstance->mIOThread->Shutdown();
+  }
+
+  CacheIndex::Shutdown();
+
+  if (CacheObserver::ClearCacheOnShutdown()) {
+    Telemetry::AutoTimer<Telemetry::NETWORK_DISK_CACHE2_SHUTDOWN_CLEAR_PRIVATE> totalTimer;
+    gInstance->SyncRemoveAllCacheFiles();
+  }
+
+  gInstance = nullptr;
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::ShutdownInternal()
+{
+  LOG(("CacheFileIOManager::ShutdownInternal() [this=%p]", this));
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  // No new handles can be created after this flag is set
+  mShuttingDown = true;
+
+  // close all handles and delete all associated files
+  nsTArray<RefPtr<CacheFileHandle> > handles;
+  mHandles.GetAllHandles(&handles);
+  handles.AppendElements(mSpecialHandles);
+
+  for (uint32_t i=0 ; i<handles.Length() ; i++) {
+    CacheFileHandle *h = handles[i];
+    h->mClosed = true;
+
+    h->Log();
+
+    // Close completely written files.
+    MaybeReleaseNSPRHandleInternal(h);
+    // Don't bother removing invalid and/or doomed files to improve
+    // shutdown perfomrance.
+    // Doomed files are already in the doomed directory from which
+    // we never reuse files and delete the dir on next session startup.
+    // Invalid files don't have metadata and thus won't load anyway
+    // (hashes won't match).
+
+    if (!h->IsSpecialFile() && !h->mIsDoomed && !h->mFileExists) {
+      CacheIndex::RemoveEntry(h->Hash());
+    }
+
+    // Remove the handle from mHandles/mSpecialHandles
+    if (h->IsSpecialFile()) {
+      mSpecialHandles.RemoveElement(h);
+    } else {
+      mHandles.RemoveHandle(h);
+    }
+
+    // Pointer to the hash is no longer valid once the last handle with the
+    // given hash is released. Null out the pointer so that we crash if there
+    // is a bug in this code and we dereference the pointer after this point.
+    if (!h->IsSpecialFile()) {
+      h->mHash = nullptr;
+    }
+  }
+
+  // Assert the table is empty. When we are here, no new handles can be added
+  // and handles will no longer remove them self from this table and we don't
+  // want to keep invalid handles here. Also, there is no lookup after this
+  // point to happen.
+  MOZ_ASSERT(mHandles.HandleCount() == 0);
+
+  // Release trash directory enumerator
+  if (mTrashDirEnumerator) {
+    mTrashDirEnumerator->Close();
+    mTrashDirEnumerator = nullptr;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::OnProfile()
+{
+  LOG(("CacheFileIOManager::OnProfile() [gInstance=%p]", gInstance.get()));
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan) {
+    // CacheFileIOManager::Init() failed, probably could not create the IO
+    // thread, just go with it...
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> directory;
+
+  CacheObserver::ParentDirOverride(getter_AddRefs(directory));
+
+#if defined(MOZ_WIDGET_ANDROID)
+  nsCOMPtr<nsIFile> profilelessDirectory;
+  char* cachePath = getenv("CACHE_DIRECTORY");
+  if (!directory && cachePath && *cachePath) {
+    rv = NS_NewNativeLocalFile(nsDependentCString(cachePath),
+                               true, getter_AddRefs(directory));
+    if (NS_SUCCEEDED(rv)) {
+      // Save this directory as the profileless path.
+      rv = directory->Clone(getter_AddRefs(profilelessDirectory));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Add profile leaf name to the directory name to distinguish
+      // multiple profiles Fennec supports.
+      nsCOMPtr<nsIFile> profD;
+      rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
+                                  getter_AddRefs(profD));
+
+      nsAutoCString leafName;
+      if (NS_SUCCEEDED(rv)) {
+        rv = profD->GetNativeLeafName(leafName);
+      }
+      if (NS_SUCCEEDED(rv)) {
+        rv = directory->AppendNative(leafName);
+      }
+      if (NS_FAILED(rv)) {
+        directory = nullptr;
+      }
+    }
+  }
+#endif
+
+  if (!directory) {
+    rv = NS_GetSpecialDirectory(NS_APP_CACHE_PARENT_DIR,
+                                getter_AddRefs(directory));
+  }
+
+  if (!directory) {
+    rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_LOCAL_50_DIR,
+                                getter_AddRefs(directory));
+  }
+
+  if (directory) {
+    rv = directory->Append(NS_LITERAL_STRING("cache2"));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // All functions return a clone.
+  ioMan->mCacheDirectory.swap(directory);
+
+#if defined(MOZ_WIDGET_ANDROID)
+  if (profilelessDirectory) {
+    rv = profilelessDirectory->Append(NS_LITERAL_STRING("cache2"));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  ioMan->mCacheProfilelessDirectory.swap(profilelessDirectory);
+#endif
+
+  if (ioMan->mCacheDirectory) {
+    CacheIndex::Init(ioMan->mCacheDirectory);
+  }
+
+  return NS_OK;
+}
+
+// static
+already_AddRefed<nsIEventTarget>
+CacheFileIOManager::IOTarget()
+{
+  nsCOMPtr<nsIEventTarget> target;
+  if (gInstance && gInstance->mIOThread) {
+    target = gInstance->mIOThread->Target();
+  }
+
+  return target.forget();
+}
+
+// static
+already_AddRefed<CacheIOThread>
+CacheFileIOManager::IOThread()
+{
+  RefPtr<CacheIOThread> thread;
+  if (gInstance) {
+    thread = gInstance->mIOThread;
+  }
+
+  return thread.forget();
+}
+
+// static
+bool
+CacheFileIOManager::IsOnIOThread()
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (ioMan && ioMan->mIOThread) {
+    return ioMan->mIOThread->IsCurrentThread();
+  }
+
+  return false;
+}
+
+// static
+bool
+CacheFileIOManager::IsOnIOThreadOrCeased()
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (ioMan && ioMan->mIOThread) {
+    return ioMan->mIOThread->IsCurrentThread();
+  }
+
+  // Ceased...
+  return true;
+}
+
+// static
+bool
+CacheFileIOManager::IsShutdown()
+{
+  if (!gInstance) {
+    return true;
+  }
+  return gInstance->mShuttingDown;
+}
+
+// static
+nsresult
+CacheFileIOManager::ScheduleMetadataWrite(CacheFile * aFile)
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  NS_ENSURE_TRUE(ioMan, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_TRUE(!ioMan->mShuttingDown, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<MetadataWriteScheduleEvent> event = new MetadataWriteScheduleEvent(
+    ioMan, aFile, MetadataWriteScheduleEvent::SCHEDULE);
+  nsCOMPtr<nsIEventTarget> target = ioMan->IOTarget();
+  NS_ENSURE_TRUE(target, NS_ERROR_UNEXPECTED);
+  return target->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult
+CacheFileIOManager::ScheduleMetadataWriteInternal(CacheFile * aFile)
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+
+  nsresult rv;
+
+  if (!mMetadataWritesTimer) {
+    mMetadataWritesTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = mMetadataWritesTimer->InitWithCallback(
+      this, kMetadataWriteDelay, nsITimer::TYPE_ONE_SHOT);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (mScheduledMetadataWrites.IndexOf(aFile) !=
+      mScheduledMetadataWrites.NoIndex) {
+    return NS_OK;
+  }
+
+  mScheduledMetadataWrites.AppendElement(aFile);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::UnscheduleMetadataWrite(CacheFile * aFile)
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  NS_ENSURE_TRUE(ioMan, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_TRUE(!ioMan->mShuttingDown, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<MetadataWriteScheduleEvent> event = new MetadataWriteScheduleEvent(
+    ioMan, aFile, MetadataWriteScheduleEvent::UNSCHEDULE);
+  nsCOMPtr<nsIEventTarget> target = ioMan->IOTarget();
+  NS_ENSURE_TRUE(target, NS_ERROR_UNEXPECTED);
+  return target->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult
+CacheFileIOManager::UnscheduleMetadataWriteInternal(CacheFile * aFile)
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+
+  mScheduledMetadataWrites.RemoveElement(aFile);
+
+  if (mScheduledMetadataWrites.Length() == 0 &&
+      mMetadataWritesTimer) {
+    mMetadataWritesTimer->Cancel();
+    mMetadataWritesTimer = nullptr;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::ShutdownMetadataWriteScheduling()
+{
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  NS_ENSURE_TRUE(ioMan, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<MetadataWriteScheduleEvent> event = new MetadataWriteScheduleEvent(
+    ioMan, nullptr, MetadataWriteScheduleEvent::SHUTDOWN);
+  nsCOMPtr<nsIEventTarget> target = ioMan->IOTarget();
+  NS_ENSURE_TRUE(target, NS_ERROR_UNEXPECTED);
+  return target->Dispatch(event, nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult
+CacheFileIOManager::ShutdownMetadataWriteSchedulingInternal()
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+
+  nsTArray<RefPtr<CacheFile> > files;
+  files.SwapElements(mScheduledMetadataWrites);
+  for (uint32_t i = 0; i < files.Length(); ++i) {
+    CacheFile * file = files[i];
+    file->WriteMetadataIfNeeded();
+  }
+
+  if (mMetadataWritesTimer) {
+    mMetadataWritesTimer->Cancel();
+    mMetadataWritesTimer = nullptr;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+CacheFileIOManager::Notify(nsITimer * aTimer)
+{
+  MOZ_ASSERT(IsOnIOThreadOrCeased());
+  MOZ_ASSERT(mMetadataWritesTimer == aTimer);
+
+  mMetadataWritesTimer = nullptr;
+
+  nsTArray<RefPtr<CacheFile> > files;
+  files.SwapElements(mScheduledMetadataWrites);
+  for (uint32_t i = 0; i < files.Length(); ++i) {
+    CacheFile * file = files[i];
+    file->WriteMetadataIfNeeded();
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::OpenFile(const nsACString &aKey,
+                             uint32_t aFlags, CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::OpenFile() [key=%s, flags=%d, listener=%p]",
+       PromiseFlatCString(aKey).get(), aFlags, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  bool priority = aFlags & CacheFileIOManager::PRIORITY;
+  RefPtr<OpenFileEvent> ev = new OpenFileEvent(aKey, aFlags, aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, priority
+    ? CacheIOThread::OPEN_PRIORITY
+    : CacheIOThread::OPEN);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OpenFileInternal(const SHA1Sum::Hash *aHash,
+                                     const nsACString &aKey,
+                                     uint32_t aFlags,
+                                     CacheFileHandle **_retval)
+{
+  LOG(("CacheFileIOManager::OpenFileInternal() [hash=%08x%08x%08x%08x%08x, "
+       "key=%s, flags=%d]", LOGSHA1(aHash), PromiseFlatCString(aKey).get(),
+       aFlags));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  CacheIOThread::Cancelable cancelable(true /* never called for special handles */);
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  CacheFileHandle::PinningStatus pinning = aFlags & PINNED
+    ? CacheFileHandle::PinningStatus::PINNED
+    : CacheFileHandle::PinningStatus::NON_PINNED;
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetFile(aHash, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CacheFileHandle> handle;
+  mHandles.GetHandle(aHash, getter_AddRefs(handle));
+
+  if ((aFlags & (OPEN | CREATE | CREATE_NEW)) == CREATE_NEW) {
+    if (handle) {
+      rv = DoomFileInternal(handle);
+      NS_ENSURE_SUCCESS(rv, rv);
+      handle = nullptr;
+    }
+
+    rv = mHandles.NewHandle(aHash, aFlags & PRIORITY, pinning, getter_AddRefs(handle));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool exists;
+    rv = file->Exists(&exists);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (exists) {
+      CacheIndex::RemoveEntry(aHash);
+
+      LOG(("CacheFileIOManager::OpenFileInternal() - Removing old file from "
+           "disk"));
+      rv = file->Remove(false);
+      if (NS_FAILED(rv)) {
+        NS_WARNING("Cannot remove old entry from the disk");
+        LOG(("CacheFileIOManager::OpenFileInternal() - Removing old file failed"
+             ". [rv=0x%08x]", rv));
+      }
+    }
+
+    CacheIndex::AddEntry(aHash);
+    handle->mFile.swap(file);
+    handle->mFileSize = 0;
+  }
+
+  if (handle) {
+    handle.swap(*_retval);
+    return NS_OK;
+  }
+
+  bool exists, evictedAsPinned = false, evictedAsNonPinned = false;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists && mContextEvictor) {
+    if (mContextEvictor->ContextsCount() == 0) {
+      mContextEvictor = nullptr;
+    } else {
+      mContextEvictor->WasEvicted(aKey, file, &evictedAsPinned, &evictedAsNonPinned);
+    }
+  }
+
+  if (!exists && (aFlags & (OPEN | CREATE | CREATE_NEW)) == OPEN) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (exists) {
+    // For existing files we determine the pinning status later, after the metadata gets parsed.
+    pinning = CacheFileHandle::PinningStatus::UNKNOWN;
+  }
+
+  rv = mHandles.NewHandle(aHash, aFlags & PRIORITY, pinning, getter_AddRefs(handle));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists) {
+    // If this file has been found evicted through the context file evictor above for
+    // any of pinned or non-pinned state, these calls ensure we doom the handle ASAP
+    // we know the real pinning state after metadta has been parsed.  DoomFileInternal
+    // on the |handle| doesn't doom right now, since the pinning state is unknown
+    // and we pass down a pinning restriction.
+    if (evictedAsPinned) {
+      rv = DoomFileInternal(handle, DOOM_WHEN_PINNED);
+      MOZ_ASSERT(!handle->IsDoomed() && NS_SUCCEEDED(rv));
+    }
+    if (evictedAsNonPinned) {
+      rv = DoomFileInternal(handle, DOOM_WHEN_NON_PINNED);
+      MOZ_ASSERT(!handle->IsDoomed() && NS_SUCCEEDED(rv));
+    }
+
+    rv = file->GetFileSize(&handle->mFileSize);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    handle->mFileExists = true;
+
+    CacheIndex::EnsureEntryExists(aHash);
+  } else {
+    handle->mFileSize = 0;
+
+    CacheIndex::AddEntry(aHash);
+  }
+
+  handle->mFile.swap(file);
+  handle.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OpenSpecialFileInternal(const nsACString &aKey,
+                                            uint32_t aFlags,
+                                            CacheFileHandle **_retval)
+{
+  LOG(("CacheFileIOManager::OpenSpecialFileInternal() [key=%s, flags=%d]",
+       PromiseFlatCString(aKey).get(), aFlags));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetSpecialFile(aKey, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CacheFileHandle> handle;
+  for (uint32_t i = 0 ; i < mSpecialHandles.Length() ; i++) {
+    if (!mSpecialHandles[i]->IsDoomed() && mSpecialHandles[i]->Key() == aKey) {
+      handle = mSpecialHandles[i];
+      break;
+    }
+  }
+
+  if ((aFlags & (OPEN | CREATE | CREATE_NEW)) == CREATE_NEW) {
+    if (handle) {
+      rv = DoomFileInternal(handle);
+      NS_ENSURE_SUCCESS(rv, rv);
+      handle = nullptr;
+    }
+
+    handle = new CacheFileHandle(aKey, aFlags & PRIORITY, CacheFileHandle::PinningStatus::NON_PINNED);
+    mSpecialHandles.AppendElement(handle);
+
+    bool exists;
+    rv = file->Exists(&exists);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (exists) {
+      LOG(("CacheFileIOManager::OpenSpecialFileInternal() - Removing file from "
+           "disk"));
+      rv = file->Remove(false);
+      if (NS_FAILED(rv)) {
+        NS_WARNING("Cannot remove old entry from the disk");
+        LOG(("CacheFileIOManager::OpenSpecialFileInternal() - Removing file "
+             "failed. [rv=0x%08x]", rv));
+      }
+    }
+
+    handle->mFile.swap(file);
+    handle->mFileSize = 0;
+  }
+
+  if (handle) {
+    handle.swap(*_retval);
+    return NS_OK;
+  }
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!exists && (aFlags & (OPEN | CREATE | CREATE_NEW)) == OPEN) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  handle = new CacheFileHandle(aKey, aFlags & PRIORITY, CacheFileHandle::PinningStatus::NON_PINNED);
+  mSpecialHandles.AppendElement(handle);
+
+  if (exists) {
+    rv = file->GetFileSize(&handle->mFileSize);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    handle->mFileExists = true;
+  } else {
+    handle->mFileSize = 0;
+  }
+
+  handle->mFile.swap(file);
+  handle.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CloseHandleInternal(CacheFileHandle *aHandle)
+{
+  nsresult rv;
+
+  LOG(("CacheFileIOManager::CloseHandleInternal() [handle=%p]", aHandle));
+
+  MOZ_ASSERT(!aHandle->IsClosed());
+
+  aHandle->Log();
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  // Maybe close file handle (can be legally bypassed after shutdown)
+  rv = MaybeReleaseNSPRHandleInternal(aHandle);
+
+  // Delete the file if the entry was doomed or invalid and
+  // filedesc properly closed
+  if ((aHandle->mIsDoomed || aHandle->mInvalid) && NS_SUCCEEDED(rv)) {
+    LOG(("CacheFileIOManager::CloseHandleInternal() - Removing file from "
+         "disk"));
+
+    aHandle->mFile->Remove(false);
+  }
+
+  if (!aHandle->IsSpecialFile() && !aHandle->mIsDoomed &&
+      (aHandle->mInvalid || !aHandle->mFileExists)) {
+    CacheIndex::RemoveEntry(aHandle->Hash());
+  }
+
+  // Don't remove handles after shutdown
+  if (!mShuttingDown) {
+    if (aHandle->IsSpecialFile()) {
+      mSpecialHandles.RemoveElement(aHandle);
+    } else {
+      mHandles.RemoveHandle(aHandle);
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::Read(CacheFileHandle *aHandle, int64_t aOffset,
+                         char *aBuf, int32_t aCount,
+                         CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::Read() [handle=%p, offset=%lld, count=%d, "
+       "listener=%p]", aHandle, aOffset, aCount, aCallback));
+
+  if (CacheObserver::ShuttingDown()) {
+    LOG(("  no reads after shutdown"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<ReadEvent> ev = new ReadEvent(aHandle, aOffset, aBuf, aCount,
+                                         aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->IsPriority()
+    ? CacheIOThread::READ_PRIORITY
+    : CacheIOThread::READ);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::ReadInternal(CacheFileHandle *aHandle, int64_t aOffset,
+                                 char *aBuf, int32_t aCount)
+{
+  LOG(("CacheFileIOManager::ReadInternal() [handle=%p, offset=%lld, count=%d]",
+       aHandle, aOffset, aCount));
+
+  nsresult rv;
+
+  if (CacheObserver::ShuttingDown()) {
+    LOG(("  no reads after shutdown"));
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!aHandle->mFileExists) {
+    NS_WARNING("Trying to read from non-existent file");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (!aHandle->mFD) {
+    rv = OpenNSPRHandle(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NSPRHandleUsed(aHandle);
+  }
+
+  // Check again, OpenNSPRHandle could figure out the file was gone.
+  if (!aHandle->mFileExists) {
+    NS_WARNING("Trying to read from non-existent file");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  int64_t offset = PR_Seek64(aHandle->mFD, aOffset, PR_SEEK_SET);
+  if (offset == -1) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t bytesRead = PR_Read(aHandle->mFD, aBuf, aCount);
+  if (bytesRead != aCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::Write(CacheFileHandle *aHandle, int64_t aOffset,
+                          const char *aBuf, int32_t aCount, bool aValidate,
+                          bool aTruncate, CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::Write() [handle=%p, offset=%lld, count=%d, "
+       "validate=%d, truncate=%d, listener=%p]", aHandle, aOffset, aCount,
+       aValidate, aTruncate, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || (aCallback && aCallback->IsKilled()) || !ioMan) {
+    if (!aCallback) {
+      // When no callback is provided, CacheFileIOManager is responsible for
+      // releasing the buffer. We must release it even in case of failure.
+      free(const_cast<char *>(aBuf));
+    }
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<WriteEvent> ev = new WriteEvent(aHandle, aOffset, aBuf, aCount,
+                                           aValidate, aTruncate, aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+static nsresult
+TruncFile(PRFileDesc *aFD, int64_t aEOF)
+{
+#if defined(XP_UNIX)
+  if (ftruncate(PR_FileDesc2NativeHandle(aFD), aEOF) != 0) {
+    NS_ERROR("ftruncate failed");
+    return NS_ERROR_FAILURE;
+  }
+#elif defined(XP_WIN)
+  int64_t cnt = PR_Seek64(aFD, aEOF, PR_SEEK_SET);
+  if (cnt == -1) {
+    return NS_ERROR_FAILURE;
+  }
+  if (!SetEndOfFile((HANDLE) PR_FileDesc2NativeHandle(aFD))) {
+    NS_ERROR("SetEndOfFile failed");
+    return NS_ERROR_FAILURE;
+  }
+#else
+  MOZ_ASSERT(false, "Not implemented!");
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::WriteInternal(CacheFileHandle *aHandle, int64_t aOffset,
+                                  const char *aBuf, int32_t aCount,
+                                  bool aValidate, bool aTruncate)
+{
+  LOG(("CacheFileIOManager::WriteInternal() [handle=%p, offset=%lld, count=%d, "
+       "validate=%d, truncate=%d]", aHandle, aOffset, aCount, aValidate,
+       aTruncate));
+
+  nsresult rv;
+
+  if (aHandle->mKilled) {
+    LOG(("  handle already killed, nothing written"));
+    return NS_OK;
+  }
+
+  if (CacheObserver::ShuttingDown() && (!aValidate || !aHandle->mFD)) {
+    aHandle->mKilled = true;
+    LOG(("  killing the handle, nothing written"));
+    return NS_OK;
+  }
+
+  if (CacheObserver::IsPastShutdownIOLag()) {
+    LOG(("  past the shutdown I/O lag, nothing written"));
+    // Pretend the write has succeeded, otherwise upper layers will doom
+    // the file and we end up with I/O anyway.
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (!aHandle->mFileExists) {
+    rv = CreateFile(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!aHandle->mFD) {
+    rv = OpenNSPRHandle(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NSPRHandleUsed(aHandle);
+  }
+
+  // Check again, OpenNSPRHandle could figure out the file was gone.
+  if (!aHandle->mFileExists) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Check whether this write would cause critical low disk space.
+  if (aHandle->mFileSize < aOffset + aCount) {
+    int64_t freeSpace = -1;
+    rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::WriteInternal() - GetDiskSpaceAvailable() "
+           "failed! [rv=0x%08x]", rv));
+    } else {
+      uint32_t limit = CacheObserver::DiskFreeSpaceHardLimit();
+      if (freeSpace - aOffset - aCount + aHandle->mFileSize < limit) {
+        LOG(("CacheFileIOManager::WriteInternal() - Low free space, refusing "
+             "to write! [freeSpace=%lld, limit=%u]", freeSpace, limit));
+        return NS_ERROR_FILE_DISK_FULL;
+      }
+    }
+  }
+
+  // Write invalidates the entry by default
+  aHandle->mInvalid = true;
+
+  int64_t offset = PR_Seek64(aHandle->mFD, aOffset, PR_SEEK_SET);
+  if (offset == -1) {
+    return NS_ERROR_FAILURE;
+  }
+
+  int32_t bytesWritten = PR_Write(aHandle->mFD, aBuf, aCount);
+
+  if (bytesWritten != -1) {
+    uint32_t oldSizeInK = aHandle->FileSizeInK();
+    int64_t writeEnd = aOffset + bytesWritten;
+
+    if (aTruncate) {
+      rv = TruncFile(aHandle->mFD, writeEnd);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      aHandle->mFileSize = writeEnd;
+    } else {
+      if (aHandle->mFileSize < writeEnd) {
+        aHandle->mFileSize = writeEnd;
+      }
+    }
+
+    uint32_t newSizeInK = aHandle->FileSizeInK();
+
+    if (oldSizeInK != newSizeInK && !aHandle->IsDoomed() &&
+        !aHandle->IsSpecialFile()) {
+      CacheIndex::UpdateEntry(aHandle->Hash(), nullptr, nullptr, &newSizeInK);
+
+      if (oldSizeInK < newSizeInK) {
+        EvictIfOverLimitInternal();
+      }
+    }
+  }
+
+  if (bytesWritten != aCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Write was successful and this write validates the entry (i.e. metadata)
+  if (aValidate) {
+    aHandle->mInvalid = false;
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::DoomFile(CacheFileHandle *aHandle,
+                             CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::DoomFile() [handle=%p, listener=%p]",
+       aHandle, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<DoomFileEvent> ev = new DoomFileEvent(aHandle, aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->IsPriority()
+    ? CacheIOThread::OPEN_PRIORITY
+    : CacheIOThread::OPEN);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::DoomFileInternal(CacheFileHandle *aHandle,
+                                     PinningDoomRestriction aPinningDoomRestriction)
+{
+  LOG(("CacheFileIOManager::DoomFileInternal() [handle=%p]", aHandle));
+  aHandle->Log();
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  nsresult rv;
+
+  if (aHandle->IsDoomed()) {
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (aPinningDoomRestriction > NO_RESTRICTION) {
+    switch (aHandle->mPinning) {
+    case CacheFileHandle::PinningStatus::NON_PINNED:
+      if (MOZ_LIKELY(aPinningDoomRestriction != DOOM_WHEN_NON_PINNED)) {
+        LOG(("  not dooming, it's a non-pinned handle"));
+        return NS_OK;
+      }
+      // Doom now
+      break;
+
+    case CacheFileHandle::PinningStatus::PINNED:
+      if (MOZ_UNLIKELY(aPinningDoomRestriction != DOOM_WHEN_PINNED)) {
+        LOG(("  not dooming, it's a pinned handle"));
+        return NS_OK;
+      }
+      // Doom now
+      break;
+
+    case CacheFileHandle::PinningStatus::UNKNOWN:
+      if (MOZ_LIKELY(aPinningDoomRestriction == DOOM_WHEN_NON_PINNED)) {
+        LOG(("  doom when non-pinned set"));
+        aHandle->mDoomWhenFoundNonPinned = true;
+      } else if (MOZ_UNLIKELY(aPinningDoomRestriction == DOOM_WHEN_PINNED)) {
+        LOG(("  doom when pinned set"));
+        aHandle->mDoomWhenFoundPinned = true;
+      }
+
+      LOG(("  pinning status not known, deferring doom decision"));
+      return NS_OK;
+    }
+  }
+
+  if (aHandle->mFileExists) {
+    // we need to move the current file to the doomed directory
+    rv = MaybeReleaseNSPRHandleInternal(aHandle, true);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // find unused filename
+    nsCOMPtr<nsIFile> file;
+    rv = GetDoomedFile(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIFile> parentDir;
+    rv = file->GetParent(getter_AddRefs(parentDir));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString leafName;
+    rv = file->GetNativeLeafName(leafName);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = aHandle->mFile->MoveToNative(parentDir, leafName);
+    if (NS_ERROR_FILE_NOT_FOUND == rv || NS_ERROR_FILE_TARGET_DOES_NOT_EXIST == rv) {
+      LOG(("  file already removed under our hands"));
+      aHandle->mFileExists = false;
+      rv = NS_OK;
+    } else {
+      NS_ENSURE_SUCCESS(rv, rv);
+      aHandle->mFile.swap(file);
+    }
+  }
+
+  if (!aHandle->IsSpecialFile()) {
+    CacheIndex::RemoveEntry(aHandle->Hash());
+  }
+
+  aHandle->mIsDoomed = true;
+
+  if (!aHandle->IsSpecialFile()) {
+    RefPtr<CacheStorageService> storageService = CacheStorageService::Self();
+    if (storageService) {
+      nsAutoCString idExtension, url;
+      nsCOMPtr<nsILoadContextInfo> info =
+        CacheFileUtils::ParseKey(aHandle->Key(), &idExtension, &url);
+      MOZ_ASSERT(info);
+      if (info) {
+        storageService->CacheFileDoomed(info, idExtension, url);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::DoomFileByKey(const nsACString &aKey,
+                                  CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::DoomFileByKey() [key=%s, listener=%p]",
+       PromiseFlatCString(aKey).get(), aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<DoomFileByKeyEvent> ev = new DoomFileByKeyEvent(aKey, aCallback);
+  rv = ioMan->mIOThread->DispatchAfterPendingOpens(ev);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::DoomFileByKeyInternal(const SHA1Sum::Hash *aHash)
+{
+  LOG(("CacheFileIOManager::DoomFileByKeyInternal() [hash=%08x%08x%08x%08x%08x]"
+       , LOGSHA1(aHash)));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  nsresult rv;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mCacheDirectory) {
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  // Find active handle
+  RefPtr<CacheFileHandle> handle;
+  mHandles.GetHandle(aHash, getter_AddRefs(handle));
+
+  if (handle) {
+    handle->Log();
+
+    return DoomFileInternal(handle);
+  }
+
+  CacheIOThread::Cancelable cancelable(true);
+
+  // There is no handle for this file, delete the file if exists
+  nsCOMPtr<nsIFile> file;
+  rv = GetFile(aHash, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!exists) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  LOG(("CacheFileIOManager::DoomFileByKeyInternal() - Removing file from "
+       "disk"));
+  rv = file->Remove(false);
+  if (NS_FAILED(rv)) {
+    NS_WARNING("Cannot remove old entry from the disk");
+    LOG(("CacheFileIOManager::DoomFileByKeyInternal() - Removing file failed. "
+         "[rv=0x%08x]", rv));
+  }
+
+  CacheIndex::RemoveEntry(aHash);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::ReleaseNSPRHandle(CacheFileHandle *aHandle)
+{
+  LOG(("CacheFileIOManager::ReleaseNSPRHandle() [handle=%p]", aHandle));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<ReleaseNSPRHandleEvent> ev = new ReleaseNSPRHandleEvent(aHandle);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::MaybeReleaseNSPRHandleInternal(CacheFileHandle *aHandle,
+                                                   bool aIgnoreShutdownLag)
+{
+  LOG(("CacheFileIOManager::MaybeReleaseNSPRHandleInternal() [handle=%p, ignore shutdown=%d]",
+       aHandle, aIgnoreShutdownLag));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+
+  if (aHandle->mFD) {
+    DebugOnly<bool> found;
+    found = mHandlesByLastUsed.RemoveElement(aHandle);
+    MOZ_ASSERT(found);
+  }
+
+  PRFileDesc *fd = aHandle->mFD;
+  aHandle->mFD = nullptr;
+
+  // Leak invalid (w/o metadata) and doomed handles immediately after shutdown.
+  // Leak other handles when past the shutdown time maximum lag.
+  if (
+#ifndef DEBUG
+      ((aHandle->mInvalid || aHandle->mIsDoomed) &&
+      MOZ_UNLIKELY(CacheObserver::ShuttingDown())) ||
+#endif
+      MOZ_UNLIKELY(!aIgnoreShutdownLag &&
+                   CacheObserver::IsPastShutdownIOLag())) {
+    // Don't bother closing this file.  Return a failure code from here will
+    // cause any following IO operation on the file (mainly removal) to be
+    // bypassed, which is what we want.
+    // For mInvalid == true the entry will never be used, since it doesn't
+    // have correct metadata, thus we don't need to worry about removing it.
+    // For mIsDoomed == true the file is already in the doomed sub-dir and
+    // will be removed on next session start.
+    LOG(("  past the shutdown I/O lag, leaking file handle"));
+    return NS_ERROR_ILLEGAL_DURING_SHUTDOWN;
+  }
+
+  if (!fd) {
+    // The filedesc has already been closed before, just let go.
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  PRStatus status = PR_Close(fd);
+  if (status != PR_SUCCESS) {
+    LOG(("CacheFileIOManager::MaybeReleaseNSPRHandleInternal() "
+         "failed to close [handle=%p, status=%u]", aHandle, status));
+    return NS_ERROR_FAILURE;
+  }
+
+  LOG(("CacheFileIOManager::MaybeReleaseNSPRHandleInternal() DONE"));
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::TruncateSeekSetEOF(CacheFileHandle *aHandle,
+                                       int64_t aTruncatePos, int64_t aEOFPos,
+                                       CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::TruncateSeekSetEOF() [handle=%p, truncatePos=%lld, "
+       "EOFPos=%lld, listener=%p]", aHandle, aTruncatePos, aEOFPos, aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || (aCallback && aCallback->IsKilled()) || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  RefPtr<TruncateSeekSetEOFEvent> ev = new TruncateSeekSetEOFEvent(
+                                           aHandle, aTruncatePos, aEOFPos,
+                                           aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// static
+void CacheFileIOManager::GetCacheDirectory(nsIFile** result)
+{
+  *result = nullptr;
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan || !ioMan->mCacheDirectory) {
+    return;
+  }
+
+  ioMan->mCacheDirectory->Clone(result);
+}
+
+#if defined(MOZ_WIDGET_ANDROID)
+
+// static
+void CacheFileIOManager::GetProfilelessCacheDirectory(nsIFile** result)
+{
+  *result = nullptr;
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan || !ioMan->mCacheProfilelessDirectory) {
+    return;
+  }
+
+  ioMan->mCacheProfilelessDirectory->Clone(result);
+}
+
+#endif
+
+// static
+nsresult
+CacheFileIOManager::GetEntryInfo(const SHA1Sum::Hash *aHash,
+                                 CacheStorageService::EntryInfoCallback *aCallback)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThread());
+
+  nsresult rv;
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsAutoCString enhanceId;
+  nsAutoCString uriSpec;
+
+  RefPtr<CacheFileHandle> handle;
+  ioMan->mHandles.GetHandle(aHash, getter_AddRefs(handle));
+  if (handle) {
+    RefPtr<nsILoadContextInfo> info =
+      CacheFileUtils::ParseKey(handle->Key(), &enhanceId, &uriSpec);
+
+    MOZ_ASSERT(info);
+    if (!info) {
+      return NS_OK; // ignore
+    }
+
+    RefPtr<CacheStorageService> service = CacheStorageService::Self();
+    if (!service) {
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+
+    // Invokes OnCacheEntryInfo when an existing entry is found
+    if (service->GetCacheEntryInfo(info, enhanceId, uriSpec, aCallback)) {
+      return NS_OK;
+    }
+
+    // When we are here, there is no existing entry and we need
+    // to synchrnously load metadata from a disk file.
+  }
+
+  // Locate the actual file
+  nsCOMPtr<nsIFile> file;
+  ioMan->GetFile(aHash, getter_AddRefs(file));
+
+  // Read metadata from the file synchronously
+  RefPtr<CacheFileMetadata> metadata = new CacheFileMetadata();
+  rv = metadata->SyncReadMetadata(file);
+  if (NS_FAILED(rv)) {
+    return NS_OK;
+  }
+
+  // Now get the context + enhance id + URL from the key.
+  nsAutoCString key;
+  metadata->GetKey(key);
+
+  RefPtr<nsILoadContextInfo> info =
+    CacheFileUtils::ParseKey(key, &enhanceId, &uriSpec);
+  MOZ_ASSERT(info);
+  if (!info) {
+    return NS_OK;
+  }
+
+  // Pick all data to pass to the callback.
+  int64_t dataSize = metadata->Offset();
+  uint32_t fetchCount;
+  if (NS_FAILED(metadata->GetFetchCount(&fetchCount))) {
+    fetchCount = 0;
+  }
+  uint32_t expirationTime;
+  if (NS_FAILED(metadata->GetExpirationTime(&expirationTime))) {
+    expirationTime = 0;
+  }
+  uint32_t lastModified;
+  if (NS_FAILED(metadata->GetLastModified(&lastModified))) {
+    lastModified = 0;
+  }
+
+  // Call directly on the callback.
+  aCallback->OnEntryInfo(uriSpec, enhanceId, dataSize, fetchCount,
+                         lastModified, expirationTime, metadata->Pinned());
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::TruncateSeekSetEOFInternal(CacheFileHandle *aHandle,
+                                               int64_t aTruncatePos,
+                                               int64_t aEOFPos)
+{
+  LOG(("CacheFileIOManager::TruncateSeekSetEOFInternal() [handle=%p, "
+       "truncatePos=%lld, EOFPos=%lld]", aHandle, aTruncatePos, aEOFPos));
+
+  nsresult rv;
+
+  if (aHandle->mKilled) {
+    LOG(("  handle already killed, file not truncated"));
+    return NS_OK;
+  }
+
+  if (CacheObserver::ShuttingDown() && !aHandle->mFD) {
+    aHandle->mKilled = true;
+    LOG(("  killing the handle, file not truncated"));
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(!aHandle->IsSpecialFile());
+
+  if (!aHandle->mFileExists) {
+    rv = CreateFile(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!aHandle->mFD) {
+    rv = OpenNSPRHandle(aHandle);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    NSPRHandleUsed(aHandle);
+  }
+
+  // Check again, OpenNSPRHandle could figure out the file was gone.
+  if (!aHandle->mFileExists) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Check whether this operation would cause critical low disk space.
+  if (aHandle->mFileSize < aEOFPos) {
+    int64_t freeSpace = -1;
+    rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::TruncateSeekSetEOFInternal() - "
+           "GetDiskSpaceAvailable() failed! [rv=0x%08x]", rv));
+    } else {
+      uint32_t limit = CacheObserver::DiskFreeSpaceHardLimit();
+      if (freeSpace - aEOFPos + aHandle->mFileSize < limit) {
+        LOG(("CacheFileIOManager::TruncateSeekSetEOFInternal() - Low free space"
+             ", refusing to write! [freeSpace=%lld, limit=%u]", freeSpace,
+             limit));
+        return NS_ERROR_FILE_DISK_FULL;
+      }
+    }
+  }
+
+  // This operation always invalidates the entry
+  aHandle->mInvalid = true;
+
+  rv = TruncFile(aHandle->mFD, aTruncatePos);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aTruncatePos != aEOFPos) {
+    rv = TruncFile(aHandle->mFD, aEOFPos);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  uint32_t oldSizeInK = aHandle->FileSizeInK();
+  aHandle->mFileSize = aEOFPos;
+  uint32_t newSizeInK = aHandle->FileSizeInK();
+
+  if (oldSizeInK != newSizeInK && !aHandle->IsDoomed() &&
+      !aHandle->IsSpecialFile()) {
+    CacheIndex::UpdateEntry(aHandle->Hash(), nullptr, nullptr, &newSizeInK);
+
+    if (oldSizeInK < newSizeInK) {
+      EvictIfOverLimitInternal();
+    }
+  }
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::RenameFile(CacheFileHandle *aHandle,
+                               const nsACString &aNewName,
+                               CacheFileIOListener *aCallback)
+{
+  LOG(("CacheFileIOManager::RenameFile() [handle=%p, newName=%s, listener=%p]",
+       aHandle, PromiseFlatCString(aNewName).get(), aCallback));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!aHandle->IsSpecialFile()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<RenameFileEvent> ev = new RenameFileEvent(aHandle, aNewName,
+                                                     aCallback);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::RenameFileInternal(CacheFileHandle *aHandle,
+                                       const nsACString &aNewName)
+{
+  LOG(("CacheFileIOManager::RenameFileInternal() [handle=%p, newName=%s]",
+       aHandle, PromiseFlatCString(aNewName).get()));
+
+  nsresult rv;
+
+  MOZ_ASSERT(aHandle->IsSpecialFile());
+
+  if (aHandle->IsDoomed()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Doom old handle if it exists and is not doomed
+  for (uint32_t i = 0 ; i < mSpecialHandles.Length() ; i++) {
+    if (!mSpecialHandles[i]->IsDoomed() &&
+        mSpecialHandles[i]->Key() == aNewName) {
+      MOZ_ASSERT(aHandle != mSpecialHandles[i]);
+      rv = DoomFileInternal(mSpecialHandles[i]);
+      NS_ENSURE_SUCCESS(rv, rv);
+      break;
+    }
+  }
+
+  nsCOMPtr<nsIFile> file;
+  rv = GetSpecialFile(aNewName, getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool exists;
+  rv = file->Exists(&exists);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (exists) {
+    LOG(("CacheFileIOManager::RenameFileInternal() - Removing old file from "
+         "disk"));
+    rv = file->Remove(false);
+    if (NS_FAILED(rv)) {
+      NS_WARNING("Cannot remove file from the disk");
+      LOG(("CacheFileIOManager::RenameFileInternal() - Removing old file failed"
+           ". [rv=0x%08x]", rv));
+    }
+  }
+
+  if (!aHandle->FileExists()) {
+    aHandle->mKey = aNewName;
+    return NS_OK;
+  }
+
+  rv = MaybeReleaseNSPRHandleInternal(aHandle, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aHandle->mFile->MoveToNative(nullptr, aNewName);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aHandle->mKey = aNewName;
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::EvictIfOverLimit()
+{
+  LOG(("CacheFileIOManager::EvictIfOverLimit()"));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(ioMan,
+			 &CacheFileIOManager::EvictIfOverLimitInternal);
+
+  rv = ioMan->mIOThread->Dispatch(ev, CacheIOThread::EVICT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::EvictIfOverLimitInternal()
+{
+  LOG(("CacheFileIOManager::EvictIfOverLimitInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (mOverLimitEvicting) {
+    LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - Eviction already "
+         "running."));
+    return NS_OK;
+  }
+
+  CacheIOThread::Cancelable cancelable(true);
+
+  int64_t freeSpace;
+  rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    freeSpace = -1;
+
+    // Do not change smart size.
+    LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - "
+         "GetDiskSpaceAvailable() failed! [rv=0x%08x]", rv));
+  } else {
+    UpdateSmartCacheSize(freeSpace);
+  }
+
+  uint32_t cacheUsage;
+  rv = CacheIndex::GetCacheSize(&cacheUsage);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint32_t cacheLimit = CacheObserver::DiskCacheCapacity() >> 10;
+  uint32_t freeSpaceLimit = CacheObserver::DiskFreeSpaceSoftLimit();
+
+  if (cacheUsage <= cacheLimit &&
+      (freeSpace == -1 || freeSpace >= freeSpaceLimit)) {
+    LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - Cache size and free "
+         "space in limits. [cacheSize=%ukB, cacheSizeLimit=%ukB, "
+         "freeSpace=%lld, freeSpaceLimit=%u]", cacheUsage, cacheLimit,
+         freeSpace, freeSpaceLimit));
+    return NS_OK;
+  }
+
+  LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - Cache size exceeded "
+       "limit. Starting overlimit eviction. [cacheSize=%u, limit=%u]",
+       cacheUsage, cacheLimit));
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(this,
+			 &CacheFileIOManager::OverLimitEvictionInternal);
+
+  rv = mIOThread->Dispatch(ev, CacheIOThread::EVICT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mOverLimitEvicting = true;
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OverLimitEvictionInternal()
+{
+  LOG(("CacheFileIOManager::OverLimitEvictionInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  // mOverLimitEvicting is accessed only on IO thread, so we can set it to false
+  // here and set it to true again once we dispatch another event that will
+  // continue with the eviction. The reason why we do so is that we can fail
+  // early anywhere in this method and the variable will contain a correct
+  // value. Otherwise we would need to set it to false on every failing place.
+  mOverLimitEvicting = false;
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  while (true) {
+    int64_t freeSpace = -1;
+    rv = mCacheDirectory->GetDiskSpaceAvailable(&freeSpace);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      // Do not change smart size.
+      LOG(("CacheFileIOManager::EvictIfOverLimitInternal() - "
+           "GetDiskSpaceAvailable() failed! [rv=0x%08x]", rv));
+    } else {
+      UpdateSmartCacheSize(freeSpace);
+    }
+
+    uint32_t cacheUsage;
+    rv = CacheIndex::GetCacheSize(&cacheUsage);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t cacheLimit = CacheObserver::DiskCacheCapacity() >> 10;
+    uint32_t freeSpaceLimit = CacheObserver::DiskFreeSpaceSoftLimit();
+
+    if (cacheUsage > cacheLimit) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Cache size over "
+           "limit. [cacheSize=%u, limit=%u]", cacheUsage, cacheLimit));
+    } else if (freeSpace != 1 && freeSpace < freeSpaceLimit) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Free space under "
+           "limit. [freeSpace=%lld, freeSpaceLimit=%u]", freeSpace,
+           freeSpaceLimit));
+    } else {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Cache size and "
+           "free space in limits. [cacheSize=%ukB, cacheSizeLimit=%ukB, "
+           "freeSpace=%lld, freeSpaceLimit=%u]", cacheUsage, cacheLimit,
+           freeSpace, freeSpaceLimit));
+      return NS_OK;
+    }
+
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - Breaking loop "
+           "for higher level events."));
+      mOverLimitEvicting = true;
+      return NS_OK;
+    }
+
+    SHA1Sum::Hash hash;
+    uint32_t cnt;
+    static uint32_t consecutiveFailures = 0;
+    rv = CacheIndex::GetEntryForEviction(false, &hash, &cnt);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = DoomFileByKeyInternal(&hash);
+    if (NS_SUCCEEDED(rv)) {
+      consecutiveFailures = 0;
+    } else if (rv == NS_ERROR_NOT_AVAILABLE) {
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - "
+           "DoomFileByKeyInternal() failed. [rv=0x%08x]", rv));
+      // TODO index is outdated, start update
+
+      // Make sure index won't return the same entry again
+      CacheIndex::RemoveEntry(&hash);
+      consecutiveFailures = 0;
+    } else {
+      // This shouldn't normally happen, but the eviction must not fail
+      // completely if we ever encounter this problem.
+      NS_WARNING("CacheFileIOManager::OverLimitEvictionInternal() - Unexpected "
+                 "failure of DoomFileByKeyInternal()");
+
+      LOG(("CacheFileIOManager::OverLimitEvictionInternal() - "
+           "DoomFileByKeyInternal() failed. [rv=0x%08x]", rv));
+
+      // Normally, CacheIndex::UpdateEntry() is called only to update newly
+      // created/opened entries which are always fresh and UpdateEntry() expects
+      // and checks this flag. The way we use UpdateEntry() here is a kind of
+      // hack and we must make sure the flag is set by calling
+      // EnsureEntryExists().
+      rv = CacheIndex::EnsureEntryExists(&hash);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Move the entry at the end of both lists to make sure we won't end up
+      // failing on one entry forever.
+      uint32_t frecency = 0;
+      uint32_t expTime = nsICacheEntry::NO_EXPIRATION_TIME;
+      rv = CacheIndex::UpdateEntry(&hash, &frecency, &expTime, nullptr);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      consecutiveFailures++;
+      if (consecutiveFailures >= cnt) {
+        // This doesn't necessarily mean that we've tried to doom every entry
+        // but we've reached a sane number of tries. It is likely that another
+        // eviction will start soon. And as said earlier, this normally doesn't
+        // happen at all.
+        return NS_OK;
+      }
+    }
+  }
+
+  NS_NOTREACHED("We should never get here");
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::EvictAll()
+{
+  LOG(("CacheFileIOManager::EvictAll()"));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(ioMan, &CacheFileIOManager::EvictAllInternal);
+
+  rv = ioMan->mIOThread->DispatchAfterPendingOpens(ev);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+namespace {
+
+class EvictionNotifierRunnable : public Runnable
+{
+public:
+  NS_DECL_NSIRUNNABLE
+};
+
+NS_IMETHODIMP
+EvictionNotifierRunnable::Run()
+{
+  nsCOMPtr<nsIObserverService> obsSvc = mozilla::services::GetObserverService();
+  if (obsSvc) {
+    obsSvc->NotifyObservers(nullptr, "cacheservice:empty-cache", nullptr);
+  }
+  return NS_OK;
+}
+
+} // namespace
+
+nsresult
+CacheFileIOManager::EvictAllInternal()
+{
+  LOG(("CacheFileIOManager::EvictAllInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  RefPtr<EvictionNotifierRunnable> r = new EvictionNotifierRunnable();
+
+  if (!mCacheDirectory) {
+    // This is a kind of hack. Somebody called EvictAll() without a profile.
+    // This happens in xpcshell tests that use cache without profile. We need
+    // to notify observers in this case since the tests are waiting for it.
+    NS_DispatchToMainThread(r);
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  // Doom all active handles
+  nsTArray<RefPtr<CacheFileHandle> > handles;
+  mHandles.GetActiveHandles(&handles);
+
+  for (uint32_t i = 0; i < handles.Length(); ++i) {
+    rv = DoomFileInternal(handles[i]);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::EvictAllInternal() - Cannot doom handle "
+           "[handle=%p]", handles[i].get()));
+    }
+  }
+
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(ENTRIES_DIR));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Trash current entries directory
+  rv = TrashDirectory(file);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // Files are now inaccessible in entries directory, notify observers.
+  NS_DispatchToMainThread(r);
+
+  // Create a new empty entries directory
+  rv = CheckAndCreateDir(mCacheDirectory, ENTRIES_DIR, false);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  CacheIndex::RemoveAll();
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::EvictByContext(nsILoadContextInfo *aLoadContextInfo, bool aPinned)
+{
+  LOG(("CacheFileIOManager::EvictByContext() [loadContextInfo=%p]",
+       aLoadContextInfo));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod<nsCOMPtr<nsILoadContextInfo>, bool>
+         (ioMan, &CacheFileIOManager::EvictByContextInternal, aLoadContextInfo, aPinned);
+
+  rv = ioMan->mIOThread->DispatchAfterPendingOpens(ev);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::EvictByContextInternal(nsILoadContextInfo *aLoadContextInfo, bool aPinned)
+{
+  LOG(("CacheFileIOManager::EvictByContextInternal() [loadContextInfo=%p, pinned=%d]",
+      aLoadContextInfo, aPinned));
+
+  nsresult rv;
+
+  if (aLoadContextInfo) {
+    nsAutoCString suffix;
+    aLoadContextInfo->OriginAttributesPtr()->CreateSuffix(suffix);
+    LOG(("  anonymous=%u, suffix=%s]", aLoadContextInfo->IsAnonymous(), suffix.get()));
+
+    MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+    MOZ_ASSERT(!aLoadContextInfo->IsPrivate());
+    if (aLoadContextInfo->IsPrivate()) {
+      return NS_ERROR_INVALID_ARG;
+    }
+  }
+
+  if (!mCacheDirectory) {
+    // This is a kind of hack. Somebody called EvictAll() without a profile.
+    // This happens in xpcshell tests that use cache without profile. We need
+    // to notify observers in this case since the tests are waiting for it.
+    // Also notify for aPinned == true, those are interested as well.
+    if (!aLoadContextInfo) {
+      RefPtr<EvictionNotifierRunnable> r = new EvictionNotifierRunnable();
+      NS_DispatchToMainThread(r);
+    }
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  // Doom all active handles that matches the load context
+  nsTArray<RefPtr<CacheFileHandle> > handles;
+  mHandles.GetActiveHandles(&handles);
+
+  for (uint32_t i = 0; i < handles.Length(); ++i) {
+    CacheFileHandle* handle = handles[i];
+
+    if (aLoadContextInfo) {
+      bool equals;
+      rv = CacheFileUtils::KeyMatchesLoadContextInfo(handle->Key(),
+                                                     aLoadContextInfo,
+                                                     &equals);
+      if (NS_FAILED(rv)) {
+        LOG(("CacheFileIOManager::EvictByContextInternal() - Cannot parse key in "
+             "handle! [handle=%p, key=%s]", handle, handle->Key().get()));
+        MOZ_CRASH("Unexpected error!");
+      }
+
+      if (!equals) {
+        continue;
+      }
+    }
+
+    // handle will be doomed only when pinning status is known and equal or
+    // doom decision will be deferred until pinning status is determined.
+    rv = DoomFileInternal(handle, aPinned
+                                  ? CacheFileIOManager::DOOM_WHEN_PINNED
+                                  : CacheFileIOManager::DOOM_WHEN_NON_PINNED);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::EvictByContextInternal() - Cannot doom handle"
+            " [handle=%p]", handle));
+    }
+  }
+
+  if (!aLoadContextInfo) {
+    RefPtr<EvictionNotifierRunnable> r = new EvictionNotifierRunnable();
+    NS_DispatchToMainThread(r);
+  }
+
+  if (!mContextEvictor) {
+    mContextEvictor = new CacheFileContextEvictor();
+    mContextEvictor->Init(mCacheDirectory);
+  }
+
+  mContextEvictor->AddContext(aLoadContextInfo, aPinned);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::CacheIndexStateChanged()
+{
+  LOG(("CacheFileIOManager::CacheIndexStateChanged()"));
+
+  nsresult rv;
+
+  // CacheFileIOManager lives longer than CacheIndex so gInstance must be
+  // non-null here.
+  MOZ_ASSERT(gInstance);
+
+  // We have to re-distatch even if we are on IO thread to prevent reentering
+  // the lock in CacheIndex
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(
+    gInstance.get(), &CacheFileIOManager::CacheIndexStateChangedInternal);
+
+  nsCOMPtr<nsIEventTarget> ioTarget = IOTarget();
+  MOZ_ASSERT(ioTarget);
+
+  rv = ioTarget->Dispatch(ev, nsIEventTarget::DISPATCH_NORMAL);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CacheIndexStateChangedInternal()
+{
+  if (mShuttingDown) {
+    // ignore notification during shutdown
+    return NS_OK;
+  }
+
+  if (!mContextEvictor) {
+    return NS_OK;
+  }
+
+  mContextEvictor->CacheIndexStateChanged();
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::TrashDirectory(nsIFile *aFile)
+{
+  nsAutoCString path;
+  aFile->GetNativePath(path);
+  LOG(("CacheFileIOManager::TrashDirectory() [file=%s]", path.get()));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+  MOZ_ASSERT(mCacheDirectory);
+
+  // When the directory is empty, it is cheaper to remove it directly instead of
+  // using the trash mechanism.
+  bool isEmpty;
+  rv = IsEmptyDirectory(aFile, &isEmpty);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (isEmpty) {
+    rv = aFile->Remove(false);
+    LOG(("CacheFileIOManager::TrashDirectory() - Directory removed [rv=0x%08x]",
+         rv));
+    return rv;
+  }
+
+#ifdef DEBUG
+  nsCOMPtr<nsIFile> dirCheck;
+  rv = aFile->GetParent(getter_AddRefs(dirCheck));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool equals = false;
+  rv = dirCheck->Equals(mCacheDirectory, &equals);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  MOZ_ASSERT(equals);
+#endif
+
+  nsCOMPtr<nsIFile> dir, trash;
+  nsAutoCString leaf;
+
+  rv = aFile->Clone(getter_AddRefs(dir));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = aFile->Clone(getter_AddRefs(trash));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  const int32_t kMaxTries = 16;
+  srand(static_cast<unsigned>(PR_Now()));
+  for (int32_t triesCount = 0; ; ++triesCount) {
+    leaf = TRASH_DIR;
+    leaf.AppendInt(rand());
+    rv = trash->SetNativeLeafName(leaf);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool exists;
+    if (NS_SUCCEEDED(trash->Exists(&exists)) && !exists) {
+      break;
+    }
+
+    LOG(("CacheFileIOManager::TrashDirectory() - Trash directory already "
+         "exists [leaf=%s]", leaf.get()));
+
+    if (triesCount == kMaxTries) {
+      LOG(("CacheFileIOManager::TrashDirectory() - Could not find unused trash "
+           "directory in %d tries.", kMaxTries));
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  LOG(("CacheFileIOManager::TrashDirectory() - Renaming directory [leaf=%s]",
+       leaf.get()));
+
+  rv = dir->MoveToNative(nullptr, leaf);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  StartRemovingTrash();
+  return NS_OK;
+}
+
+// static
+void
+CacheFileIOManager::OnTrashTimer(nsITimer *aTimer, void *aClosure)
+{
+  LOG(("CacheFileIOManager::OnTrashTimer() [timer=%p, closure=%p]", aTimer,
+       aClosure));
+
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (!ioMan) {
+    return;
+  }
+
+  ioMan->mTrashTimer = nullptr;
+  ioMan->StartRemovingTrash();
+}
+
+nsresult
+CacheFileIOManager::StartRemovingTrash()
+{
+  LOG(("CacheFileIOManager::StartRemovingTrash()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (!mCacheDirectory) {
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  if (mTrashTimer) {
+    LOG(("CacheFileIOManager::StartRemovingTrash() - Trash timer exists."));
+    return NS_OK;
+  }
+
+  if (mRemovingTrashDirs) {
+    LOG(("CacheFileIOManager::StartRemovingTrash() - Trash removing in "
+         "progress."));
+    return NS_OK;
+  }
+
+  uint32_t elapsed = (TimeStamp::NowLoRes() - mStartTime).ToMilliseconds();
+  if (elapsed < kRemoveTrashStartDelay) {
+    nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIEventTarget> ioTarget = IOTarget();
+    MOZ_ASSERT(ioTarget);
+
+    rv = timer->SetTarget(ioTarget);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = timer->InitWithFuncCallback(CacheFileIOManager::OnTrashTimer, nullptr,
+                                     kRemoveTrashStartDelay - elapsed,
+                                     nsITimer::TYPE_ONE_SHOT);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mTrashTimer.swap(timer);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIRunnable> ev;
+  ev = NewRunnableMethod(this,
+			 &CacheFileIOManager::RemoveTrashInternal);
+
+  rv = mIOThread->Dispatch(ev, CacheIOThread::EVICT);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mRemovingTrashDirs = true;
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::RemoveTrashInternal()
+{
+  LOG(("CacheFileIOManager::RemoveTrashInternal()"));
+
+  nsresult rv;
+
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  if (mShuttingDown) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  CacheIOThread::Cancelable cancelable(true);
+
+  MOZ_ASSERT(!mTrashTimer);
+  MOZ_ASSERT(mRemovingTrashDirs);
+
+  if (!mTreeCreated) {
+    rv = CreateCacheTree();
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  // mRemovingTrashDirs is accessed only on IO thread, so we can drop the flag
+  // here and set it again once we dispatch a continuation event. By doing so,
+  // we don't have to drop the flag on any possible early return.
+  mRemovingTrashDirs = false;
+
+  while (true) {
+    if (CacheIOThread::YieldAndRerun()) {
+      LOG(("CacheFileIOManager::RemoveTrashInternal() - Breaking loop for "
+           "higher level events."));
+      mRemovingTrashDirs = true;
+      return NS_OK;
+    }
+
+    // Find some trash directory
+    if (!mTrashDir) {
+      MOZ_ASSERT(!mTrashDirEnumerator);
+
+      rv = FindTrashDirToRemove();
+      if (rv == NS_ERROR_NOT_AVAILABLE) {
+        LOG(("CacheFileIOManager::RemoveTrashInternal() - No trash directory "
+             "found."));
+        return NS_OK;
+      }
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      nsCOMPtr<nsISimpleEnumerator> enumerator;
+      rv = mTrashDir->GetDirectoryEntries(getter_AddRefs(enumerator));
+      if (NS_SUCCEEDED(rv)) {
+        mTrashDirEnumerator = do_QueryInterface(enumerator, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      continue; // check elapsed time
+    }
+
+    // We null out mTrashDirEnumerator once we remove all files in the
+    // directory, so remove the trash directory if we don't have enumerator.
+    if (!mTrashDirEnumerator) {
+      rv = mTrashDir->Remove(false);
+      if (NS_FAILED(rv)) {
+        // There is no reason why removing an empty directory should fail, but
+        // if it does, we should continue and try to remove all other trash
+        // directories.
+        nsAutoCString leafName;
+        mTrashDir->GetNativeLeafName(leafName);
+        mFailedTrashDirs.AppendElement(leafName);
+        LOG(("CacheFileIOManager::RemoveTrashInternal() - Cannot remove "
+             "trashdir. [name=%s]", leafName.get()));
+      }
+
+      mTrashDir = nullptr;
+      continue; // check elapsed time
+    }
+
+    nsCOMPtr<nsIFile> file;
+    rv = mTrashDirEnumerator->GetNextFile(getter_AddRefs(file));
+    if (!file) {
+      mTrashDirEnumerator->Close();
+      mTrashDirEnumerator = nullptr;
+      continue; // check elapsed time
+    } else {
+      bool isDir = false;
+      file->IsDirectory(&isDir);
+      if (isDir) {
+        NS_WARNING("Found a directory in a trash directory! It will be removed "
+                   "recursively, but this can block IO thread for a while!");
+        if (LOG_ENABLED()) {
+          nsAutoCString path;
+          file->GetNativePath(path);
+          LOG(("CacheFileIOManager::RemoveTrashInternal() - Found a directory in a trash "
+              "directory! It will be removed recursively, but this can block IO "
+              "thread for a while! [file=%s]", path.get()));
+        }
+      }
+      file->Remove(isDir);
+    }
+  }
+
+  NS_NOTREACHED("We should never get here");
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::FindTrashDirToRemove()
+{
+  LOG(("CacheFileIOManager::FindTrashDirToRemove()"));
+
+  nsresult rv;
+
+  // We call this method on the main thread during shutdown when user wants to
+  // remove all cache files.
+  MOZ_ASSERT(mIOThread->IsCurrentThread() || mShuttingDown);
+
+  nsCOMPtr<nsISimpleEnumerator> iter;
+  rv = mCacheDirectory->GetDirectoryEntries(getter_AddRefs(iter));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool more;
+  nsCOMPtr<nsISupports> elem;
+
+  while (NS_SUCCEEDED(iter->HasMoreElements(&more)) && more) {
+    rv = iter->GetNext(getter_AddRefs(elem));
+    if (NS_FAILED(rv)) {
+      continue;
+    }
+
+    nsCOMPtr<nsIFile> file = do_QueryInterface(elem);
+    if (!file) {
+      continue;
+    }
+
+    bool isDir = false;
+    file->IsDirectory(&isDir);
+    if (!isDir) {
+      continue;
+    }
+
+    nsAutoCString leafName;
+    rv = file->GetNativeLeafName(leafName);
+    if (NS_FAILED(rv)) {
+      continue;
+    }
+
+    if (leafName.Length() < strlen(TRASH_DIR)) {
+      continue;
+    }
+
+    if (!StringBeginsWith(leafName, NS_LITERAL_CSTRING(TRASH_DIR))) {
+      continue;
+    }
+
+    if (mFailedTrashDirs.Contains(leafName)) {
+      continue;
+    }
+
+    LOG(("CacheFileIOManager::FindTrashDirToRemove() - Returning directory %s",
+         leafName.get()));
+
+    mTrashDir = file;
+    return NS_OK;
+  }
+
+  // When we're here we've tried to delete all trash directories. Clear
+  // mFailedTrashDirs so we will try to delete them again when we start removing
+  // trash directories next time.
+  mFailedTrashDirs.Clear();
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+// static
+nsresult
+CacheFileIOManager::InitIndexEntry(CacheFileHandle *aHandle,
+                                   OriginAttrsHash  aOriginAttrsHash,
+                                   bool             aAnonymous,
+                                   bool             aPinning)
+{
+  LOG(("CacheFileIOManager::InitIndexEntry() [handle=%p, originAttrsHash=%llx, "
+       "anonymous=%d, pinning=%d]", aHandle, aOriginAttrsHash, aAnonymous,
+       aPinning));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (aHandle->IsSpecialFile()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<InitIndexEntryEvent> ev =
+    new InitIndexEntryEvent(aHandle, aOriginAttrsHash, aAnonymous, aPinning);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// static
+nsresult
+CacheFileIOManager::UpdateIndexEntry(CacheFileHandle *aHandle,
+                                     const uint32_t  *aFrecency,
+                                     const uint32_t  *aExpirationTime)
+{
+  LOG(("CacheFileIOManager::UpdateIndexEntry() [handle=%p, frecency=%s, "
+       "expirationTime=%s]", aHandle,
+       aFrecency ? nsPrintfCString("%u", *aFrecency).get() : "",
+       aExpirationTime ? nsPrintfCString("%u", *aExpirationTime).get() : ""));
+
+  nsresult rv;
+  RefPtr<CacheFileIOManager> ioMan = gInstance;
+
+  if (aHandle->IsClosed() || !ioMan) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  if (aHandle->IsSpecialFile()) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  RefPtr<UpdateIndexEntryEvent> ev =
+    new UpdateIndexEntryEvent(aHandle, aFrecency, aExpirationTime);
+  rv = ioMan->mIOThread->Dispatch(ev, aHandle->mPriority
+                                  ? CacheIOThread::WRITE_PRIORITY
+                                  : CacheIOThread::WRITE);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CreateFile(CacheFileHandle *aHandle)
+{
+  MOZ_ASSERT(!aHandle->mFD);
+  MOZ_ASSERT(aHandle->mFile);
+
+  nsresult rv;
+
+  if (aHandle->IsDoomed()) {
+    nsCOMPtr<nsIFile> file;
+
+    rv = GetDoomedFile(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aHandle->mFile.swap(file);
+  } else {
+    bool exists;
+    if (NS_SUCCEEDED(aHandle->mFile->Exists(&exists)) && exists) {
+      NS_WARNING("Found a file that should not exist!");
+    }
+  }
+
+  rv = OpenNSPRHandle(aHandle, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  aHandle->mFileSize = 0;
+  return NS_OK;
+}
+
+// static
+void
+CacheFileIOManager::HashToStr(const SHA1Sum::Hash *aHash, nsACString &_retval)
+{
+  _retval.Truncate();
+  const char hexChars[] = {'0', '1', '2', '3', '4', '5', '6', '7',
+                           '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+  for (uint32_t i=0 ; i<sizeof(SHA1Sum::Hash) ; i++) {
+    _retval.Append(hexChars[(*aHash)[i] >> 4]);
+    _retval.Append(hexChars[(*aHash)[i] & 0xF]);
+  }
+}
+
+// static
+nsresult
+CacheFileIOManager::StrToHash(const nsACString &aHash, SHA1Sum::Hash *_retval)
+{
+  if (aHash.Length() != 2*sizeof(SHA1Sum::Hash)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  for (uint32_t i=0 ; i<aHash.Length() ; i++) {
+    uint8_t value;
+
+    if (aHash[i] >= '0' && aHash[i] <= '9') {
+      value = aHash[i] - '0';
+    } else if (aHash[i] >= 'A' && aHash[i] <= 'F') {
+      value = aHash[i] - 'A' + 10;
+    } else if (aHash[i] >= 'a' && aHash[i] <= 'f') {
+      value = aHash[i] - 'a' + 10;
+    } else {
+      return NS_ERROR_INVALID_ARG;
+    }
+
+    if (i%2 == 0) {
+      (reinterpret_cast<uint8_t *>(_retval))[i/2] = value << 4;
+    } else {
+      (reinterpret_cast<uint8_t *>(_retval))[i/2] += value;
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::GetFile(const SHA1Sum::Hash *aHash, nsIFile **_retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(ENTRIES_DIR));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString leafName;
+  HashToStr(aHash, leafName);
+
+  rv = file->AppendNative(leafName);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::GetSpecialFile(const nsACString &aKey, nsIFile **_retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(aKey);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::GetDoomedFile(nsIFile **_retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+  rv = mCacheDirectory->Clone(getter_AddRefs(file));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING(DOOMED_DIR));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = file->AppendNative(NS_LITERAL_CSTRING("dummyleaf"));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  const int32_t kMaxTries = 64;
+  srand(static_cast<unsigned>(PR_Now()));
+  nsAutoCString leafName;
+  for (int32_t triesCount = 0; ; ++triesCount) {
+    leafName.AppendInt(rand());
+    rv = file->SetNativeLeafName(leafName);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool exists;
+    if (NS_SUCCEEDED(file->Exists(&exists)) && !exists) {
+      break;
+    }
+
+    if (triesCount == kMaxTries) {
+      LOG(("CacheFileIOManager::GetDoomedFile() - Could not find unused file "
+           "name in %d tries.", kMaxTries));
+      return NS_ERROR_FAILURE;
+    }
+
+    leafName.Truncate();
+  }
+
+  file.swap(*_retval);
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::IsEmptyDirectory(nsIFile *aFile, bool *_retval)
+{
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  nsresult rv;
+
+  nsCOMPtr<nsISimpleEnumerator> enumerator;
+  rv = aFile->GetDirectoryEntries(getter_AddRefs(enumerator));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool hasMoreElements = false;
+  rv = enumerator->HasMoreElements(&hasMoreElements);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *_retval = !hasMoreElements;
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CheckAndCreateDir(nsIFile *aFile, const char *aDir,
+                                      bool aEnsureEmptyDir)
+{
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> file;
+  if (!aDir) {
+    file = aFile;
+  } else {
+    nsAutoCString dir(aDir);
+    rv = aFile->Clone(getter_AddRefs(file));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = file->AppendNative(dir);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  bool exists = false;
+  rv = file->Exists(&exists);
+  if (NS_SUCCEEDED(rv) && exists) {
+    bool isDirectory = false;
+    rv = file->IsDirectory(&isDirectory);
+    if (NS_FAILED(rv) || !isDirectory) {
+      // Try to remove the file
+      rv = file->Remove(false);
+      if (NS_SUCCEEDED(rv)) {
+        exists = false;
+      }
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aEnsureEmptyDir && NS_SUCCEEDED(rv) && exists) {
+    bool isEmpty;
+    rv = IsEmptyDirectory(file, &isEmpty);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!isEmpty) {
+      // Don't check the result, if this fails, it's OK.  We do this
+      // only for the doomed directory that doesn't need to be deleted
+      // for the cost of completely disabling the whole browser.
+      TrashDirectory(file);
+    }
+  }
+
+  if (NS_SUCCEEDED(rv) && !exists) {
+    rv = file->Create(nsIFile::DIRECTORY_TYPE, 0700);
+  }
+  if (NS_FAILED(rv)) {
+    NS_WARNING("Cannot create directory");
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::CreateCacheTree()
+{
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+  MOZ_ASSERT(!mTreeCreated);
+
+  if (!mCacheDirectory || mTreeCreationFailed) {
+    return NS_ERROR_FILE_INVALID_PATH;
+  }
+
+  nsresult rv;
+
+  // Set the flag here and clear it again below when the tree is created
+  // successfully.
+  mTreeCreationFailed = true;
+
+  // ensure parent directory exists
+  nsCOMPtr<nsIFile> parentDir;
+  rv = mCacheDirectory->GetParent(getter_AddRefs(parentDir));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = CheckAndCreateDir(parentDir, nullptr, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ensure cache directory exists
+  rv = CheckAndCreateDir(mCacheDirectory, nullptr, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ensure entries directory exists
+  rv = CheckAndCreateDir(mCacheDirectory, ENTRIES_DIR, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ensure doomed directory exists
+  rv = CheckAndCreateDir(mCacheDirectory, DOOMED_DIR, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mTreeCreated = true;
+  mTreeCreationFailed = false;
+
+  if (!mContextEvictor) {
+    RefPtr<CacheFileContextEvictor> contextEvictor;
+    contextEvictor = new CacheFileContextEvictor();
+
+    // Init() method will try to load unfinished contexts from the disk. Store
+    // the evictor as a member only when there is some unfinished job.
+    contextEvictor->Init(mCacheDirectory);
+    if (contextEvictor->ContextsCount()) {
+      contextEvictor.swap(mContextEvictor);
+    }
+  }
+
+  StartRemovingTrash();
+
+  if (!CacheObserver::CacheFSReported()) {
+    uint32_t fsType = 4; // Other OS
+
+#ifdef XP_WIN
+    nsAutoString target;
+    nsresult rv = mCacheDirectory->GetTarget(target);
+    if (NS_FAILED(rv)) {
+      return NS_OK;
+    }
+
+    wchar_t volume_path[MAX_PATH + 1] = { 0 };
+    if (!::GetVolumePathNameW(target.get(),
+                              volume_path,
+                              mozilla::ArrayLength(volume_path))) {
+      return NS_OK;
+    }
+
+    wchar_t fsName[6] = { 0 };
+    if (!::GetVolumeInformationW(volume_path, nullptr, 0, nullptr, nullptr,
+                                 nullptr, fsName,
+                                 mozilla::ArrayLength(fsName))) {
+      return NS_OK;
+    }
+
+    if (wcscmp(fsName, L"NTFS") == 0) {
+      fsType = 0;
+    } else if (wcscmp(fsName, L"FAT32") == 0) {
+      fsType = 1;
+    } else if (wcscmp(fsName, L"FAT") == 0) {
+      fsType = 2;
+    } else {
+      fsType = 3;
+    }
+#endif
+
+    Telemetry::Accumulate(Telemetry::NETWORK_CACHE_FS_TYPE, fsType);
+    CacheObserver::SetCacheFSReported();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+CacheFileIOManager::OpenNSPRHandle(CacheFileHandle *aHandle, bool aCreate)
+{
+  LOG(("CacheFileIOManager::OpenNSPRHandle BEGIN, handle=%p", aHandle));
+
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(!aHandle->mFD);
+  MOZ_ASSERT(mHandlesByLastUsed.IndexOf(aHandle) == mHandlesByLastUsed.NoIndex);
+  MOZ_ASSERT(mHandlesByLastUsed.Length() <= kOpenHandlesLimit);
+  MOZ_ASSERT((aCreate && !aHandle->mFileExists) ||
+             (!aCreate && aHandle->mFileExists));
+
+  nsresult rv;
+
+  if (mHandlesByLastUsed.Length() == kOpenHandlesLimit) {
+    // close handle that hasn't been used for the longest time
+    rv = MaybeReleaseNSPRHandleInternal(mHandlesByLastUsed[0], true);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (aCreate) {
+    rv = aHandle->mFile->OpenNSPRFileDesc(
+           PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE, 0600, &aHandle->mFD);
+    if (rv == NS_ERROR_FILE_ALREADY_EXISTS ||  // error from nsLocalFileWin
+        rv == NS_ERROR_FILE_NO_DEVICE_SPACE) { // error from nsLocalFileUnix
+      LOG(("CacheFileIOManager::OpenNSPRHandle() - Cannot create a new file, we"
+           " might reached a limit on FAT32. Will evict a single entry and try "
+           "again. [hash=%08x%08x%08x%08x%08x]", LOGSHA1(aHandle->Hash())));
+
+      SHA1Sum::Hash hash;
+      uint32_t cnt;
+
+      rv = CacheIndex::GetEntryForEviction(true, &hash, &cnt);
+      if (NS_SUCCEEDED(rv)) {
+        rv = DoomFileByKeyInternal(&hash);
+      }
+      if (NS_SUCCEEDED(rv)) {
+        rv = aHandle->mFile->OpenNSPRFileDesc(
+               PR_RDWR | PR_CREATE_FILE | PR_TRUNCATE, 0600, &aHandle->mFD);
+        LOG(("CacheFileIOManager::OpenNSPRHandle() - Successfully evicted entry"
+             " with hash %08x%08x%08x%08x%08x. %s to create the new file.",
+             LOGSHA1(&hash), NS_SUCCEEDED(rv) ? "Succeeded" : "Failed"));
+
+        // Report the full size only once per session
+        static bool sSizeReported = false;
+        if (!sSizeReported) {
+          uint32_t cacheUsage;
+          if (NS_SUCCEEDED(CacheIndex::GetCacheSize(&cacheUsage))) {
+            cacheUsage >>= 10;
+            Telemetry::Accumulate(Telemetry::NETWORK_CACHE_SIZE_FULL_FAT,
+                                  cacheUsage);
+            sSizeReported = true;
+          }
+        }
+      } else {
+        LOG(("CacheFileIOManager::OpenNSPRHandle() - Couldn't evict an existing"
+             " entry."));
+        rv = NS_ERROR_FILE_NO_DEVICE_SPACE;
+      }
+    }
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileIOManager::OpenNSPRHandle() Create failed with 0x%08x", rv));
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aHandle->mFileExists = true;
+  } else {
+    rv = aHandle->mFile->OpenNSPRFileDesc(PR_RDWR, 0600, &aHandle->mFD);
+    if (NS_ERROR_FILE_NOT_FOUND == rv) {
+      LOG(("  file doesn't exists"));
+      aHandle->mFileExists = false;
+      return DoomFileInternal(aHandle);
+    }
+    if (NS_FAILED(rv)) {
+      LOG(("CacheFileIOManager::OpenNSPRHandle() Open failed with 0x%08x", rv));
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  mHandlesByLastUsed.AppendElement(aHandle);
+
+  LOG(("CacheFileIOManager::OpenNSPRHandle END, handle=%p", aHandle));
+
+  return NS_OK;
+}
+
+void
+CacheFileIOManager::NSPRHandleUsed(CacheFileHandle *aHandle)
+{
+  MOZ_ASSERT(CacheFileIOManager::IsOnIOThreadOrCeased());
+  MOZ_ASSERT(aHandle->mFD);
+
+  DebugOnly<bool> found;
+  found = mHandlesByLastUsed.RemoveElement(aHandle);
+  MOZ_ASSERT(found);
+
+  mHandlesByLastUsed.AppendElement(aHandle);
+}
+
+nsresult
+CacheFileIOManager::SyncRemoveDir(nsIFile *aFile, const char *aDir)
+{
+  nsresult rv;
+  nsCOMPtr<nsIFile> file;
+
+  if (!aDir) {
+    file = aFile;
+  } else {
+    rv = aFile->Clone(getter_AddRefs(file));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    rv = file->AppendNative(nsDependentCString(aDir));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  if (LOG_ENABLED()) {
+    nsAutoCString path;
+    file->GetNativePath(path);
+    LOG(("CacheFileIOManager::SyncRemoveDir() - Removing directory %s",
+         path.get()));
+  }
+
+  rv = file->Remove(true);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("CacheFileIOManager::SyncRemoveDir() - Removing failed! [rv=0x%08x]",
+         rv));
+  }
+
+  return rv;
+}
+
+void
+CacheFileIOManager::SyncRemoveAllCacheFiles()
+{
+  LOG(("CacheFileIOManager::SyncRemoveAllCacheFiles()"));
+
+  nsresult rv;
+
+  SyncRemoveDir(mCacheDirectory, ENTRIES_DIR);
+  SyncRemoveDir(mCacheDirectory, DOOMED_DIR);
+
+  // Clear any intermediate state of trash dir enumeration.
+  mFailedTrashDirs.Clear();
+  mTrashDir = nullptr;
+
+  while (true) {
+    // FindTrashDirToRemove() fills mTrashDir if there is any trash directory.
+    rv = FindTrashDirToRemove();
+    if (rv == NS_ERROR_NOT_AVAILABLE) {
+      LOG(("CacheFileIOManager::SyncRemoveAllCacheFiles() - No trash directory "
+           "found."));
+      break;
+    }
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      LOG(("CacheFileIOManager::SyncRemoveAllCacheFiles() - "
+           "FindTrashDirToRemove() returned an unexpected error. [rv=0x%08x]",
+           rv));
+      break;
+    }
+
+    rv = SyncRemoveDir(mTrashDir, nullptr);
+    if (NS_FAILED(rv)) {
+      nsAutoCString leafName;
+      mTrashDir->GetNativeLeafName(leafName);
+      mFailedTrashDirs.AppendElement(leafName);
+    }
+  }
+}
+
+// Returns default ("smart") size (in KB) of cache, given available disk space
+// (also in KB)
+static uint32_t
+SmartCacheSize(const uint32_t availKB)
+{
+  uint32_t maxSize = kMaxCacheSizeKB;
+
+  if (availKB > 100 * 1024 * 1024) {
+    return maxSize;  // skip computing if we're over 100 GB
+  }
+
+  // Grow/shrink in 10 MB units, deliberately, so that in the common case we
+  // don't shrink cache and evict items every time we startup (it's important
+  // that we don't slow down startup benchmarks).
+  uint32_t sz10MBs = 0;
+  uint32_t avail10MBs = availKB / (1024*10);
+
+  // .5% of space above 25 GB
+  if (avail10MBs > 2500) {
+    sz10MBs += static_cast<uint32_t>((avail10MBs - 2500)*.005);
+    avail10MBs = 2500;
+  }
+  // 1% of space between 7GB -> 25 GB
+  if (avail10MBs > 700) {
+    sz10MBs += static_cast<uint32_t>((avail10MBs - 700)*.01);
+    avail10MBs = 700;
+  }
+  // 5% of space between 500 MB -> 7 GB
+  if (avail10MBs > 50) {
+    sz10MBs += static_cast<uint32_t>((avail10MBs - 50)*.05);
+    avail10MBs = 50;
+  }
+
+#ifdef ANDROID
+  // On Android, smaller/older devices may have very little storage and
+  // device owners may be sensitive to storage footprint: Use a smaller
+  // percentage of available space and a smaller minimum.
+
+  // 20% of space up to 500 MB (10 MB min)
+  sz10MBs += std::max<uint32_t>(1, static_cast<uint32_t>(avail10MBs * .2));
+#else
+  // 40% of space up to 500 MB (50 MB min)
+  sz10MBs += std::max<uint32_t>(5, static_cast<uint32_t>(avail10MBs * .4));
+#endif
+
+  return std::min<uint32_t>(maxSize, sz10MBs * 10 * 1024);
+}
+
+nsresult
+CacheFileIOManager::UpdateSmartCacheSize(int64_t aFreeSpace)
+{
+  MOZ_ASSERT(mIOThread->IsCurrentThread());
+
+  nsresult rv;
+
+  if (!CacheObserver::UseNewCache()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!CacheObserver::SmartCacheSizeEnabled()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Wait at least kSmartSizeUpdateInterval before recomputing smart size.
+  static const TimeDuration kUpdateLimit =
+    TimeDuration::FromMilliseconds(kSmartSizeUpdateInterval);
+  if (!mLastSmartSizeTime.IsNull() &&
+      (TimeStamp::NowLoRes() - mLastSmartSizeTime) < kUpdateLimit) {
+    return NS_OK;
+  }
+
+  // Do not compute smart size when cache size is not reliable.
+  bool isUpToDate = false;
+  CacheIndex::IsUpToDate(&isUpToDate);
+  if (!isUpToDate) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  uint32_t cacheUsage;
+  rv = CacheIndex::GetCacheSize(&cacheUsage);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    LOG(("CacheFileIOManager::UpdateSmartCacheSize() - Cannot get cacheUsage! "
+         "[rv=0x%08x]", rv));
+    return rv;
+  }
+
+  mLastSmartSizeTime = TimeStamp::NowLoRes();
+
+  uint32_t smartSize = SmartCacheSize(static_cast<uint32_t>(aFreeSpace / 1024) +
+                                      cacheUsage);
+
+  if (smartSize == (CacheObserver::DiskCacheCapacity() >> 10)) {
+    // Smart size has not changed.
+    return NS_OK;
+  }
+
+  CacheObserver::SetDiskCacheCapacity(smartSize << 10);
+
+  return NS_OK;
+}
+
+// Memory reporting
+
+namespace {
+
+// A helper class that dispatches and waits for an event that gets result of
+// CacheFileIOManager->mHandles.SizeOfExcludingThis() on the I/O thread
+// to safely get handles memory report.
+// We must do this, since the handle list is only accessed and managed w/o
+// locking on the I/O thread.  That is by design.
+class SizeOfHandlesRunnable : public Runnable
+{
+public:
+  SizeOfHandlesRunnable(mozilla::MallocSizeOf mallocSizeOf,
+                        CacheFileHandles const &handles,
+                        nsTArray<CacheFileHandle *> const &specialHandles)
+    : mMonitor("SizeOfHandlesRunnable.mMonitor")
+    , mMallocSizeOf(mallocSizeOf)
+    , mHandles(handles)
+    , mSpecialHandles(specialHandles)
+  {
+  }
+
+  size_t Get(CacheIOThread* thread)
+  {
+    nsCOMPtr<nsIEventTarget> target = thread->Target();
+    if (!target) {
+      NS_ERROR("If we have the I/O thread we also must have the I/O target");
+      return 0;
+    }
+
+    mozilla::MonitorAutoLock mon(mMonitor);
+    mMonitorNotified = false;
+    nsresult rv = target->Dispatch(this, nsIEventTarget::DISPATCH_NORMAL);
+    if (NS_FAILED(rv)) {
+      NS_ERROR("Dispatch failed, cannot do memory report of CacheFileHandles");
+      return 0;
+    }
+
+    while (!mMonitorNotified) {
+      mon.Wait();
+    }
+    return mSize;
+  }
+
+  NS_IMETHOD Run() override
+  {
+    mozilla::MonitorAutoLock mon(mMonitor);
+    // Excluding this since the object itself is a member of CacheFileIOManager
+    // reported in CacheFileIOManager::SizeOfIncludingThis as part of |this|.
+    mSize = mHandles.SizeOfExcludingThis(mMallocSizeOf);
+    for (uint32_t i = 0; i < mSpecialHandles.Length(); ++i) {
+      mSize += mSpecialHandles[i]->SizeOfIncludingThis(mMallocSizeOf);
+    }
+
+    mMonitorNotified = true;
+    mon.Notify();
+    return NS_OK;
+  }
+
+private:
+  mozilla::Monitor mMonitor;
+  bool mMonitorNotified;
+  mozilla::MallocSizeOf mMallocSizeOf;
+  CacheFileHandles const &mHandles;
+  nsTArray<CacheFileHandle *> const &mSpecialHandles;
+  size_t mSize;
+};
+
+} // namespace
+
+size_t
+CacheFileIOManager::SizeOfExcludingThisInternal(mozilla::MallocSizeOf mallocSizeOf) const
+{
+  size_t n = 0;
+  nsCOMPtr<nsISizeOf> sizeOf;
+
+  if (mIOThread) {
+    n += mIOThread->SizeOfIncludingThis(mallocSizeOf);
+
+    // mHandles and mSpecialHandles must be accessed only on the I/O thread,
+    // must sync dispatch.
+    RefPtr<SizeOfHandlesRunnable> sizeOfHandlesRunnable =
+      new SizeOfHandlesRunnable(mallocSizeOf, mHandles, mSpecialHandles);
+    n += sizeOfHandlesRunnable->Get(mIOThread);
+  }
+
+  // mHandlesByLastUsed just refers handles reported by mHandles.
+
+  sizeOf = do_QueryInterface(mCacheDirectory);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  sizeOf = do_QueryInterface(mMetadataWritesTimer);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  sizeOf = do_QueryInterface(mTrashTimer);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  sizeOf = do_QueryInterface(mTrashDir);
+  if (sizeOf)
+    n += sizeOf->SizeOfIncludingThis(mallocSizeOf);
+
+  for (uint32_t i = 0; i < mFailedTrashDirs.Length(); ++i) {
+    n += mFailedTrashDirs[i].SizeOfExcludingThisIfUnshared(mallocSizeOf);
+  }
+
+  return n;
+}
+
+// static
+size_t
+CacheFileIOManager::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+  if (!gInstance)
+    return 0;
+
+  return gInstance->SizeOfExcludingThisInternal(mallocSizeOf);
+}
+
+// static
+size_t
+CacheFileIOManager::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+  return mallocSizeOf(gInstance) + SizeOfExcludingThis(mallocSizeOf);
+}
+
+} // namespace net
+} // namespace mozilla