/* 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 "CacheFile.h"

#include "CacheFileChunk.h"
#include "CacheFileInputStream.h"
#include "CacheFileOutputStream.h"
#include "nsThreadUtils.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Move.h"
#include <algorithm>
#include "nsComponentManagerUtils.h"
#include "nsProxyRelease.h"
#include "mozilla/Telemetry.h"

// When CACHE_CHUNKS is defined we always cache unused chunks in mCacheChunks.
// When it is not defined, we always release the chunks ASAP, i.e. we cache
// unused chunks only when:
//  - CacheFile is memory-only
//  - CacheFile is still waiting for the handle
//  - the chunk is preloaded

//#define CACHE_CHUNKS

namespace mozilla {
namespace net {

class NotifyCacheFileListenerEvent : public nsRunnable {
public:
  NotifyCacheFileListenerEvent(CacheFileListener *aCallback,
                               nsresult aResult,
                               bool aIsNew)
    : mCallback(aCallback)
    , mRV(aResult)
    , mIsNew(aIsNew)
  {
    LOG(("NotifyCacheFileListenerEvent::NotifyCacheFileListenerEvent() "
         "[this=%p]", this));
    MOZ_COUNT_CTOR(NotifyCacheFileListenerEvent);
  }

protected:
  ~NotifyCacheFileListenerEvent()
  {
    LOG(("NotifyCacheFileListenerEvent::~NotifyCacheFileListenerEvent() "
         "[this=%p]", this));
    MOZ_COUNT_DTOR(NotifyCacheFileListenerEvent);
  }

public:
  NS_IMETHOD Run()
  {
    LOG(("NotifyCacheFileListenerEvent::Run() [this=%p]", this));

    mCallback->OnFileReady(mRV, mIsNew);
    return NS_OK;
  }

protected:
  nsCOMPtr<CacheFileListener> mCallback;
  nsresult                    mRV;
  bool                        mIsNew;
};

class NotifyChunkListenerEvent : public nsRunnable {
public:
  NotifyChunkListenerEvent(CacheFileChunkListener *aCallback,
                           nsresult aResult,
                           uint32_t aChunkIdx,
                           CacheFileChunk *aChunk)
    : mCallback(aCallback)
    , mRV(aResult)
    , mChunkIdx(aChunkIdx)
    , mChunk(aChunk)
  {
    LOG(("NotifyChunkListenerEvent::NotifyChunkListenerEvent() [this=%p]",
         this));
    MOZ_COUNT_CTOR(NotifyChunkListenerEvent);
  }

protected:
  ~NotifyChunkListenerEvent()
  {
    LOG(("NotifyChunkListenerEvent::~NotifyChunkListenerEvent() [this=%p]",
         this));
    MOZ_COUNT_DTOR(NotifyChunkListenerEvent);
  }

public:
  NS_IMETHOD Run()
  {
    LOG(("NotifyChunkListenerEvent::Run() [this=%p]", this));

    mCallback->OnChunkAvailable(mRV, mChunkIdx, mChunk);
    return NS_OK;
  }

protected:
  nsCOMPtr<CacheFileChunkListener> mCallback;
  nsresult                         mRV;
  uint32_t                         mChunkIdx;
  RefPtr<CacheFileChunk>           mChunk;
};


class DoomFileHelper : public CacheFileIOListener
{
public:
  NS_DECL_THREADSAFE_ISUPPORTS

  explicit DoomFileHelper(CacheFileListener *aListener)
    : mListener(aListener)
  {
    MOZ_COUNT_CTOR(DoomFileHelper);
  }


  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override
  {
    MOZ_CRASH("DoomFileHelper::OnFileOpened should not be called!");
    return NS_ERROR_UNEXPECTED;
  }

  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
                           nsresult aResult) override
  {
    MOZ_CRASH("DoomFileHelper::OnDataWritten should not be called!");
    return NS_ERROR_UNEXPECTED;
  }

  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override
  {
    MOZ_CRASH("DoomFileHelper::OnDataRead should not be called!");
    return NS_ERROR_UNEXPECTED;
  }

  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override
  {
    if (mListener)
      mListener->OnFileDoomed(aResult);
    return NS_OK;
  }

  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override
  {
    MOZ_CRASH("DoomFileHelper::OnEOFSet should not be called!");
    return NS_ERROR_UNEXPECTED;
  }

  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override
  {
    MOZ_CRASH("DoomFileHelper::OnFileRenamed should not be called!");
    return NS_ERROR_UNEXPECTED;
  }

private:
  virtual ~DoomFileHelper()
  {
    MOZ_COUNT_DTOR(DoomFileHelper);
  }

  nsCOMPtr<CacheFileListener>  mListener;
};

NS_IMPL_ISUPPORTS(DoomFileHelper, CacheFileIOListener)


NS_IMPL_ADDREF(CacheFile)
NS_IMPL_RELEASE(CacheFile)
NS_INTERFACE_MAP_BEGIN(CacheFile)
  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileChunkListener)
  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileIOListener)
  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileMetadataListener)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports,
                                   mozilla::net::CacheFileChunkListener)
NS_INTERFACE_MAP_END_THREADSAFE

CacheFile::CacheFile()
  : mLock("CacheFile.mLock")
  , mOpeningFile(false)
  , mReady(false)
  , mMemoryOnly(false)
  , mSkipSizeCheck(false)
  , mOpenAsMemoryOnly(false)
  , mPinned(false)
  , mPriority(false)
  , mDataAccessed(false)
  , mDataIsDirty(false)
  , mWritingMetadata(false)
  , mPreloadWithoutInputStreams(true)
  , mPreloadChunkCount(0)
  , mStatus(NS_OK)
  , mDataSize(-1)
  , mKill(false)
  , mOutput(nullptr)
{
  LOG(("CacheFile::CacheFile() [this=%p]", this));
}

CacheFile::~CacheFile()
{
  LOG(("CacheFile::~CacheFile() [this=%p]", this));

  MutexAutoLock lock(mLock);
  if (!mMemoryOnly && mReady && !mKill) {
    // mReady flag indicates we have metadata plus in a valid state.
    WriteMetadataIfNeededLocked(true);
  }
}

nsresult
CacheFile::Init(const nsACString &aKey,
                bool aCreateNew,
                bool aMemoryOnly,
                bool aSkipSizeCheck,
                bool aPriority,
                bool aPinned,
                CacheFileListener *aCallback)
{
  MOZ_ASSERT(!mListener);
  MOZ_ASSERT(!mHandle);

  MOZ_ASSERT(!(aMemoryOnly && aPinned));

  nsresult rv;

  mKey = aKey;
  mOpenAsMemoryOnly = mMemoryOnly = aMemoryOnly;
  mSkipSizeCheck = aSkipSizeCheck;
  mPriority = aPriority;
  mPinned = aPinned;

  // Some consumers (at least nsHTTPCompressConv) assume that Read() can read
  // such amount of data that was announced by Available().
  // CacheFileInputStream::Available() uses also preloaded chunks to compute
  // number of available bytes in the input stream, so we have to make sure the
  // preloadChunkCount won't change during CacheFile's lifetime since otherwise
  // we could potentially release some cached chunks that was used to calculate
  // available bytes but would not be available later during call to
  // CacheFileInputStream::Read().
  mPreloadChunkCount = CacheObserver::PreloadChunkCount();

  LOG(("CacheFile::Init() [this=%p, key=%s, createNew=%d, memoryOnly=%d, "
       "priority=%d, listener=%p]", this, mKey.get(), aCreateNew, aMemoryOnly,
       aPriority, aCallback));

  if (mMemoryOnly) {
    MOZ_ASSERT(!aCallback);

    mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, false, mKey);
    mReady = true;
    mDataSize = mMetadata->Offset();
    return NS_OK;
  }
  else {
    uint32_t flags;
    if (aCreateNew) {
      MOZ_ASSERT(!aCallback);
      flags = CacheFileIOManager::CREATE_NEW;

      // make sure we can use this entry immediately
      mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, mPinned, mKey);
      mReady = true;
      mDataSize = mMetadata->Offset();
    } else {
      flags = CacheFileIOManager::CREATE;
    }

    if (mPriority) {
      flags |= CacheFileIOManager::PRIORITY;
    }

    if (mPinned) {
      flags |= CacheFileIOManager::PINNED;
    }

    mOpeningFile = true;
    mListener = aCallback;
    rv = CacheFileIOManager::OpenFile(mKey, flags, this);
    if (NS_FAILED(rv)) {
      mListener = nullptr;
      mOpeningFile = false;

      if (mPinned) {
        LOG(("CacheFile::Init() - CacheFileIOManager::OpenFile() failed "
             "but we want to pin, fail the file opening. [this=%p]", this));
        return NS_ERROR_NOT_AVAILABLE;
      }

      if (aCreateNew) {
        NS_WARNING("Forcing memory-only entry since OpenFile failed");
        LOG(("CacheFile::Init() - CacheFileIOManager::OpenFile() failed "
             "synchronously. We can continue in memory-only mode since "
             "aCreateNew == true. [this=%p]", this));

        mMemoryOnly = true;
      }
      else if (rv == NS_ERROR_NOT_INITIALIZED) {
        NS_WARNING("Forcing memory-only entry since CacheIOManager isn't "
                   "initialized.");
        LOG(("CacheFile::Init() - CacheFileIOManager isn't initialized, "
             "initializing entry as memory-only. [this=%p]", this));

        mMemoryOnly = true;
        mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, mPinned, mKey);
        mReady = true;
        mDataSize = mMetadata->Offset();

        RefPtr<NotifyCacheFileListenerEvent> ev;
        ev = new NotifyCacheFileListenerEvent(aCallback, NS_OK, true);
        rv = NS_DispatchToCurrentThread(ev);
        NS_ENSURE_SUCCESS(rv, rv);
      }
      else {
        NS_ENSURE_SUCCESS(rv, rv);
      }
    }
  }

  return NS_OK;
}

nsresult
CacheFile::OnChunkRead(nsresult aResult, CacheFileChunk *aChunk)
{
  CacheFileAutoLock lock(this);

  nsresult rv;

  uint32_t index = aChunk->Index();

  LOG(("CacheFile::OnChunkRead() [this=%p, rv=0x%08x, chunk=%p, idx=%u]",
       this, aResult, aChunk, index));

  if (NS_FAILED(aResult)) {
    SetError(aResult);
  }

  if (HaveChunkListeners(index)) {
    rv = NotifyChunkListeners(index, aResult, aChunk);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

nsresult
CacheFile::OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk)
{
  // In case the chunk was reused, made dirty and released between calls to
  // CacheFileChunk::Write() and CacheFile::OnChunkWritten(), we must write
  // the chunk to the disk again. When the chunk is unused and is dirty simply
  // addref and release (outside the lock) the chunk which ensures that
  // CacheFile::DeactivateChunk() will be called again.
  RefPtr<CacheFileChunk> deactivateChunkAgain;

  CacheFileAutoLock lock(this);

  nsresult rv;

  LOG(("CacheFile::OnChunkWritten() [this=%p, rv=0x%08x, chunk=%p, idx=%u]",
       this, aResult, aChunk, aChunk->Index()));

  MOZ_ASSERT(!mMemoryOnly);
  MOZ_ASSERT(!mOpeningFile);
  MOZ_ASSERT(mHandle);

  if (NS_FAILED(aResult)) {
    SetError(aResult);
  }

  if (NS_SUCCEEDED(aResult) && !aChunk->IsDirty()) {
    // update hash value in metadata
    mMetadata->SetHash(aChunk->Index(), aChunk->Hash());
  }

  // notify listeners if there is any
  if (HaveChunkListeners(aChunk->Index())) {
    // don't release the chunk since there are some listeners queued
    rv = NotifyChunkListeners(aChunk->Index(), aResult, aChunk);
    if (NS_SUCCEEDED(rv)) {
      MOZ_ASSERT(aChunk->mRefCnt != 2);
      return NS_OK;
    }
  }

  if (aChunk->mRefCnt != 2) {
    LOG(("CacheFile::OnChunkWritten() - Chunk is still used [this=%p, chunk=%p,"
         " refcnt=%d]", this, aChunk, aChunk->mRefCnt.get()));

    return NS_OK;
  }

  if (aChunk->IsDirty()) {
    LOG(("CacheFile::OnChunkWritten() - Unused chunk is dirty. We must go "
         "through deactivation again. [this=%p, chunk=%p]", this, aChunk));

    deactivateChunkAgain = aChunk;
    return NS_OK;
  }

  bool keepChunk = false;
  if (NS_SUCCEEDED(aResult)) {
    keepChunk = ShouldCacheChunk(aChunk->Index());
    LOG(("CacheFile::OnChunkWritten() - %s unused chunk [this=%p, chunk=%p]",
         keepChunk ? "Caching" : "Releasing", this, aChunk));
  } else {
    LOG(("CacheFile::OnChunkWritten() - Releasing failed chunk [this=%p, "
         "chunk=%p]", this, aChunk));
  }

  RemoveChunkInternal(aChunk, keepChunk);

  WriteMetadataIfNeededLocked();

  return NS_OK;
}

nsresult
CacheFile::OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
                            CacheFileChunk *aChunk)
{
  MOZ_CRASH("CacheFile::OnChunkAvailable should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult
CacheFile::OnChunkUpdated(CacheFileChunk *aChunk)
{
  MOZ_CRASH("CacheFile::OnChunkUpdated should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult
CacheFile::OnFileOpened(CacheFileHandle *aHandle, nsresult aResult)
{
  nsresult rv;

  // Using an 'auto' class to perform doom or fail the listener
  // outside the CacheFile's lock.
  class AutoFailDoomListener
  {
  public:
    explicit AutoFailDoomListener(CacheFileHandle *aHandle)
      : mHandle(aHandle)
      , mAlreadyDoomed(false)
    {}
    ~AutoFailDoomListener()
    {
      if (!mListener)
        return;

      if (mHandle) {
        if (mAlreadyDoomed) {
          mListener->OnFileDoomed(mHandle, NS_OK);
        } else {
          CacheFileIOManager::DoomFile(mHandle, mListener);
        }
      } else {
        mListener->OnFileDoomed(nullptr, NS_ERROR_NOT_AVAILABLE);
      }
    }

    CacheFileHandle* mHandle;
    nsCOMPtr<CacheFileIOListener> mListener;
    bool mAlreadyDoomed;
  } autoDoom(aHandle);

  nsCOMPtr<CacheFileListener> listener;
  bool isNew = false;
  nsresult retval = NS_OK;

  {
    CacheFileAutoLock lock(this);

    MOZ_ASSERT(mOpeningFile);
    MOZ_ASSERT((NS_SUCCEEDED(aResult) && aHandle) ||
               (NS_FAILED(aResult) && !aHandle));
    MOZ_ASSERT((mListener && !mMetadata) || // !createNew
               (!mListener && mMetadata));  // createNew
    MOZ_ASSERT(!mMemoryOnly || mMetadata); // memory-only was set on new entry

    LOG(("CacheFile::OnFileOpened() [this=%p, rv=0x%08x, handle=%p]",
         this, aResult, aHandle));

    mOpeningFile = false;

    autoDoom.mListener.swap(mDoomAfterOpenListener);

    if (mMemoryOnly) {
      // We can be here only in case the entry was initilized as createNew and
      // SetMemoryOnly() was called.

      // Just don't store the handle into mHandle and exit
      autoDoom.mAlreadyDoomed = true;
      return NS_OK;
    }

    if (NS_FAILED(aResult)) {
      if (mMetadata) {
        // This entry was initialized as createNew, just switch to memory-only
        // mode.
        NS_WARNING("Forcing memory-only entry since OpenFile failed");
        LOG(("CacheFile::OnFileOpened() - CacheFileIOManager::OpenFile() "
             "failed asynchronously. We can continue in memory-only mode since "
             "aCreateNew == true. [this=%p]", this));

        mMemoryOnly = true;
        return NS_OK;
      }

      if (aResult == NS_ERROR_FILE_INVALID_PATH) {
        // CacheFileIOManager doesn't have mCacheDirectory, switch to
        // memory-only mode.
        NS_WARNING("Forcing memory-only entry since CacheFileIOManager doesn't "
                   "have mCacheDirectory.");
        LOG(("CacheFile::OnFileOpened() - CacheFileIOManager doesn't have "
             "mCacheDirectory, initializing entry as memory-only. [this=%p]",
             this));

        mMemoryOnly = true;
        mMetadata = new CacheFileMetadata(mOpenAsMemoryOnly, mPinned, mKey);
        mReady = true;
        mDataSize = mMetadata->Offset();

        isNew = true;
        retval = NS_OK;
      } else {
        // CacheFileIOManager::OpenFile() failed for another reason.
        isNew = false;
        retval = aResult;
      }

      mListener.swap(listener);
    } else {
      mHandle = aHandle;
      if (NS_FAILED(mStatus)) {
        CacheFileIOManager::DoomFile(mHandle, nullptr);
      }

      if (mMetadata) {
        InitIndexEntry();

        // The entry was initialized as createNew, don't try to read metadata.
        mMetadata->SetHandle(mHandle);

        // Write all cached chunks, otherwise they may stay unwritten.
        for (auto iter = mCachedChunks.Iter(); !iter.Done(); iter.Next()) {
          uint32_t idx = iter.Key();
          const RefPtr<CacheFileChunk>& chunk = iter.Data();

          LOG(("CacheFile::OnFileOpened() - write [this=%p, idx=%u, chunk=%p]",
               this, idx, chunk.get()));

          mChunks.Put(idx, chunk);
          chunk->mFile = this;
          chunk->mActiveChunk = true;

          MOZ_ASSERT(chunk->IsReady());

          // This would be cleaner if we had an nsRefPtr constructor that took
          // a RefPtr<Derived>.
          ReleaseOutsideLock(RefPtr<nsISupports>(chunk));

          iter.Remove();
        }

        return NS_OK;
      }
    }
  }

  if (listener) {
    listener->OnFileReady(retval, isNew);
    return NS_OK;
  }

  MOZ_ASSERT(NS_SUCCEEDED(aResult));
  MOZ_ASSERT(!mMetadata);
  MOZ_ASSERT(mListener);

  mMetadata = new CacheFileMetadata(mHandle, mKey);

  rv = mMetadata->ReadMetadata(this);
  if (NS_FAILED(rv)) {
    mListener.swap(listener);
    listener->OnFileReady(rv, false);
  }

  return NS_OK;
}

nsresult
CacheFile::OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
                         nsresult aResult)
{
  MOZ_CRASH("CacheFile::OnDataWritten should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult
CacheFile::OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult)
{
  MOZ_CRASH("CacheFile::OnDataRead should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult
CacheFile::OnMetadataRead(nsresult aResult)
{
  MOZ_ASSERT(mListener);

  LOG(("CacheFile::OnMetadataRead() [this=%p, rv=0x%08x]", this, aResult));

  bool isNew = false;
  if (NS_SUCCEEDED(aResult)) {
    mPinned = mMetadata->Pinned();
    mReady = true;
    mDataSize = mMetadata->Offset();
    if (mDataSize == 0 && mMetadata->ElementsSize() == 0) {
      isNew = true;
      mMetadata->MarkDirty();
    } else {
      CacheFileAutoLock lock(this);
      PreloadChunks(0);
    }

    InitIndexEntry();
  }

  nsCOMPtr<CacheFileListener> listener;
  mListener.swap(listener);
  listener->OnFileReady(aResult, isNew);
  return NS_OK;
}

nsresult
CacheFile::OnMetadataWritten(nsresult aResult)
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::OnMetadataWritten() [this=%p, rv=0x%08x]", this, aResult));

  MOZ_ASSERT(mWritingMetadata);
  mWritingMetadata = false;

  MOZ_ASSERT(!mMemoryOnly);
  MOZ_ASSERT(!mOpeningFile);

  if (NS_WARN_IF(NS_FAILED(aResult))) {
    // TODO close streams with an error ???
    SetError(aResult);
  }

  if (mOutput || mInputs.Length() || mChunks.Count())
    return NS_OK;

  if (IsDirty())
    WriteMetadataIfNeededLocked();

  if (!mWritingMetadata) {
    LOG(("CacheFile::OnMetadataWritten() - Releasing file handle [this=%p]",
         this));
    CacheFileIOManager::ReleaseNSPRHandle(mHandle);
  }

  return NS_OK;
}

nsresult
CacheFile::OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult)
{
  nsCOMPtr<CacheFileListener> listener;

  {
    CacheFileAutoLock lock(this);

    MOZ_ASSERT(mListener);

    LOG(("CacheFile::OnFileDoomed() [this=%p, rv=0x%08x, handle=%p]",
         this, aResult, aHandle));

    mListener.swap(listener);
  }

  listener->OnFileDoomed(aResult);
  return NS_OK;
}

nsresult
CacheFile::OnEOFSet(CacheFileHandle *aHandle, nsresult aResult)
{
  MOZ_CRASH("CacheFile::OnEOFSet should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult
CacheFile::OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult)
{
  MOZ_CRASH("CacheFile::OnFileRenamed should not be called!");
  return NS_ERROR_UNEXPECTED;
}

bool CacheFile::IsKilled()
{
  bool killed = mKill;
  if (killed) {
    LOG(("CacheFile is killed, this=%p", this));
  }

  return killed;
}

nsresult
CacheFile::OpenInputStream(nsICacheEntry *aEntryHandle, nsIInputStream **_retval)
{
  CacheFileAutoLock lock(this);

  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);

  if (!mReady) {
    LOG(("CacheFile::OpenInputStream() - CacheFile is not ready [this=%p]",
         this));

    return NS_ERROR_NOT_AVAILABLE;
  }

  if (NS_FAILED(mStatus)) {
    LOG(("CacheFile::OpenInputStream() - CacheFile is in a failure state "
         "[this=%p, status=0x%08x]", this, mStatus));

    // Don't allow opening the input stream when this CacheFile is in
    // a failed state.  This is the only way to protect consumers correctly
    // from reading a broken entry.  When the file is in the failed state,
    // it's also doomed, so reopening the entry won't make any difference -
    // data will still be inaccessible anymore.  Note that for just doomed 
    // files, we must allow reading the data.
    return mStatus;
  }

  // Once we open input stream we no longer allow preloading of chunks without
  // input stream, i.e. we will no longer keep first few chunks preloaded when
  // the last input stream is closed.
  mPreloadWithoutInputStreams = false;

  CacheFileInputStream *input = new CacheFileInputStream(this, aEntryHandle);

  LOG(("CacheFile::OpenInputStream() - Creating new input stream %p [this=%p]",
       input, this));

  mInputs.AppendElement(input);
  NS_ADDREF(input);

  mDataAccessed = true;
  NS_ADDREF(*_retval = input);
  return NS_OK;
}

nsresult
CacheFile::OpenOutputStream(CacheOutputCloseListener *aCloseListener, nsIOutputStream **_retval)
{
  CacheFileAutoLock lock(this);

  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);

  if (!mReady) {
    LOG(("CacheFile::OpenOutputStream() - CacheFile is not ready [this=%p]",
         this));

    return NS_ERROR_NOT_AVAILABLE;
  }

  if (mOutput) {
    LOG(("CacheFile::OpenOutputStream() - We already have output stream %p "
         "[this=%p]", mOutput, this));

    return NS_ERROR_NOT_AVAILABLE;
  }

  // Once we open output stream we no longer allow preloading of chunks without
  // input stream. There is no reason to believe that some input stream will be
  // opened soon. Otherwise we would cache unused chunks of all newly created
  // entries until the CacheFile is destroyed.
  mPreloadWithoutInputStreams = false;

  mOutput = new CacheFileOutputStream(this, aCloseListener);

  LOG(("CacheFile::OpenOutputStream() - Creating new output stream %p "
       "[this=%p]", mOutput, this));

  mDataAccessed = true;
  NS_ADDREF(*_retval = mOutput);
  return NS_OK;
}

nsresult
CacheFile::SetMemoryOnly()
{
  LOG(("CacheFile::SetMemoryOnly() mMemoryOnly=%d [this=%p]",
       mMemoryOnly, this));

  if (mMemoryOnly)
    return NS_OK;

  MOZ_ASSERT(mReady);

  if (!mReady) {
    LOG(("CacheFile::SetMemoryOnly() - CacheFile is not ready [this=%p]",
         this));

    return NS_ERROR_NOT_AVAILABLE;
  }

  if (mDataAccessed) {
    LOG(("CacheFile::SetMemoryOnly() - Data was already accessed [this=%p]", this));
    return NS_ERROR_NOT_AVAILABLE;
  }

  // TODO what to do when this isn't a new entry and has an existing metadata???
  mMemoryOnly = true;
  return NS_OK;
}

nsresult
CacheFile::Doom(CacheFileListener *aCallback)
{
  LOG(("CacheFile::Doom() [this=%p, listener=%p]", this, aCallback));

  CacheFileAutoLock lock(this);

  return DoomLocked(aCallback);
}

nsresult
CacheFile::DoomLocked(CacheFileListener *aCallback)
{
  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);

  LOG(("CacheFile::DoomLocked() [this=%p, listener=%p]", this, aCallback));

  nsresult rv = NS_OK;

  if (mMemoryOnly) {
    return NS_ERROR_FILE_NOT_FOUND;
  }

  if (mHandle && mHandle->IsDoomed()) {
    return NS_ERROR_FILE_NOT_FOUND;
  }

  nsCOMPtr<CacheFileIOListener> listener;
  if (aCallback || !mHandle) {
    listener = new DoomFileHelper(aCallback);
  }
  if (mHandle) {
    rv = CacheFileIOManager::DoomFile(mHandle, listener);
  } else if (mOpeningFile) {
    mDoomAfterOpenListener = listener;
  }

  return rv;
}

nsresult
CacheFile::ThrowMemoryCachedData()
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::ThrowMemoryCachedData() [this=%p]", this));

  if (mMemoryOnly) {
    // This method should not be called when the CacheFile was initialized as
    // memory-only, but it can be called when CacheFile end up as memory-only
    // due to e.g. IO failure since CacheEntry doesn't know it.
    LOG(("CacheFile::ThrowMemoryCachedData() - Ignoring request because the "
         "entry is memory-only. [this=%p]", this));

    return NS_ERROR_NOT_AVAILABLE;
  }

  if (mOpeningFile) {
    // mayhemer, note: we shouldn't get here, since CacheEntry prevents loading
    // entries from being purged.

    LOG(("CacheFile::ThrowMemoryCachedData() - Ignoring request because the "
         "entry is still opening the file [this=%p]", this));

    return NS_ERROR_ABORT;
  }

  // We cannot release all cached chunks since we need to keep preloaded chunks
  // in memory. See initialization of mPreloadChunkCount for explanation.
  CleanUpCachedChunks();

  return NS_OK;
}

nsresult
CacheFile::GetElement(const char *aKey, char **_retval)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  const char *value;
  value = mMetadata->GetElement(aKey);
  if (!value)
    return NS_ERROR_NOT_AVAILABLE;

  *_retval = NS_strdup(value);
  return NS_OK;
}

nsresult
CacheFile::SetElement(const char *aKey, const char *aValue)
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::SetElement() this=%p", this));

  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  PostWriteTimer();
  return mMetadata->SetElement(aKey, aValue);
}

nsresult
CacheFile::VisitMetaData(nsICacheEntryMetaDataVisitor *aVisitor)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  MOZ_ASSERT(mReady);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  return mMetadata->Visit(aVisitor);
}

nsresult
CacheFile::ElementsSize(uint32_t *_retval)
{
  CacheFileAutoLock lock(this);

  if (!mMetadata)
    return NS_ERROR_NOT_AVAILABLE;

  *_retval = mMetadata->ElementsSize();
  return NS_OK;
}

nsresult
CacheFile::SetExpirationTime(uint32_t aExpirationTime)
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::SetExpirationTime() this=%p, expiration=%u",
       this, aExpirationTime));

  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  PostWriteTimer();

  if (mHandle && !mHandle->IsDoomed())
    CacheFileIOManager::UpdateIndexEntry(mHandle, nullptr, &aExpirationTime);

  return mMetadata->SetExpirationTime(aExpirationTime);
}

nsresult
CacheFile::GetExpirationTime(uint32_t *_retval)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  return mMetadata->GetExpirationTime(_retval);
}

nsresult
CacheFile::SetFrecency(uint32_t aFrecency)
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::SetFrecency() this=%p, frecency=%u",
       this, aFrecency));

  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  PostWriteTimer();

  if (mHandle && !mHandle->IsDoomed())
    CacheFileIOManager::UpdateIndexEntry(mHandle, &aFrecency, nullptr);

  return mMetadata->SetFrecency(aFrecency);
}

nsresult
CacheFile::GetFrecency(uint32_t *_retval)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  return mMetadata->GetFrecency(_retval);
}

nsresult
CacheFile::GetLastModified(uint32_t *_retval)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  return mMetadata->GetLastModified(_retval);
}

nsresult
CacheFile::GetLastFetched(uint32_t *_retval)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  return mMetadata->GetLastFetched(_retval);
}

nsresult
CacheFile::GetFetchCount(uint32_t *_retval)
{
  CacheFileAutoLock lock(this);
  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  return mMetadata->GetFetchCount(_retval);
}

nsresult
CacheFile::OnFetched()
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::OnFetched() this=%p", this));

  MOZ_ASSERT(mMetadata);
  NS_ENSURE_TRUE(mMetadata, NS_ERROR_UNEXPECTED);

  PostWriteTimer();

  return mMetadata->OnFetched();
}

void
CacheFile::Lock()
{
  mLock.Lock();
}

void
CacheFile::Unlock()
{
  // move the elements out of mObjsToRelease
  // so that they can be released after we unlock
  nsTArray<RefPtr<nsISupports>> objs;
  objs.SwapElements(mObjsToRelease);

  mLock.Unlock();

}

void
CacheFile::AssertOwnsLock() const
{
  mLock.AssertCurrentThreadOwns();
}

void
CacheFile::ReleaseOutsideLock(RefPtr<nsISupports> aObject)
{
  AssertOwnsLock();

  mObjsToRelease.AppendElement(Move(aObject));
}

nsresult
CacheFile::GetChunk(uint32_t aIndex, ECallerType aCaller,
                    CacheFileChunkListener *aCallback, CacheFileChunk **_retval)
{
  CacheFileAutoLock lock(this);
  return GetChunkLocked(aIndex, aCaller, aCallback, _retval);
}

nsresult
CacheFile::GetChunkLocked(uint32_t aIndex, ECallerType aCaller,
                          CacheFileChunkListener *aCallback,
                          CacheFileChunk **_retval)
{
  AssertOwnsLock();

  LOG(("CacheFile::GetChunkLocked() [this=%p, idx=%u, caller=%d, listener=%p]",
       this, aIndex, aCaller, aCallback));

  MOZ_ASSERT(mReady);
  MOZ_ASSERT(mHandle || mMemoryOnly || mOpeningFile);
  MOZ_ASSERT((aCaller == READER && aCallback) ||
             (aCaller == WRITER && !aCallback) ||
             (aCaller == PRELOADER && !aCallback));

  // Preload chunks from disk when this is disk backed entry and the listener
  // is reader.
  bool preload = !mMemoryOnly && (aCaller == READER);

  nsresult rv;

  RefPtr<CacheFileChunk> chunk;
  if (mChunks.Get(aIndex, getter_AddRefs(chunk))) {
    LOG(("CacheFile::GetChunkLocked() - Found chunk %p in mChunks [this=%p]",
         chunk.get(), this));

    // Preloader calls this method to preload only non-loaded chunks.
    MOZ_ASSERT(aCaller != PRELOADER, "Unexpected!");

    // We might get failed chunk between releasing the lock in
    // CacheFileChunk::OnDataWritten/Read and CacheFile::OnChunkWritten/Read
    rv = chunk->GetStatus();
    if (NS_FAILED(rv)) {
      SetError(rv);
      LOG(("CacheFile::GetChunkLocked() - Found failed chunk in mChunks "
           "[this=%p]", this));
      return rv;
    }

    if (chunk->IsReady() || aCaller == WRITER) {
      chunk.swap(*_retval);
    } else {
      rv = QueueChunkListener(aIndex, aCallback);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    if (preload) {
      PreloadChunks(aIndex + 1);
    }

    return NS_OK;
  }

  if (mCachedChunks.Get(aIndex, getter_AddRefs(chunk))) {
    LOG(("CacheFile::GetChunkLocked() - Reusing cached chunk %p [this=%p]",
         chunk.get(), this));

    // Preloader calls this method to preload only non-loaded chunks.
    MOZ_ASSERT(aCaller != PRELOADER, "Unexpected!");

    mChunks.Put(aIndex, chunk);
    mCachedChunks.Remove(aIndex);
    chunk->mFile = this;
    chunk->mActiveChunk = true;

    MOZ_ASSERT(chunk->IsReady());

    chunk.swap(*_retval);

    if (preload) {
      PreloadChunks(aIndex + 1);
    }

    return NS_OK;
  }

  int64_t off = aIndex * static_cast<int64_t>(kChunkSize);

  if (off < mDataSize) {
    // We cannot be here if this is memory only entry since the chunk must exist
    MOZ_ASSERT(!mMemoryOnly);
    if (mMemoryOnly) {
      // If this ever really happen it is better to fail rather than crashing on
      // a null handle.
      LOG(("CacheFile::GetChunkLocked() - Unexpected state! Offset < mDataSize "
           "for memory-only entry. [this=%p, off=%lld, mDataSize=%lld]",
           this, off, mDataSize));

      return NS_ERROR_UNEXPECTED;
    }

    chunk = new CacheFileChunk(this, aIndex, aCaller == WRITER);
    mChunks.Put(aIndex, chunk);
    chunk->mActiveChunk = true;

    LOG(("CacheFile::GetChunkLocked() - Reading newly created chunk %p from "
         "the disk [this=%p]", chunk.get(), this));

    // Read the chunk from the disk
    rv = chunk->Read(mHandle, std::min(static_cast<uint32_t>(mDataSize - off),
                     static_cast<uint32_t>(kChunkSize)),
                     mMetadata->GetHash(aIndex), this);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      RemoveChunkInternal(chunk, false);
      return rv;
    }

    if (aCaller == WRITER) {
      chunk.swap(*_retval);
    } else if (aCaller != PRELOADER) {
      rv = QueueChunkListener(aIndex, aCallback);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    if (preload) {
      PreloadChunks(aIndex + 1);
    }

    return NS_OK;
  } else if (off == mDataSize) {
    if (aCaller == WRITER) {
      // this listener is going to write to the chunk
      chunk = new CacheFileChunk(this, aIndex, true);
      mChunks.Put(aIndex, chunk);
      chunk->mActiveChunk = true;

      LOG(("CacheFile::GetChunkLocked() - Created new empty chunk %p [this=%p]",
           chunk.get(), this));

      chunk->InitNew();
      mMetadata->SetHash(aIndex, chunk->Hash());

      if (HaveChunkListeners(aIndex)) {
        rv = NotifyChunkListeners(aIndex, NS_OK, chunk);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      chunk.swap(*_retval);
      return NS_OK;
    }
  } else {
    if (aCaller == WRITER) {
      // this chunk was requested by writer, but we need to fill the gap first

      // Fill with zero the last chunk if it is incomplete
      if (mDataSize % kChunkSize) {
        rv = PadChunkWithZeroes(mDataSize / kChunkSize);
        NS_ENSURE_SUCCESS(rv, rv);

        MOZ_ASSERT(!(mDataSize % kChunkSize));
      }

      uint32_t startChunk = mDataSize / kChunkSize;

      if (mMemoryOnly) {
        // We need to create all missing CacheFileChunks if this is memory-only
        // entry
        for (uint32_t i = startChunk ; i < aIndex ; i++) {
          rv = PadChunkWithZeroes(i);
          NS_ENSURE_SUCCESS(rv, rv);
        }
      } else {
        // We don't need to create CacheFileChunk for other empty chunks unless
        // there is some input stream waiting for this chunk.

        if (startChunk != aIndex) {
          // Make sure the file contains zeroes at the end of the file
          rv = CacheFileIOManager::TruncateSeekSetEOF(mHandle,
                                                      startChunk * kChunkSize,
                                                      aIndex * kChunkSize,
                                                      nullptr);
          NS_ENSURE_SUCCESS(rv, rv);
        }

        for (uint32_t i = startChunk ; i < aIndex ; i++) {
          if (HaveChunkListeners(i)) {
            rv = PadChunkWithZeroes(i);
            NS_ENSURE_SUCCESS(rv, rv);
          } else {
            mMetadata->SetHash(i, kEmptyChunkHash);
            mDataSize = (i + 1) * kChunkSize;
          }
        }
      }

      MOZ_ASSERT(mDataSize == off);
      rv = GetChunkLocked(aIndex, WRITER, nullptr, getter_AddRefs(chunk));
      NS_ENSURE_SUCCESS(rv, rv);

      chunk.swap(*_retval);
      return NS_OK;
    }
  }

  // We can be here only if the caller is reader since writer always create a
  // new chunk above and preloader calls this method to preload only chunks that
  // are not loaded but that do exist.
  MOZ_ASSERT(aCaller == READER, "Unexpected!");

  if (mOutput) {
    // the chunk doesn't exist but mOutput may create it
    rv = QueueChunkListener(aIndex, aCallback);
    NS_ENSURE_SUCCESS(rv, rv);
  } else {
    return NS_ERROR_NOT_AVAILABLE;
  }

  return NS_OK;
}

void
CacheFile::PreloadChunks(uint32_t aIndex)
{
  AssertOwnsLock();

  uint32_t limit = aIndex + mPreloadChunkCount;

  for (uint32_t i = aIndex; i < limit; ++i) {
    int64_t off = i * static_cast<int64_t>(kChunkSize);

    if (off >= mDataSize) {
      // This chunk is beyond EOF.
      return;
    }

    if (mChunks.GetWeak(i) || mCachedChunks.GetWeak(i)) {
      // This chunk is already in memory or is being read right now.
      continue;
    }

    LOG(("CacheFile::PreloadChunks() - Preloading chunk [this=%p, idx=%u]",
         this, i));

    RefPtr<CacheFileChunk> chunk;
    GetChunkLocked(i, PRELOADER, nullptr, getter_AddRefs(chunk));
    // We've checked that we don't have this chunk, so no chunk must be
    // returned.
    MOZ_ASSERT(!chunk);
  }
}

bool
CacheFile::ShouldCacheChunk(uint32_t aIndex)
{
  AssertOwnsLock();

#ifdef CACHE_CHUNKS
  // We cache all chunks.
  return true;
#else

  if (mPreloadChunkCount != 0 && mInputs.Length() == 0 &&
      mPreloadWithoutInputStreams && aIndex < mPreloadChunkCount) {
    // We don't have any input stream yet, but it is likely that some will be
    // opened soon. Keep first mPreloadChunkCount chunks in memory. The
    // condition is here instead of in MustKeepCachedChunk() since these
    // chunks should be preloaded and can be kept in memory as an optimization,
    // but they can be released at any time until they are considered as
    // preloaded chunks for any input stream.
    return true;
  }

  // Cache only chunks that we really need to keep.
  return MustKeepCachedChunk(aIndex);
#endif
}

bool
CacheFile::MustKeepCachedChunk(uint32_t aIndex)
{
  AssertOwnsLock();

  // We must keep the chunk when this is memory only entry or we don't have
  // a handle yet.
  if (mMemoryOnly || mOpeningFile) {
    return true;
  }

  if (mPreloadChunkCount == 0) {
    // Preloading of chunks is disabled
    return false;
  }

  // Check whether this chunk should be considered as preloaded chunk for any
  // existing input stream.

  // maxPos is the position of the last byte in the given chunk
  int64_t maxPos = static_cast<int64_t>(aIndex + 1) * kChunkSize - 1;

  // minPos is the position of the first byte in a chunk that precedes the given
  // chunk by mPreloadChunkCount chunks
  int64_t minPos;
  if (mPreloadChunkCount >= aIndex) {
    minPos = 0;
  } else {
    minPos = static_cast<int64_t>(aIndex - mPreloadChunkCount) * kChunkSize;
  }

  for (uint32_t i = 0; i < mInputs.Length(); ++i) {
    int64_t inputPos = mInputs[i]->GetPosition();
    if (inputPos >= minPos && inputPos <= maxPos) {
      return true;
    }
  }

  return false;
}

nsresult
CacheFile::DeactivateChunk(CacheFileChunk *aChunk)
{
  nsresult rv;

  // Avoid lock reentrancy by increasing the RefCnt
  RefPtr<CacheFileChunk> chunk = aChunk;

  {
    CacheFileAutoLock lock(this);

    LOG(("CacheFile::DeactivateChunk() [this=%p, chunk=%p, idx=%u]",
         this, aChunk, aChunk->Index()));

    MOZ_ASSERT(mReady);
    MOZ_ASSERT((mHandle && !mMemoryOnly && !mOpeningFile) ||
               (!mHandle && mMemoryOnly && !mOpeningFile) ||
               (!mHandle && !mMemoryOnly && mOpeningFile));

    if (aChunk->mRefCnt != 2) {
      LOG(("CacheFile::DeactivateChunk() - Chunk is still used [this=%p, "
           "chunk=%p, refcnt=%d]", this, aChunk, aChunk->mRefCnt.get()));

      // somebody got the reference before the lock was acquired
      return NS_OK;
    }

#ifdef DEBUG
    {
      // We can be here iff the chunk is in the hash table
      RefPtr<CacheFileChunk> chunkCheck;
      mChunks.Get(chunk->Index(), getter_AddRefs(chunkCheck));
      MOZ_ASSERT(chunkCheck == chunk);

      // We also shouldn't have any queued listener for this chunk
      ChunkListeners *listeners;
      mChunkListeners.Get(chunk->Index(), &listeners);
      MOZ_ASSERT(!listeners);
    }
#endif

    if (NS_FAILED(chunk->GetStatus())) {
      SetError(chunk->GetStatus());
    }

    if (NS_FAILED(mStatus)) {
      // Don't write any chunk to disk since this entry will be doomed
      LOG(("CacheFile::DeactivateChunk() - Releasing chunk because of status "
           "[this=%p, chunk=%p, mStatus=0x%08x]", this, chunk.get(), mStatus));

      RemoveChunkInternal(chunk, false);
      return mStatus;
    }

    if (chunk->IsDirty() && !mMemoryOnly && !mOpeningFile) {
      LOG(("CacheFile::DeactivateChunk() - Writing dirty chunk to the disk "
           "[this=%p]", this));

      mDataIsDirty = true;

      rv = chunk->Write(mHandle, this);
      if (NS_FAILED(rv)) {
        LOG(("CacheFile::DeactivateChunk() - CacheFileChunk::Write() failed "
             "synchronously. Removing it. [this=%p, chunk=%p, rv=0x%08x]",
             this, chunk.get(), rv));

        RemoveChunkInternal(chunk, false);

        SetError(rv);
        return rv;
      }

      // Chunk will be removed in OnChunkWritten if it is still unused

      // chunk needs to be released under the lock to be able to rely on
      // CacheFileChunk::mRefCnt in CacheFile::OnChunkWritten()
      chunk = nullptr;
      return NS_OK;
    }

    bool keepChunk = ShouldCacheChunk(aChunk->Index());
    LOG(("CacheFile::DeactivateChunk() - %s unused chunk [this=%p, chunk=%p]",
         keepChunk ? "Caching" : "Releasing", this, chunk.get()));

    RemoveChunkInternal(chunk, keepChunk);

    if (!mMemoryOnly)
      WriteMetadataIfNeededLocked();
  }

  return NS_OK;
}

void
CacheFile::RemoveChunkInternal(CacheFileChunk *aChunk, bool aCacheChunk)
{
  AssertOwnsLock();

  aChunk->mActiveChunk = false;
  ReleaseOutsideLock(RefPtr<CacheFileChunkListener>(aChunk->mFile.forget()).forget());

  if (aCacheChunk) {
    mCachedChunks.Put(aChunk->Index(), aChunk);
  }

  mChunks.Remove(aChunk->Index());
}

int64_t
CacheFile::BytesFromChunk(uint32_t aIndex)
{
  AssertOwnsLock();

  if (!mDataSize)
    return 0;

  // Index of the last existing chunk.
  uint32_t lastChunk = (mDataSize - 1) / kChunkSize;
  if (aIndex > lastChunk)
    return 0;

  // We can use only preloaded chunks for the given stream to calculate
  // available bytes if this is an entry stored on disk, since only those
  // chunks are guaranteed not to be released.
  uint32_t maxPreloadedChunk;
  if (mMemoryOnly) {
    maxPreloadedChunk = lastChunk;
  } else {
    maxPreloadedChunk = std::min(aIndex + mPreloadChunkCount, lastChunk);
  }

  uint32_t i;
  for (i = aIndex; i <= maxPreloadedChunk; ++i) {
    CacheFileChunk * chunk;

    chunk = mChunks.GetWeak(i);
    if (chunk) {
      MOZ_ASSERT(i == lastChunk || chunk->mDataSize == kChunkSize);
      if (chunk->IsReady()) {
        continue;
      }

      // don't search this chunk in cached
      break;
    }

    chunk = mCachedChunks.GetWeak(i);
    if (chunk) {
      MOZ_ASSERT(i == lastChunk || chunk->mDataSize == kChunkSize);
      continue;
    }

    break;
  }

  // theoretic bytes in advance
  int64_t advance = int64_t(i - aIndex) * kChunkSize;
  // real bytes till the end of the file
  int64_t tail = mDataSize - (aIndex * kChunkSize);

  return std::min(advance, tail);
}

static uint32_t
StatusToTelemetryEnum(nsresult aStatus)
{
  if (NS_SUCCEEDED(aStatus)) {
    return 0;
  }

  switch (aStatus) {
    case NS_BASE_STREAM_CLOSED:
      return 0; // Log this as a success
    case NS_ERROR_OUT_OF_MEMORY:
      return 2;
    case NS_ERROR_FILE_DISK_FULL:
      return 3;
    case NS_ERROR_FILE_CORRUPTED:
      return 4;
    case NS_ERROR_FILE_NOT_FOUND:
      return 5;
    case NS_BINDING_ABORTED:
      return 6;
    default:
      return 1; // other error
  }

  NS_NOTREACHED("We should never get here");
}

nsresult
CacheFile::RemoveInput(CacheFileInputStream *aInput, nsresult aStatus)
{
  CacheFileAutoLock lock(this);

  LOG(("CacheFile::RemoveInput() [this=%p, input=%p, status=0x%08x]", this,
       aInput, aStatus));

  DebugOnly<bool> found;
  found = mInputs.RemoveElement(aInput);
  MOZ_ASSERT(found);

  ReleaseOutsideLock(already_AddRefed<nsIInputStream>(static_cast<nsIInputStream*>(aInput)));

  if (!mMemoryOnly)
    WriteMetadataIfNeededLocked();

  // If the input didn't read all data, there might be left some preloaded
  // chunks that won't be used anymore.
  CleanUpCachedChunks();

  Telemetry::Accumulate(Telemetry::NETWORK_CACHE_V2_INPUT_STREAM_STATUS,
                        StatusToTelemetryEnum(aStatus));

  return NS_OK;
}

nsresult
CacheFile::RemoveOutput(CacheFileOutputStream *aOutput, nsresult aStatus)
{
  AssertOwnsLock();

  LOG(("CacheFile::RemoveOutput() [this=%p, output=%p, status=0x%08x]", this,
       aOutput, aStatus));

  if (mOutput != aOutput) {
    LOG(("CacheFile::RemoveOutput() - This output was already removed, ignoring"
         " call [this=%p]", this));
    return NS_OK;
  }

  mOutput = nullptr;

  // Cancel all queued chunk and update listeners that cannot be satisfied
  NotifyListenersAboutOutputRemoval();

  if (!mMemoryOnly)
    WriteMetadataIfNeededLocked();

  // Make sure the CacheFile status is set to a failure when the output stream
  // is closed with a fatal error.  This way we propagate correctly and w/o any
  // windows the failure state of this entry to end consumers.
  if (NS_SUCCEEDED(mStatus) && NS_FAILED(aStatus) && aStatus != NS_BASE_STREAM_CLOSED) {
    mStatus = aStatus;
  }

  // Notify close listener as the last action
  aOutput->NotifyCloseListener();

  Telemetry::Accumulate(Telemetry::NETWORK_CACHE_V2_OUTPUT_STREAM_STATUS,
                        StatusToTelemetryEnum(aStatus));

  return NS_OK;
}

nsresult
CacheFile::NotifyChunkListener(CacheFileChunkListener *aCallback,
                               nsIEventTarget *aTarget,
                               nsresult aResult,
                               uint32_t aChunkIdx,
                               CacheFileChunk *aChunk)
{
  LOG(("CacheFile::NotifyChunkListener() [this=%p, listener=%p, target=%p, "
       "rv=0x%08x, idx=%u, chunk=%p]", this, aCallback, aTarget, aResult,
       aChunkIdx, aChunk));

  nsresult rv;
  RefPtr<NotifyChunkListenerEvent> ev;
  ev = new NotifyChunkListenerEvent(aCallback, aResult, aChunkIdx, aChunk);
  if (aTarget)
    rv = aTarget->Dispatch(ev, NS_DISPATCH_NORMAL);
  else
    rv = NS_DispatchToCurrentThread(ev);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

nsresult
CacheFile::QueueChunkListener(uint32_t aIndex,
                              CacheFileChunkListener *aCallback)
{
  LOG(("CacheFile::QueueChunkListener() [this=%p, idx=%u, listener=%p]",
       this, aIndex, aCallback));

  AssertOwnsLock();

  MOZ_ASSERT(aCallback);

  ChunkListenerItem *item = new ChunkListenerItem();
  item->mTarget = CacheFileIOManager::IOTarget();
  if (!item->mTarget) {
    LOG(("CacheFile::QueueChunkListener() - Cannot get Cache I/O thread! Using "
         "main thread for callback."));
    item->mTarget = do_GetMainThread();
  }
  item->mCallback = aCallback;

  ChunkListeners *listeners;
  if (!mChunkListeners.Get(aIndex, &listeners)) {
    listeners = new ChunkListeners();
    mChunkListeners.Put(aIndex, listeners);
  }

  listeners->mItems.AppendElement(item);
  return NS_OK;
}

nsresult
CacheFile::NotifyChunkListeners(uint32_t aIndex, nsresult aResult,
                                CacheFileChunk *aChunk)
{
  LOG(("CacheFile::NotifyChunkListeners() [this=%p, idx=%u, rv=0x%08x, "
       "chunk=%p]", this, aIndex, aResult, aChunk));

  AssertOwnsLock();

  nsresult rv, rv2;

  ChunkListeners *listeners;
  mChunkListeners.Get(aIndex, &listeners);
  MOZ_ASSERT(listeners);

  rv = NS_OK;
  for (uint32_t i = 0 ; i < listeners->mItems.Length() ; i++) {
    ChunkListenerItem *item = listeners->mItems[i];
    rv2 = NotifyChunkListener(item->mCallback, item->mTarget, aResult, aIndex,
                              aChunk);
    if (NS_FAILED(rv2) && NS_SUCCEEDED(rv))
      rv = rv2;
    delete item;
  }

  mChunkListeners.Remove(aIndex);

  return rv;
}

bool
CacheFile::HaveChunkListeners(uint32_t aIndex)
{
  ChunkListeners *listeners;
  mChunkListeners.Get(aIndex, &listeners);
  return !!listeners;
}

void
CacheFile::NotifyListenersAboutOutputRemoval()
{
  LOG(("CacheFile::NotifyListenersAboutOutputRemoval() [this=%p]", this));

  AssertOwnsLock();

  // First fail all chunk listeners that wait for non-existent chunk
  for (auto iter = mChunkListeners.Iter(); !iter.Done(); iter.Next()) {
    uint32_t idx = iter.Key();
    nsAutoPtr<ChunkListeners>& listeners = iter.Data();

    LOG(("CacheFile::NotifyListenersAboutOutputRemoval() - fail "
         "[this=%p, idx=%u]", this, idx));

    RefPtr<CacheFileChunk> chunk;
    mChunks.Get(idx, getter_AddRefs(chunk));
    if (chunk) {
      MOZ_ASSERT(!chunk->IsReady());
      continue;
    }

    for (uint32_t i = 0 ; i < listeners->mItems.Length() ; i++) {
      ChunkListenerItem *item = listeners->mItems[i];
      NotifyChunkListener(item->mCallback, item->mTarget,
                          NS_ERROR_NOT_AVAILABLE, idx, nullptr);
      delete item;
    }

    iter.Remove();
  }

  // Fail all update listeners
  for (auto iter = mChunks.Iter(); !iter.Done(); iter.Next()) {
    const RefPtr<CacheFileChunk>& chunk = iter.Data();
    LOG(("CacheFile::NotifyListenersAboutOutputRemoval() - fail2 "
         "[this=%p, idx=%u]", this, iter.Key()));

    if (chunk->IsReady()) {
      chunk->NotifyUpdateListeners();
    }
  }
}

bool
CacheFile::DataSize(int64_t* aSize)
{
  CacheFileAutoLock lock(this);

  if (mOutput)
    return false;

  *aSize = mDataSize;
  return true;
}

bool
CacheFile::IsDoomed()
{
  CacheFileAutoLock lock(this);

  if (!mHandle)
    return false;

  return mHandle->IsDoomed();
}

bool
CacheFile::IsWriteInProgress()
{
  // Returns true when there is a potentially unfinished write operation.
  // Not using lock for performance reasons.  mMetadata is never released
  // during life time of CacheFile.

  bool result = false;

  if (!mMemoryOnly) {
    result = mDataIsDirty ||
             (mMetadata && mMetadata->IsDirty()) ||
             mWritingMetadata;
  }

  result = result ||
           mOpeningFile ||
           mOutput ||
           mChunks.Count();

  return result;
}

bool
CacheFile::IsDirty()
{
  return mDataIsDirty || mMetadata->IsDirty();
}

void
CacheFile::WriteMetadataIfNeeded()
{
  LOG(("CacheFile::WriteMetadataIfNeeded() [this=%p]", this));

  CacheFileAutoLock lock(this);

  if (!mMemoryOnly)
    WriteMetadataIfNeededLocked();
}

void
CacheFile::WriteMetadataIfNeededLocked(bool aFireAndForget)
{
  // When aFireAndForget is set to true, we are called from dtor.
  // |this| must not be referenced after this method returns!

  LOG(("CacheFile::WriteMetadataIfNeededLocked() [this=%p]", this));

  nsresult rv;

  AssertOwnsLock();
  MOZ_ASSERT(!mMemoryOnly);

  if (!mMetadata) {
    MOZ_CRASH("Must have metadata here");
    return;
  }

  if (NS_FAILED(mStatus))
    return;

  if (!IsDirty() || mOutput || mInputs.Length() || mChunks.Count() ||
      mWritingMetadata || mOpeningFile || mKill)
    return;

  if (!aFireAndForget) {
    // if aFireAndForget is set, we are called from dtor. Write
    // scheduler hard-refers CacheFile otherwise, so we cannot be here.
    CacheFileIOManager::UnscheduleMetadataWrite(this);
  }

  LOG(("CacheFile::WriteMetadataIfNeededLocked() - Writing metadata [this=%p]",
       this));

  rv = mMetadata->WriteMetadata(mDataSize, aFireAndForget ? nullptr : this);
  if (NS_SUCCEEDED(rv)) {
    mWritingMetadata = true;
    mDataIsDirty = false;
  } else {
    LOG(("CacheFile::WriteMetadataIfNeededLocked() - Writing synchronously "
         "failed [this=%p]", this));
    // TODO: close streams with error
    SetError(rv);
  }
}

void
CacheFile::PostWriteTimer()
{
  if (mMemoryOnly)
    return;

  LOG(("CacheFile::PostWriteTimer() [this=%p]", this));

  CacheFileIOManager::ScheduleMetadataWrite(this);
}

void
CacheFile::CleanUpCachedChunks()
{
  for (auto iter = mCachedChunks.Iter(); !iter.Done(); iter.Next()) {
    uint32_t idx = iter.Key();
    const RefPtr<CacheFileChunk>& chunk = iter.Data();

    LOG(("CacheFile::CleanUpCachedChunks() [this=%p, idx=%u, chunk=%p]", this,
         idx, chunk.get()));

    if (MustKeepCachedChunk(idx)) {
      LOG(("CacheFile::CleanUpCachedChunks() - Keeping chunk"));
      continue;
    }

    LOG(("CacheFile::CleanUpCachedChunks() - Removing chunk"));
    iter.Remove();
  }
}

nsresult
CacheFile::PadChunkWithZeroes(uint32_t aChunkIdx)
{
  AssertOwnsLock();

  // This method is used to pad last incomplete chunk with zeroes or create
  // a new chunk full of zeroes
  MOZ_ASSERT(mDataSize / kChunkSize == aChunkIdx);

  nsresult rv;
  RefPtr<CacheFileChunk> chunk;
  rv = GetChunkLocked(aChunkIdx, WRITER, nullptr, getter_AddRefs(chunk));
  NS_ENSURE_SUCCESS(rv, rv);

  LOG(("CacheFile::PadChunkWithZeroes() - Zeroing hole in chunk %d, range %d-%d"
       " [this=%p]", aChunkIdx, chunk->DataSize(), kChunkSize - 1, this));

  rv = chunk->EnsureBufSize(kChunkSize);
  if (NS_FAILED(rv)) {
    ReleaseOutsideLock(chunk.forget());
    SetError(rv);
    return rv;
  }
  memset(chunk->BufForWriting() + chunk->DataSize(), 0, kChunkSize - chunk->DataSize());

  chunk->UpdateDataSize(chunk->DataSize(), kChunkSize - chunk->DataSize(),
                        false);

  ReleaseOutsideLock(chunk.forget());

  return NS_OK;
}

void
CacheFile::SetError(nsresult aStatus)
{
  AssertOwnsLock();

  if (NS_SUCCEEDED(mStatus)) {
    mStatus = aStatus;
    if (mHandle) {
      CacheFileIOManager::DoomFile(mHandle, nullptr);
    }
  }
}

nsresult
CacheFile::InitIndexEntry()
{
  MOZ_ASSERT(mHandle);

  if (mHandle->IsDoomed())
    return NS_OK;

  nsresult rv;

  // Bug 1201042 - will pass OriginAttributes directly.
  rv = CacheFileIOManager::InitIndexEntry(mHandle,
                                          mMetadata->OriginAttributes().mAppId,
                                          mMetadata->IsAnonymous(),
                                          mMetadata->OriginAttributes().mInIsolatedMozBrowser,
                                          mPinned);
  NS_ENSURE_SUCCESS(rv, rv);

  uint32_t expTime;
  mMetadata->GetExpirationTime(&expTime);

  uint32_t frecency;
  mMetadata->GetFrecency(&frecency);

  rv = CacheFileIOManager::UpdateIndexEntry(mHandle, &frecency, &expTime);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

size_t
CacheFile::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
{
  CacheFileAutoLock lock(const_cast<CacheFile*>(this));

  size_t n = 0;
  n += mKey.SizeOfExcludingThisIfUnshared(mallocSizeOf);
  n += mChunks.ShallowSizeOfExcludingThis(mallocSizeOf);
  for (auto iter = mChunks.ConstIter(); !iter.Done(); iter.Next()) {
      n += iter.Data()->SizeOfIncludingThis(mallocSizeOf);
  }
  n += mCachedChunks.ShallowSizeOfExcludingThis(mallocSizeOf);
  for (auto iter = mCachedChunks.ConstIter(); !iter.Done(); iter.Next()) {
      n += iter.Data()->SizeOfIncludingThis(mallocSizeOf);
  }
  if (mMetadata) {
    n += mMetadata->SizeOfIncludingThis(mallocSizeOf);
  }

  // Input streams are not elsewhere reported.
  n += mInputs.ShallowSizeOfExcludingThis(mallocSizeOf);
  for (uint32_t i = 0; i < mInputs.Length(); ++i) {
    n += mInputs[i]->SizeOfIncludingThis(mallocSizeOf);
  }

  // Output streams are not elsewhere reported.
  if (mOutput) {
    n += mOutput->SizeOfIncludingThis(mallocSizeOf);
  }

  // The listeners are usually classes reported just above.
  n += mChunkListeners.ShallowSizeOfExcludingThis(mallocSizeOf);
  n += mObjsToRelease.ShallowSizeOfExcludingThis(mallocSizeOf);

  // mHandle reported directly from CacheFileIOManager.

  return n;
}

size_t
CacheFile::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
{
  return mallocSizeOf(this) + SizeOfExcludingThis(mallocSizeOf);
}

} // namespace net
} // namespace mozilla
