/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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 "TemporaryFileBlobImpl.h"

#include "IPCBlobInputStreamThread.h"

#include "nsFileStreams.h"

#include "nsIFile.h"

#include "nsIFileStreams.h"

#include "nsNetUtil.h"

#include "nsThreadUtils.h"

#include "nsXULAppAPI.h"

using namespace mozilla::ipc;

namespace mozilla {

namespace dom {

namespace {

// Here the flags needed in order to keep the temporary file opened.

// 1. REOPEN_ON_REWIND -> otherwise the stream is not serializable more than

//                        once.

// 2. no DEFER_OPEN -> the file must be kept open on windows in order to be

//                     deleted when used.

// 3. no CLOSE_ON_EOF -> the file will be closed by the DTOR. No needs. Also

//                       because the inputStream will not be read directly.

// 4. no SHARE_DELETE -> We don't want to allow this file to be deleted.

const uint32_t sTemporaryFileStreamFlags =

  nsIFileInputStream::REOPEN_ON_REWIND;

class TemporaryFileInputStream final : public nsFileInputStream

{

public:

  static nsresult

  Create(nsIFile* aFile, nsIInputStream** aInputStream)

  {

    MOZ_ASSERT(aFile);

    MOZ_ASSERT(aInputStream);

    MOZ_ASSERT(XRE_IsParentProcess());

    RefPtr<TemporaryFileInputStream> stream =

      new TemporaryFileInputStream(aFile);

    nsresult rv = stream->Init(aFile, -1, -1, sTemporaryFileStreamFlags);

    if (NS_WARN_IF(NS_FAILED(rv))) {

      return rv;

    }

    stream.forget(aInputStream);

    return NS_OK;

  }

  void

  Serialize(InputStreamParams& aParams,

            FileDescriptorArray& aFileDescriptors) override

  {

    MOZ_CRASH("This inputStream cannot be serialized.");

  }

  bool

  Deserialize(const InputStreamParams& aParams,

              const FileDescriptorArray& aFileDescriptors) override

  {

    MOZ_CRASH("This inputStream cannot be deserialized.");

    return false;

  }

private:

  explicit TemporaryFileInputStream(nsIFile* aFile)

    : mFile(aFile)

  {

    MOZ_ASSERT(XRE_IsParentProcess());

  }

  ~TemporaryFileInputStream()

  {

    // Let's delete the file on the IPCBlob Thread.

    RefPtr<IPCBlobInputStreamThread> thread =

      IPCBlobInputStreamThread::GetOrCreate();

    if (NS_WARN_IF(!thread)) {

      return;

    }

    nsCOMPtr<nsIFile> file = std::move(mFile);

    thread->Dispatch(NS_NewRunnableFunction(

      "TemporaryFileInputStream::Runnable",

      [file]() {

        file->Remove(false);

      }

    ));

  }

  nsCOMPtr<nsIFile> mFile;

};

} // anonymous

TemporaryFileBlobImpl::TemporaryFileBlobImpl(nsIFile* aFile,

                                             const nsAString& aContentType)

  : FileBlobImpl(aFile, EmptyString(), aContentType)

#ifdef DEBUG

  , mInputStreamCreated(false)

#endif

{

  MOZ_ASSERT(XRE_IsParentProcess());

}

TemporaryFileBlobImpl::~TemporaryFileBlobImpl()

{

  MOZ_ASSERT(mInputStreamCreated);

}

already_AddRefed<BlobImpl>

TemporaryFileBlobImpl::CreateSlice(uint64_t aStart, uint64_t aLength,

                                   const nsAString& aContentType,

                                   ErrorResult& aRv)

{

  MOZ_CRASH("This BlobImpl is not meant to be sliced!");

  return nullptr;

}

void

TemporaryFileBlobImpl::CreateInputStream(nsIInputStream** aStream, ErrorResult& aRv)

{

#ifdef DEBUG

  MOZ_ASSERT(!mInputStreamCreated);

  // CreateInputStream can be called only once.

  mInputStreamCreated = true;

#endif

  aRv = TemporaryFileInputStream::Create(mFile, aStream);

  if (NS_WARN_IF(aRv.Failed())) {

    return;

  }

}

} // namespace dom

} // namespace mozilla