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

/* 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 "MemoryDownloader.h"

#include "mozilla/Assertions.h"

#include "nsIInputStream.h"

namespace mozilla {

namespace net {

NS_IMPL_ISUPPORTS(MemoryDownloader,

      nsIStreamListener,

      nsIRequestObserver)

MemoryDownloader::MemoryDownloader(IObserver* aObserver)

: mObserver(aObserver)

, mStatus(NS_ERROR_NOT_INITIALIZED)

{

}

NS_IMETHODIMP

MemoryDownloader::OnStartRequest(nsIRequest* aRequest, nsISupports* aCtxt)

{

  MOZ_ASSERT(!mData);

  mData.reset(new FallibleTArray<uint8_t>());

  mStatus = NS_OK;

  return NS_OK;

}

NS_IMETHODIMP

MemoryDownloader::OnStopRequest(nsIRequest* aRequest,

                                nsISupports* aCtxt,

                                nsresult aStatus)

{

  MOZ_ASSERT_IF(NS_FAILED(mStatus), NS_FAILED(aStatus));

  MOZ_ASSERT(!mData == NS_FAILED(mStatus));

  Data data;

  data.swap(mData);

  RefPtr<IObserver> observer;

  observer.swap(mObserver);

  observer->OnDownloadComplete(this, aRequest, aCtxt, aStatus,

                               std::move(data));

  return NS_OK;

}

nsresult

MemoryDownloader::ConsumeData(nsIInputStream* aIn,

                              void* aClosure,

                              const char* aFromRawSegment,

                              uint32_t aToOffset,

                              uint32_t aCount,

                              uint32_t* aWriteCount)

{

  MemoryDownloader* self = static_cast<MemoryDownloader*>(aClosure);

  if (!self->mData->AppendElements(aFromRawSegment, aCount, fallible)) {

    // The error returned by ConsumeData isn't propagated to the

    // return of ReadSegments, so it has to be passed as state.

    self->mStatus = NS_ERROR_OUT_OF_MEMORY;

    return NS_ERROR_OUT_OF_MEMORY;

  }

  *aWriteCount = aCount;

  return NS_OK;

}

NS_IMETHODIMP

MemoryDownloader::OnDataAvailable(nsIRequest* aRequest,

                                  nsISupports* aCtxt,

                                  nsIInputStream* aInStr,

                                  uint64_t aSourceOffset,

                                  uint32_t aCount)

{

  uint32_t n;

  MOZ_ASSERT(mData);

  nsresult rv = aInStr->ReadSegments(ConsumeData, this, aCount, &n);

  if (NS_SUCCEEDED(mStatus) && NS_FAILED(rv)) {

    mStatus = rv;

  }

  if (NS_WARN_IF(NS_FAILED(mStatus))) {

    mData.reset(nullptr);

    return mStatus;

  }

  return NS_OK;

}

} // namespace net

} // namespace mozilla