netwerk/base/nsBufferedStreams.cpp
author Dorel Luca <dluca@mozilla.com>
Thu, 15 Aug 2019 01:04:46 +0300
changeset 488131 3cf55b7f12f2cb7dfcdbcbcd817d77e298e76fbd
parent 488060 3449c2eba4c6b196fc3f0be090a5aa48058b8173
child 488294 f9e8d4068c06c1339efddad1d558e32a87f8ead6
permissions -rw-r--r--
Backed out 22 changesets (bug 1231213) for Browser-chrome failures on /workers/remoteworkers/RemoteWorkerChild.cpp Backed out changeset 7e09ad9ceea6 (bug 1231213) Backed out changeset a275eb0b1a19 (bug 1231213) Backed out changeset 906b80778539 (bug 1231213) Backed out changeset 6a40ab6852cb (bug 1231213) Backed out changeset 216591953f97 (bug 1231213) Backed out changeset 1de357bc1921 (bug 1231213) Backed out changeset 8e3fedf6502a (bug 1231213) Backed out changeset 1b9a8b022fce (bug 1231213) Backed out changeset 85df1959eb98 (bug 1231213) Backed out changeset 666bf4260046 (bug 1231213) Backed out changeset 0b03a19a6dc1 (bug 1231213) Backed out changeset 11f010e6d6e7 (bug 1231213) Backed out changeset 6ed55807374f (bug 1231213) Backed out changeset 395062aef2ec (bug 1231213) Backed out changeset bacf8499ba7b (bug 1231213) Backed out changeset bf5d60c7a85a (bug 1231213) Backed out changeset cd434b787ce6 (bug 1231213) Backed out changeset ee4565104217 (bug 1231213) Backed out changeset 581653ef33dd (bug 1231213) Backed out changeset 2d5628a0e52d (bug 1231213) Backed out changeset 3449c2eba4c6 (bug 1231213) Backed out changeset ae221b628899 (bug 1231213)

/* -*- Mode: C++; tab-width: 2; 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 "ipc/IPCMessageUtils.h"

#include "nsBufferedStreams.h"
#include "nsStreamUtils.h"
#include "nsNetCID.h"
#include "nsIClassInfoImpl.h"
#include "mozilla/ipc/InputStreamUtils.h"
#include <algorithm>

#ifdef DEBUG_brendan
#  define METERING
#endif

#ifdef METERING
#  include <stdio.h>
#  define METER(x) x
#  define MAX_BIG_SEEKS 20

static struct {
  uint32_t mSeeksWithinBuffer;
  uint32_t mSeeksOutsideBuffer;
  uint32_t mBufferReadUponSeek;
  uint32_t mBufferUnreadUponSeek;
  uint32_t mBytesReadFromBuffer;
  uint32_t mBigSeekIndex;
  struct {
    int64_t mOldOffset;
    int64_t mNewOffset;
  } mBigSeek[MAX_BIG_SEEKS];
} bufstats;
#else
#  define METER(x) /* nothing */
#endif

using namespace mozilla::ipc;
using mozilla::Maybe;
using mozilla::MutexAutoLock;
using mozilla::Nothing;
using mozilla::Some;

////////////////////////////////////////////////////////////////////////////////
// nsBufferedStream

nsBufferedStream::nsBufferedStream()
    : mBufferSize(0),
      mBuffer(nullptr),
      mBufferStartOffset(0),
      mCursor(0),
      mFillPoint(0),
      mStream(nullptr),
      mBufferDisabled(false),
      mEOF(false),
      mGetBufferCount(0) {}

nsBufferedStream::~nsBufferedStream() { Close(); }

NS_IMPL_ISUPPORTS(nsBufferedStream, nsITellableStream, nsISeekableStream)

nsresult nsBufferedStream::Init(nsISupports* aStream, uint32_t bufferSize) {
  NS_ASSERTION(aStream, "need to supply a stream");
  NS_ASSERTION(mStream == nullptr, "already inited");
  mStream = aStream;  // we keep a reference until nsBufferedStream::Close
  mBufferSize = bufferSize;
  mBufferStartOffset = 0;
  mCursor = 0;
  mBuffer = new (mozilla::fallible) char[bufferSize];
  if (mBuffer == nullptr) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  return NS_OK;
}

nsresult nsBufferedStream::Close() {
  // Drop the reference from nsBufferedStream::Init()
  mStream = nullptr;
  if (mBuffer) {
    delete[] mBuffer;
    mBuffer = nullptr;
    mBufferSize = 0;
    mBufferStartOffset = 0;
    mCursor = 0;
    mFillPoint = 0;
  }
#ifdef METERING
  {
    static FILE* tfp;
    if (!tfp) {
      tfp = fopen("/tmp/bufstats", "w");
      if (tfp) {
        setvbuf(tfp, nullptr, _IOLBF, 0);
      }
    }
    if (tfp) {
      fprintf(tfp, "seeks within buffer:    %u\n", bufstats.mSeeksWithinBuffer);
      fprintf(tfp, "seeks outside buffer:   %u\n",
              bufstats.mSeeksOutsideBuffer);
      fprintf(tfp, "buffer read on seek:    %u\n",
              bufstats.mBufferReadUponSeek);
      fprintf(tfp, "buffer unread on seek:  %u\n",
              bufstats.mBufferUnreadUponSeek);
      fprintf(tfp, "bytes read from buffer: %u\n",
              bufstats.mBytesReadFromBuffer);
      for (uint32_t i = 0; i < bufstats.mBigSeekIndex; i++) {
        fprintf(tfp, "bigseek[%u] = {old: %u, new: %u}\n", i,
                bufstats.mBigSeek[i].mOldOffset,
                bufstats.mBigSeek[i].mNewOffset);
      }
    }
  }
#endif
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedStream::Seek(int32_t whence, int64_t offset) {
  if (mStream == nullptr) {
    return NS_BASE_STREAM_CLOSED;
  }

  // If the underlying stream isn't a random access store, then fail early.
  // We could possibly succeed for the case where the seek position denotes
  // something that happens to be read into the buffer, but that would make
  // the failure data-dependent.
  nsresult rv;
  nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv);
  if (NS_FAILED(rv)) {
#ifdef DEBUG
    NS_WARNING("mStream doesn't QI to nsISeekableStream");
#endif
    return rv;
  }

  int64_t absPos = 0;
  switch (whence) {
    case nsISeekableStream::NS_SEEK_SET:
      absPos = offset;
      break;
    case nsISeekableStream::NS_SEEK_CUR:
      absPos = mBufferStartOffset;
      absPos += mCursor;
      absPos += offset;
      break;
    case nsISeekableStream::NS_SEEK_END:
      absPos = -1;
      break;
    default:
      MOZ_ASSERT_UNREACHABLE("bogus seek whence parameter");
      return NS_ERROR_UNEXPECTED;
  }

  // Let mCursor point into the existing buffer if the new position is
  // between the current cursor and the mFillPoint "fencepost" -- the
  // client may never get around to a Read or Write after this Seek.
  // Read and Write worry about flushing and filling in that event.
  // But if we're at EOF, make sure to pass the seek through to the
  // underlying stream, because it may have auto-closed itself and
  // needs to reopen.
  uint32_t offsetInBuffer = uint32_t(absPos - mBufferStartOffset);
  if (offsetInBuffer <= mFillPoint && !mEOF) {
    METER(bufstats.mSeeksWithinBuffer++);
    mCursor = offsetInBuffer;
    return NS_OK;
  }

  METER(bufstats.mSeeksOutsideBuffer++);
  METER(bufstats.mBufferReadUponSeek += mCursor);
  METER(bufstats.mBufferUnreadUponSeek += mFillPoint - mCursor);
  rv = Flush();
  if (NS_FAILED(rv)) {
#ifdef DEBUG
    NS_WARNING(
        "(debug) Flush returned error within nsBufferedStream::Seek, so we "
        "exit early.");
#endif
    return rv;
  }

  rv = ras->Seek(whence, offset);
  if (NS_FAILED(rv)) {
#ifdef DEBUG
    NS_WARNING(
        "(debug) Error: ras->Seek() returned error within "
        "nsBufferedStream::Seek, so we exit early.");
#endif
    return rv;
  }

  mEOF = false;

  // Recompute whether the offset we're seeking to is in our buffer.
  // Note that we need to recompute because Flush() might have
  // changed mBufferStartOffset.
  offsetInBuffer = uint32_t(absPos - mBufferStartOffset);
  if (offsetInBuffer <= mFillPoint) {
    // It's safe to just set mCursor to offsetInBuffer.  In particular, we
    // want to avoid calling Fill() here since we already have the data that
    // was seeked to and calling Fill() might auto-close our underlying
    // stream in some cases.
    mCursor = offsetInBuffer;
    return NS_OK;
  }

  METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS)
            bufstats.mBigSeek[bufstats.mBigSeekIndex]
                .mOldOffset = mBufferStartOffset + int64_t(mCursor));
  const int64_t minus1 = -1;
  if (absPos == minus1) {
    // then we had the SEEK_END case, above
    int64_t tellPos;
    rv = ras->Tell(&tellPos);
    mBufferStartOffset = tellPos;
    if (NS_FAILED(rv)) {
      return rv;
    }
  } else {
    mBufferStartOffset = absPos;
  }
  METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS)
            bufstats.mBigSeek[bufstats.mBigSeekIndex++]
                .mNewOffset = mBufferStartOffset);

  mFillPoint = mCursor = 0;
  return Fill();
}

NS_IMETHODIMP
nsBufferedStream::Tell(int64_t* result) {
  if (mStream == nullptr) {
    return NS_BASE_STREAM_CLOSED;
  }

  int64_t result64 = mBufferStartOffset;
  result64 += mCursor;
  *result = result64;
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedStream::SetEOF() {
  if (mStream == nullptr) {
    return NS_BASE_STREAM_CLOSED;
  }

  nsresult rv;
  nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv);
  if (NS_FAILED(rv)) {
    return rv;
  }

  rv = ras->SetEOF();
  if (NS_SUCCEEDED(rv)) {
    mEOF = true;
  }

  return rv;
}

nsresult nsBufferedStream::GetData(nsISupports** aResult) {
  nsCOMPtr<nsISupports> stream(mStream);
  stream.forget(aResult);
  return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////
// nsBufferedInputStream

NS_IMPL_ADDREF_INHERITED(nsBufferedInputStream, nsBufferedStream)
NS_IMPL_RELEASE_INHERITED(nsBufferedInputStream, nsBufferedStream)

NS_IMPL_CLASSINFO(nsBufferedInputStream, nullptr, nsIClassInfo::THREADSAFE,
                  NS_BUFFEREDINPUTSTREAM_CID)

NS_INTERFACE_MAP_BEGIN(nsBufferedInputStream)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsIInputStream, nsIBufferedInputStream)
  NS_INTERFACE_MAP_ENTRY(nsIBufferedInputStream)
  NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIIPCSerializableInputStream,
                                     mIsIPCSerializable)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mIsAsyncInputStream)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamCallback,
                                     mIsAsyncInputStream)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream,
                                     mIsCloneableInputStream)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLength, mIsInputStreamLength)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStreamLength,
                                     mIsAsyncInputStreamLength)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLengthCallback,
                                     mIsAsyncInputStreamLength)
  NS_IMPL_QUERY_CLASSINFO(nsBufferedInputStream)
NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream)

NS_IMPL_CI_INTERFACE_GETTER(nsBufferedInputStream, nsIInputStream,
                            nsIBufferedInputStream, nsISeekableStream,
                            nsITellableStream, nsIStreamBufferAccess)

nsBufferedInputStream::nsBufferedInputStream()
    : nsBufferedStream(),
      mMutex("nsBufferedInputStream::mMutex"),
      mIsIPCSerializable(true),
      mIsAsyncInputStream(false),
      mIsCloneableInputStream(false),
      mIsInputStreamLength(false),
      mIsAsyncInputStreamLength(false) {}

nsresult nsBufferedInputStream::Create(nsISupports* aOuter, REFNSIID aIID,
                                       void** aResult) {
  NS_ENSURE_NO_AGGREGATION(aOuter);

  RefPtr<nsBufferedInputStream> stream = new nsBufferedInputStream();
  return stream->QueryInterface(aIID, aResult);
}

NS_IMETHODIMP
nsBufferedInputStream::Init(nsIInputStream* stream, uint32_t bufferSize) {
  nsresult rv = nsBufferedStream::Init(stream, bufferSize);
  NS_ENSURE_SUCCESS(rv, rv);

  {
    nsCOMPtr<nsIIPCSerializableInputStream> stream = do_QueryInterface(mStream);
    mIsIPCSerializable = !!stream;
  }

  {
    nsCOMPtr<nsIAsyncInputStream> stream = do_QueryInterface(mStream);
    mIsAsyncInputStream = !!stream;
  }

  {
    nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
    mIsCloneableInputStream = !!stream;
  }

  {
    nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream);
    mIsInputStreamLength = !!stream;
  }

  {
    nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream);
    mIsAsyncInputStreamLength = !!stream;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsBufferedInputStream::Close() {
  nsresult rv1 = NS_OK, rv2;
  if (mStream) {
    rv1 = Source()->Close();
#ifdef DEBUG
    if (NS_FAILED(rv1)) {
      NS_WARNING(
          "(debug) Error: Source()->Close() returned error (rv1) in "
          "bsBuffedInputStream::Close().");
    };
#endif
  }

  rv2 = nsBufferedStream::Close();

#ifdef DEBUG
  if (NS_FAILED(rv2)) {
    NS_WARNING(
        "(debug) Error: nsBufferedStream::Close() returned error (rv2) within "
        "nsBufferedInputStream::Close().");
  };
#endif

  if (NS_FAILED(rv1)) {
    return rv1;
  }
  return rv2;
}

NS_IMETHODIMP
nsBufferedInputStream::Available(uint64_t* result) {
  *result = 0;

  if (!mStream) {
    return NS_OK;
  }

  uint64_t avail = mFillPoint - mCursor;

  uint64_t tmp;
  nsresult rv = Source()->Available(&tmp);
  if (NS_SUCCEEDED(rv)) {
    avail += tmp;
  }

  if (avail) {
    *result = avail;
    return NS_OK;
  }

  return rv;
}

NS_IMETHODIMP
nsBufferedInputStream::Read(char* buf, uint32_t count, uint32_t* result) {
  if (mBufferDisabled) {
    if (!mStream) {
      *result = 0;
      return NS_OK;
    }
    nsresult rv = Source()->Read(buf, count, result);
    if (NS_SUCCEEDED(rv)) {
      mBufferStartOffset += *result;  // so nsBufferedStream::Tell works
      if (*result == 0) {
        mEOF = true;
      }
    }
    return rv;
  }

  return ReadSegments(NS_CopySegmentToBuffer, buf, count, result);
}

NS_IMETHODIMP
nsBufferedInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure,
                                    uint32_t count, uint32_t* result) {
  *result = 0;

  if (!mStream) {
    return NS_OK;
  }

  nsresult rv = NS_OK;
  while (count > 0) {
    uint32_t amt = std::min(count, mFillPoint - mCursor);
    if (amt > 0) {
      uint32_t read = 0;
      rv = writer(static_cast<nsIBufferedInputStream*>(this), closure,
                  mBuffer + mCursor, *result, amt, &read);
      if (NS_FAILED(rv)) {
        // errors returned from the writer end here!
        rv = NS_OK;
        break;
      }
      *result += read;
      count -= read;
      mCursor += read;
    } else {
      rv = Fill();
      if (NS_FAILED(rv) || mFillPoint == mCursor) {
        break;
      }
    }
  }
  return (*result > 0) ? NS_OK : rv;
}

NS_IMETHODIMP
nsBufferedInputStream::IsNonBlocking(bool* aNonBlocking) {
  if (mStream) {
    return Source()->IsNonBlocking(aNonBlocking);
  }
  return NS_ERROR_NOT_INITIALIZED;
}

NS_IMETHODIMP
nsBufferedInputStream::Fill() {
  if (mBufferDisabled) {
    return NS_OK;
  }
  NS_ENSURE_TRUE(mStream, NS_ERROR_NOT_INITIALIZED);

  nsresult rv;
  int32_t rem = int32_t(mFillPoint - mCursor);
  if (rem > 0) {
    // slide the remainder down to the start of the buffer
    // |<------------->|<--rem-->|<--->|
    // b               c         f     s
    memcpy(mBuffer, mBuffer + mCursor, rem);
  }
  mBufferStartOffset += mCursor;
  mFillPoint = rem;
  mCursor = 0;

  uint32_t amt;
  rv = Source()->Read(mBuffer + mFillPoint, mBufferSize - mFillPoint, &amt);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (amt == 0) {
    mEOF = true;
  }

  mFillPoint += amt;
  return NS_OK;
}

NS_IMETHODIMP_(char*)
nsBufferedInputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask) {
  NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!");
  if (mGetBufferCount != 0) {
    return nullptr;
  }

  if (mBufferDisabled) {
    return nullptr;
  }

  char* buf = mBuffer + mCursor;
  uint32_t rem = mFillPoint - mCursor;
  if (rem == 0) {
    if (NS_FAILED(Fill())) {
      return nullptr;
    }
    buf = mBuffer + mCursor;
    rem = mFillPoint - mCursor;
  }

  uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask);
  if (mod) {
    uint32_t pad = aAlignMask + 1 - mod;
    if (pad > rem) {
      return nullptr;
    }

    memset(buf, 0, pad);
    mCursor += pad;
    buf += pad;
    rem -= pad;
  }

  if (aLength > rem) {
    return nullptr;
  }
  mGetBufferCount++;
  return buf;
}

NS_IMETHODIMP_(void)
nsBufferedInputStream::PutBuffer(char* aBuffer, uint32_t aLength) {
  NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!");
  if (--mGetBufferCount != 0) {
    return;
  }

  NS_ASSERTION(mCursor + aLength <= mFillPoint, "PutBuffer botch");
  mCursor += aLength;
}

NS_IMETHODIMP
nsBufferedInputStream::DisableBuffering() {
  NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!");
  NS_ASSERTION(mGetBufferCount == 0,
               "DisableBuffer call between GetBuffer and PutBuffer!");
  if (mGetBufferCount != 0) {
    return NS_ERROR_UNEXPECTED;
  }

  // Empty the buffer so nsBufferedStream::Tell works.
  mBufferStartOffset += mCursor;
  mFillPoint = mCursor = 0;
  mBufferDisabled = true;
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedInputStream::EnableBuffering() {
  NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!");
  mBufferDisabled = false;
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedInputStream::GetUnbufferedStream(nsISupports** aStream) {
  // Empty the buffer so subsequent i/o trumps any buffered data.
  mBufferStartOffset += mCursor;
  mFillPoint = mCursor = 0;

  nsCOMPtr<nsISupports> stream = mStream;
  stream.forget(aStream);
  return NS_OK;
}

void nsBufferedInputStream::Serialize(InputStreamParams& aParams,
                                      FileDescriptorArray& aFileDescriptors,
                                      bool aDelayedStart, uint32_t aMaxSize,
                                      uint32_t* aSizeUsed,
                                      mozilla::dom::ContentChild* aManager) {
  SerializeInternal(aParams, aFileDescriptors, aDelayedStart, aMaxSize,
                    aSizeUsed, aManager);
}

void nsBufferedInputStream::Serialize(InputStreamParams& aParams,
                                      FileDescriptorArray& aFileDescriptors,
                                      bool aDelayedStart, uint32_t aMaxSize,
                                      uint32_t* aSizeUsed,
                                      PBackgroundChild* aManager) {
  SerializeInternal(aParams, aFileDescriptors, aDelayedStart, aMaxSize,
                    aSizeUsed, aManager);
}

void nsBufferedInputStream::Serialize(InputStreamParams& aParams,
                                      FileDescriptorArray& aFileDescriptors,
                                      bool aDelayedStart, uint32_t aMaxSize,
                                      uint32_t* aSizeUsed,
                                      mozilla::dom::ContentParent* aManager) {
  SerializeInternal(aParams, aFileDescriptors, aDelayedStart, aMaxSize,
                    aSizeUsed, aManager);
}

void nsBufferedInputStream::Serialize(InputStreamParams& aParams,
                                      FileDescriptorArray& aFileDescriptors,
                                      bool aDelayedStart, uint32_t aMaxSize,
                                      uint32_t* aSizeUsed,
                                      PBackgroundParent* aManager) {
  SerializeInternal(aParams, aFileDescriptors, aDelayedStart, aMaxSize,
                    aSizeUsed, aManager);
}

template <typename M>
void nsBufferedInputStream::SerializeInternal(
    InputStreamParams& aParams, FileDescriptorArray& aFileDescriptors,
    bool aDelayedStart, uint32_t aMaxSize, uint32_t* aSizeUsed, M* aManager) {
  MOZ_ASSERT(aSizeUsed);
  *aSizeUsed = 0;

  BufferedInputStreamParams params;

  if (mStream) {
    nsCOMPtr<nsIInputStream> stream = do_QueryInterface(mStream);
    MOZ_ASSERT(stream);

    InputStreamParams wrappedParams;
    InputStreamHelper::SerializeInputStream(stream, wrappedParams,
                                            aFileDescriptors, aDelayedStart,
                                            aMaxSize, aSizeUsed, aManager);

    params.optionalStream().emplace(wrappedParams);
  }

  params.bufferSize() = mBufferSize;

  aParams = params;
}

bool nsBufferedInputStream::Deserialize(
    const InputStreamParams& aParams,
    const FileDescriptorArray& aFileDescriptors) {
  if (aParams.type() != InputStreamParams::TBufferedInputStreamParams) {
    NS_ERROR("Received unknown parameters from the other process!");
    return false;
  }

  const BufferedInputStreamParams& params =
      aParams.get_BufferedInputStreamParams();
  const Maybe<InputStreamParams>& wrappedParams = params.optionalStream();

  nsCOMPtr<nsIInputStream> stream;
  if (wrappedParams.isSome()) {
    stream = InputStreamHelper::DeserializeInputStream(wrappedParams.ref(),
                                                       aFileDescriptors);
    if (!stream) {
      NS_WARNING("Failed to deserialize wrapped stream!");
      return false;
    }
  }

  nsresult rv = Init(stream, params.bufferSize());
  NS_ENSURE_SUCCESS(rv, false);

  return true;
}

NS_IMETHODIMP
nsBufferedInputStream::CloseWithStatus(nsresult aStatus) { return Close(); }

NS_IMETHODIMP
nsBufferedInputStream::AsyncWait(nsIInputStreamCallback* aCallback,
                                 uint32_t aFlags, uint32_t aRequestedCount,
                                 nsIEventTarget* aEventTarget) {
  nsCOMPtr<nsIAsyncInputStream> stream = do_QueryInterface(mStream);
  if (!stream) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIInputStreamCallback> callback = aCallback ? this : nullptr;
  {
    MutexAutoLock lock(mMutex);

    if (mAsyncWaitCallback && aCallback) {
      return NS_ERROR_FAILURE;
    }

    mAsyncWaitCallback = aCallback;
  }

  return stream->AsyncWait(callback, aFlags, aRequestedCount, aEventTarget);
}

NS_IMETHODIMP
nsBufferedInputStream::OnInputStreamReady(nsIAsyncInputStream* aStream) {
  nsCOMPtr<nsIInputStreamCallback> callback;
  {
    MutexAutoLock lock(mMutex);

    // We have been canceled in the meanwhile.
    if (!mAsyncWaitCallback) {
      return NS_OK;
    }

    callback.swap(mAsyncWaitCallback);
  }

  MOZ_ASSERT(callback);
  return callback->OnInputStreamReady(this);
}

NS_IMETHODIMP
nsBufferedInputStream::GetData(nsIInputStream** aResult) {
  nsCOMPtr<nsISupports> stream;
  nsBufferedStream::GetData(getter_AddRefs(stream));
  nsCOMPtr<nsIInputStream> inputStream = do_QueryInterface(stream);
  inputStream.forget(aResult);
  return NS_OK;
}

// nsICloneableInputStream interface

NS_IMETHODIMP
nsBufferedInputStream::GetCloneable(bool* aCloneable) {
  *aCloneable = false;

  // If we don't have the buffer, the inputStream has been already closed.
  // If mBufferStartOffset is not 0, the stream has been seeked or read.
  // In both case the cloning is not supported.
  if (!mBuffer || mBufferStartOffset) {
    return NS_OK;
  }

  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);

  // GetCloneable is infallible.
  NS_ENSURE_TRUE(stream, NS_OK);

  return stream->GetCloneable(aCloneable);
}

NS_IMETHODIMP
nsBufferedInputStream::Clone(nsIInputStream** aResult) {
  if (!mBuffer || mBufferStartOffset) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream);
  NS_ENSURE_TRUE(stream, NS_ERROR_FAILURE);

  nsCOMPtr<nsIInputStream> clonedStream;
  nsresult rv = stream->Clone(getter_AddRefs(clonedStream));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIBufferedInputStream> bis = new nsBufferedInputStream();
  rv = bis->Init(clonedStream, mBufferSize);
  NS_ENSURE_SUCCESS(rv, rv);

  bis.forget(aResult);
  return NS_OK;
}

// nsIInputStreamLength

NS_IMETHODIMP
nsBufferedInputStream::Length(int64_t* aLength) {
  nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream);
  NS_ENSURE_TRUE(stream, NS_ERROR_FAILURE);

  return stream->Length(aLength);
}

// nsIAsyncInputStreamLength

NS_IMETHODIMP
nsBufferedInputStream::AsyncLengthWait(nsIInputStreamLengthCallback* aCallback,
                                       nsIEventTarget* aEventTarget) {
  nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream);
  if (!stream) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIInputStreamLengthCallback> callback = aCallback ? this : nullptr;
  {
    MutexAutoLock lock(mMutex);
    mAsyncInputStreamLengthCallback = aCallback;
  }

  MOZ_ASSERT(stream);
  return stream->AsyncLengthWait(callback, aEventTarget);
}

// nsIInputStreamLengthCallback

NS_IMETHODIMP
nsBufferedInputStream::OnInputStreamLengthReady(
    nsIAsyncInputStreamLength* aStream, int64_t aLength) {
  nsCOMPtr<nsIInputStreamLengthCallback> callback;
  {
    MutexAutoLock lock(mMutex);
    // We have been canceled in the meanwhile.
    if (!mAsyncInputStreamLengthCallback) {
      return NS_OK;
    }

    callback.swap(mAsyncInputStreamLengthCallback);
  }

  MOZ_ASSERT(callback);
  return callback->OnInputStreamLengthReady(this, aLength);
}

////////////////////////////////////////////////////////////////////////////////
// nsBufferedOutputStream

NS_IMPL_ADDREF_INHERITED(nsBufferedOutputStream, nsBufferedStream)
NS_IMPL_RELEASE_INHERITED(nsBufferedOutputStream, nsBufferedStream)
// This QI uses NS_INTERFACE_MAP_ENTRY_CONDITIONAL to check for
// non-nullness of mSafeStream.
NS_INTERFACE_MAP_BEGIN(nsBufferedOutputStream)
  NS_INTERFACE_MAP_ENTRY(nsIOutputStream)
  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISafeOutputStream, mSafeStream)
  NS_INTERFACE_MAP_ENTRY(nsIBufferedOutputStream)
  NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess)
NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream)

nsresult nsBufferedOutputStream::Create(nsISupports* aOuter, REFNSIID aIID,
                                        void** aResult) {
  NS_ENSURE_NO_AGGREGATION(aOuter);

  RefPtr<nsBufferedOutputStream> stream = new nsBufferedOutputStream();
  return stream->QueryInterface(aIID, aResult);
}

NS_IMETHODIMP
nsBufferedOutputStream::Init(nsIOutputStream* stream, uint32_t bufferSize) {
  // QI stream to an nsISafeOutputStream, to see if we should support it
  mSafeStream = do_QueryInterface(stream);

  return nsBufferedStream::Init(stream, bufferSize);
}

NS_IMETHODIMP
nsBufferedOutputStream::Close() {
  nsresult rv1, rv2 = NS_OK, rv3;

  rv1 = Flush();

#ifdef DEBUG
  if (NS_FAILED(rv1)) {
    NS_WARNING(
        "(debug) Flush() inside nsBufferedOutputStream::Close() returned error "
        "(rv1).");
  }
#endif

  // If we fail to Flush all the data, then we close anyway and drop the
  // remaining data in the buffer. We do this because it's what Unix does
  // for fclose and close. However, we report the error from Flush anyway.
  if (mStream) {
    rv2 = Sink()->Close();
#ifdef DEBUG
    if (NS_FAILED(rv2)) {
      NS_WARNING(
          "(debug) Sink->Close() inside nsBufferedOutputStream::Close() "
          "returned error (rv2).");
    }
#endif
  }
  rv3 = nsBufferedStream::Close();

#ifdef DEBUG
  if (NS_FAILED(rv3)) {
    NS_WARNING(
        "(debug) nsBufferedStream:Close() inside "
        "nsBufferedOutputStream::Close() returned error (rv3).");
  }
#endif

  if (NS_FAILED(rv1)) {
    return rv1;
  }
  if (NS_FAILED(rv2)) {
    return rv2;
  }
  return rv3;
}

NS_IMETHODIMP
nsBufferedOutputStream::Write(const char* buf, uint32_t count,
                              uint32_t* result) {
  nsresult rv = NS_OK;
  uint32_t written = 0;
  *result = 0;
  if (!mStream) {
    // We special case this situtaion.
    // We should catch the failure, NS_BASE_STREAM_CLOSED ASAP, here.
    // If we don't, eventually Flush() is called in the while loop below
    // after so many writes.
    // However, Flush() returns NS_OK when mStream is null (!!),
    // and we don't get a meaningful error, NS_BASE_STREAM_CLOSED,
    // soon enough when we use buffered output.
#ifdef DEBUG
    NS_WARNING(
        "(info) nsBufferedOutputStream::Write returns NS_BASE_STREAM_CLOSED "
        "immediately (mStream==null).");
#endif
    return NS_BASE_STREAM_CLOSED;
  }

  while (count > 0) {
    uint32_t amt = std::min(count, mBufferSize - mCursor);
    if (amt > 0) {
      memcpy(mBuffer + mCursor, buf + written, amt);
      written += amt;
      count -= amt;
      mCursor += amt;
      if (mFillPoint < mCursor) mFillPoint = mCursor;
    } else {
      NS_ASSERTION(mFillPoint, "loop in nsBufferedOutputStream::Write!");
      rv = Flush();
      if (NS_FAILED(rv)) {
#ifdef DEBUG
        NS_WARNING(
            "(debug) Flush() returned error in nsBufferedOutputStream::Write.");
#endif
        break;
      }
    }
  }
  *result = written;
  return (written > 0) ? NS_OK : rv;
}

NS_IMETHODIMP
nsBufferedOutputStream::Flush() {
  nsresult rv;
  uint32_t amt;
  if (!mStream) {
    // Stream already cancelled/flushed; probably because of previous error.
    return NS_OK;
  }
  // optimize : some code within C-C needs to call Seek -> Flush() often.
  if (mFillPoint == 0) {
    return NS_OK;
  }
  rv = Sink()->Write(mBuffer, mFillPoint, &amt);
  if (NS_FAILED(rv)) {
    return rv;
  }
  mBufferStartOffset += amt;
  if (amt == mFillPoint) {
    mFillPoint = mCursor = 0;
    return NS_OK;  // flushed everything
  }

  // slide the remainder down to the start of the buffer
  // |<-------------->|<---|----->|
  // b                a    c      s
  uint32_t rem = mFillPoint - amt;
  memmove(mBuffer, mBuffer + amt, rem);
  mFillPoint = mCursor = rem;
  return NS_ERROR_FAILURE;  // didn't flush all
}

// nsISafeOutputStream
NS_IMETHODIMP
nsBufferedOutputStream::Finish() {
  // flush the stream, to write out any buffered data...
  nsresult rv1 = nsBufferedOutputStream::Flush();
  nsresult rv2 = NS_OK, rv3;

  if (NS_FAILED(rv1)) {
    NS_WARNING(
        "(debug) nsBufferedOutputStream::Flush() failed in "
        "nsBufferedOutputStream::Finish()! Possible dataloss.");

    rv2 = Sink()->Close();
    if (NS_FAILED(rv2)) {
      NS_WARNING(
          "(debug) Sink()->Close() failed in nsBufferedOutputStream::Finish()! "
          "Possible dataloss.");
    }
  } else {
    rv2 = mSafeStream->Finish();
    if (NS_FAILED(rv2)) {
      NS_WARNING(
          "(debug) mSafeStream->Finish() failed within "
          "nsBufferedOutputStream::Flush()! Possible dataloss.");
    }
  }

  // ... and close the buffered stream, so any further attempts to flush/close
  // the buffered stream won't cause errors.
  rv3 = nsBufferedStream::Close();

  // We want to return the errors precisely from Finish()
  // and mimick the existing error handling in
  // nsBufferedOutputStream::Close() as reference.

  if (NS_FAILED(rv1)) {
    return rv1;
  }
  if (NS_FAILED(rv2)) {
    return rv2;
  }
  return rv3;
}

static nsresult nsReadFromInputStream(nsIOutputStream* outStr, void* closure,
                                      char* toRawSegment, uint32_t offset,
                                      uint32_t count, uint32_t* readCount) {
  nsIInputStream* fromStream = (nsIInputStream*)closure;
  return fromStream->Read(toRawSegment, count, readCount);
}

NS_IMETHODIMP
nsBufferedOutputStream::WriteFrom(nsIInputStream* inStr, uint32_t count,
                                  uint32_t* _retval) {
  return WriteSegments(nsReadFromInputStream, inStr, count, _retval);
}

NS_IMETHODIMP
nsBufferedOutputStream::WriteSegments(nsReadSegmentFun reader, void* closure,
                                      uint32_t count, uint32_t* _retval) {
  *_retval = 0;
  nsresult rv;
  while (count > 0) {
    uint32_t left = std::min(count, mBufferSize - mCursor);
    if (left == 0) {
      rv = Flush();
      if (NS_FAILED(rv)) {
        return (*_retval > 0) ? NS_OK : rv;
      }

      continue;
    }

    uint32_t read = 0;
    rv = reader(this, closure, mBuffer + mCursor, *_retval, left, &read);

    if (NS_FAILED(rv)) {  // If we have read some data, return ok
      return (*_retval > 0) ? NS_OK : rv;
    }
    mCursor += read;
    *_retval += read;
    count -= read;
    mFillPoint = std::max(mFillPoint, mCursor);
  }
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedOutputStream::IsNonBlocking(bool* aNonBlocking) {
  if (mStream) {
    return Sink()->IsNonBlocking(aNonBlocking);
  }
  return NS_ERROR_NOT_INITIALIZED;
}

NS_IMETHODIMP_(char*)
nsBufferedOutputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask) {
  NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!");
  if (mGetBufferCount != 0) {
    return nullptr;
  }

  if (mBufferDisabled) {
    return nullptr;
  }

  char* buf = mBuffer + mCursor;
  uint32_t rem = mBufferSize - mCursor;
  if (rem == 0) {
    if (NS_FAILED(Flush())) {
      return nullptr;
    }
    buf = mBuffer + mCursor;
    rem = mBufferSize - mCursor;
  }

  uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask);
  if (mod) {
    uint32_t pad = aAlignMask + 1 - mod;
    if (pad > rem) {
      return nullptr;
    }

    memset(buf, 0, pad);
    mCursor += pad;
    buf += pad;
    rem -= pad;
  }

  if (aLength > rem) {
    return nullptr;
  }
  mGetBufferCount++;
  return buf;
}

NS_IMETHODIMP_(void)
nsBufferedOutputStream::PutBuffer(char* aBuffer, uint32_t aLength) {
  NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!");
  if (--mGetBufferCount != 0) {
    return;
  }

  NS_ASSERTION(mCursor + aLength <= mBufferSize, "PutBuffer botch");
  mCursor += aLength;
  if (mFillPoint < mCursor) {
    mFillPoint = mCursor;
  }
}

NS_IMETHODIMP
nsBufferedOutputStream::DisableBuffering() {
  NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!");
  NS_ASSERTION(mGetBufferCount == 0,
               "DisableBuffer call between GetBuffer and PutBuffer!");
  if (mGetBufferCount != 0) {
    return NS_ERROR_UNEXPECTED;
  }

  // Empty the buffer so nsBufferedStream::Tell works.
  nsresult rv = Flush();
  if (NS_FAILED(rv)) {
    return rv;
  }

  mBufferDisabled = true;
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedOutputStream::EnableBuffering() {
  NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!");
  mBufferDisabled = false;
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedOutputStream::GetUnbufferedStream(nsISupports** aStream) {
  // Empty the buffer so subsequent i/o trumps any buffered data.
  if (mFillPoint) {
    nsresult rv = Flush();
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  nsCOMPtr<nsISupports> stream = mStream;
  stream.forget(aStream);
  return NS_OK;
}

NS_IMETHODIMP
nsBufferedOutputStream::GetData(nsIOutputStream** aResult) {
  nsCOMPtr<nsISupports> stream;
  nsBufferedStream::GetData(getter_AddRefs(stream));
  nsCOMPtr<nsIOutputStream> outputStream = do_QueryInterface(stream);
  outputStream.forget(aResult);
  return NS_OK;
}
#undef METER

////////////////////////////////////////////////////////////////////////////////