C++ (Cpp) bigLengthRangeの例

コード例 #1

ファイル: Box.cpp プロジェクト: AtulKumar2/gecko-dev

Box::Box(BoxContext* aContext, uint64_t aOffset, const Box* aParent)
  : mContext(aContext), mParent(aParent)
{
  uint8_t header[8];
  MediaByteRange headerRange(aOffset, aOffset + sizeof(header));
  if (mParent && !mParent->mRange.Contains(headerRange)) {
    return;
  }

  const MediaByteRange* byteRange;
  for (int i = 0; ; i++) {
    if (i == mContext->mByteRanges.Length()) {
      return;
    }

    byteRange = &mContext->mByteRanges[i];
    if (byteRange->Contains(headerRange)) {
      break;
    }
  }

  size_t bytes;
  if (!mContext->mSource->CachedReadAt(aOffset, header, sizeof(header),
                                       &bytes) ||
      bytes != sizeof(header)) {
    return;
  }

  uint64_t size = BigEndian::readUint32(header);
  if (size == 1) {
    uint8_t bigLength[8];
    MediaByteRange bigLengthRange(headerRange.mEnd,
                                  headerRange.mEnd + sizeof(bigLength));
    if ((mParent && !mParent->mRange.Contains(bigLengthRange)) ||
        !byteRange->Contains(bigLengthRange) ||
        !mContext->mSource->CachedReadAt(aOffset, bigLength,
                                         sizeof(bigLength), &bytes) ||
        bytes != sizeof(bigLength)) {
      return;
    }
    size = BigEndian::readUint64(bigLength);
    mBodyOffset = bigLengthRange.mEnd;
  } else {
    mBodyOffset = headerRange.mEnd;
  }

  mType = BigEndian::readUint32(&header[4]);
  mChildOffset = mBodyOffset + BoxOffset(mType);

  MediaByteRange boxRange(aOffset, aOffset + size);
  if (mChildOffset > boxRange.mEnd ||
      (mParent && !mParent->mRange.Contains(boxRange)) ||
      !byteRange->Contains(boxRange)) {
    return;
  }

  mRange = boxRange;
}

コード例 #2

ファイル: Box.cpp プロジェクト: logicoftekk/cyberfox

Box::Box(BoxContext* aContext, uint64_t aOffset, const Box* aParent)
  : mContext(aContext), mParent(aParent)
{
  uint8_t header[8];

  if (aOffset > INT64_MAX - sizeof(header)) {
    return;
  }

  MediaByteRange headerRange(aOffset, aOffset + sizeof(header));
  if (mParent && !mParent->mRange.Contains(headerRange)) {
    return;
  }

  const MediaByteRange* byteRange;
  for (int i = 0; ; i++) {
    if (i == mContext->mByteRanges.Length()) {
      return;
    }

    byteRange = &mContext->mByteRanges[i];
    if (byteRange->Contains(headerRange)) {
      break;
    }
  }

  size_t bytes;
  if (!mContext->mSource->CachedReadAt(aOffset, header, sizeof(header),
                                       &bytes) ||
      bytes != sizeof(header)) {
    return;
  }

  uint64_t size = BigEndian::readUint32(header);
  if (size == 1) {
    uint8_t bigLength[8];
    if (aOffset > INT64_MAX - sizeof(header) - sizeof(bigLength)) {
      return;
    }
    MediaByteRange bigLengthRange(headerRange.mEnd,
                                  headerRange.mEnd + sizeof(bigLength));
    if ((mParent && !mParent->mRange.Contains(bigLengthRange)) ||
        !byteRange->Contains(bigLengthRange) ||
        !mContext->mSource->CachedReadAt(aOffset + sizeof(header), bigLength,
                                         sizeof(bigLength), &bytes) ||
        bytes != sizeof(bigLength)) {
      return;
    }
    size = BigEndian::readUint64(bigLength);
    mBodyOffset = bigLengthRange.mEnd;
  } else if (size == 0) {
    // box extends to end of file.
    size = mContext->mByteRanges.LastElement().mEnd - aOffset;
    mBodyOffset = headerRange.mEnd;
  } else {
    mBodyOffset = headerRange.mEnd;
  }

  if (size > INT64_MAX) {
    return;
  }
  int64_t end = static_cast<int64_t>(aOffset) + static_cast<int64_t>(size);
  if (end < static_cast<int64_t>(aOffset)) {
    // Overflowed.
    return;
  }

  mType = BigEndian::readUint32(&header[4]);
  mChildOffset = mBodyOffset + BoxOffset(mType);

  MediaByteRange boxRange(aOffset, end);
  if (mChildOffset > boxRange.mEnd ||
      (mParent && !mParent->mRange.Contains(boxRange)) ||
      !byteRange->Contains(boxRange)) {
    return;
  }

  mRange = boxRange;
}