C++ nsCOMPtr::Available方法代码示例

nsresult
nsJARInputThunk::Init()
{
    nsresult rv;
    if (ENTRY_IS_DIRECTORY(mJarEntry)) {
        // A directory stream also needs the Spec of the FullJarURI
        // because is included in the stream data itself.

        NS_ENSURE_STATE(!mJarDirSpec.IsEmpty());

        rv = mJarReader->GetInputStreamWithSpec(mJarDirSpec,
                                                mJarEntry,
                                                getter_AddRefs(mJarStream));
    }
    else {
        rv = mJarReader->GetInputStream(mJarEntry,
                                        getter_AddRefs(mJarStream));
    }
    if (NS_FAILED(rv)) {
        // convert to the proper result if the entry wasn't found
        // so that error pages work
        if (rv == NS_ERROR_FILE_TARGET_DOES_NOT_EXIST)
            rv = NS_ERROR_FILE_NOT_FOUND;
        return rv;
    }

    // ask the JarStream for the content length
    uint64_t avail;
    rv = mJarStream->Available((uint64_t *) &avail);
    if (NS_FAILED(rv)) return rv;

    mContentLength = avail < INT64_MAX ? (int64_t) avail : -1;

    return NS_OK;
}

nsresult FileMediaResource::Open(nsIStreamListener** aStreamListener)
{
  NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");

  if (aStreamListener) {
    *aStreamListener = nullptr;
  }

  nsresult rv = NS_OK;
  if (aStreamListener) {
    // The channel is already open. We need a synchronous stream that
    // implements nsISeekableStream, so we have to find the underlying
    // file and reopen it
    nsCOMPtr<nsIFileChannel> fc(do_QueryInterface(mChannel));
    if (!fc)
      return NS_ERROR_UNEXPECTED;

    nsCOMPtr<nsIFile> file;
    rv = fc->GetFile(getter_AddRefs(file));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = NS_NewLocalFileInputStream(getter_AddRefs(mInput), file);
  } else {
    // Ensure that we never load a local file from some page on a
    // web server.
    nsHTMLMediaElement* element = mDecoder->GetMediaElement();
    NS_ENSURE_TRUE(element, NS_ERROR_FAILURE);

    rv = nsContentUtils::GetSecurityManager()->
           CheckLoadURIWithPrincipal(element->NodePrincipal(),
                                     mURI,
                                     nsIScriptSecurityManager::STANDARD);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = mChannel->Open(getter_AddRefs(mInput));
  }
  NS_ENSURE_SUCCESS(rv, rv);

  mSeekable = do_QueryInterface(mInput);
  if (!mSeekable) {
    // XXX The file may just be a .url or similar
    // shortcut that points to a Web site. We need to fix this by
    // doing an async open and waiting until we locate the real resource,
    // then using that (if it's still a file!).
    return NS_ERROR_FAILURE;
  }

  // Get the file size and inform the decoder. Only files up to 4GB are
  // supported here.
  PRUint32 size;
  rv = mInput->Available(&size);
  if (NS_SUCCEEDED(rv)) {
    mSize = size;
  }

  nsCOMPtr<nsIRunnable> event = new LoadedEvent(mDecoder);
  NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
  return NS_OK;
}

NS_IMETHODIMP
nsJARInputThunk::Available(PRUint32 *avail)
{
    nsresult rv = EnsureJarStream();
    if (NS_FAILED(rv)) return rv;

    return mJarStream->Available(avail);
}

NS_IMETHODIMP
nsInputStreamTee::Available(uint64_t* aAvail)
{
  if (NS_WARN_IF(!mSource)) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  return mSource->Available(aAvail);
}

NS_IMETHODIMP
nsGopherContentStream::Available(PRUint32 *result)
{
    if (mSocketInput)
        return mSocketInput->Available(result);

    return nsBaseContentStream::Available(result);
}

nsresult
nsJARInputThunk::EnsureJarStream()
{
    if (mJarStream)
        return NS_OK;

    nsresult rv;
    if (mJarCache)
        rv = mJarCache->GetZip(mJarFile, getter_AddRefs(mJarReader));
    else {
        // create an uncached jar reader
        mJarReader = do_CreateInstance(kZipReaderCID, &rv);
        if (NS_FAILED(rv)) return rv;

        rv = mJarReader->Open(mJarFile);
    }
    if (NS_FAILED(rv)) return rv;

    if (ENTRY_IS_DIRECTORY(mJarEntry)) {
        // A directory stream also needs the Spec of the FullJarURI
        // because is included in the stream data itself.

        NS_ENSURE_STATE(!mJarDirSpec.IsEmpty());

        rv = mJarReader->GetInputStreamWithSpec(mJarDirSpec,
                                                mJarEntry.get(),
                                                getter_AddRefs(mJarStream));
    }
    else {
        rv = mJarReader->GetInputStream(mJarEntry.get(),
                                        getter_AddRefs(mJarStream));
    }
    if (NS_FAILED(rv)) {
        // convert to the proper result if the entry wasn't found
        // so that error pages work
        if (rv == NS_ERROR_FILE_TARGET_DOES_NOT_EXIST)
            rv = NS_ERROR_FILE_NOT_FOUND;
        return rv;
    }

    // ask the JarStream for the content length
    // XXX want a 64-bit value from nsIInputStream::Available()
    PRUint32 contentLength;
    rv = mJarStream->Available(&contentLength);
    if (NS_FAILED(rv)) return rv;
    mContentLength = contentLength;

    return NS_OK;
}

void FileMediaResource::EnsureSizeInitialized()
{
  mLock.AssertCurrentThreadOwns();
  NS_ASSERTION(mInput, "Must have file input stream");
  if (mSizeInitialized) {
    return;
  }
  mSizeInitialized = true;
  // Get the file size and inform the decoder.
  uint64_t size;
  nsresult res = mInput->Available(&size);
  if (NS_SUCCEEDED(res) && size <= INT64_MAX) {
    mSize = (int64_t)size;
    mCallback->NotifyDataEnded(NS_OK);
  }
}

void FileMediaResource::EnsureSizeInitialized()
{
    mLock.AssertCurrentThreadOwns();
    NS_ASSERTION(mInput, "Must have file input stream");
    if (mSizeInitialized) {
        return;
    }
    mSizeInitialized = true;
    // Get the file size and inform the decoder.
    uint64_t size;
    nsresult res = mInput->Available(&size);
    if (NS_SUCCEEDED(res) && size <= PR_INT64_MAX) {
        mSize = (int64_t)size;
        nsCOMPtr<nsIRunnable> event = new LoadedEvent(mDecoder);
        NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
    }
}

// set up the internal streams
void nsMIMEInputStream::InitStreams()
{
    NS_ASSERTION(!mStartedReading,
                 "Don't call initStreams twice without rewinding");

    mStartedReading = true;

    // We'll use the content-length stream to add the final \r\n
    if (mAddContentLength) {
        uint64_t cl = 0;
        if (mData) {
            mData->Available(&cl);
        }
        mContentLength.AssignLiteral("Content-Length: ");
        mContentLength.AppendInt(cl);
        mContentLength.AppendLiteral("\r\n\r\n");
    }
    else {
        mContentLength.AssignLiteral("\r\n");
    }
    mCLStream->ShareData(mContentLength.get(), -1);
    mHeaderStream->ShareData(mHeaders.get(), -1);
}

#endif /* HAVE_PR_MEMMAP */
        } else {
            nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
            NS_ENSURE_SUCCESS(rv, rv);

            nsCOMPtr<nsIChannel> scriptChannel;
            rv = ioService->NewChannelFromURI(aURI, getter_AddRefs(scriptChannel));
            NS_ENSURE_SUCCESS(rv, rv);

            nsCOMPtr<nsIInputStream> scriptStream;
            rv = scriptChannel->Open(getter_AddRefs(scriptStream));
            NS_ENSURE_SUCCESS(rv, rv);

            PRUint32 len, bytesRead;

            rv = scriptStream->Available(&len);
            NS_ENSURE_SUCCESS(rv, rv);
            if (!len)
                return NS_ERROR_FAILURE;

            /* malloc an internal buf the size of the file */
            nsAutoArrayPtr<char> buf(new char[len + 1]);
            if (!buf)
                return NS_ERROR_OUT_OF_MEMORY;

            /* read the file in one swoop */
            rv = scriptStream->Read(buf, len, &bytesRead);
            if (bytesRead != len)
                return NS_BASE_STREAM_OSERROR;

            buf[len] = '\0';

NS_IMETHODIMP nsMIMEInputStream::Available(uint64_t *_retval) { INITSTREAMS; return mStream->Available(_retval); }

 NS_IMETHOD
 Available(uint64_t* aLength) override
 {
   return mStream->Available(aLength);
 }