gecko-dev/xpcom/io/InputStreamLengthHelper.h

58 строки
1.6 KiB
C++

/* -*- 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/. */
#ifndef mozilla_InputStreamLengthHelper_h
#define mozilla_InputStreamLengthHelper_h
#include <functional>
#include "nsISupportsImpl.h"
#include "nsIInputStreamLength.h"
#include "nsThreadUtils.h"
class nsIInputStream;
namespace mozilla {
// This class helps to retrieve the stream's length.
class InputStreamLengthHelper final : public Runnable,
public nsIInputStreamLengthCallback {
public:
NS_DECL_ISUPPORTS_INHERITED
// This is one of the 2 entry points of this class. It returns false if the
// length cannot be taken synchronously.
static bool GetSyncLength(nsIInputStream* aStream, int64_t* aLength);
// This is one of the 2 entry points of this class. The callback is executed
// asynchronously when the length is known.
static void GetAsyncLength(
nsIInputStream* aStream,
const std::function<void(int64_t aLength)>& aCallback);
private:
NS_DECL_NSIINPUTSTREAMLENGTHCALLBACK
InputStreamLengthHelper(
nsIInputStream* aStream,
const std::function<void(int64_t aLength)>& aCallback);
~InputStreamLengthHelper();
NS_IMETHOD
Run() override;
void ExecCallback(int64_t aLength);
nsCOMPtr<nsIInputStream> mStream;
std::function<void(int64_t aLength)> mCallback;
};
} // namespace mozilla
#endif // mozilla_InputStreamLengthHelper_h