ReadStream.h - mozsearch

Enable keyboard shortcuts

/* -*- 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_dom_cache_ReadStream_h

#define mozilla_dom_cache_ReadStream_h

#include "mozilla/dom/SafeRefPtr.h"

#include "mozilla/ipc/FileDescriptor.h"

#include "mozilla/RefPtr.h"

#include "nsCOMPtr.h"

#include "nsID.h"

#include "nsIInputStream.h"

#include "nsISupportsImpl.h"

#include "nsTArrayForwardDeclare.h"

namespace mozilla {

class ErrorResult;

namespace dom::cache {

class CacheReadStream;

class PCacheStreamControlParent;

// IID for the dom::cache::ReadStream interface

#define NS_DOM_CACHE_READSTREAM_IID                  \

  {                                                  \

    0x8e5da7c9, 0x0940, 0x4f1d, {                    \

      0x97, 0x25, 0x5c, 0x59, 0x38, 0xdd, 0xb9, 0x9f \

    }                                                \

// Custom stream class for Request and Response bodies being read from

// a Cache.  The main purpose of this class is to report back to the

// Cache's Manager when the stream is closed.  This allows the Cache to

// accurately determine when the underlying body file can be deleted,

// etc.

//

// The ReadStream class also provides us with a convenient QI'able

// interface that we can use to pass additional meta-data with the

// stream channel.  For example, Cache.put() can detect that the content

// script is passing a Cache-originated-stream back into the Cache

// again.  This enables certain optimizations.

class ReadStream final : public nsIInputStream {

 public:

  // Interface that lets the StreamControl classes interact with

  // our private inner stream.

  class Controllable : public AtomicSafeRefCounted<Controllable> {

   public:

    virtual ~Controllable() = default;

    // Closes the stream, notifies the stream control, and then forgets

    // the stream control.

    virtual void CloseStream() = 0;

    // Closes the stream and then forgets the stream control.  Does not

    // notify.

    virtual void CloseStreamWithoutReporting() = 0;

    virtual bool HasEverBeenRead() const = 0;

    MOZ_DECLARE_REFCOUNTED_TYPENAME(ReadStream::Controllable);

};

  static already_AddRefed<ReadStream> Create(

      const Maybe<CacheReadStream>& aMaybeReadStream);

  static already_AddRefed<ReadStream> Create(

      const CacheReadStream& aReadStream);

  static already_AddRefed<ReadStream> Create(

      PCacheStreamControlParent* aControl, const nsID& aId,

      nsIInputStream* aStream);

  void Serialize(Maybe<CacheReadStream>* aReadStreamOut, ErrorResult& aRv);

  void Serialize(CacheReadStream* aReadStreamOut, ErrorResult& aRv);

 private:

  class Inner;

  ~ReadStream();

  // Hold a strong ref to an inner class that actually implements the

  // majority of the stream logic.  Before releasing this ref the outer

  // ReadStream guarantees it will call Close() on the inner stream.

  // This is essential for the inner stream to avoid dealing with the

  // implicit close that can happen when a stream is destroyed.

  SafeRefPtr<ReadStream::Inner> mInner;

 public:

  explicit ReadStream(SafeRefPtr<ReadStream::Inner> aInner);

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_CACHE_READSTREAM_IID);

  NS_DECL_THREADSAFE_ISUPPORTS

  NS_DECL_NSIINPUTSTREAM

};

NS_DEFINE_STATIC_IID_ACCESSOR(ReadStream, NS_DOM_CACHE_READSTREAM_IID);

}  // namespace dom::cache

}  // namespace mozilla

#endif  // mozilla_dom_cache_ReadStream_h