gecko-dev/xpcom/base/nsConsoleService.h

/* -*- 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/. */

/*
 * nsConsoleService class declaration.
 */

#ifndef __nsconsoleservice_h__
#define __nsconsoleservice_h__

#include "mozilla/Attributes.h"
#include "mozilla/Mutex.h"

#include "nsInterfaceHashtable.h"
#include "nsHashKeys.h"

#include "nsIConsoleService.h"
#include "nsIObserver.h"

class nsConsoleService final : public nsIConsoleService,
                               public nsIObserver
{
public:
  nsConsoleService();
  nsresult Init();

  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSICONSOLESERVICE
  NS_DECL_NSIOBSERVER

  void SetIsDelivering()
  {
    MOZ_ASSERT(NS_IsMainThread());
    MOZ_ASSERT(!mDeliveringMessage);
    mDeliveringMessage = true;
  }

  void SetDoneDelivering()
  {
    MOZ_ASSERT(NS_IsMainThread());
    MOZ_ASSERT(mDeliveringMessage);
    mDeliveringMessage = false;
  }

  // This is a variant of LogMessage which allows the caller to determine
  // if the message should be output to an OS-specific log. This is used on
  // B2G to control whether the message is logged to the android log or not.

  enum OutputMode {
    SuppressLog,
    OutputToLog
  };
  virtual nsresult LogMessageWithMode(nsIConsoleMessage* aMessage,
                                      OutputMode aOutputMode);

  typedef nsInterfaceHashtable<nsISupportsHashKey,
                               nsIConsoleListener> ListenerHash;
  void CollectCurrentListeners(nsCOMArray<nsIConsoleListener>& aListeners);

private:
  class MessageElement : public mozilla::LinkedListElement<MessageElement>
  {
  public:
    explicit MessageElement(nsIConsoleMessage* aMessage) : mMessage(aMessage)
    {}

    nsIConsoleMessage* Get()
    {
      return mMessage.get();
    }

    // Swap directly into an nsCOMPtr to avoid spurious refcount
    // traffic off the main thread in debug builds from
    // NSCAP_ASSERT_NO_QUERY_NEEDED().
    void swapMessage(nsCOMPtr<nsIConsoleMessage>& aRetVal)
    {
      mMessage.swap(aRetVal);
    }

    ~MessageElement();

  private:
    nsCOMPtr<nsIConsoleMessage> mMessage;

    MessageElement(const MessageElement&) = delete;
    MessageElement& operator=(const MessageElement&) = delete;
    MessageElement(MessageElement&&) = delete;
    MessageElement& operator=(MessageElement&&) = delete;
  };

  ~nsConsoleService();

  void ClearMessagesForWindowID(const uint64_t innerID);
  void ClearMessages();

  mozilla::LinkedList<MessageElement> mMessages;

  // The current size of mMessages.
  uint32_t mCurrentSize;

  // The maximum size of mMessages.
  uint32_t mMaximumSize;

  // Are we currently delivering a console message on the main thread? If
  // so, we suppress incoming messages on the main thread only, to avoid
  // infinite repitition.
  bool mDeliveringMessage;

  // Listeners to notify whenever a new message is logged.
  ListenerHash mListeners;

  // To serialize interesting methods.
  mozilla::Mutex mLock;
};

#endif /* __nsconsoleservice_h__ */