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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
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 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
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 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 2007
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *   Dave Camp <dcamp@mozilla.com>
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#include "nsISupports.idl"

interface nsIChannel;

/**
 * An nsIChannelClassifier object checks a channel's URI against the
 * URI classifier service, and cancels the channel before OnStartRequest
 * if it is found on a blacklist.
 */
[scriptable, uuid(1481c5b5-9f6e-4995-8fe3-2aad5c06440d)]
interface nsIChannelClassifier : nsISupports
{
  /**
   * Checks a channel against the URI classifier service (if it exists).
   *
   * The channel will be suspended while the classifier is checked.  The
   * channel may be cancelled with an error code determined by the classifier
   * before it is resumed.
   *
   * If there is no URI classifier service, NS_ERROR_FACTORY_NOT_REGISTERED
   * will be returned.
   *
   * This method must be called immediately after AsyncOpen() has been called
   * on the channel.
   *
   * @param aChannel
   *        The channel to suspend.
   * @param aInstallListener
   *        If true, the classifier will install notification
   *        callbacks to listen for redirects.  The classifier will
   *        pass all notifications on to the channel's existing
   *        notification callbacks.
   */
  void start(in nsIChannel aChannel, in boolean aInstallListener);

  /**
   * Notify the classifier that the channel was redirected.  The new channel
   * will be suspended pending a new classifier lookup.
   *
   * @param aOldChannel
   *        The channel that's being redirected.
   * @param aNewChannel
   *        The new channel. This channel is not opened yet.
   */
  void onRedirect(in nsIChannel aOldChannel, in nsIChannel aNewChannel);

  /**
   * Cancel an existing query.  If a channel has been suspended, it will
   * be resumed.
   */
  void cancel();
};