text: /*
   * libjingle
   * Copyright 2004--2006, Google Inc.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *  1. Redistributions of source code must retain the above copyright notice,
   *     this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright notice,
   *     this list of conditions and the following disclaimer in the documentation
   *     and/or other materials provided with the distribution.
   *  3. The name of the author may not be used to endorse or promote products
   *     derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
   * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
   * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
   * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifndef TALK_XMPP_XMPPTASK_H_
  #define TALK_XMPP_XMPPTASK_H_
  
  #include <string>
  #include <deque>
  #include "talk/base/sigslot.h"
  #include "talk/xmpp/xmppengine.h"
  #include "talk/base/task.h"
  
  namespace buzz {
  
  /////////////////////////////////////////////////////////////////////
  //
  // XMPPTASK
  //
  /////////////////////////////////////////////////////////////////////
  //
  // See Task and XmppClient first.
  //
  // XmppTask is a task that is designed to go underneath XmppClient and be
  // useful there.  It has a way of finding its XmppClient parent so you
  // can have it nested arbitrarily deep under an XmppClient and it can
  // still find the XMPP services.
  //
  // Tasks register themselves to listen to particular kinds of stanzas
  // that are sent out by the client.  Rather than processing stanzas
  // right away, they should decide if they own the sent stanza,
  // and if so, queue it and Wake() the task, or if a stanza does not belong
  // to you, return false right away so the next XmppTask can take a crack.
  // This technique (synchronous recognize, but asynchronous processing)
  // allows you to have arbitrary logic for recognizing stanzas yet still,
  // for example, disconnect a client while processing a stanza -
  // without reentrancy problems.
  //
  /////////////////////////////////////////////////////////////////////
  
  class XmppClient;
  
  class XmppTask :
    public talk_base::Task,
    public XmppStanzaHandler,
    public sigslot::has_slots<>
  {
   public:
    XmppTask(talk_base::TaskParent* parent,
             XmppEngine::HandlerLevel level = XmppEngine::HL_NONE);
    virtual ~XmppTask();
  
    virtual XmppClient* GetClient() const { return client_; }
    std::string task_id() const { return id_; }
    void set_task_id(std::string id) { id_ = id; }
  
  #ifdef _DEBUG
    void set_debug_force_timeout(const bool f) { debug_force_timeout_ = f; }
  #endif
  
   protected:
    friend class XmppClient;
  
    XmppReturnStatus SendStanza(const XmlElement* stanza);
    XmppReturnStatus SetResult(const std::string& code);
    XmppReturnStatus SendStanzaError(const XmlElement* element_original,
                                     XmppStanzaError code,
                                     const std::string& text);
  
    virtual void Stop();
    virtual bool HandleStanza(const XmlElement* stanza) { return false; }
    virtual void OnDisconnect();
    virtual int ProcessReponse() { return STATE_DONE; }
  
    virtual void QueueStanza(const XmlElement* stanza);
    const XmlElement* NextStanza();
  
    bool MatchStanzaFrom(const XmlElement* stanza, const Jid& match_jid);
  
    bool MatchResponseIq(const XmlElement* stanza, const Jid& to,
                         const std::string& task_id);
  
    static bool MatchRequestIq(const XmlElement* stanza, const std::string& type,
                               const QName& qn);
    static XmlElement *MakeIqResult(const XmlElement* query);
    static XmlElement *MakeIq(const std::string& type,
                              const Jid& to, const std::string& task_id);
  
    // Returns true if the task is under the specified rate limit and updates the
    // rate limit accordingly
    bool VerifyTaskRateLimit(const std::string task_name, int max_count,
                             int per_x_seconds);
  
  private:
    void StopImpl();
  
    XmppClient* client_;
    std::deque<XmlElement*> stanza_queue_;
    talk_base::scoped_ptr<XmlElement> next_stanza_;
    std::string id_;
  
  #ifdef _DEBUG
    bool debug_force_timeout_;
  #endif
  };
  
  }  // namespace buzz
  
  #endif // TALK_XMPP_XMPPTASK_H_
  