timercache.h

对POSIX timer的面向对象的封装。

#ifndef _TIMER_CACHE_H
#define _TIMER_CACHE_H

#include <pthread.h>

class ITimer;

// timer node.
typedef struct tag_Timer
{
  struct tag_Timer * next;

  // common interface for the client application.
  ITimer * timer;
  // the identity id for the timer.
  int timerId;
  // false: this is not a periodical timer.
  // true: this is a periodical timer.
  bool isPeriodical;
  // the start time of the timer.
  int startTime;
  // the timeout for the timer (second).
  int interval;
  // when the timer timeouts, this argument will be with
  // the timeout callback function.
  void * args;

  tag_Timer()
  {
    timer = 0;
    timerId = -1;
    next = 0;
    isPeriodical = false;
    startTime = -1;
    interval = -1;
    args = 0;
  }
}Timer;

// timer array.
typedef struct tag_TimerList
{ 
  Timer * nextTimer;

  tag_TimerList()
  {
    nextTimer = 0;
  }
}TimerList;

class TimerCache
{
public:
  TimerCache();
  virtual ~TimerCache();

  // insert a timer into the hash table.
  int insert(ITimer * timer , int currentTime , int interval , bool isPeriodical = false , void * args = 0);
  // remove the timer from the hash table with the timer id.
  int remove(int timerId);
  // when the timer is expired, this function will be called.
  void handleTimeout(int currentTime);
   
private:
  // the granularity of the hash table. 
  static const int LIST_CAPACITY = 50;
  // the timer array.
  TimerList timerList_m[LIST_CAPACITY];
  // the lock for the cache accessing.
  pthread_mutex_t mutex_m;

  // if the timer is periodical, after timeout, the timer will be re-inserted into the 
  // hash table.
  void reInsert(Timer * timer , int currentTime);
  // reclaim the hash table.
  void destroyAll();
  // get the timer id 
  int getTimerId();
  // when the timer is expired, this function will be called.
  void expire(int currentTime);
};

#endif