/*
   Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#include "TimeQueue.hpp"
#include <ErrorHandlingMacros.hpp>
#include <GlobalData.hpp>
#include <FastScheduler.hpp>
#include <VMSignal.hpp>

#define JAM_FILE_ID 273


static const int MAX_TIME_QUEUE_VALUE = 32000;

TimeQueue::TimeQueue()
{
  clear();
}

TimeQueue::~TimeQueue()
{
}

void 
TimeQueue::clear()
{
  globalData.theNextTimerJob = 65535;
  globalData.theCurrentTimer = 0;
  globalData.theShortTQIndex = 0;
  globalData.theLongTQIndex = 0;
  for (int i = 0; i < MAX_NO_OF_TQ; i++)
    theFreeIndex[i] = i+1;
  theFreeIndex[MAX_NO_OF_TQ - 1] = NULL_TQ_ENTRY;
  globalData.theFirstFreeTQIndex = 0;
}

void 
TimeQueue::insert(Signal* signal, BlockNumber bnr, 
		  GlobalSignalNumber gsn, Uint32 delayTime)
{
  if (delayTime == 0)
    delayTime = 1;
  register Uint32 regCurrentTime = globalData.theCurrentTimer;
  register Uint32 i;
  register Uint32 regSave;
  register TimerEntry newEntry;
  
  newEntry.time_struct.delay_time = regCurrentTime + delayTime;
  newEntry.time_struct.job_index = getIndex();
  regSave = newEntry.copy_struct;
  
  globalScheduler.insertTimeQueue(signal, bnr, gsn, 
				  newEntry.time_struct.job_index);
  
  if (newEntry.time_struct.delay_time < globalData.theNextTimerJob)
    globalData.theNextTimerJob = newEntry.time_struct.delay_time;
  if (delayTime < 100){
    register Uint32 regShortIndex = globalData.theShortTQIndex;
    if (regShortIndex == 0){
      theShortQueue[0].copy_struct = newEntry.copy_struct;
    } else if (regShortIndex >= MAX_NO_OF_SHORT_TQ - 1) {
      ERROR_SET(ecError, NDBD_EXIT_TIME_QUEUE_SHORT, 
		"Too many in Short Time Queue", "TimeQueue.C" );
    } else {
      for (i = 0; i < regShortIndex; i++) {
        if (theShortQueue[i].time_struct.delay_time > 
	    newEntry.time_struct.delay_time)  {
	  
          regSave = theShortQueue[i].copy_struct;
          theShortQueue[i].copy_struct = newEntry.copy_struct;
          break;
	}
      }
      if (i == regShortIndex) {
        theShortQueue[regShortIndex].copy_struct = regSave;
      } else {
        for (i++; i < regShortIndex; i++) {
	  register Uint32 regTmp = theShortQueue[i].copy_struct;
	  theShortQueue[i].copy_struct = regSave;
	  regSave = regTmp;
        }
        theShortQueue[regShortIndex].copy_struct = regSave;
      }
    }
    globalData.theShortTQIndex = regShortIndex + 1;
  } else if (delayTime <= (unsigned)MAX_TIME_QUEUE_VALUE) {
    register Uint32 regLongIndex = globalData.theLongTQIndex;
    if (regLongIndex == 0) {
      theLongQueue[0].copy_struct = newEntry.copy_struct;
    } else if (regLongIndex >= MAX_NO_OF_LONG_TQ - 1) {
      ERROR_SET(ecError, NDBD_EXIT_TIME_QUEUE_LONG, 
		"Too many in Long Time Queue", "TimeQueue.C" );
    } else {
      for (i = 0; i < regLongIndex; i++) {
        if (theLongQueue[i].time_struct.delay_time > 
	    newEntry.time_struct.delay_time) {
	  
          regSave = theLongQueue[i].copy_struct;
          theLongQueue[i].copy_struct = newEntry.copy_struct;
          break;
        }
      }
      if (i == regLongIndex) {
        theLongQueue[regLongIndex].copy_struct = regSave;
      } else {
        for (i++; i < regLongIndex; i++) {
          register Uint32 regTmp = theLongQueue[i].copy_struct;
          theLongQueue[i].copy_struct = regSave;
          regSave = regTmp;
        }
        theLongQueue[regLongIndex].copy_struct = regSave;
      }
    }
    globalData.theLongTQIndex = regLongIndex + 1;
  } else {
    ERROR_SET(ecError, NDBD_EXIT_TIME_QUEUE_DELAY, 
	      "Too long delay for Time Queue", "TimeQueue.C" );
  }
}

// executes the expired signals;
void
TimeQueue::scanTable()
{
  register Uint32 i, j;
  
  globalData.theCurrentTimer++;
  if (globalData.theCurrentTimer == 32000)
    recount_timers();
  if (globalData.theNextTimerJob > globalData.theCurrentTimer)
    return;
  globalData.theNextTimerJob = 65535; // If no more timer jobs
  for (i = 0; i < globalData.theShortTQIndex; i++) {
    if (theShortQueue[i].time_struct.delay_time > globalData.theCurrentTimer){
      break;
    } else {
      releaseIndex((Uint32)theShortQueue[i].time_struct.job_index);
      globalScheduler.scheduleTimeQueue(theShortQueue[i].time_struct.job_index);
    }
  }
  if (i > 0) {
    for (j = i; j < globalData.theShortTQIndex; j++)
      theShortQueue[j - i].copy_struct = theShortQueue[j].copy_struct;
    globalData.theShortTQIndex -= i;
  }
  if (globalData.theShortTQIndex != 0) // If not empty
    globalData.theNextTimerJob = theShortQueue[0].time_struct.delay_time;
  for (i = 0; i < globalData.theLongTQIndex; i++) {
    if (theLongQueue[i].time_struct.delay_time > globalData.theCurrentTimer) {
      break;
    } else {
      releaseIndex((Uint32)theLongQueue[i].time_struct.job_index);
      globalScheduler.scheduleTimeQueue(theLongQueue[i].time_struct.job_index);
    }
  }
  if (i > 0) {
    for (j = i; j < globalData.theLongTQIndex; j++)
      theLongQueue[j - i].copy_struct = theLongQueue[j].copy_struct;
    globalData.theLongTQIndex -= i;
  }  
  if (globalData.theLongTQIndex != 0) // If not empty
    if (globalData.theNextTimerJob > theLongQueue[0].time_struct.delay_time)
      globalData.theNextTimerJob = theLongQueue[0].time_struct.delay_time;
}

void
TimeQueue::recount_timers()
{
  Uint32 i;

  globalData.theCurrentTimer = 0;
  globalData.theNextTimerJob -= 32000;

  for (i = 0; i < globalData.theShortTQIndex; i++)
    theShortQueue[i].time_struct.delay_time -= 32000;
  for (i = 0; i < globalData.theLongTQIndex; i++)
    theLongQueue[i].time_struct.delay_time -= 32000;
}

Uint32
TimeQueue::getIndex()
{
  Uint32 retValue = globalData.theFirstFreeTQIndex;
  globalData.theFirstFreeTQIndex = (Uint32)theFreeIndex[retValue];
  if (retValue >= MAX_NO_OF_TQ)
    ERROR_SET(fatal, NDBD_EXIT_TIME_QUEUE_INDEX, 
	      "Index out of range", "TimeQueue.C" );
  return retValue;
}

void
TimeQueue::releaseIndex(Uint32 aIndex)
{
  theFreeIndex[aIndex] = globalData.theFirstFreeTQIndex;
  globalData.theFirstFreeTQIndex = aIndex;
}


