/*****************************************************************************/
/* D2K: A Doom Source Port for the 21st Century                              */
/*                                                                           */
/* Copyright (C) 2014: See COPYRIGHT file                                    */
/*                                                                           */
/* This file is part of D2K.                                                 */
/*                                                                           */
/* D2K is free software: you can redistribute it and/or modify it under the  */
/* terms of the GNU General Public License as published by the Free Software */
/* Foundation, either version 2 of the License, or (at your option) any      */
/* later version.                                                            */
/*                                                                           */
/* D2K 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 for more    */
/* details.                                                                  */
/*                                                                           */
/* You should have received a copy of the GNU General Public License along   */
/* with D2K.  If not, see <http://www.gnu.org/licenses/>.                    */
/*                                                                           */
/*****************************************************************************/


#include "z_zone.h"

#include "doomstat.h"

#ifdef __GNUG__
#pragma implementation "w_wad.h"
#endif
#include "w_wad.h"
#include "z_zone.h"
#include "lprintf.h"

static struct {
  void *cache;
#ifdef TIMEDIAG
  int locktic;
#endif
  unsigned int locks;
} *cachelump;

#ifdef HEAPDUMP
void W_PrintLump(FILE* fp, void* p) {
  int i;
  for (i=0; i<numlumps; i++)
    if (cachelump[i].cache == p) {
      fprintf(fp, " %8.8s %6u %2d %6d", lumpinfo[i].name,
	      W_LumpLength(i), cachelump[i].locks, gametic - cachelump[i].locktic);
      return;
    }
  fprintf(fp, " not found");
}
#endif

#ifdef TIMEDIAG
static void W_ReportLocks(void)
{
  int i;
  lprintf(LO_DEBUG, "W_ReportLocks:\nLump     Size   Locks  Tics\n");
  for (i=0; i<numlumps; i++) {
    if (cachelump[i].locks)
      lprintf(LO_DEBUG, "%8.8s %6u %2d   %6d\n", lumpinfo[i].name,
	      W_LumpLength(i), cachelump[i].locks, gametic - cachelump[i].locktic);
  }
}
#endif

/* W_InitCache
 *
 * cph 2001/07/07 - split from W_Init
 */
void W_InitCache(void)
{
  // set up caching
  cachelump = calloc(sizeof *cachelump, numlumps);
  if (!cachelump)
    I_Error ("W_Init: Couldn't allocate lumpcache");

#ifdef TIMEDIAG
  atexit(W_ReportLocks);
#endif
}

void W_DoneCache(void)
{
}

/* W_CacheLumpNum
 * killough 4/25/98: simplified
 * CPhipps - modified for new lump locking scheme
 *           returns a const*
 */

const void *W_CacheLumpNum(int lump)
{
  const int locks = 1;
#ifdef RANGECHECK
  if ((unsigned)lump >= (unsigned)numlumps)
    I_Error("W_CacheLumpNum: %i >= numlumps", lump);
#endif

  if (!cachelump[lump].cache)      // read the lump in
    W_ReadLump(lump, Z_Malloc(W_LumpLength(lump), PU_CACHE, &cachelump[lump].cache));

  /* cph - if wasn't locked but now is, tell z_zone to hold it */
  if (!cachelump[lump].locks && locks) {
    Z_ChangeTag(cachelump[lump].cache,PU_STATIC);
#ifdef TIMEDIAG
    cachelump[lump].locktic = gametic;
#endif
  }
  cachelump[lump].locks += locks;

#ifdef SIMPLECHECKS
  if (!((cachelump[lump].locks+1) & 0xf))
    lprintf(LO_DEBUG, "W_CacheLumpNum: High lock on %8s (%d)\n",
	    lumpinfo[lump].name, cachelump[lump].locks);
#endif

  return cachelump[lump].cache;
}

const void *W_LockLumpNum(int lump)
{
  return W_CacheLumpNum(lump);
}

/*
 * W_UnlockLumpNum
 *
 * CPhipps - this changes (should reduce) the number of locks on a lump
 */

void W_UnlockLumpNum(int lump)
{
  const int unlocks = 1;
#ifdef SIMPLECHECKS
  if ((signed short)cachelump[lump].locks < unlocks)
    lprintf(LO_DEBUG, "W_UnlockLumpNum: Excess unlocks on %8s (%d-%d)\n",
	    lumpinfo[lump].name, cachelump[lump].locks, unlocks);
#endif
  cachelump[lump].locks -= unlocks;
  /* cph - Note: must only tell z_zone to make purgeable if currently locked,
   * else it might already have been purged
   */
  if (unlocks && !cachelump[lump].locks)
    Z_ChangeTag(cachelump[lump].cache, PU_CACHE);
}

/* vi: set et ts=2 sw=2: */

