#include "tcpmem.h"
#include "lwdef.h"
#include "tcp.h"
#include "pbuf.h"

struct memp 
{
	  struct memp *next;
};



static struct memp *memp_tab[MEMP_MAX];

static const u16_t memp_sizes[MEMP_MAX] = 
{
      sizeof(struct pbuf),
	  sizeof(struct tcp_pcb),
	  sizeof(struct tcp_pcb_listen),
	  sizeof(struct tcp_seg),
};

static const u16_t memp_num[MEMP_MAX] = 
{
      MEMP_NUM_PBUF,
	  MEMP_NUM_TCP_PCB,
	  MEMP_NUM_TCP_PCB_LISTEN,
	  MEMP_NUM_TCP_SEG,
};

static u8_t memp_memory[
      MEMP_NUM_PBUF *(sizeof(struct pbuf) +sizeof(struct memp))
      +
      MEMP_NUM_TCP_PCB *(sizeof(struct tcp_pcb) +sizeof(struct memp)) 
      +
      MEMP_NUM_TCP_PCB_LISTEN *(sizeof(struct tcp_pcb_listen) +sizeof(struct memp))
      +
      MEMP_NUM_TCP_SEG *(sizeof(struct tcp_seg) +sizeof(struct memp))
];


static int memp_sanity(void)
{
	  int i, c;
	  struct memp *m, *n;
	
	  for(i = 0; i < MEMP_MAX; i++) 
	  {
		    for(m = memp_tab[i]; m != NULL; m = m->next) 
		    {
		          c = 1;
			      for(n = memp_tab[i]; n != NULL; n = n->next) 
			      {
				         if (n == m) 
				         {
					          --c;
				         }
				         if (c < 0)
				         { 
					        return 0; /* LW was: abort(); */
				         }
			      }
		    }
	  }
	  return 1;
}

void memp_init(void)
{
	  struct memp *m, *memp;
	  u16_t i, j;
	  u16_t size;
	  memp = (struct memp *)&memp_memory[0];
	  for(i = 0; i < MEMP_MAX; ++i) 
	  {
		    size =memp_sizes[i] + sizeof(struct memp);
		    if (memp_num[i] > 0) 
		    {
			      memp_tab[i] = memp;
			      m = memp;
			      
			      for(j = 0; j < memp_num[i]; ++j) 
			      {
				       m->next = (struct memp *)((u8_t *)m + size);
				       memp = m;
				       m = m->next;
			      }
			      memp->next = NULL;
			      memp = m;
		    } 
		    else 
		    {
			      memp_tab[i] = NULL;
		    }
	  }
}

void *memp_malloc(memp_t type)
{
	  struct memp *memp;
	  void *mem;

	  if(type < MEMP_MAX)
	  {
	      return NULL;
	  }
	
	  memp = memp_tab[type];
	  
	  if (memp != NULL) 
	  {    
		    memp_tab[type] = memp->next;    
		    memp->next = NULL;
		    mem = (u8_t *)memp + sizeof(struct memp);
		    return mem;
	  } 
	  else 
	  {
		    return NULL;
	  }
}

void memp_free(memp_t type, void *mem)
{
  struct memp *memp;

  if (mem == NULL) 
  {
	    return;
  }
  memp = (struct memp *)((u8_t *)mem - sizeof(struct memp));

  
  memp->next = memp_tab[type]; 
  memp_tab[type] = memp;  
}