/* This file is in the public domain. */

#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/time.h>

#include "alloc.h"
#undef malloc
#undef realloc
#undef free

struct blk {
  BLK *ablink;
  BLK *aflink;
  BLK *lblink;
  BLK *lflink;
  int len;
  unsigned int flags;
#define BF_FREE 0x00000001
  SLOC *a;
  SLOC *r;
  SLOC *f;
  } ;

static char dummy __attribute__((__aligned__));
#define ALIGNMENT (__alignof__(dummy))
#define GUARD ALIGNMENT

static int didinit = 0;
static unsigned int rstate[64];
static char *rsp;
static BLK *allblk;

static unsigned char guard1[GUARD];
static unsigned char guard2[GUARD];

static void init(void)
{
 struct timeval tv;
 char *os;
 int i;

 if (didinit) return;
 os = initstate(tv.tv_sec^tv.tv_usec,(void *)&rstate[0],sizeof(rstate));
 for (i=GUARD-1;i>=0;i--)
  { guard1[i] = (random() >> 20) & 0xff;
    guard2[i] = (random() >> 19) & 0xff;
  }
 rsp = setstate(os);
 didinit = 1;
}

static void blk_link(BLK *b)
{
 b->aflink = allblk;
 b->ablink = 0;
 allblk = b;
 if (b->aflink) b->aflink->ablink = b;
 b->lflink = b->a->chain;
 b->lblink = 0;
 b->a->chain = b;
 if (b->lflink) b->lflink->lblink = b;
}

static void blk_unlink(BLK *b)
{
 if (b->aflink) b->aflink->ablink = b->ablink;
 if (b->ablink) b->ablink->aflink = b->aflink; else allblk = b->aflink;
 if (b->lflink) b->lflink->lblink = b->lblink;
 if (b->lblink) b->lblink->lflink = b->lflink; else b->a->chain = b->lflink;
}

void *loc_malloc(SLOC *l, int nb)
{
 char *v;
 BLK *b;
 void *d;

 init();
 if (nb == 0) return(0);
 v = malloc(sizeof(BLK)+GUARD+nb+GUARD);
 b = (void *)v;
 d = b + 1;
 b->len = nb;
 b->flags = 0;
 b->a = l;
 b->r = 0;
 b->f = 0;
 blk_link(b);
 bcopy(&guard1[0],d,GUARD);
 bcopy(&guard2[0],((char *)d)+GUARD+nb,GUARD);
 return(((char *)d)+GUARD);
}

void *loc_realloc(SLOC *l, void *data, int nb)
{
 char *v;
 BLK *b;
 char *r;

 init();
 if (data == 0) return(loc_malloc(l,nb));
 if (nb < 1)
  { loc_free(l,data);
    return(0);
  }
 v = ((char *)data) - GUARD;
 b = ((BLK *)v) - 1;
 if (bcmp(v,&guard1[0],GUARD)) abort();
 if (bcmp(((char *)data)+b->len,&guard2[0],GUARD)) abort();
 blk_unlink(b);
 b->flags = BF_FREE;
 r = realloc(b,sizeof(BLK)+GUARD+nb+GUARD);
 if (r == 0)
  { blk_link(b);
    return(0);
  }
 b = (void *)r;
 b->r = l;
 b->len = nb;
 b->flags &= ~BF_FREE;
 blk_link(b);
 bcopy(&guard1[0],b+1,GUARD);
 bcopy(&guard2[0],((char *)(b+1))+GUARD+nb,GUARD);
 return(((char *)(b+1))+GUARD);
}

void loc_free(SLOC *l, void *data)
{
 char *v;
 BLK *b;

 init();
 if (data == 0) return;
 v = ((char *)data) - GUARD;
 b = ((BLK *)v) - 1;
 if (bcmp(v,&guard1[0],GUARD)) abort();
 if (bcmp(((char *)data)+b->len,&guard2[0],GUARD)) abort();
 blk_unlink(b);
 b->f = l;
 b->flags = BF_FREE;
 free(b);
}

void loc_dump(void)
{
 BLK *b;
 BLK *c;
 int fd;
 FILE *f;

 fd = open("loc.dbg",O_WRONLY|O_APPEND,0);
 if (fd < 0) return;
 f = fdopen(fd,"a");
 fprintf(f,"dump, offset %d\n",(int)(sizeof(BLK)+GUARD));
 for (b=allblk;b;b=b->aflink)
  { if (b == b->a->chain)
     { fprintf(f,"    %s %s %d:\n",b->a->file,b->a->func,b->a->ln);
       for (c=b;c;c=c->lflink)
	{ fprintf(f,"\t%p\n",(void *)(((char *)c)+sizeof(BLK)+GUARD));
	}
     }
  }
 fclose(f);
}