#include "io.h"
#include <stdlib.h>
#ifndef _MSC_VER
#include <unistd.h>
#endif


/* FIXME: make allocation dynamic */


#ifdef IMAGER_DEBUG_MALLOC

#define MAXMAL 102400
#define MAXDESC 65

#define UNDRRNVAL 10
#define OVERRNVAL 10

#define PADBYTE 0xaa


static int malloc_need_init = 1;

typedef struct {
  void* ptr;
  size_t size;
  char comm[MAXDESC];
} malloc_entry;

malloc_entry malloc_pointers[MAXMAL];




/* Utility functions */


static
void
malloc_init(void) {
  int i;
  for(i=0; i<MAXMAL; i++) malloc_pointers[i].ptr = NULL;
  malloc_need_init = 0;
  atexit(malloc_state);
}


static
int 
find_ptr(void *p) {
  int i;
  for(i=0;i<MAXMAL;i++)
    if (malloc_pointers[i].ptr == p)
      return i;
  return -1;
}


/* Takes a pointer to real start of array,
 * sets the entries in the table, returns
 * the offset corrected pointer */

static
void *
set_entry(int i, char *buf, size_t size, char *file, int line) {
  memset( buf, PADBYTE, UNDRRNVAL );
  memset( &buf[UNDRRNVAL+size], PADBYTE, OVERRNVAL );
  buf += UNDRRNVAL;
  malloc_pointers[i].ptr  = buf;
  malloc_pointers[i].size = size;
  sprintf(malloc_pointers[i].comm,"%s (%d)", file, line);
  return buf;
}




void
malloc_state(void) {
  int i, total = 0;

  i_clear_error();
  mm_log((0,"malloc_state()\n"));
  bndcheck_all();
  for(i=0; i<MAXMAL; i++) if (malloc_pointers[i].ptr != NULL) {
    mm_log((0,"%d: %d (0x%x) : %s\n", i, malloc_pointers[i].size, malloc_pointers[i].ptr, malloc_pointers[i].comm));
    total += malloc_pointers[i].size;
  }
  if (total == 0) mm_log((0,"No memory currently used!\n"))
		    else mm_log((0,"total: %d\n",total));
}



void*
mymalloc_file_line(size_t size, char* file, int line) {
  char *buf;
  int i;
  if (malloc_need_init) malloc_init();
  
  /* bndcheck_all(); Uncomment for LOTS OF THRASHING */
  
  if ( (i = find_ptr(NULL)) < 0 ) {
    mm_log((0,"more than %d segments allocated at %s (%d)\n", MAXMAL, file, line));
    exit(3);
  }

  if ( (buf = malloc(size+UNDRRNVAL+OVERRNVAL)) == NULL ) {
    mm_log((1,"Unable to allocate %i for %s (%i)\n", size, file, line));
    exit(3);
  }
  
  buf = set_entry(i, buf, size, file, line);
  mm_log((1,"mymalloc_file_line: slot <%d> %d bytes allocated at %p for %s (%d)\n", i, size, buf, file, line));
  return buf;
}







void*
myrealloc_file_line(void *ptr, size_t newsize, char* file, int line) {
  char *buf;
  int i;

  if (malloc_need_init) malloc_init();
  /* bndcheck_all(); ACTIVATE FOR LOTS OF THRASHING */
  
  if (!ptr) {
    mm_log((1, "realloc called with ptr = NULL, sending request to malloc\n"));
    return mymalloc_file_line(newsize, file, line);
  }
  
  if (!newsize) {
    mm_log((1, "newsize = 0, sending request to free\n"));
    myfree_file_line(ptr, file, line);
    return NULL;
  }

  if ( (i = find_ptr(ptr)) == -1) {
    mm_log((0, "Unable to find %p in realloc for %s (%i)\n", ptr, file, line));
    exit(3);
  }
  
  if ( (buf = realloc(((char *)ptr)-UNDRRNVAL, UNDRRNVAL+OVERRNVAL+newsize)) == NULL ) {
    mm_log((1,"Unable to reallocate %i bytes at %p for %s (%i)\n", newsize, ptr, file, line));
    exit(3); 
  }
  
  buf = set_entry(i, buf, newsize, file, line);
  mm_log((1,"realloc_file_line: slot <%d> %d bytes allocated at %p for %s (%d)\n", i, newsize, buf, file, line));
  return buf;
}




static
void
bndcheck(int idx) {
  int i;
  size_t s = malloc_pointers[idx].size;
  unsigned char *pp = malloc_pointers[idx].ptr;
  if (!pp) {
    mm_log((1, "bndcheck: No pointer in slot %d\n", idx));
    return;
  }
  
  for(i=0;i<UNDRRNVAL;i++)
     if (pp[-(1+i)] != PADBYTE)
     mm_log((1,"bndcheck: UNDERRUN OF %d bytes detected: slot = %d, point = %p, size = %d\n", i+1, idx, pp, s ));
  
     for(i=0;i<OVERRNVAL;i++)
    if (pp[s+i] != PADBYTE)
      mm_log((1,"bndcheck: OVERRUN OF %d bytes detected: slot = %d, point = %p, size = %d\n", i+1, idx, pp, s ));
}

void
bndcheck_all() {
  int idx;
  mm_log((1, "bndcheck_all()\n"));
  for(idx=0; idx<MAXMAL; idx++)
    if (malloc_pointers[idx].ptr)
      bndcheck(idx);
}





void
myfree_file_line(void *p, char *file, int line) {
  char  *pp = p;
  int match = 0;
  int i;
  
  for(i=0; i<MAXMAL; i++) if (malloc_pointers[i].ptr == p) {
    mm_log((1,"myfree_file_line: pointer %i (%s) freed at %s (%i)\n", i, malloc_pointers[i].comm, file, line));
    bndcheck(i);
    malloc_pointers[i].ptr = NULL;
    match++;
  }

  mm_log((1, "myfree_file_line: freeing address %p (real %p)\n", pp, pp-UNDRRNVAL));
  
  if (match != 1) {
    mm_log((1, "myfree_file_line: INCONSISTENT REFCOUNT %d at %s (%i)\n", match, file, line));
    fprintf(stderr, "myfree_file_line: INCONSISTENT REFCOUNT %d at %s (%i)\n", match, file, line);
		exit(255);
  }
  
  
  free(pp-UNDRRNVAL);
}

#else 

#define malloc_comm(a,b) (mymalloc(a))

void
malloc_state() {
  printf("malloc_state: not in debug mode\n");
}

void*
mymalloc(int size) {
  void *buf;

  if ( (buf = malloc(size)) == NULL ) {
    mm_log((1, "mymalloc: unable to malloc %d\n", size));
    fprintf(stderr,"Unable to malloc %d.\n", size); exit(3);
  }
  mm_log((1, "mymalloc(size %d) -> %p\n", size, buf));
  return buf;
}

void
myfree(void *p) {
  mm_log((1, "myfree(p %p)\n", p));
  free(p);
}

void *
myrealloc(void *block, size_t size) {
  void *result;

  mm_log((1, "myrealloc(block %p, size %u)\n", block, size));
  if ((result = realloc(block, size)) == NULL) {
    mm_log((1, "myrealloc: out of memory\n"));
    fprintf(stderr, "Out of memory.\n");
    exit(3);
  }
  return result;
}

#endif /* IMAGER_MALLOC_DEBUG */




/* memory pool implementation */

void
i_mempool_init(i_mempool *mp) {
  mp->alloc = 10;
  mp->used  = 0;
  mp->p = mymalloc(sizeof(void*)*mp->alloc);
}

void
i_mempool_extend(i_mempool *mp) {
  mp->p = myrealloc(mp->p, mp->alloc * 2);
  mp->alloc *=2;
}

void *
i_mempool_alloc(i_mempool *mp, size_t size) {
  if (mp->used == mp->alloc) i_mempool_extend(mp);
  mp->p[mp->used] = mymalloc(size);
  mp->used++;
  return mp->p[mp->used-1];
}


void
i_mempool_destroy(i_mempool *mp) {
  unsigned int i;
  for(i=0; i<mp->used; i++) myfree(mp->p[i]);
  myfree(mp->p);
}



/* Should these really be here? */

#undef min
#undef max

int
i_min(int a,int b) {
  if (a<b) return a; else return b;
}

int
i_max(int a,int b) {
  if (a>b) return a; else return b;
}


struct utf8_size {
  int mask, expect;
  int size;
};

struct utf8_size utf8_sizes[] =
{
  { 0x80, 0x00, 1 },
  { 0xE0, 0xC0, 2 },
  { 0xF0, 0xE0, 3 },
  { 0xF8, 0xF0, 4 },
};

/*
=item utf8_advance(char **p, int *len)

Retreive a UTF8 character from the stream.

Modifies *p and *len to indicate the consumed characters.

This doesn't support the extended UTF8 encoding used by later versions
of Perl.

=cut
*/

unsigned long i_utf8_advance(char const **p, int *len) {
  unsigned char c;
  int i, ci, clen = 0;
  unsigned char codes[3];
  if (*len == 0)
    return ~0UL;
  c = *(*p)++; --*len;

  for (i = 0; i < sizeof(utf8_sizes)/sizeof(*utf8_sizes); ++i) {
    if ((c & utf8_sizes[i].mask) == utf8_sizes[i].expect) {
      clen = utf8_sizes[i].size;
    }
  }
  if (clen == 0 || *len < clen-1) {
    --*p; ++*len;
    return ~0UL;
  }

  /* check that each character is well formed */
  i = 1;
  ci = 0;
  while (i < clen) {
    if (((*p)[ci] & 0xC0) != 0x80) {
      --*p; ++*len;
      return ~0UL;
    }
    codes[ci] = (*p)[ci];
    ++ci; ++i;
  }
  *p += clen-1; *len -= clen-1;
  if (c & 0x80) {
    if ((c & 0xE0) == 0xC0) {
      return ((c & 0x1F) << 6) + (codes[0] & 0x3F);
    }
    else if ((c & 0xF0) == 0xE0) {
      return ((c & 0x0F) << 12) | ((codes[0] & 0x3F) << 6) | (codes[1] & 0x3f);
    }
    else if ((c & 0xF8) == 0xF0) {
      return ((c & 0x07) << 18) | ((codes[0] & 0x3F) << 12) 
              | ((codes[1] & 0x3F) << 6) | (codes[2] & 0x3F);
    }
    else {
      *p -= clen; *len += clen;
      return ~0UL;
    }
  }
  else {
    return c;
  }
}