/*
 * Memory alllocation for the Wine Library toolkit
 *
 * Copyright (C) 1994 Miguel de Icaza
 *
 * All the memory management is being done by the libc malloc and friends.
 */

/* #ifndef __STDC__ */
#include <malloc.h>
#include <stdio.h>
#include <string.h>
/* #endif */
#include "windows.h"
#include "xmalloc.h"

#ifdef WINELIB16

/* Controls the blocks per handle table */
#define MAXBLOCKS 1024

static char Copyright [] = "Copyright (C) 1994 Miguel de Icaza";

typedef struct handle_table {
    struct handle_table *next;
    void *blocks [MAXBLOCKS];
} handle_table_t;

static handle_table_t handle_table;

static void **HEAP_GetFreeSlot (HANDLE *hNum)
{
    handle_table_t *table, *last;
    int i, j;

    for (table = &handle_table, j = 0; table; table = table->next, j++){
	for (i = 0; i < MAXBLOCKS; i++)
	    if (!table->blocks [i])
		goto AssignBlock;
	last = table;
    }

    /* No free slots */
    last->next = xmalloc (sizeof (handle_table_t));
    table = last->next;
    memset (table, 0, sizeof (handle_table_t));
    i = 0;
    
 AssignBlock:
    *hNum = j*MAXBLOCKS+i;
    return &table->blocks [i];
}

static void HEAP_Handle_is_Zero ()
{
    printf ("Warning: Handle is Zero, segmentation fault comming\n");
}

static void **HEAP_FindSlot (HANDLE hNum)
{
    handle_table_t *table = &handle_table;
    int i, j;

    if (!hNum)
	HEAP_Handle_is_Zero ();

    hNum--;
    for (j = hNum; j > MAXBLOCKS; j -= MAXBLOCKS){
	table = table->next;
	if (!table) return 0;
    }
    return &table->blocks [hNum%MAXBLOCKS];
}

HANDLE LocalAlloc (WORD flags, WORD bytes)
{
    void *m;
    void **slot;
    HANDLE hMem;

    slot = HEAP_GetFreeSlot (&hMem);
    if ((m = malloc (bytes)))
    {
	*slot = m;
	if (flags & LMEM_ZEROINIT) memset( m, 0, bytes );

#ifdef DEBUG_HEAP
	printf ("Handle %d [%d] = %p\n", hMem+1, bytes, m);
#endif
	return hMem+1;
    }
    return 0;
}

WORD LocalCompact (WORD min_free)
{
    return min_free;
}

WORD LocalFlags (HANDLE hMem)
{
    return 0;
}

HANDLE LocalFree (HANDLE hMem)
{
    void **m;
  if(!hMem)
    return 0;
  m = HEAP_FindSlot (hMem);

    free (*m);
    *m = 0;
    return 0;
}

BOOL LocalInit (WORD segment, WORD start, WORD end)
{
    return 1;
}

WORD LocalLock (HANDLE hMem)
{
    void **m = HEAP_FindSlot (hMem);
#ifdef DEBUG_HEAP
    printf (">%d->%p\n", hMem, *m);
#endif
    return m ? *m : 0;
}

HANDLE LocalReAlloc (HANDLE hMem, WORD flags, WORD bytes)
{
    void **m = HEAP_FindSlot (hMem);

    xrealloc (*m, bytes);
}

WORD LocalSize (HANDLE hMem)
{
    /* Not implemented yet */
}


BOOL LocalUnlock (HANDLE hMem)
{
    return 0;
}

HANDLE GlobalAlloc (WORD flags, DWORD size)
{
    return LocalAlloc (flags, size);
}

HANDLE GlobalFree (HANDLE hMem)
{
    return LocalFree (hMem);
}

char *GlobalLock (HANDLE hMem)
{
    return LocalLock (hMem);
}

BOOL GlobalUnlock (HANDLE hMem)
{
    return LocalUnlock (hMem);
}

WORD GlobalFlags (HANDLE hMem)
{
    return LocalFlags (hMem);
}

DWORD GlobalSize (HANDLE hMem)
{
    return LocalSize (hMem);
}

DWORD GlobalCompact(DWORD desired)
{
    if (desired)
	return desired;
    else
	return 0x01000000;	/* Should check the available core. */
}

HANDLE GlobalReAlloc(HANDLE hMem, DWORD new_size, WORD flags)
{
    if (!(flags & GMEM_MODIFY))
	return LocalReAlloc (hMem, new_size, flags);
}

int HEAP_LocalSize ()
{
    return 0;
}

int HEAP_LocalFindHeap ()
{
    return 0;
}

#ifdef UNIMPLEMENTED

DWORD int GlobalHandle(WORD selector)
{
}

#endif

#else /* WINELIB16 */

typedef struct { DWORD Size; DWORD Padding[3]; } HeapData;

HANDLE HEAP_Alloc (WORD flags, DWORD bytes)
{
    HeapData* m;

    bytes+=sizeof(HeapData);
    if ((m = malloc (bytes)))
    {
	if (flags & LMEM_ZEROINIT) memset( m, 0, bytes );
    }
    m->Size=bytes-sizeof(HeapData);
    return m+1;
}

HANDLE HEAP_Free (HANDLE hMem)
{
  HeapData* m;
  if(!hMem)
    return 0;
  m=(HeapData*)hMem;
  free(m-1);
  return 0;
}

DWORD HEAP_Size (HANDLE hMem)
{
  HeapData* m=(HeapData*)hMem;
  return (m-1)->Size;
}

HANDLE HEAP_ReAlloc(HANDLE hMem,DWORD bytes,UINT flags)
{
  HeapData* m=(HeapData*)hMem;
  if(!bytes)
  {
    free(m-1);
    return 0; /* Inaccurate behavior, but should suffice */
  }
  m=realloc (m-1, bytes+sizeof(HeapData));
  if(flags & LMEM_ZEROINIT && bytes > m->Size)
    memset( (char*)m+sizeof(HeapData)+m->Size, 0, bytes-m->Size );
  m->Size=bytes;
  return m+1;
}

HANDLE LocalAlloc (WORD flags, WORD bytes)
{
  return HEAP_Alloc(flags,bytes);
}

UINT LocalFlags (HANDLE hMem)
{
  return 0;
}

HANDLE LocalFree (HANDLE hMem)
{
  return HEAP_Free(hMem);
}

BOOL LocalInit (HANDLE segment, WORD start, WORD end)
{
  return TRUE;
}

LPVOID LocalLock (HANDLE hMem)
{
  return hMem;
}

HANDLE LocalReAlloc (HANDLE hMem, WORD new_size, WORD flags)
{
  if (!(flags & LMEM_MODIFY))
    return HEAP_ReAlloc (hMem, new_size, flags);
  else
    return hMem;
}

UINT LocalSize (HANDLE hMem)
{
  return HEAP_Size(hMem);
}

BOOL LocalUnlock (HANDLE hMem)
{
  return 0;
}

HANDLE GlobalAlloc (WORD flags, DWORD size)
{
  return HEAP_Alloc (flags,size);
}

HANDLE GlobalFree (HANDLE hMem)
{
  return HEAP_Free (hMem);
}

LPVOID GlobalLock (HGLOBAL hMem)
{
  return hMem;
}

BOOL GlobalUnlock (HANDLE hMem)
{
  return 0;
}

WORD GlobalFlags (HANDLE hMem)
{
  return LocalFlags (hMem);
}

DWORD GlobalSize (HANDLE hMem)
{
  return HEAP_Size (hMem);
}

HANDLE GlobalReAlloc(HANDLE hMem, DWORD new_size, WORD flags)
{
  if (!(flags & GMEM_MODIFY))
    return HEAP_ReAlloc (hMem, new_size, flags);
  else
    return hMem;
}

#endif