/*
** ObjectiveAmiga: Archiving
** See GNU:lib/libobjam/ReadMe for details
*/


#include "runtime.h"
#include "typedstream.h"
#include "hash.h"

#include <proto/dos.h>


/*
** Local definitions
*/

#define OBJC_TYPED_STREAM_VERSION 0x01

#define OBJC_MANAGED_STREAM  0x01
#define OBJC_FILE_STREAM     0x02
#define OBJC_MEMORY_STREAM   0x04

/* opcode masks */
#define _B_VALUE   0x1fU
#define _B_CODE    0xe0U
#define _B_SIGN    0x10U
#define _B_NUMBER  0x0fU

/* standard opcodes */
#define _B_INVALID 0x00U
#define _B_SINT    0x20U
#define _B_NINT    0x40U
#define _B_SSTR    0x60U
#define _B_NSTR    0x80U
#define _B_RCOMM   0xa0U
#define _B_UCOMM   0xc0U
#define _B_EXT     0xe0U

/* eXtension opcodes */
#define _BX_OBJECT  0x00U
#define _BX_CLASS   0x01U
#define _BX_SEL     0x02U
#define _BX_OBJREF  0x03U
#define _BX_OBJROOT 0x04U
#define _BX_EXT     0x1fU


/*
** Declare some functions
*/

static int objc_read_class (struct objc_typed_stream* stream, OCClass** class);
static int objc_write_use_common (struct objc_typed_stream* stream, unsigned int key);
static int objc_write_register_common (struct objc_typed_stream* stream, unsigned int key);
static int objc_write_class (struct objc_typed_stream* stream, struct objc_class* class);
static const char*__objc_skip_type (const char* type);
static void __objc_finish_write_root_object(struct objc_typed_stream*);
static void __objc_finish_read_root_object(struct objc_typed_stream*);


/*
** Auxiliary functions
*/

static __inline__ int
__objc_code_unsigned_char (unsigned char* buf, unsigned char val)
{
  if ((val&_B_VALUE) == val)
    { buf[0] = val|_B_SINT; return 1; }
  else
    { buf[0] = _B_NINT|0x01; buf[1] = val; return 2; }
}


int
objc_write_unsigned_char (struct objc_typed_stream* stream, unsigned char value)
{
  unsigned char buf[sizeof (unsigned char)+1];
  int len = __objc_code_unsigned_char (buf, value);
  return (*stream->write)(stream->physical, buf, len);
}


static __inline__ int
__objc_code_char (unsigned char* buf, char val)
{
  if (val >= 0) return __objc_code_unsigned_char (buf, val);
  else { buf[0] = _B_NINT|_B_SIGN|0x01; buf[1] = -val; return 2; }
}


int
objc_write_char (struct objc_typed_stream* stream, char value)
{
  unsigned char buf[sizeof (char)+1];
  int len = __objc_code_char (buf, value);
  return (*stream->write)(stream->physical, buf, len);
}


static __inline__ int
__objc_code_unsigned_short (unsigned char* buf, unsigned short val)
{
  if (val <= 0xffU) return __objc_code_unsigned_char (buf, val);
  else 
  {
    buf[0] = _B_NINT|0x02;
    buf[1] = val/0x100;
    buf[2] = val%0x100;
    return 3;
  }
}


int
objc_write_unsigned_short (struct objc_typed_stream* stream, unsigned short value)
{
  unsigned char buf[sizeof (unsigned short)+1];
  int len = __objc_code_unsigned_short (buf, value);
  return (*stream->write)(stream->physical, buf, len);
}

      
static __inline__ int
__objc_code_short (unsigned char* buf, short val)
{
  if (val > 0) return __objc_code_unsigned_short (buf, val);
  if (val > -0x7f) /* val > -128 */ return __objc_code_char (buf, val);
  else 
  {
    int len = __objc_code_unsigned_short (buf, -val);
    buf[0] |= _B_SIGN;
    return len;
  }
}


int
objc_write_short (struct objc_typed_stream* stream, short value)
{
  unsigned char buf[sizeof (short)+1];
  int len = __objc_code_short (buf, value);
  return (*stream->write)(stream->physical, buf, len);
}

      
static __inline__ int
__objc_code_unsigned_int (unsigned char* buf, unsigned int val)
{
  if (val < 0x10000) return __objc_code_unsigned_short (buf, val%0x10000);
  else if (val < 0x1000000)
  {
    buf[0] = _B_NINT|3;
    buf[1] = val/0x10000;
    buf[2] = (val%0x10000)/0x100;
    buf[3] = val%0x100;
    return 4;
  }
  else 
  {
    buf[0] = _B_NINT|4;
    buf[1] = val/0x1000000;
    buf[2] = (val%0x1000000)/0x10000;
    buf[3] = (val%0x10000)/0x100;
    buf[4] = val%0x100;
    return 5;
  }
}


int
objc_write_unsigned_int (struct objc_typed_stream* stream, unsigned int value)
{
  unsigned char buf[sizeof(unsigned int)+1];
  int len = __objc_code_unsigned_int (buf, value);
  return (*stream->write)(stream->physical, buf, len);
}


static __inline__ int
__objc_code_int (unsigned char* buf, int val)
{
  if (val >= 0) return __objc_code_unsigned_int (buf, val);
  if (val > -0x7f) return __objc_code_char (buf, val);
  else 
  {
    int len = __objc_code_unsigned_int (buf, -val);
    buf[0] |= _B_SIGN;
    return len;
  }
}


int
objc_write_int (struct objc_typed_stream* stream, int value)
{
  unsigned char buf[sizeof(int)+1];
  int len = __objc_code_int (buf, value);
  return (*stream->write)(stream->physical, buf, len);
}


int
objc_write_string (struct objc_typed_stream* stream, const unsigned char* string, unsigned int nbytes)
{
  unsigned char buf[sizeof(unsigned int)+1];
  int len = __objc_code_unsigned_int (buf, nbytes);
  
  if ((buf[0]&_B_CODE) == _B_SINT) buf[0] = (buf[0]&_B_VALUE)|_B_SSTR;
  else /* _B_NINT */ buf[0] = (buf[0]&_B_VALUE)|_B_NSTR;

  if ((*stream->write)(stream->physical, buf, len) != 0)
    return (*stream->write)(stream->physical, string, nbytes);
  else return 0;
}


int
objc_write_string_atomic (struct objc_typed_stream* stream, unsigned char* string, unsigned int nbytes)
{
  unsigned int key;
  if ((key = (unsigned int)hash_value_for_key (stream->stream_table, string)))
    return objc_write_use_common (stream, key);
  else
  {
    int length;
    hash_add (&stream->stream_table, (void*)key=(unsigned int)string, string);
    if ((length = objc_write_register_common (stream, key)))
      return objc_write_string (stream, string, nbytes);
    return length;
  }
}


static int
objc_write_register_common (struct objc_typed_stream* stream, unsigned int key)
{
  unsigned char buf[sizeof (unsigned int)+2];
  int len = __objc_code_unsigned_int (buf+1, key);
  if (len == 1)
  {
    buf[0] = _B_RCOMM|0x01;
    buf[1] &= _B_VALUE;
    return (*stream->write)(stream->physical, buf, len+1);
  }
  else
  {
    buf[1] = (buf[1]&_B_VALUE)|_B_RCOMM;
    return (*stream->write)(stream->physical, buf+1, len);
  }
}


static int
objc_write_use_common (struct objc_typed_stream* stream, unsigned int key)
{
  unsigned char buf[sizeof (unsigned int)+2];
  int len = __objc_code_unsigned_int (buf+1, key);
  if (len == 1)
  {
    buf[0] = _B_UCOMM|0x01;
    buf[1] &= _B_VALUE;
    return (*stream->write)(stream->physical, buf, 2);
  }
  else
  {
    buf[1] = (buf[1]&_B_VALUE)|_B_UCOMM;
    return (*stream->write)(stream->physical, buf+1, len);
  }
}


static __inline__ int
__objc_write_extension (struct objc_typed_stream* stream, unsigned char code)
{
  if (code <= _B_VALUE)
  {
    unsigned char buf = code|_B_EXT;
    return (*stream->write)(stream->physical, &buf, 1);
  }
  else abort();
}


__inline__ int
__objc_write_object (struct objc_typed_stream* stream, id object)
{
  unsigned char buf = '\0';
  SEL write_sel = sel_get_uid ("write:");
  if (object)
  {
    __objc_write_extension (stream, _BX_OBJECT);
    objc_write_class (stream, object->class_pointer);
    (*objc_msg_lookup(object, write_sel))(object, write_sel, stream);
    return (*stream->write)(stream->physical, &buf, 1);
  }
  else return objc_write_use_common(stream, 0);
}


int 
objc_write_object_reference (struct objc_typed_stream* stream, id object)
{
  unsigned int key;
  if ((key = (unsigned int)hash_value_for_key (stream->object_table, object)))
    return objc_write_use_common (stream, key);

  __objc_write_extension (stream, _BX_OBJREF);
  return objc_write_unsigned_int (stream, (unsigned int)object);
}


int 
objc_write_root_object (struct objc_typed_stream* stream, id object)
{
  int len;
  if (stream->writing_root_p)
    __objc_archiving_fatal ("Function objc_write_root_object() called recursively",0);
  else
  {
    stream->writing_root_p = 1;
    __objc_write_extension (stream, _BX_OBJROOT);
    if((len = objc_write_object (stream, object))) __objc_finish_write_root_object(stream);
    stream->writing_root_p = 0;
  }
  return len;
}


int 
objc_write_object (struct objc_typed_stream* stream, id object)
{
  unsigned int key;
  if ((key = (unsigned int)hash_value_for_key (stream->object_table, object)))
    return objc_write_use_common (stream, key);
  else if (object == nil) return objc_write_use_common(stream, 0);
  else
  {
    int length;
    hash_add (&stream->object_table, (void*)key=(unsigned int)object, object);
    if ((length = objc_write_register_common (stream, key))) return __objc_write_object (stream, object);
    return length;
  }
}


__inline__ int
__objc_write_class (struct objc_typed_stream* stream, struct objc_class* class)
{
  __objc_write_extension (stream, _BX_CLASS);
  objc_write_string_atomic(stream, (char*)class->name, strlen((char*)class->name));
  return objc_write_unsigned_int (stream, CLS_GETNUMBER(class));
}


static int 
objc_write_class (struct objc_typed_stream* stream, struct objc_class* class)
{
  unsigned int key;
  if ((key = (unsigned int)hash_value_for_key (stream->stream_table, class)))
    return objc_write_use_common (stream, key);
  else
  {
    int length;
    hash_add (&stream->stream_table, (void*)key=(unsigned int)class, class);
    if ((length = objc_write_register_common (stream, key))) return __objc_write_class (stream, class);
    return length;
  }
}


__inline__ int 
__objc_write_selector (struct objc_typed_stream* stream, SEL selector)
{
  const char* sel_name = sel_get_name (selector);
  __objc_write_extension (stream, _BX_SEL);
  return objc_write_string (stream, sel_name, strlen ((char*)sel_name));
}


int 
objc_write_selector (struct objc_typed_stream* stream, SEL selector)
{
  const char* sel_name = sel_get_name (selector);
  unsigned int key;
  if ((key = (unsigned int)hash_value_for_key (stream->stream_table, sel_name)))
    return objc_write_use_common (stream, key);
  else
  {
    int length;
    hash_add (&stream->stream_table, (void*)key=(unsigned int)sel_name, (char*)sel_name);
    if ((length = objc_write_register_common (stream, key))) return __objc_write_selector (stream, selector);
    return length;
  }
}


/*
** Read operations 
*/

__inline__ int
objc_read_char (struct objc_typed_stream* stream, char* val)
{
  unsigned char buf;
  int len;
  len = (*stream->read)(stream->physical, &buf, 1);
  if (len != 0)
  {
    if ((buf & _B_CODE) == _B_SINT) (*val) = (buf & _B_VALUE);
    else if ((buf & _B_NUMBER) == 1)
    {
      len = (*stream->read)(stream->physical, val, 1);
      if (buf&_B_SIGN) (*val) = -1*(*val);
    }
    else __objc_archiving_fatal("Expected 8bit signed int, got %dbit int", (int)(buf&_B_NUMBER)*8);
  }
  return len;
}


__inline__ int
objc_read_unsigned_char (struct objc_typed_stream* stream, unsigned char* val)
{
  unsigned char buf;
  int len;
  if ((len = (*stream->read)(stream->physical, &buf, 1)))
  {
    if ((buf & _B_CODE) == _B_SINT) (*val) = (buf & _B_VALUE);
    else if ((buf & _B_NUMBER) == 1) len = (*stream->read)(stream->physical, val, 1);
    else __objc_archiving_fatal("Expected 8bit unsigned int, got %dbit int", (int)(buf&_B_NUMBER)*8);
  }
  return len;
}

__inline__ int
objc_read_short (struct objc_typed_stream* stream, short* value)
{
  unsigned char buf[sizeof(short)+1];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    if ((buf[0] & _B_CODE) == _B_SINT) (*value) = (buf[0] & _B_VALUE);
    else
    {
      int pos = 1;
      int nbytes = buf[0] & _B_NUMBER;
      if (nbytes > sizeof (short)) __objc_archiving_fatal("Expected short, got bigger (%dbits)", nbytes*8);
      len = (*stream->read)(stream->physical, buf+1, nbytes);
      (*value) = 0;
      while (pos <= nbytes) (*value) = ((*value)*0x100) + buf[pos++];
      if (buf[0] & _B_SIGN) (*value) = -(*value);
    }
  }
  return len;
}

__inline__ int
objc_read_unsigned_short (struct objc_typed_stream* stream, unsigned short* value)
{
  unsigned char buf[sizeof(unsigned short)+1];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    if ((buf[0] & _B_CODE) == _B_SINT) (*value) = (buf[0] & _B_VALUE);
    else
    {
      int pos = 1;
      int nbytes = buf[0] & _B_NUMBER;
      if (nbytes > sizeof (short)) __objc_archiving_fatal("Expected short, got int or bigger",0);
      len = (*stream->read)(stream->physical, buf+1, nbytes);
      (*value) = 0;
      while (pos <= nbytes) (*value) = ((*value)*0x100) + buf[pos++];
    }
  }
  return len;
}


__inline__ int
objc_read_int (struct objc_typed_stream* stream, int* value)
{
  unsigned char buf[sizeof(int)+1];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    if ((buf[0] & _B_CODE) == _B_SINT) (*value) = (buf[0] & _B_VALUE);
    else
    {
      int pos = 1;
      int nbytes = buf[0] & _B_NUMBER;
      if (nbytes > sizeof (int)) __objc_archiving_fatal("Expected int, got bigger",0);
      len = (*stream->read)(stream->physical, buf+1, nbytes);
      (*value) = 0;
      while (pos <= nbytes) (*value) = ((*value)*0x100) + buf[pos++];
      if (buf[0] & _B_SIGN) (*value) = -(*value);
    }
  }
  return len;
}

__inline__ int
__objc_read_nbyte_uint (struct objc_typed_stream* stream, unsigned int nbytes, unsigned int* val)
{
  int len, pos = 0;
  unsigned char buf[sizeof(unsigned int)+1];

  if (nbytes > sizeof (int)) __objc_archiving_fatal("Expected int, got bigger",0);

  len = (*stream->read)(stream->physical, buf, nbytes);
  (*val) = 0;
  while (pos < nbytes) (*val) = ((*val)*0x100) + buf[pos++];
  return len;
}
  

__inline__ int
objc_read_unsigned_int (struct objc_typed_stream* stream, unsigned int* value)
{
  unsigned char buf[sizeof(unsigned int)+1];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    if ((buf[0] & _B_CODE) == _B_SINT) (*value) = (buf[0] & _B_VALUE);
    else len = __objc_read_nbyte_uint (stream, (buf[0] & _B_VALUE), value);
  }
  return len;
}

__inline__ int
objc_read_string (struct objc_typed_stream* stream, char** string)
{
  unsigned char buf[sizeof(unsigned int)+1];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    unsigned int key = 0;

    if ((buf[0]&_B_CODE) == _B_RCOMM)	/* register following */
    {
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      len = (*stream->read)(stream->physical, buf, 1);
    }

    switch (buf[0]&_B_CODE)
    {
      case _B_SSTR:
	{
	  int length = buf[0]&_B_VALUE;
	  (*string) = (char*)__objc_xmalloc(length+1);
	  if (key) hash_add (&stream->stream_table, (void*)key, *string);
	  len = (*stream->read)(stream->physical, *string, length);
	  (*string)[length] = '\0';
	}
	break;

      case _B_UCOMM:
	{
	  char *tmp;
	  len = __objc_read_nbyte_uint (stream, (buf[0] & _B_VALUE), &key);
	  tmp = hash_value_for_key (stream->stream_table, (void*)key);
	  *string = __objc_xmalloc (strlen (tmp) + 1);
	  strcpy (*string, tmp);
	}
	break;

      case _B_NSTR:
	{
	  unsigned int nbytes = buf[0]&_B_VALUE;
	  len = __objc_read_nbyte_uint(stream, nbytes, &nbytes);
	  if (len)
	  {
	    (*string) = (char*)__objc_xmalloc(nbytes+1);
	    if (key) hash_add (&stream->stream_table, (void*)key, *string);
	    len = (*stream->read)(stream->physical, *string, nbytes);
	    (*string)[nbytes] = '\0';
	  }
	}
	break;
	
      default:
	__objc_archiving_fatal("Expected string, got opcode %c\n", (buf[0]&_B_CODE));
    }
  }

  return len;
}


int
objc_read_object (struct objc_typed_stream* stream, id* object)
{
  unsigned char buf[sizeof (unsigned int)];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    SEL read_sel = sel_get_uid ("read:");
    unsigned int key = 0;

    if ((buf[0]&_B_CODE) == _B_RCOMM)	/* register common */
    {
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      len = (*stream->read)(stream->physical, buf, 1);
    }

    if (buf[0] == (_B_EXT | _BX_OBJECT))
    {
      OCClass* class;

      /* get class */
      len = objc_read_class (stream, &class);

      /* create instance */
      (*object) = class_create_instance(class);

      /* register? */
      if (key) hash_add (&stream->object_table, (void*)key, *object);

      /* send -read: */
      if (__objc_responds_to (*object, read_sel)) (*get_imp(class, read_sel))(*object, read_sel, stream);

      /* check null-byte */
      len = (*stream->read)(stream->physical, buf, 1);
      if (buf[0] != '\0') __objc_archiving_fatal("Expected null-byte, got opcode %c", buf[0]);
    }
    else if ((buf[0]&_B_CODE) == _B_UCOMM)
    {
      if (key) __objc_archiving_fatal("Cannot register use upcode...",0);
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      (*object) = hash_value_for_key (stream->object_table, (void*)key);
    }
    else if (buf[0] == (_B_EXT | _BX_OBJREF))	/* a forward reference */
    {
      struct objc_list* other;
      len = objc_read_unsigned_int (stream, &key);
      other = (struct objc_list*)hash_value_for_key (stream->object_refs, (void*)key);
      hash_add (&stream->object_refs, (void*)key, (void*)list_cons(object, other));
    }
    else if (buf[0] == (_B_EXT | _BX_OBJROOT)) /* a root object */
    {
      if (key) __objc_archiving_fatal("Cannot register root object...",0);
      len = objc_read_object (stream, object);
      __objc_finish_read_root_object (stream);
    }
    else __objc_archiving_fatal("Expected object, got opcode %c", buf[0]);
  }
  return len;
}

static int
objc_read_class (struct objc_typed_stream* stream, OCClass** class)
{
  unsigned char buf[sizeof (unsigned int)];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    unsigned int key = 0;

    if ((buf[0]&_B_CODE) == _B_RCOMM)	/* register following */
    {
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      len = (*stream->read)(stream->physical, buf, 1);
    }

    if (buf[0] == (_B_EXT | _BX_CLASS))
    {
      char* class_name;
      int version;

      /* get class */
      len = objc_read_string (stream, &class_name);
      (*class) = objc_get_class(class_name);
      __objc_xfree (class_name);

      /* register */
      if (key) hash_add (&stream->stream_table, (void*)key, *class);
      objc_read_unsigned_int(stream, &version);
      hash_add (&stream->class_table, (*class)->name, (void*)version);
    }
    else if ((buf[0]&_B_CODE) == _B_UCOMM)
    {
      if (key) __objc_archiving_fatal("Cannot register use upcode...",0);
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      (*class) = hash_value_for_key (stream->stream_table, (void*)key);
      if (!*class) __objc_archiving_fatal("Cannot find class for key %x", key);
    }
    else __objc_archiving_fatal("Expected class, got opcode %c", buf[0]);
  }
  return len;
}

int
objc_read_selector (struct objc_typed_stream* stream, SEL* selector)
{
  unsigned char buf[sizeof (unsigned int)];
  int len;
  if ((len = (*stream->read)(stream->physical, buf, 1)))
  {
    unsigned int key = 0;

    if ((buf[0]&_B_CODE) == _B_RCOMM)	/* register following */
    {
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      len = (*stream->read)(stream->physical, buf, 1);
    }

    if (buf[0] == (_B_EXT|_BX_SEL)) /* selector! */
    {
      char* selector_name;

      /* get selector */
      len = objc_read_string (stream, &selector_name);
      (*selector) = sel_get_uid(selector_name);
      __objc_xfree (selector_name);

      /* register */
      if (key) hash_add (&stream->stream_table, (void*)key, (unsigned char *)(*selector));
    }
    else if ((buf[0]&_B_CODE) == _B_UCOMM)
    {
      if (key) __objc_archiving_fatal("Cannot register use upcode...",0);
      len = __objc_read_nbyte_uint(stream, (buf[0] & _B_VALUE), &key);
      (*selector) = hash_value_for_key (stream->stream_table, (void*)key);
    }
    else __objc_archiving_fatal("Expected selector, got opcode %c", buf[0]);
  }
  return len;
}


static const char*
__objc_skip_type (const char* type)
{
  switch (*type)
  {
    case _C_ID:
    case _C_CLASS:
    case _C_SEL:
    case _C_CHR:
    case _C_UCHR:
    case _C_CHARPTR:
    case _C_ATOM:
    case _C_SHT:
    case _C_USHT:
    case _C_INT:
    case _C_UINT:
    case _C_LNG:
    case _C_ULNG:
    case _C_FLT:
    case _C_DBL:
      return ++type;
      break;

    case _C_ARY_B:
      while(isdigit(*++type));
      type = __objc_skip_type(type);
      if (*type == _C_ARY_E) return ++type;
      else __objc_archiving_fatal("Cannot parse typespec: %s", (int)type);
      break;

    default:
      fprintf(stderr, "__objc_skip_type: cannot parse typespec: %s\n", type);
      abort();
  }
}


/*
** User level functions
*/

/* Write one object, encoded in TYPE and pointed to by DATA to the typed stream STREAM. */

int
objc_write_type(TypedStream* stream, const char* type, const void* data)
{
  switch(*type)
  {
    case _C_ID:
      return objc_write_object (stream, *(id*)data);
      break;

    case _C_CLASS:
      return objc_write_class (stream, *(OCClass**)data);
      break;

    case _C_SEL:
      return objc_write_selector (stream, *(SEL*)data);
      break;

    case _C_CHR:
      return objc_write_char(stream, *(char*)data);
      break;
    
    case _C_UCHR:
      return objc_write_unsigned_char(stream, *(unsigned char*)data);
      break;

    case _C_SHT:
      return objc_write_short(stream, *(short*)data);
      break;

    case _C_USHT:
      return objc_write_unsigned_short(stream, *(unsigned short*)data);
      break;

    case _C_INT:
    case _C_LNG:
      return objc_write_int(stream, *(int*)data);
      break;

    case _C_UINT:
    case _C_ULNG:
      return objc_write_unsigned_int(stream, *(unsigned int*)data);
      break;

    case _C_CHARPTR:
      return objc_write_string (stream, *(char**)data, strlen(*(char**)data));
      break;

    case _C_ATOM:
      return objc_write_string_atomic (stream, *(char**)data, strlen(*(char**)data));
      break;

    case _C_ARY_B:
      {
	int len = atoi(type+1);
	while (isdigit(*++type));
	return objc_write_array (stream, type, len, data);
      }
      break; 

    default:
      fprintf(stderr, "objc_write_type: cannot parse typespec: %s\n", type);
      abort();
  }
}


/* Read one object, encoded in TYPE and pointed to by DATA to the typed stream STREAM.
   DATA specifies the address of the types to read.  Expected type is checked against
   the type actually present on the stream. */

int
objc_read_type(TypedStream* stream, const char* type, void* data)
{
  char c;
  switch(c = *type)
  {
    case _C_ID:
      return objc_read_object (stream, (id*)data);
      break;

    case _C_CLASS:
      return objc_read_class (stream, (OCClass**)data);
      break;

    case _C_SEL:
      return objc_read_selector (stream, (SEL*)data);
      break;

    case _C_CHR:
      return objc_read_char (stream, (char*)data);
      break;
    
    case _C_UCHR:
      return objc_read_unsigned_char (stream, (unsigned char*)data);
      break;

    case _C_SHT:
      return objc_read_short (stream, (short*)data);
      break;

    case _C_USHT:
      return objc_read_unsigned_short (stream, (unsigned short*)data);
      break;

    case _C_INT:
    case _C_LNG:
      return objc_read_int (stream, (int*)data);
      break;

    case _C_UINT:
    case _C_ULNG:
      return objc_read_unsigned_int (stream, (unsigned int*)data);
      break;

    case _C_CHARPTR:
    case _C_ATOM:
      return objc_read_string (stream, (char**)data);
      break;

    case _C_ARY_B:
      {
	int len = atoi(type+1);
	while (isdigit(*++type));
	return objc_read_array (stream, type, len, data);
      }
      break; 

    default:
      fprintf(stderr, "objc_read_type: cannot parse typespec: %s\n", type);
      abort();
  }
}


/* Write the object specified by the template TYPE to STREAM.  Last arguments specify
   addresses of values to be written.  It might seem surprising to specify values by
   address, but this is extremely convenient for copy-paste with objc_read_types calls.
   A more down-to-the-earth cause for this passing of addresses is that values of
   arbitrary size is not well supported in ANSI C for functions with variable number of
   arguments. */

int 
objc_write_types (TypedStream* stream, const char* type, ...)
{
  va_list args;
  const char *c;
  int res = 0;

  va_start(args, type);

  for (c = type; *c; c = __objc_skip_type (c))
  {
    switch(*c)
    {
      case _C_ID:
        res = objc_write_object (stream, *va_arg (args, id*));
	break;

      case _C_CLASS:
	res = objc_write_class (stream, *va_arg(args, OCClass**));
	break;

      case _C_SEL:
	res = objc_write_selector (stream, *va_arg(args, SEL*));
	break;
	
      case _C_CHR:
	res = objc_write_char (stream, *va_arg (args, char*));
	break;
	
      case _C_UCHR:
	res = objc_write_unsigned_char (stream, *va_arg (args, unsigned char*));
	break;
	
      case _C_SHT:
	res = objc_write_short (stream, *va_arg(args, short*));
	break;

      case _C_USHT:
	res = objc_write_unsigned_short (stream, *va_arg(args, unsigned short*));
	break;

      case _C_INT:
      case _C_LNG:
	res = objc_write_int(stream, *va_arg(args, int*));
	break;
	
      case _C_UINT:
      case _C_ULNG:
	res = objc_write_unsigned_int(stream, *va_arg(args, unsigned int*));
	break;

      case _C_CHARPTR:
	{
	  char** str = va_arg(args, char**);
	  res = objc_write_string (stream, *str, strlen(*str));
	}
	break;

      case _C_ATOM:
	{
	  char** str = va_arg(args, char**);
	  res = objc_write_string_atomic (stream, *str, strlen(*str));
	}
	break;

      case _C_ARY_B:
	{
	  int len = atoi(c+1);
	  const char* t = c;
	  while (isdigit(*++t));
	  res = objc_write_array (stream, t, len, va_arg(args, void*));
	  t = __objc_skip_type (t);
	  if (*t != _C_ARY_E) __objc_archiving_fatal("Expected `]', got: %s", (int)t);
	}
	break; 
	
      default:
	fprintf(stderr, "objc_write_types: cannot parse typespec: %s\n", type);
	abort();
    }
  }
  va_end(args);
  return res;
}


/* Last arguments specify addresses of values to be read.  Expected type
   is checked against the type actually present on the stream. */

int 
objc_read_types(TypedStream* stream, const char* type, ...)
{
  va_list args;
  const char *c;
  int res = 0;

  va_start(args, type);

  for (c = type; *c; c = __objc_skip_type(c))
  {
    switch(*c)
    {
      case _C_ID:
        res = objc_read_object(stream, va_arg(args, id*));
	break;

      case _C_CLASS:
	res = objc_read_class(stream, va_arg(args, OCClass**));
	break;

      case _C_SEL:
	res = objc_read_selector(stream, va_arg(args, SEL*));
	break;
	
      case _C_CHR:
	res = objc_read_char(stream, va_arg(args, char*));
	break;
	
      case _C_UCHR:
	res = objc_read_unsigned_char(stream, va_arg(args, unsigned char*));
	break;
	
      case _C_SHT:
	res = objc_read_short(stream, va_arg(args, short*));
	break;

      case _C_USHT:
	res = objc_read_unsigned_short(stream, va_arg(args, unsigned short*));
	break;

      case _C_INT:
      case _C_LNG:
	res = objc_read_int(stream, va_arg(args, int*));
	break;
	
      case _C_UINT:
      case _C_ULNG:
	res = objc_read_unsigned_int(stream, va_arg(args, unsigned int*));
	break;

      case _C_CHARPTR:
      case _C_ATOM:
	{
	  char** str = va_arg(args, char**);
	  res = objc_read_string (stream, str);
	}
	break;

      case _C_ARY_B:
	{
	  int len = atoi(c+1);
	  const char* t = c;
	  while (isdigit(*++t));
	  res = objc_read_array (stream, t, len, va_arg(args, void*));
	  t = __objc_skip_type (t);
	  if (*t != _C_ARY_E) __objc_archiving_fatal("Expected `]', got: %s", (int)t);
	}
	break; 
	
      default:
	fprintf(stderr, "objc_read_types: cannot parse typespec: %s\n", type);
	abort();
    }
  }
  va_end(args);
  return res;
}


/* Write an array of COUNT elements of TYPE from the memory address DATA.
   This is equivalent of objc_write_type (stream, "[N<type>]", data) */

int
objc_write_array (TypedStream* stream, const char* type, int count, const void* data)
{
  int off = objc_sizeof_type(type);
  const char* where = data;

  while (count-- > 0)
  {
    objc_write_type(stream, type, where);
    where += off;
  }
  return 1;
}


/* Read an array of COUNT elements of TYPE into the memory address DATA.
   The memory pointed to by data is supposed to be allocated by the callee.
   This is equivalent of objc_read_type (stream, "[N<type>]", data) */

int
objc_read_array (TypedStream* stream, const char* type, int count, void* data)
{
  int off = objc_sizeof_type(type);
  char* where = (char*)data;

  while (count-- > 0)
  {
    objc_read_type(stream, type, where);
    where += off;
  }
  return 1;
}


static int 
__objc_fread(BPTR file, char* data, int len)
{
  return FRead(file, data, len, 1);
}


static int 
__objc_fwrite(BPTR file, char* data, int len)
{
  return FWrite(file, data, len, 1);
}


static int
__objc_feof(BPTR file)
{
  int c;
  if((c=FGetC(file))==EOF) return 1;
  UnGetC(file,c);
  return 0;
}


static int 
__objc_no_write(BPTR file, char* data, int len)
{
  __objc_archiving_fatal ("TypedStream not open for writing",0);
}


static int 
__objc_no_read(BPTR file, char* data, int len)
{
  __objc_archiving_fatal ("TypedStream not open for reading",0);
}


static int
__objc_read_typed_stream_signature (TypedStream* stream)
{
  char buffer[80];
  int pos = 0;
  do (*stream->read)(stream->physical, buffer+pos, 1); while (buffer[pos++] != '\0');
  sscanf (buffer, "GNU TypedStream %d", &stream->version);
  if (stream->version != OBJC_TYPED_STREAM_VERSION)
    __objc_archiving_fatal ("Cannot handle TypedStream version %d", stream->version);
  return 1;
}


static int
__objc_write_typed_stream_signature (TypedStream* stream)
{
  char buffer[80];
  sprintf(buffer, "GNU TypedStream %d", OBJC_TYPED_STREAM_VERSION);
  stream->version = OBJC_TYPED_STREAM_VERSION;
  (*stream->write)(stream->physical, buffer, strlen(buffer)+1);
  return 1;
}


static void __objc_finish_write_root_object(struct objc_typed_stream* stream)
{
  hash_delete (stream->object_table);
  stream->object_table = hash_new(64, (hash_func_type)hash_ptr, (compare_func_type)compare_ptrs);
}


static void __objc_finish_read_root_object(struct objc_typed_stream* stream)
{
  node_ptr node;
  SEL awake_sel = sel_get_uid ("awake");

  /* resolve object forward references */
  for (node = hash_next (stream->object_refs, NULL); node; node = hash_next (stream->object_refs, node))
  {
    struct objc_list* reflist = node->value;
    const void* key = node->key;
    id object = hash_value_for_key (stream->object_table, key);
    while(reflist)
    {
      *((id*)reflist->head) = object;
      reflist = reflist->tail;
    }
    list_free (node->value);
  }

  /* empty object reference table */
  hash_delete (stream->object_refs);
  stream->object_refs = hash_new(8, (hash_func_type)hash_ptr, (compare_func_type)compare_ptrs);

  /* call -awake for all objects read  */
  if (awake_sel)
  {
    for (node = hash_next (stream->object_table, NULL); node; node = hash_next (stream->object_table, node))
    {
      id object = node->value;
      if (__objc_responds_to (object, awake_sel)) (*objc_msg_lookup(object, awake_sel))(object, awake_sel);
    }
  }

  /* empty object table */
  hash_delete (stream->object_table);
  stream->object_table = hash_new(64, (hash_func_type)hash_ptr, (compare_func_type)compare_ptrs);
}


/* Flush a physical file */

int __objc_fflush(BPTR fp)
{
  if(Flush(fp)) return 0; else return -1;
}


/* Open the stream PHYSICAL in MODE */

TypedStream* 
objc_amigaopen_typed_stream (BPTR physical, int mode)
{
  TypedStream* s = (TypedStream*)__objc_xmalloc(sizeof(TypedStream));

  s->mode = mode;
  s->physical = (void *)physical;
  s->stream_table = hash_new(64, (hash_func_type)hash_ptr, (compare_func_type)compare_ptrs);
  s->object_table = hash_new(64, (hash_func_type)hash_ptr, (compare_func_type)compare_ptrs);
  s->eof = (objc_typed_eof_func)__objc_feof;
  s->flush = (objc_typed_flush_func)__objc_fflush;
  s->writing_root_p = 0;
  if (mode == OBJC_READONLY)
  {
    s->class_table = hash_new(8, (hash_func_type)hash_string, (compare_func_type)compare_strings);
    s->object_refs = hash_new(8, (hash_func_type)hash_ptr, (compare_func_type)compare_ptrs);
    s->read = (objc_typed_read_func)__objc_fread;
    s->write = (objc_typed_write_func)__objc_no_write;
    __objc_read_typed_stream_signature (s);
  }
  else if (mode == OBJC_WRITEONLY)
  {
    s->class_table = 0;
    s->object_refs = 0;
    s->read = (objc_typed_read_func)__objc_no_read;
    s->write = (objc_typed_write_func)__objc_fwrite;
    __objc_write_typed_stream_signature (s);
  }      
  else
  {
    objc_close_typed_stream (s);
    return NULL;
  }
  s->type = OBJC_FILE_STREAM;
  return s;
}


/* Open the file named by FILE_NAME in MODE */

TypedStream*
objc_open_typed_stream_for_file (const char* file_name, int mode)
{
  BPTR file = NULL;
  TypedStream* s;

  if (mode == OBJC_READONLY) file = Open ((char *)file_name, MODE_OLDFILE);
  else file = Open ((char *)file_name, MODE_NEWFILE);

  if (file)
  {
    s = objc_amigaopen_typed_stream (file, mode);
    if (s) s->type |= OBJC_MANAGED_STREAM;
    return s;
  }
  else return NULL;
}


/* Close STREAM freeing the structure it self.  If it was opened with
   objc_open_typed_stream_for_file, the file will also be closed. */

void
objc_close_typed_stream (TypedStream* stream)
{
  if (stream->mode == OBJC_READONLY)
  {
    __objc_finish_read_root_object (stream); /* Just in case... */
    hash_delete (stream->class_table);
    hash_delete (stream->object_refs);
  }

  hash_delete (stream->stream_table);
  hash_delete (stream->object_table);

  if (stream->type == (OBJC_MANAGED_STREAM | OBJC_FILE_STREAM)) Close ((BPTR)stream->physical);
  __objc_xfree (stream);
}


BOOL
objc_end_of_typed_stream (TypedStream* stream)
{
  return (*stream->eof)(stream->physical);
}


void
objc_flush_typed_stream (TypedStream* stream)
{
  (*stream->flush)(stream->physical);
}


int 
objc_get_stream_class_version (TypedStream* stream, OCClass* class)
{
  if (stream->class_table) return (int) hash_value_for_key (stream->class_table, class->name);
  else return class_get_version (class);
}