/* Copyright (C) 1989, 1992, 1993, 1994 Aladdin Enterprises.  All rights reserved.
  
  This file is part of Aladdin Ghostscript.
  
  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
  or distributor accepts any responsibility for the consequences of using it,
  or for whether it serves any particular purpose or works at all, unless he
  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
  License (the "License") for full details.
  
  Every copy of Aladdin Ghostscript must include a copy of the License,
  normally in a plain ASCII text file named PUBLIC.  The License grants you
  the right to copy, modify and redistribute Aladdin Ghostscript, but only
  under certain conditions described in the License.  Among other things, the
  License requires that the copyright notice and this notice be preserved on
  all copies.
*/

/* zdict.c */
/* Dictionary operators */
#include "ghost.h"
#include "errors.h"
#include "oper.h"
#include "idict.h"
#include "dstack.h"
#include "ilevel.h"			/* for [count]dictstack */
#include "iname.h"			/* for dict_find_name */
#include "ipacked.h"			/* for inline dict lookup */
#include "ivmspace.h"			/* for check_store_space */
#include "store.h"

/* Imported operators */
extern int zput(P1(os_ptr));

/* <int> dict <dict> */
int
zdict(register os_ptr op)
{	check_type(*op, t_integer);
	if ( op->value.intval < 0 || op->value.intval > dict_max_size )
		return_error(e_rangecheck);
	return dict_create((uint)op->value.intval, op);
}

/* <dict> maxlength <int> */
int
zmaxlength(register os_ptr op)
{	check_type(*op, t_dictionary);
	check_dict_read(*op);
	make_int(op, dict_maxlength(op));
	return 0;
}

/* <dict> <int> .setmaxlength - */
int
zsetmaxlength(register os_ptr op)
{	uint new_size;
	int code;
	os_ptr op1 = op - 1;
	check_type(*op1, t_dictionary);
	check_dict_write(*op1);
	check_type(*op, t_integer);
	if ( op->value.intval < 0 || op->value.intval > dict_max_size )
		return_error(e_rangecheck);
	new_size = (uint)op->value.intval;
	if ( dict_length(op - 1) > new_size )
		return_error(e_dictfull);
	code = dict_resize(op - 1, new_size);
	if ( code >= 0 ) pop(2);
	return code;
}

/* <dict> begin - */
int
zbegin(register os_ptr op)
{	check_type(*op, t_dictionary);
	check_dict_read(*op);
	if ( dsp == dstop )
		return_error(e_dictstackoverflow);
	++dsp;
	ref_assign(dsp, op);
	dict_set_top();
	pop(1);
	return 0;
}

/* - end - */
int
zend(register os_ptr op)
{	if ( ref_stack_count_inline(&d_stack) == min_dstack_size )
	  {	/* We would underflow the d-stack. */
		return_error(e_dictstackunderflow);
	  }
	if ( dsp == dsbot )
	  {	/* We're about to underflow the current block. */
		  return_error(e_dictstackunderflow);
	  }
	dsp--;
	dict_set_top();
	return 0;
}

/* <key> <value> def - */
/* We make this into a separate procedure because */
/* the interpreter will almost always call it directly. */
int
zop_def(register os_ptr op)
{	register os_ptr op1 = op - 1;
	ref *pvslot;
	/* The following combines a check_op(2) with a type check. */
	switch ( r_type(op1) )
	{
	case t_name:
	{	/* We can use the fast single-probe lookup here. */
		uint nidx = name_index(op1);
		uint htemp;
		if_dict_find_name_by_index_top(nidx, htemp, pvslot)
		{	if ( (r_type_attrs(op) & dsmask) == 0 )
				goto ra;
		}
		break;			/* handle all slower cases */
	}
	case t_null:
		return_error(e_typecheck);
	case t__invalid:
		return_error(e_stackunderflow);
	}
	/* Combine the check for a writable top dictionary with */
	/* the global/local store check.  See dstack.h for details. */
	if ( (r_type_attrs(op) & dsmask) != 0 )
	{	int code;
		check_dict_write(*dsp);
		/*
		 * If the dictionary is writable, the problem must be
		 * an invalid store.  We need a special check to allow
		 * storing references to local objects in systemdict,
		 * or in dictionaries known in systemdict,
		 * during initialization (see ivmspace.h).
		 */
		if ( ialloc_is_in_save() )
		  return_error(e_invalidaccess);
		if ( dsp->value.pdict != systemdict->value.pdict )
		  {	/* See if systemdict is still writable, */
			/* i.e., we are still doing initialization. */
			int index;
			ref elt[2];		/* key, value */
			check_dict_write(*systemdict);
			/* See if this dictionary is known in systemdict. */
			for ( index = dict_first(systemdict);
			      (index = dict_next(systemdict, index, &elt[0])) >= 0;
			    )
			  if ( r_has_type(&elt[1], t_dictionary) &&
			       elt[1].value.pdict == dsp->value.pdict
			     )
			    break;
			if ( index < 0 )
			  return_error(e_invalidaccess);
		  }
		switch ( code = dict_find(dsp, op1, &pvslot) )
		{
		case 1:				/* found */
			goto ra;
		default:			/* some other error */
			return code;
		/*
		 * If we have to grow the dictionary, do it now, so that
		 * the allocator will allocate the copy in the correct space.
		 */
		case e_dictfull:
			if ( !dict_auto_expand )
				return_error(e_dictfull);
			code = dict_grow(dsp);
			if ( code < 0 )
				return code;
		case 0:
			;
		}
		/* Temporarily identify the dictionary as local, */
		/* so the store check in dict_put won't fail. */
		r_set_attrs(dsp, a_local);
		code = dict_put(dsp, op1, op);
		r_clear_attrs(dsp, a_local);
	}
	/* Save a level of procedure call in the common (redefinition) */
	/* case.  With the current interfaces, we pay a double lookup */
	/* in the uncommon case. */
	if ( dict_find(dsp, op1, &pvslot) <= 0 )
		return dict_put(dsp, op1, op);
ra:	ref_assign_old_inline(dsp, pvslot, op, "dict_put(value)");
	return 0;
}
int
zdef(os_ptr op)
{	int code = zop_def(op);
	if ( code >= 0 ) { pop(2); }
	return code;
}

/* <key> load <value> */
int
zload(register os_ptr op)
{	ref *pvalue;
	check_op(1);
	switch ( r_type(op) )
	{
	case t_name:
		/* Use the fast lookup. */
		if ( (pvalue = dict_find_name(op)) == 0 )
			return_error(e_undefined);
		ref_assign(op, pvalue);
		return 0;
	case t_null:
		return_error(e_typecheck);
	default:
	{	/* Use an explicit loop. */
		uint size = ref_stack_count(&d_stack);
		uint i;
		for ( i = 0; i < size; i++ )
		  {	ref *dp = ref_stack_index(&d_stack, i);
			check_dict_read(*dp);
			if ( dict_find(dp, op, &pvalue) > 0 )
			  {	ref_assign(op, pvalue);
				return 0;
			  }
		  }
		return_error(e_undefined);
	}
	}
}

/* get - implemented in zgeneric.c */

/* put - implemented in zgeneric.c */

/* <dict> <key> undef - */
int
zundef(register os_ptr op)
{	check_type(op[-1], t_dictionary);
	check_dict_write(op[-1]);
	if ( !r_has_type(op, t_null) )
		dict_undef(op - 1, op);	/* ignore undefined error */
	pop(2);
	return 0;
}

/* <dict> <key> known <bool> */
int
zknown(register os_ptr op)
{	register os_ptr op1 = op - 1;
	ref *pvalue;
	check_type(*op1, t_dictionary);
	check_dict_read(*op1);
	make_bool(op1,
		  (r_has_type(op, t_null) ? 0 :
		   dict_find(op1, op, &pvalue) > 0 ? 1 : 0));
	pop(1);
	return 0;
}

/* <dict> <key> .knownget <value> true */
/* <dict> <key> .knownget false */
int
zknownget(register os_ptr op)
{	register os_ptr op1 = op - 1;
	ref *pvalue;
	check_type(*op1, t_dictionary);
	check_dict_read(*op1);
	if ( r_has_type(op, t_null) || dict_find(op1, op, &pvalue) <= 0 )
	{	make_false(op1);
		pop(1);
	}
	else
	{	ref_assign(op1, pvalue);
		make_true(op);
	}
	return 0;
}

/* <key> where <dict> true */
/* <key> where false */
int
zwhere(register os_ptr op)
{	check_op(1);
	if ( r_has_type(op, t_null) )
	  {	make_false(op);
		return 0;
	  }
	STACK_LOOP_BEGIN(&d_stack, bot, size)
	  {	const ref *pdref = bot + size;
		ref *pvalue;
		while ( pdref-- > bot )
		  {	check_dict_read(*pdref);
			if ( dict_find(pdref, op, &pvalue) > 0 )
			  {	push(1);
				ref_assign(op - 1, pdref);
				make_true(op);
				return 0;
			  }
		  }
	   }
	STACK_LOOP_END(bot, size)
	make_false(op);
	return 0;
}

/* copy for dictionaries -- called from zcopy in zgeneric.c. */
/* Only the type of *op has been checked. */
int
zcopy_dict(register os_ptr op)
{	os_ptr op1 = op - 1;
	int code;
	check_type(*op1, t_dictionary);
	check_dict_read(*op1);
	check_dict_write(*op);
	if ( !dict_auto_expand &&
	     (dict_length(op) != 0 || dict_maxlength(op) < dict_length(op1))
	   )
	  return_error(e_rangecheck);
	code = dict_copy(op1, op);
	if ( code < 0 )
	  return code;
	ref_assign(op1, op);
	pop(1);
	return 0;
}

/* - currentdict <dict> */
int
zcurrentdict(register os_ptr op)
{	push(1);
	ref_assign(op, dsp);
	return 0;
}

/* - countdictstack <int> */
int
zcountdictstack(register os_ptr op)
{	uint count = ref_stack_count(&d_stack);
	push(1);
	if ( !level2_enabled )
	  count--;		/* see dstack.h */
	make_int(op, count);
	return 0;
}

/* <array> dictstack <subarray> */
int
zdictstack(register os_ptr op)
{	uint count = ref_stack_count(&d_stack);
	check_write_type(*op, t_array);
	if ( !level2_enabled )
	  count--;		/* see dstack.h */
	return ref_stack_store(&d_stack, op, count, 0, 0, true, "dictstack");
}

/* - cleardictstack - */
int
zcleardictstack(os_ptr op)
{	while ( zend(op) >= 0 ) ;
	return 0;
}

/* ------ Extensions ------ */

/* <dict> <key> <value> .forceput - */
/*
 * This forces a "put" even if the dictionary is not writable, and (if
 * the dictionary is systemdict) even if the value is in local VM.
 * It is meant to be used only for replacing the value of FontDirectory
 * in systemdict when switching between local and global VM,
 * and a few similar applications.  After initialization, this operator
 * should no longer be accessible by name.
 */
private int
zforceput(register os_ptr op)
{	os_ptr dp = op - 2;
	int code;
	check_type(*dp, t_dictionary);
	if ( dp->value.pdict == systemdict->value.pdict )
	  {	r_set_attrs(dp, a_local);
		code = dict_put(dp, op - 1, op);
		if ( code < 0 )
		  {	r_clear_attrs(dp, a_local);
			return 0;
		  }
	  }
	else
	  code = dict_put(dp, op - 1, op);
	if ( code < 0 )
	  return code;
	pop(3);
	return 0;
}

/* ------ Initialization procedure ------ */

op_def zdict_op_defs[] = {
	{"0cleardictstack", zcleardictstack},
	{"1begin", zbegin},
	{"0countdictstack", zcountdictstack},
	{"0currentdict", zcurrentdict},
	{"2def", zdef},
	{"1dict", zdict},
	{"0dictstack", zdictstack},
	{"0end", zend},
	{"3.forceput", zforceput},
	{"2known", zknown},
	{"2.knownget", zknownget},
	{"1load", zload},
	{"1maxlength", zmaxlength},
	{"2.setmaxlength", zsetmaxlength},
	{"2undef", zundef},
	{"1where", zwhere},
	op_def_end(0)
};
