/* Copyright (C) 1989, 1996, 1997, 1998 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.
 */

/*$Id: zdict.c $ */
/* Dictionary operators */
#include "ghost.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"
#include "store.h"

/* <int> dict <dict> */
int
zdict(register os_ptr op)
{
    check_type(*op, t_integer);
#if arch_sizeof_int < arch_sizeof_long
    check_int_leu(*op, max_uint);
#else
    if (op->value.intval < 0)
	return_error(e_rangecheck);
#endif
    return dict_create((uint) op->value.intval, op);
}

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

/* <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);
    }
    while (dsp == dsbot) {
	/* We would underflow the current block. */
	ref_stack_pop_block(&d_stack);
    }
    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 (dtop_can_store(op))
		    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 (!dtop_can_store(op)) {
	check_dict_write(*dsp);
	/*
	 * If the dictionary is writable, the problem must be
	 * an invalid store.
	 */
	return_error(e_invalidaccess);
    }
    /*
     * 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->value.pdict->values, 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> */
private int
zload(register os_ptr op)
{
    ref *pvalue;

    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);
	case t__invalid:
	    return_error(e_stackunderflow);
	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 - */
/* <dict> <key> undef - */
private int
zundef(register os_ptr op)
{
    check_type(op[-1], t_dictionary);
    check_dict_write(op[-1]);
    dict_undef(op - 1, op);	/* ignore undefined error */
    pop(2);
    return 0;
}

/* <dict> <key> known <bool> */
private 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, (dict_find(op1, op, &pvalue) > 0 ? 1 : 0));
    pop(1);
    return 0;
}

/* <key> where <dict> true */
/* <key> where false */
int
zwhere(register os_ptr op)
{
    ref_stack_enum_t rsenum;

    check_op(1);
    ref_stack_enum_begin(&rsenum, &d_stack);
    do {
	const ref *const bot = rsenum.ptr;
	const ref *pdref = bot + rsenum.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;
	    }
	}
    } while (ref_stack_enum_next(&rsenum));
    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;
    /*
     * In Level 1 systems, we must copy the access attributes too.
     * The only possible effect this can have is to make the
     * copy read-only if the original dictionary is read-only.
     */
    if (!level2_enabled)
	r_copy_attrs(dict_access_ref(op), a_write, dict_access_ref(op1));
    ref_assign(op1, op);
    pop(1);
    return 0;
}

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

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

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

/* <dict1> <dict2> .dictcopynew <dict2> */
private int
zdictcopynew(register os_ptr op)
{
    os_ptr op1 = op - 1;
    int code;

    check_type(*op1, t_dictionary);
    check_dict_read(*op1);
    check_type(*op, t_dictionary);
    check_dict_write(*op);
    /* This is only recognized in Level 2 mode. */
    if (!dict_auto_expand)
	return_error(e_undefined);
    code = dict_copy_new(op1, op);
    if (code < 0)
	return code;
    ref_assign(op1, op);
    pop(1);
    return 0;
}

/* -mark- <key0> <value0> <key1> <value1> ... .dicttomark <dict> */
/* This is the Level 2 >> operator. */
private int
zdicttomark(register os_ptr op)
{
    uint count2 = ref_stack_counttomark(&o_stack);
    ref rdict;
    int code;
    uint idx;

    if (count2 == 0)
	return_error(e_unmatchedmark);
    count2--;
    if ((count2 & 1) != 0)
	return_error(e_rangecheck);
    code = dict_create(count2 >> 1, &rdict);
    if (code < 0)
	return code;
    /* << /a 1 /a 2 >> => << /a 1 >>, i.e., */
    /* we must enter the keys in top-to-bottom order. */
    for (idx = 0; idx < count2; idx += 2) {
	code = dict_put(&rdict,
			ref_stack_index(&o_stack, idx + 1),
			ref_stack_index(&o_stack, idx));
	if (code < 0) {		/* There's no way to free the dictionary -- too bad. */
	    return code;
	}
    }
    ref_stack_pop(&o_stack, count2);
    ref_assign(osp, &rdict);
    return code;
}

/* <dict> <key> <value> .forceput - */
/*
 * This forces a "put" even if the dictionary is not writable, and (if the
 * dictionary is systemdict or the save level is 0) 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 odp = op - 2;
    int code;

    check_type(*odp, t_dictionary);
    if (odp->value.pdict == systemdict->value.pdict ||
	!ialloc_is_in_save()
	) {
	uint space = r_space(odp);

	r_set_space(odp, avm_local);
	code = dict_put(odp, op - 1, op);
	r_set_space(odp, space);
    } else
	code = dict_put(odp, op - 1, op);
    if (code < 0)
	return code;
    pop(3);
    return 0;
}

/* <dict> <key> .forceundef - */
/*
 * This forces an "undef" even if the dictionary is not writable.
 * Like .forceput, it is meant to be used only in a few special situations,
 * and should not be accessible by name after initialization.
 */
private int
zforceundef(register os_ptr op)
{
    check_type(op[-1], t_dictionary);
    /* Don't check_dict_write */
    dict_undef(op - 1, op);	/* ignore undefined error */
    pop(2);
    return 0;
}

/* <dict> <key> .knownget <value> true */
/* <dict> <key> .knownget false */
private int
zknownget(register os_ptr op)
{
    register os_ptr op1 = op - 1;
    ref *pvalue;

    check_type(*op1, t_dictionary);
    check_dict_read(*op1);
    if (dict_find(op1, op, &pvalue) <= 0) {
	make_false(op1);
	pop(1);
    } else {
	ref_assign(op1, pvalue);
	make_true(op);
    }
    return 0;
}

/* <dict> <key> .knownundef <bool> */
private int
zknownundef(register os_ptr op)
{
    os_ptr op1 = op - 1;
    int code;

    check_type(*op1, t_dictionary);
    check_dict_write(*op1);
    code = dict_undef(op1, op);
    make_bool(op1, code == 0);
    pop(1);
    return 0;
}

/* <dict> <int> .setmaxlength - */
private int
zsetmaxlength(register os_ptr op)
{
    os_ptr op1 = op - 1;
    uint new_size;
    int code;

    check_type(*op1, t_dictionary);
    check_dict_write(*op1);
    check_type(*op, t_integer);
#if arch_sizeof_int < arch_sizeof_long
    check_int_leu(*op, max_uint);
#else
    if (op->value.intval < 0)
	return_error(e_rangecheck);
#endif
    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;
}

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

const op_def zdict_op_defs[] =
{
    {"0cleardictstack", zcleardictstack},
    {"1begin", zbegin},
    {"0countdictstack", zcountdictstack},
    {"0currentdict", zcurrentdict},
    {"2def", zdef},
    {"1dict", zdict},
    {"0dictstack", zdictstack},
    {"0end", zend},
    {"2known", zknown},
    {"1load", zload},
    {"1maxlength", zmaxlength},
    {"2.undef", zundef},	/* we need this even in Level 1 */
    {"1where", zwhere},
		/* Extensions */
    {"2.dictcopynew", zdictcopynew},
    {"1.dicttomark", zdicttomark},
    {"3.forceput", zforceput},
    {"2.forceundef", zforceundef},
    {"2.knownget", zknownget},
    {"1.knownundef", zknownundef},
    {"2.setmaxlength", zsetmaxlength},
    op_def_end(0)
};
