/* Copyright (C) 1998 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
  to anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
*/

/*$RCSfile: gsparam2.c,v $ $Revision: 1.2.2.1 $ */
/* Serialize and unserialize parameter lists */

/* Initial version 2/1/98 by John Desrosiers (soho@crl.com) */
/* 8/8/98 L. Peter Deutsch (ghost@aladdin.com) Rewritten to use streams */

#include "gx.h"
#include "memory_.h"
#include "gserrors.h"
#include "gsparams.h"

#define MAX_PARAM_KEY 255

/* ---------------- Serializer ---------------- */

/* Forward references */
private int sput_word(P2(stream *dest, uint value));
private int sput_bytes(P3(stream *dest, const byte *data, uint size));

/*
 * Serialize the contents of a gs_param_list, including sub-dictionaries,
 * onto a stream.  The list must be in READ mode.
 */
int
gs_param_list_puts(stream *dest, gs_param_list *list)
{
    int code = 0;
    gs_param_enumerator_t key_enum;
    gs_param_key_t key;

    param_init_enumerator(&key_enum);

    /* Each item is serialized as ("word" means compressed word):
     *  word: key sizeof + 1, or 0 if end of list/dict
     *  word: data type(gs_param_type_xxx)
     *  byte[]: key, including trailing \0 
     *  (if simple type)
     *    byte[]: unpacked representation of data
     *  (if simple array or string)
     *    word: # of elements
     *    byte[]: data associated with array contents
     *  (if string/name array)
     *    word: # of elements
     *    { word: length of string
     *      byte[]: string data
     *    } for each string in array
     *  (if dict/dict_int_keys/hetero_array)
     *    word: # of entries in collection
     *    entries follow immediately
     */
    /* Enumerate all the keys; use keys to get their typed values */
    while ((code = param_get_next_key(list, &key_enum, &key)) == 0) {
	int value_top_sizeof;
	int value_base_sizeof;
	const void *data;
	uint size;

	/* Get next datum & put its type & key to stream */
	gs_param_typed_value value;
	char string_key[MAX_PARAM_KEY + 1];

	if (sizeof(string_key) < key.size + 1) {
	    code = gs_note_error(gs_error_rangecheck);
	    break;
	}
	memcpy(string_key, key.data, key.size);
	string_key[key.size] = 0;
	if ((code = param_read_typed(list, string_key, &value)) != 0) {
	    if (code > 0)
		code = gs_note_error(gs_error_unknownerror);
	    break;
	}
	sput_word(dest, (unsigned)key.size + 1);
	sput_word(dest, (unsigned)value.type);
	sput_bytes(dest, (byte *)string_key, key.size + 1);

	/* Put value & its size to stream */
	value_top_sizeof = gs_param_type_sizes[value.type];
	value_base_sizeof = gs_param_type_base_sizes[value.type];
	switch (value.type) {
	    case gs_param_type_bool:
	    case gs_param_type_int:
	    case gs_param_type_long:
	    case gs_param_type_float:
		sput_bytes(dest, (byte *)&value.value, value_top_sizeof);
	    case gs_param_type_null:
		break;

	    case gs_param_type_string:
		data = value.value.s.data, size = value.value.s.size;
		goto scalar_array;
	    case gs_param_type_name:
		data = value.value.n.data, size = value.value.n.size;
		goto scalar_array;
	    case gs_param_type_int_array:
		data = value.value.ia.data, size = value.value.ia.size;
		goto scalar_array;
	    case gs_param_type_float_array:
		data = value.value.fa.data, size = value.value.fa.size;
scalar_array:	sput_word(dest, size);
		sput_bytes(dest, data, value_base_sizeof * size);
		break;

	    case gs_param_type_string_array:
		data = value.value.sa.data, size = value.value.sa.size;
		goto string_array;
	    case gs_param_type_name_array:
		data = value.value.na.data, size = value.value.na.size;
string_array:	sput_word(dest, size);
		{
		    uint count;
		    const gs_param_string *sa;

		    for (count = size, sa = data; count-- > 0; ++sa) {
			sput_word(dest, sa->size);
			sput_bytes(dest, sa->data, sa->size);
		    }
		}
		break;

	    case gs_param_type_dict:
	    case gs_param_type_dict_int_keys:
	    case gs_param_type_array:
		sput_word(dest, value.value.d.size);
		code = gs_param_list_puts(dest, value.value.d.list);
		{
		    int end_code =
			param_end_read_dict(list, key.data, &value.value.d);

		    if (code >= 0)
			code = end_code;
		}
		break;

	    default:
		code = gs_note_error(gs_error_unknownerror);
		break;
	}
	if (code < 0)
	    break;
    }

    /* Write end marker, which is an (illegal) 0 key length */
    return (code < 0 ? code : sput_word(dest, 0));
}

/* Put a variable-length value on a stream. */
private int
sput_word(stream *dest, uint value)
{
    int code = 0;

    do {
	byte chunk = value & 0x7f;

	if ((value >>= 7) != 0)
	    chunk |= 0x80;
	if ((code = sputc(dest, chunk)) < 0)
	    break;
    }
    while (value != 0);
    return code;
}

/* Put bytes on a stream. */
private int
sput_bytes(stream *dest, const byte *data, uint size)
{
    uint ignore_count;

    return sputs(dest, data, size, &ignore_count);
}

/* ---------------- Unserializer ---------------- */

/* Forward references */
private int sget_word(P2(stream *src, uint *pvalue));
private int sget_bytes(P3(stream *src, byte *data, uint size));

/*
 * Unserialize a parameter list from a stream.  The list must be in WRITE
 * mode.
 */
int
gs_param_list_gets(stream *src, gs_param_list *list, gs_memory_t *mem)
{
    int code = 0;

    do {
	gs_param_typed_value typed;
	uint key_sizeof;
	int value_top_sizeof;
	int value_base_sizeof;
	uint temp;
	void *data;
	uint size;
	gs_param_type type;
	char string_key[MAX_PARAM_KEY + 1];

	/* key length 0 indicates end of data */
	if ((code = sget_word(src, &key_sizeof)) < 0 ||
	    key_sizeof == 0 ||
	    /* data type */
	    (code = sget_word(src, &temp)) < 0)
	    break;

	if (key_sizeof > sizeof(string_key)) {
	    code = gs_note_error(gs_error_rangecheck);
	    break;
	}
	/* key */
	code = sget_bytes(src, (byte *)string_key, key_sizeof);
	if (code < 0)
	    break;

	/* Data values */
	type = (gs_param_type)temp;
	value_top_sizeof = gs_param_type_sizes[type];
	value_base_sizeof = gs_param_type_base_sizes[type];
	typed.type = type;
	switch (type) {
	    case gs_param_type_bool:
	    case gs_param_type_int:
	    case gs_param_type_long:
	    case gs_param_type_float:
		code = sget_bytes(src, (byte *)&typed.value, value_top_sizeof);
	    case gs_param_type_null:
		goto put;
	    default:
		;
	}
	/* All other data values start with a size. */
	code = sget_word(src, &size);
	if (code < 0)
	    break;

	switch (type) {
	    case gs_param_type_string:
	    case gs_param_type_name:
	    case gs_param_type_int_array:
	    case gs_param_type_float_array:
		data =
		    (value_base_sizeof == 1 ?
		     gs_alloc_string(mem, size, "param string/name") :
		     gs_alloc_byte_array(mem, size, value_base_sizeof,
					 "param scalar array"));
		if (data == 0) {
		    code = gs_note_error(gs_error_VMerror);
		    break;
		}
		typed.value.s.data = data;
		typed.value.s.persistent = false;
		typed.value.s.size = size;
		code = sget_bytes(src, data, size * value_base_sizeof);
		break;

	    case gs_param_type_string_array:
	    case gs_param_type_name_array:
		/****** SHOULD BE STRUCT ARRAY ******/
		data = gs_alloc_byte_array(mem, size, value_top_sizeof,
					   "param string/name array");
		if (data == 0) {
		    code = gs_note_error(gs_error_VMerror);
		    break;
		}
		typed.value.sa.data = data;
		typed.value.sa.persistent = false;
		typed.value.sa.size = size;
		{
		    gs_param_string *sa = data;
		    byte *str_data;
		    uint index, str_size;

		    /* Clean pointers in case we bail out. */
		    for (index = 0; index < size; ++index)
			sa[index].data = 0, sa[index].size = 0;
		    for (index = 0; index < size; ++index, ++sa) {
			code = sget_word(src, &str_size);
			if (code < 0)
			    break;
			str_data = gs_alloc_string(mem, str_size,
						"param string/name element");
			if (str_data == 0) {
			    code = gs_note_error(gs_error_VMerror);
			    break;
			}
			code = sget_bytes(src, str_data, str_size);
			if (code < 0)
			    break;
		    }
		}
		break;

	    case gs_param_type_dict:
	    case gs_param_type_dict_int_keys:
	    case gs_param_type_array:
		typed.value.d.size = size;
		code = param_begin_write_collection
		    (list, string_key, &typed.value.d,
		     type - gs_param_type_dict);
		if (code < 0)
		    break;
		code = gs_param_list_gets(src, typed.value.d.list, mem);
		{
		    int end_code =
			param_end_write_collection(list, string_key,
						   &typed.value.d);

		    if (code >= 0)
			code = end_code;
		}
		break;

	    default:
		code = gs_note_error(gs_error_unknownerror);
		break;
	}
put:	if (code < 0)
	    break;
	if (typed.type != gs_param_type_dict &&
	    typed.type != gs_param_type_dict_int_keys &&
	    typed.type != gs_param_type_array
	    )
	    code = param_write_typed(list, string_key, &typed);
    }
    while (code >= 0);

    return code;
}


/* ---------- Utility functions -------- */

/* Get a value stored with sput_word */
private int
sget_word(stream *src, uint *pvalue)
{
    uint value = 0;
    int chunk;
    uint shift = 0;

    do {
	chunk = sgetc(src);
	if (chunk < 0)
	    return chunk;
	value |= (chunk & 0x7f) << shift;
	shift += 7;
    }
    while (chunk & 0x80);

    *pvalue = value;
    return 0;
}

/* Get bytes from a stream */
private int
sget_bytes(stream *src, byte *data, uint size)
{
    uint ignore_count;

    return sgets(src, data, size, &ignore_count);
}
