/*

 * rwarray.c - Builtin functions to binary read / write arrays to a file.

 *

 * Arnold Robbins

 * May 2009

 * Redone June 2012

 * Improved September 2017

 */

/*

 * Copyright (C) 2009-2014, 2017 the Free Software Foundation, Inc.

 *

 * This file is part of GAWK, the GNU implementation of the

 * AWK Programming Language.

 *

 * GAWK is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or

 * (at your option) any later version.

 *

 * GAWK is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdio.h>

#include <assert.h>

#include <errno.h>

#include <fcntl.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#ifdef __MINGW32__

#include <winsock2.h>

#include <stdint.h>

#else

#include <arpa/inet.h>

#endif

#include <sys/types.h>

#include <sys/stat.h>

#include "gawkapi.h"

#include "gettext.h"

#define _(msgid)  gettext(msgid)

#define N_(msgid) msgid

#define MAGIC "awkrulz\n"

#define MAJOR 3

#define MINOR 1

static const gawk_api_t *api;	/* for convenience macros to work */

static awk_ext_id_t ext_id;

static const char *ext_version = "rwarray extension: version 1.2";

static awk_bool_t (*init_func)(void) = NULL;

int plugin_is_GPL_compatible;

static awk_bool_t write_array(FILE *fp, awk_array_t array);

static awk_bool_t write_elem(FILE *fp, awk_element_t *element);

static awk_bool_t write_value(FILE *fp, awk_value_t *val);

static awk_bool_t read_array(FILE *fp, awk_array_t array);

static awk_bool_t read_elem(FILE *fp, awk_element_t *element);

static awk_bool_t read_value(FILE *fp, awk_value_t *value);

/*

 * Format of array info:

 *

 * MAGIC		8 bytes

 * Major version	4 bytes - network order

 * Minor version	4 bytes - network order

 * Element count	4 bytes - network order

 * Elements

 *

 * For each element:

 * Length of index val:	4 bytes - network order

 * Index val as characters (N bytes)

 * Value type		4 bytes (0 = string, 1 = number, 2 = array, 3 = regex, 4 = strnum, 5 = undefined)

 * IF string:

 * 	Length of value	4 bytes

 * 	Value as characters (N bytes)

 * ELSE IF number:

 * 	8 bytes as native double

 * ELSE

 * 	Element count

 * 	Elements

 * END IF

 */

/* do_writea --- write an array */

static awk_value_t *

do_writea(int nargs, awk_value_t *result, struct awk_ext_func *unused)

{

	awk_value_t filename, array;

	FILE *fp = NULL;

	uint32_t major = MAJOR;

	uint32_t minor = MINOR;

	assert(result != NULL);

	make_number(0.0, result);

	if (nargs < 2)

		goto out;

	/* filename is first arg, array to dump is second */

	if (! get_argument(0, AWK_STRING, & filename)) {

		fprintf(stderr, _("do_writea: argument 0 is not a string\n"));

		errno = EINVAL;

		goto done1;

	}

	if (! get_argument(1, AWK_ARRAY, & array)) {

		fprintf(stderr, _("do_writea: argument 1 is not an array\n"));

		errno = EINVAL;

		goto done1;

	}

	/* open the file, if error, set ERRNO and return */

	fp = fopen(filename.str_value.str, "wb");

	if (fp == NULL)

		goto done1;

	if (fwrite(MAGIC, 1, strlen(MAGIC), fp) != strlen(MAGIC))

		goto done1;

	major = htonl(major);

	if (fwrite(& major, 1, sizeof(major), fp) != sizeof(major))

		goto done1;

	minor = htonl(minor);

	if (fwrite(& minor, 1, sizeof(minor), fp) != sizeof(minor))

		goto done1;

	if (write_array(fp, array.array_cookie)) {

		make_number(1.0, result);

		goto done0;

	}

done1:

	update_ERRNO_int(errno);

	unlink(filename.str_value.str);

done0:

	fclose(fp);

out:

	return result;

}

/* write_array --- write out an array or a sub-array */

static awk_bool_t

write_array(FILE *fp, awk_array_t array)

{

	uint32_t i;

	uint32_t count;

	awk_flat_array_t *flat_array;

	if (! flatten_array(array, & flat_array)) {

		fprintf(stderr, _("write_array: could not flatten array\n"));

		return awk_false;

	}

	count = htonl(flat_array->count);

	if (fwrite(& count, 1, sizeof(count), fp) != sizeof(count))

		return awk_false;

	for (i = 0; i < flat_array->count; i++) {

		if (! write_elem(fp, & flat_array->elements[i])) {

			(void) release_flattened_array(array, flat_array);

			return awk_false;

		}

	}

	if (! release_flattened_array(array, flat_array)) {

		fprintf(stderr, _("write_array: could not release flattened array\n"));

		return awk_false;

	}

	return awk_true;

}

/* write_elem --- write out a single element */

static awk_bool_t

write_elem(FILE *fp, awk_element_t *element)

{

	uint32_t indexval_len;

	ssize_t write_count;

	indexval_len = htonl(element->index.str_value.len);

	if (fwrite(& indexval_len, 1, sizeof(indexval_len), fp) != sizeof(indexval_len))

		return awk_false;

	if (element->index.str_value.len > 0) {

		write_count = fwrite(element->index.str_value.str,

				1, element->index.str_value.len, fp);

		if (write_count != (ssize_t) element->index.str_value.len)

			return awk_false;

	}

	return write_value(fp, & element->value);

}

/* write_value --- write a number or a string or a strnum or a regex or an array */

static awk_bool_t

write_value(FILE *fp, awk_value_t *val)

{

	uint32_t code, len;

	if (val->val_type == AWK_ARRAY) {

		code = htonl(2);

		if (fwrite(& code, 1, sizeof(code), fp) != sizeof(code))

			return awk_false;

		return write_array(fp, val->array_cookie);

	}

	if (val->val_type == AWK_NUMBER) {

		code = htonl(1);

		if (fwrite(& code, 1, sizeof(code), fp) != sizeof(code))

			return awk_false;

		if (fwrite(& val->num_value, 1, sizeof(val->num_value), fp) != sizeof(val->num_value))

			return awk_false;

	} else {

		switch (val->val_type) {

		case AWK_STRING:

			code = htonl(0);

			break;

		case AWK_STRNUM:

			code = htonl(4);

			break;

		case AWK_REGEX:

			code = htonl(3);

			break;

		case AWK_UNDEFINED:

			code = htonl(5);

			break;

		default:

			/* XXX can this happen? */

			code = htonl(0);

			warning(ext_id, _("array value has unknown type %d"), val->val_type);

			break;

		}

		if (fwrite(& code, 1, sizeof(code), fp) != sizeof(code))

			return awk_false;

		len = htonl(val->str_value.len);

		if (fwrite(& len, 1, sizeof(len), fp) != sizeof(len))

			return awk_false;

		if (fwrite(val->str_value.str, 1, val->str_value.len, fp)

				!= (ssize_t) val->str_value.len)

			return awk_false;

	}

	return awk_true;

}

/* do_reada --- read an array */

static awk_value_t *

do_reada(int nargs, awk_value_t *result, struct awk_ext_func *unused)

{

	awk_value_t filename, array;

	FILE *fp = NULL;

	uint32_t major;

	uint32_t minor;

	char magic_buf[30];

	assert(result != NULL);

	make_number(0.0, result);

	if (nargs < 2)

		goto out;

	/* directory is first arg, array to read is second */

	if (! get_argument(0, AWK_STRING, & filename)) {

		fprintf(stderr, _("do_reada: argument 0 is not a string\n"));

		errno = EINVAL;

		goto done1;

	}

	if (! get_argument(1, AWK_ARRAY, & array)) {

		fprintf(stderr, _("do_reada: argument 1 is not an array\n"));

		errno = EINVAL;

		goto done1;

	}

	fp = fopen(filename.str_value.str, "rb");

	if (fp == NULL)

		goto done1;

	memset(magic_buf, '\0', sizeof(magic_buf));

	if (fread(magic_buf, 1, strlen(MAGIC), fp) != strlen(MAGIC)) {

		errno = EBADF;

		goto done1;

	}

	if (strcmp(magic_buf, MAGIC) != 0) {

		errno = EBADF;

		goto done1;

	}

	if (fread(& major, 1, sizeof(major), fp) != sizeof(major)) {

		errno = EBADF;

		goto done1;

	}

	major = ntohl(major);

	if (major != MAJOR) {

		errno = EBADF;

		goto done1;

	}

	if (fread(& minor, 1, sizeof(minor), fp) != sizeof(minor)) {

		/* read() sets errno */

		goto done1;

	}

	minor = ntohl(minor);

	if (minor != MINOR) {

		errno = EBADF;

		goto done1;

	}

	if (! clear_array(array.array_cookie)) {

		errno = ENOMEM;

		fprintf(stderr, _("do_reada: clear_array failed\n"));

		goto done1;

	}

	if (read_array(fp, array.array_cookie)) {

		make_number(1.0, result);

		goto done0;

	}

done1:

	update_ERRNO_int(errno);

done0:

	if (fp != NULL)

		fclose(fp);

out:

	return result;

}

/* read_array --- read in an array or sub-array */

static awk_bool_t

read_array(FILE *fp, awk_array_t array)

{

	uint32_t i;

	uint32_t count;

	awk_element_t new_elem;

	if (fread(& count, 1, sizeof(count), fp) != sizeof(count))

		return awk_false;

	count = ntohl(count);

	for (i = 0; i < count; i++) {

		if (read_elem(fp, & new_elem)) {

			/* add to array */

			if (! set_array_element_by_elem(array, & new_elem)) {

				fprintf(stderr, _("read_array: set_array_element failed\n"));

				return awk_false;

			}

		} else

			break;

	}

	if (i != count)

		return awk_false;

	return awk_true;

}

/* read_elem --- read in a single element */

static awk_bool_t

read_elem(FILE *fp, awk_element_t *element)

{

	uint32_t index_len;

	static char *buffer;

	static uint32_t buflen;

	ssize_t ret;

	if ((ret = fread(& index_len, 1, sizeof(index_len), fp)) != sizeof(index_len)) {

		return awk_false;

	}

	index_len = ntohl(index_len);

	memset(element, 0, sizeof(*element));

	if (index_len > 0) {

		if (buffer == NULL) {

			/* allocate buffer */

			emalloc(buffer, char *, index_len, "read_elem");

			buflen = index_len;

		} else if (buflen < index_len) {

			/* reallocate buffer */

			char *cp = gawk_realloc(buffer, index_len);

			if (cp == NULL)

				return awk_false;

			buffer = cp;

			buflen = index_len;

		}

		if (fread(buffer, 1, index_len, fp) != (ssize_t) index_len) {

			return awk_false;

		}

		make_const_string(buffer, index_len, & element->index);

	} else {

		make_null_string(& element->index);

	}

	if (! read_value(fp, & element->value))

		return awk_false;

	return awk_true;

}

/* read_value --- read a number or a string */

static awk_bool_t

read_value(FILE *fp, awk_value_t *value)

{

	uint32_t code, len;

	if (fread(& code, 1, sizeof(code), fp) != sizeof(code))

		return awk_false;

	code = ntohl(code);

	if (code == 2) {

		awk_array_t array = create_array();

		if (! read_array(fp, array))

			return awk_false;

		/* hook into value */

		value->val_type = AWK_ARRAY;

		value->array_cookie = array;

	} else if (code == 1) {

		double d;

		if (fread(& d, 1, sizeof(d), fp) != sizeof(d))

			return awk_false;

		/* hook into value */

		value->val_type = AWK_NUMBER;

		value->num_value = d;

	} else {

		if (fread(& len, 1, sizeof(len), fp) != sizeof(len)) {

			return awk_false;

		}

		len = ntohl(len);

		switch (code) {

		case 0:

			value->val_type = AWK_STRING;

			break;

		case 3:

			value->val_type = AWK_REGEX;

			break;

		case 4:

			value->val_type = AWK_STRNUM;

			break;

		case 5:

			value->val_type = AWK_UNDEFINED;

			break;

		default:

			/* this cannot happen! */

			warning(ext_id, _("treating recovered value with unknown type code %d as a string"), code);

			value->val_type = AWK_STRING;

			break;

		}

		value->str_value.len = len;

		value->str_value.str = gawk_malloc(len + 1);

		if (fread(value->str_value.str, 1, len, fp) != (ssize_t) len) {

			gawk_free(value->str_value.str);

			return awk_false;

		}

		value->str_value.str[len] = '\0';

	}

	return awk_true;

}

static awk_ext_func_t func_table[] = {

	{ "writea", do_writea, 2, 2, awk_false, NULL },

	{ "reada", do_reada, 2, 2, awk_false, NULL },

};

/* define the dl_load function using the boilerplate macro */

dl_load_func(func_table, rwarray, "")