/*

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

 *

 * Arnold Robbins

 * May 2009

 * Redone June 2012

 */

/*

 * Copyright (C) 2009, 2010, 2011, 2012, 2013 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>

#include <arpa/inet.h>

#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 0

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

static awk_ext_id_t ext_id;

static const char *ext_version = "rwarray0 extension: version 1.0";

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

int plugin_is_GPL_compatible;

static awk_bool_t write_array(int fd, awk_array_t array);

static awk_bool_t write_elem(int fd, awk_element_t *element);

static awk_bool_t write_value(int fd, awk_value_t *val);

static awk_bool_t read_array(int fd, awk_array_t array);

static awk_bool_t read_elem(int fd, awk_element_t *element);

static awk_bool_t read_value(int fd, 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)

 * 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;

	int fd = -1;

	uint32_t major = MAJOR;

	uint32_t minor = MINOR;

	assert(result != NULL);

	make_number(0.0, result);

	if (nargs < 2)

		goto out;

	/* directory 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 */

	fd = creat(filename.str_value.str, 0600);

	if (fd < 0)

		goto done1;

	if (write(fd, MAGIC, strlen(MAGIC)) != strlen(MAGIC))

		goto done1;

	major = htonl(major);

	if (write(fd, & major, sizeof(major)) != sizeof(major))

		goto done1;

	minor = htonl(minor);

	if (write(fd, & minor, sizeof(minor)) != sizeof(minor))

		goto done1;

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

		make_number(1.0, result);

		goto done0;

	}

done1:

	update_ERRNO_int(errno);

	unlink(filename.str_value.str);

done0:

	close(fd);

out:

	return result;

}

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

static awk_bool_t

write_array(int fd, 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 (write(fd, & count, sizeof(count)) != sizeof(count))

		return awk_false;

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

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

			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(int fd, awk_element_t *element)

{

	uint32_t indexval_len;

	ssize_t write_count;

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

	if (write(fd, & indexval_len, sizeof(indexval_len)) != sizeof(indexval_len))

		return awk_false;

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

		write_count = write(fd, element->index.str_value.str,

				element->index.str_value.len);

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

			return awk_false;

	}

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

}

/* write_value --- write a number or a string or a array */

static awk_bool_t

write_value(int fd, awk_value_t *val)

{

	uint32_t code, len;

	if (val->val_type == AWK_ARRAY) {

		code = htonl(2);

		if (write(fd, & code, sizeof(code)) != sizeof(code))

			return awk_false;

		return write_array(fd, val->array_cookie);

	}

	if (val->val_type == AWK_NUMBER) {

		code = htonl(1);

		if (write(fd, & code, sizeof(code)) != sizeof(code))

			return awk_false;

		if (write(fd, & val->num_value, sizeof(val->num_value)) != sizeof(val->num_value))

			return awk_false;

	} else {

		code = 0;

		if (write(fd, & code, sizeof(code)) != sizeof(code))

			return awk_false;

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

		if (write(fd, & len, sizeof(len)) != sizeof(len))

			return awk_false;

		if (write(fd, val->str_value.str, val->str_value.len)

				!= (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;

	int fd = -1;

	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;

	}

	fd = open(filename.str_value.str, O_RDONLY);

	if (fd < 0)

		goto done1;

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

	if (read(fd, magic_buf, strlen(MAGIC)) != strlen(MAGIC)) {

		errno = EBADF;

		goto done1;

	}

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

		errno = EBADF;

		goto done1;

	}

	if (read(fd, & major, sizeof(major)) != sizeof(major)) {

		errno = EBADF;

		goto done1;

	}

	major = ntohl(major);

	if (major != MAJOR) {

		errno = EBADF;

		goto done1;

	}

	if (read(fd, & minor, sizeof(minor)) != 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(fd, array.array_cookie)) {

		make_number(1.0, result);

		goto done0;

	}

done1:

	update_ERRNO_int(errno);

done0:

	close(fd);

out:

	return result;

}

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

static awk_bool_t

read_array(int fd, awk_array_t array)

{

	uint32_t i;

	uint32_t count;

	awk_element_t new_elem;

	if (read(fd, & count, sizeof(count)) != sizeof(count)) {

		return awk_false;

	}

	count = ntohl(count);

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

		if (read_elem(fd, & 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(int fd, awk_element_t *element)

{

	uint32_t index_len;

	static char *buffer;

	static uint32_t buflen;

	ssize_t ret;

	if ((ret = read(fd, & index_len, sizeof(index_len))) != 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 = realloc(buffer, index_len);

			if (cp == NULL)

				return awk_false;

			buffer = cp;

			buflen = index_len;

		}

		if (read(fd, buffer, index_len) != (ssize_t) index_len) {

			return awk_false;

		}

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

	} else {

		make_null_string(& element->index);

	}

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

		return awk_false;

	return awk_true;

}

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

static awk_bool_t

read_value(int fd, awk_value_t *value)

{

	uint32_t code, len;

	if (read(fd, & code, sizeof(code)) != sizeof(code))

		return awk_false;

	code = ntohl(code);

	if (code == 2) {

		awk_array_t array = create_array();

		if (read_array(fd, array) != 0)

			return awk_false;

		/* hook into value */

		value->val_type = AWK_ARRAY;

		value->array_cookie = array;

	} else if (code == 1) {

		double d;

		if (read(fd, & d, sizeof(d)) != sizeof(d))

			return awk_false;

		/* hook into value */

		value->val_type = AWK_NUMBER;

		value->num_value = d;

	} else {

		if (read(fd, & len, sizeof(len)) != sizeof(len)) {

			return awk_false;

		}

		len = ntohl(len);

		value->val_type = AWK_STRING;

		value->str_value.len = len;

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

		if (read(fd, value->str_value.str, len) != (ssize_t) len) {

			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, "")