freeswitch/src/mod/databases/mod_mariadb/mod_mariadb.c

/*
* mod_mariadb for FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
* Copyright (C) 2019, Andrey Volk <andywolk@gmail.com>
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is ported from FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
*
* The Initial Developer of the Original Code is
* Anthony Minessale II <anthm@freeswitch.org>
* Portions created by the Initial Developer are Copyright (C)
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Andrey Volk <andywolk@gmail.com>
*
* mod_mariadb.c -- MariaDB (MySQL) FreeSWITCH module
*
*/

#include <switch.h>

#ifndef _WIN32
#include <poll.h>
#else
#include <winsock2.h>
#endif

#include <mysql.h>

#include "mariadb_dsn.hpp"

switch_loadable_module_interface_t *MODULE_INTERFACE;

SWITCH_MODULE_LOAD_FUNCTION(mod_mariadb_load);
SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_mariadb_shutdown);
SWITCH_MODULE_DEFINITION(mod_mariadb, mod_mariadb_load, mod_mariadb_shutdown, NULL);

MYSQL *mariadb_dsn_connect(MYSQL *mysql, const char *host, const char *user, const char *passwd,
	const char *db, unsigned int port, const char *unix_socket, unsigned long clientflag);
void mariadb_dsn_close(MYSQL *mysql);
int mariadb_db_set_connection(MYSQL *mysql, enum enum_server_command command, const char *arg,
	size_t length, my_bool skipp_check, void *opt_arg);
my_bool mariadb_db_dsn_reconnect(MYSQL *mysql);

my_bool reconnect = 1;

#define DEFAULT_MARIADB_RETRIES 120

#ifndef MIN
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#endif

typedef enum {
	MARIADB_STATE_INIT,
	MARIADB_STATE_DOWN,
	MARIADB_STATE_CONNECTED,
	MARIADB_STATE_ERROR
} mariadb_state_t;

struct mariadb_handle {
	char *dsn;
	char *sql;
	MYSQL con;
	my_socket sock;
	mariadb_state_t state;
	int affected_rows;
	int num_retries;
	switch_bool_t auto_commit;
	switch_bool_t in_txn;
	int stored_results;
};

typedef struct mariadb_handle mariadb_handle_t;

struct mariadb_result {
	MYSQL_RES *result;
	char *err;
	int rows;
	int cols;
};

typedef struct mariadb_result mariadb_result_t;

switch_status_t mariadb_handle_destroy(switch_database_interface_handle_t **dih);
switch_status_t mariadb_flush(mariadb_handle_t *handle);
static int db_is_up(mariadb_handle_t *handle);
static char *mariadb_handle_get_error(mariadb_handle_t *handle);

#define mariadb_handle_exec_base(handle, sql, err) mariadb_handle_exec_base_detailed(__FILE__, (char * )__SWITCH_FUNC__, __LINE__, handle, sql, err)
#define mariadb_next_result(h, r) mariadb_next_result_timed(h, r, 10000)
#define mariadb_finish_results(handle) mariadb_finish_results_real(__FILE__, (char * )__SWITCH_FUNC__, __LINE__, handle)

static char *supported_prefixes[4] = { 0 };

static int wait_for_mysql(mariadb_handle_t *handle, int status, int msec)
{
	int res = -1;
#ifdef _WIN32
	/*
	On Windows, select() must be used due to a bug in WSAPoll()
	which is supposed to be identical to BSD's poll(), but it is not,
	"Windows 8 Bugs 309411 – WSAPoll does not report failed connections":
	https://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/18769abd-fca0-4d3c-9884-1a38ce27ae90/wsapoll-and-nonblocking-connects-to-nonexistent-ports?forum=wsk
	*/

	fd_set rs, ws, es;
	struct timeval tv, *timeout = NULL;

	FD_ZERO(&rs);
	FD_ZERO(&ws);
	FD_ZERO(&es);

	if (status & MYSQL_WAIT_READ) FD_SET(handle->sock, &rs);
	if (status & MYSQL_WAIT_WRITE) FD_SET(handle->sock, &ws);
	if (status & MYSQL_WAIT_EXCEPT) FD_SET(handle->sock, &es);

	if (status & MYSQL_WAIT_TIMEOUT) {
		tv.tv_sec = MIN(mysql_get_timeout_value(&handle->con), (unsigned int)msec * 1000);
		tv.tv_usec = 0;
		timeout = &tv;
	}

	res = select(1, &rs, &ws, &es, timeout);
#else
	struct pollfd pfd = { 0 };
	int timeout = -1;

	pfd.fd = handle->sock;
	pfd.events |= (status & MYSQL_WAIT_READ ? POLLIN : 0);
	pfd.events |= (status & MYSQL_WAIT_WRITE ? POLLOUT : 0);
	pfd.events |= (status & MYSQL_WAIT_EXCEPT ? POLLPRI : 0);

	if (status & MYSQL_WAIT_TIMEOUT) {
		timeout = MIN(mysql_get_timeout_value(&handle->con), (unsigned int)msec * 1000);
	}

	do {
		res = poll(&pfd, 1, timeout);
	} while (res == -1 && errno == EINTR);
#endif

	if (res == 0) goto timeout;
	else if (res < 0) goto error;

	status = 0;

#ifdef _WIN32
	if (FD_ISSET(handle->sock, &rs)) status |= MYSQL_WAIT_READ;
	if (FD_ISSET(handle->sock, &ws)) status |= MYSQL_WAIT_WRITE;
	if (FD_ISSET(handle->sock, &es)) status |= MYSQL_WAIT_EXCEPT;
#else
	if (pfd.revents & POLLIN) status |= MYSQL_WAIT_READ;
	if (pfd.revents & POLLOUT) status |= MYSQL_WAIT_WRITE;
	if (pfd.revents & POLLPRI) status |= MYSQL_WAIT_EXCEPT;
#endif

	return status;

error:
	// en error
timeout:
	return MYSQL_WAIT_TIMEOUT;
}


static int db_is_up(mariadb_handle_t *handle)
{
	int ret = 0;
	switch_event_t *event;
	char *err_str = NULL;
	int max_tries = DEFAULT_MARIADB_RETRIES;
	int code = 0, recon = 0;

	if (handle) {
		max_tries = handle->num_retries;
		if (max_tries < 1)
			max_tries = DEFAULT_MARIADB_RETRIES;
	}

top:

	if (!handle) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "No DB Handle\n");
		goto done;
	}

	if (mysql_ping(&handle->con) != 0) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "mysql_ping returned bad connection [Error: %s]; reconnecting...\n", mysql_error(&handle->con));
		handle->state = MARIADB_STATE_ERROR;
		if (mariadb_reconnect(&handle->con) != 0) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "mariadb_reconnect returned bad connection -- reconnection failed! [Error: %s]\n", mysql_error(&handle->con));
			goto error;
		}
		handle->state = MARIADB_STATE_CONNECTED;
		handle->sock = mysql_get_socket(&handle->con);
	}

	ret = 1;
	goto done;

error:
	err_str = mariadb_handle_get_error(handle);

	if (mysql_ping(&handle->con) != 0) {
		handle->state = MARIADB_STATE_ERROR;
		if (mariadb_reconnect(&handle->con) == 0) {
			handle->state = MARIADB_STATE_CONNECTED;
			recon = SWITCH_STATUS_SUCCESS;
			handle->sock = mysql_get_socket(&handle->con);
		}
	}

	max_tries--;

	if (switch_event_create(&event, SWITCH_EVENT_TRAP) == SWITCH_STATUS_SUCCESS) {
		switch_event_add_header(event, SWITCH_STACK_BOTTOM, "Failure-Message", "The sql server is not responding for DSN %s [%s][%d]",
			switch_str_nil(handle->dsn), switch_str_nil(err_str), code);
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "The sql server is not responding for DSN %s [%s][%d]\n",
			switch_str_nil(handle->dsn), switch_str_nil(err_str), code);

		if (recon == SWITCH_STATUS_SUCCESS) {
			switch_event_add_header(event, SWITCH_STACK_BOTTOM, "Additional-Info", "The connection has been re-established");
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "The connection has been re-established\n");
		} else {
			switch_event_add_header(event, SWITCH_STACK_BOTTOM, "Additional-Info", "The connection could not be re-established");
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "The connection could not be re-established\n");
		}
		if (!max_tries) {
			switch_event_add_header(event, SWITCH_STACK_BOTTOM, "Additional-Info", "Giving up!");
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Giving up!\n");
		}

		switch_event_fire(&event);
	}

	if (!max_tries) {
		goto done;
	}

	switch_safe_free(err_str);
	switch_yield(1000000);
	goto top;

done:

	switch_safe_free(err_str);

	return ret;
}

switch_status_t mariadb_SQLEndTran(mariadb_handle_t *handle, switch_bool_t commit)
{
	char * err_str = NULL;

	if (!handle)
		return SWITCH_STATUS_FALSE;

	if (commit) {
		char *sql = "COMMIT";
		handle->stored_results = 0;
		if (mysql_query(&handle->con, sql)) {
			err_str = mariadb_handle_get_error(handle);
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Could not commit transaction: %s\n", err_str);
			switch_safe_free(err_str);
			return SWITCH_STATUS_FALSE;
		}
	} else {
		char *sql = "ROLLBACK";
		handle->stored_results = 0;
		if (mysql_query(&handle->con, sql)) {
			err_str = mariadb_handle_get_error(handle);
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Could not rollback transaction: %s\n", err_str);
			switch_safe_free(err_str);
			return SWITCH_STATUS_FALSE;
		}
	}
	handle->in_txn = SWITCH_FALSE;

	return SWITCH_STATUS_SUCCESS;
}

switch_status_t mariadb_next_result_timed(mariadb_handle_t *handle, mariadb_result_t **result_out, int msec)
{
	int status = 0;
	mariadb_result_t *res;
	switch_time_t start;
	switch_time_t ctime;
	unsigned int usec = msec * 1000;
	char *err_str;

	if (!handle) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "**BUG** Null handle passed to mariadb_next_result.\n");
		return SWITCH_STATUS_FALSE;
	}

	if (handle->stored_results)	{
		if ( (status = mysql_next_result(&handle->con)) ) {
			if (status > 0)	{
				err_str = mariadb_handle_get_error(handle);
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "An error occurred trying to get next for query (%s): %s\n", handle->sql, err_str);
				switch_safe_free(err_str);

				goto error;
			}

			return SWITCH_STATUS_SUCCESS;
		}
	}

	if (!(res = malloc(sizeof(mariadb_result_t)))) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Malloc failed!\n");
		goto error;
	}

	memset(res, 0, sizeof(mariadb_result_t));

	if ( (status = mysql_store_result_start(&res->result, &handle->con)) ) {
		/* Wait for a result to become available, up to msec milliseconds */
		start = switch_micro_time_now();
		while ((ctime = switch_micro_time_now()) - start <= usec) {
			int wait_time = (usec - (unsigned int)(ctime - start)) / 1000;

			/* Wait for the mariadb socket to be ready for data reads. */
			status = wait_for_mysql(handle, status, wait_time);
			status = mysql_store_result_cont(&res->result, &handle->con, status);

			if (!status)
				break;
		}
	}

	/* At this point, we know we can read a full result without blocking. */

	if (res->result) {
		*result_out = res;

		res->rows = (int)mysql_num_rows(res->result);
		handle->affected_rows = res->rows;
		handle->stored_results++;
		res->cols = mysql_num_fields(res->result);		
	} else {
		if (mysql_field_count(&handle->con) != 0) {
			// mysql_store_result_() should have returned data

			err_str = mariadb_handle_get_error(handle);
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "An error occurred trying to use result for query (%s): %s\n", handle->sql, err_str);
			switch_safe_free(err_str);
		}

		free(res);
		res = NULL;
		*result_out = NULL;
	}

	return SWITCH_STATUS_SUCCESS;

error:

	/* Make sure the failed connection does not have any transactions marked as in progress */
	mariadb_flush(handle);

	/* Try to reconnect to the DB if we were dropped */
	db_is_up(handle);

	return SWITCH_STATUS_FALSE;
}

void mariadb_free_result(mariadb_result_t **result)
{
	if (!*result) {
		return;
	}

	if ((*result)->result) {
		mysql_free_result((*result)->result);
	}

	free(*result);
	*result = NULL;
}

switch_status_t mariadb_finish_results_real(const char* file, const char* func, int line, mariadb_handle_t *handle)
{
	char *err_str;
	mariadb_result_t *res = NULL;
	switch_status_t final_status = SWITCH_STATUS_SUCCESS;
	int done = 0, status;

	do {
		mariadb_next_result(handle, &res);
		if (res && res->err && !switch_stristr("already exists", res->err) && !switch_stristr("duplicate key name", res->err)) {
			switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "Error executing query:\n%s\n", res->err);
			final_status = SWITCH_STATUS_FALSE;
		}

		if (!res) {
			if (!mysql_more_results(&handle->con)) {
				done = 1;
			} else {
				if ((status = mysql_next_result(&handle->con))) {
					if (status > 0) {
						err_str = mariadb_handle_get_error(handle);
						switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "An error occurred trying to get next for query (%s): %s\n", handle->sql, switch_str_nil(err_str));
						switch_safe_free(err_str);

						break;
					}
				}
			}
		} else if (res->result) {
			handle->affected_rows = (int)mysql_affected_rows(&handle->con);
		}

		mariadb_free_result(&res);
	} while (!done);

	return final_status;
}

switch_status_t mariadb_handle_disconnect(mariadb_handle_t *handle)
{
	if (!handle) {
		return SWITCH_STATUS_FALSE;
	}

	if (handle->state == MARIADB_STATE_CONNECTED) {
		mysql_close(&handle->con);
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG10, "Disconnected from [%s]\n", handle->dsn);
	}
	switch_safe_free(handle->sql);
	handle->state = MARIADB_STATE_DOWN;

	return SWITCH_STATUS_SUCCESS;
}

static char * mariadb_handle_get_error(mariadb_handle_t *handle)
{
	char *err_str = NULL;

	if (!handle) {
		return NULL;
	}

	switch_strdup(err_str, mysql_error(&handle->con));

	return err_str;
}

switch_status_t mariadb_handle_connect(mariadb_handle_t *handle)
{
	if (!handle) {
		return SWITCH_STATUS_FALSE;
	}

	if (handle->state == MARIADB_STATE_CONNECTED) {
		mariadb_handle_disconnect(handle);
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "Re-connecting %s\n", handle->dsn);
	}

	if (handle->state == MARIADB_STATE_CONNECTED) {
		mariadb_handle_disconnect(handle);
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "Re-connecting %s\n", handle->dsn);
	}

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "Connecting %s\n", handle->dsn);
	mysql_init(&handle->con);

	/* Enable non-blocking operation */
	/* https://mariadb.com/kb/en/library/using-the-non-blocking-library */
	mysql_options(&handle->con, MYSQL_OPT_NONBLOCK, 0);

	/* Enable automatic reconnect with the mariadb_reconnect function, without this that function does not work */
	mysql_options(&handle->con, MYSQL_OPT_RECONNECT, &reconnect);

	/* set timeouts to 300 microseconds */
	/*int default_timeout = 3;
	mysql_options(&handle->con, MYSQL_OPT_READ_TIMEOUT, &default_timeout);
	mysql_options(&handle->con, MYSQL_OPT_CONNECT_TIMEOUT, &default_timeout);
	mysql_options(&handle->con, MYSQL_OPT_WRITE_TIMEOUT, &default_timeout);*/

	if (!mysql_dsn_connect(&handle->con, handle->dsn, CLIENT_MULTI_STATEMENTS)) {
		char *err_str;
		if ((err_str = mariadb_handle_get_error(handle))) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "%s\n", err_str);
			switch_safe_free(err_str);
		} else {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to connect to the database [%s]\n", handle->dsn);
			mariadb_handle_disconnect(handle);
		}
		return SWITCH_STATUS_FALSE;
	}

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "Connected to [%s]\n", handle->dsn);
	handle->state = MARIADB_STATE_CONNECTED;
	handle->sock = mysql_get_socket(&handle->con);

	return SWITCH_STATUS_SUCCESS;
}

switch_status_t mariadb_handle_new(switch_cache_db_database_interface_options_t database_interface_options, switch_database_interface_handle_t **dih)
{
	mariadb_handle_t *new_handle = NULL;

	if (!(*dih = malloc(sizeof(**dih)))) {
		goto err;
	}

	if (!(new_handle = malloc(sizeof(*new_handle)))) {
		goto err;
	}

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

	if (!(new_handle->dsn = strdup(database_interface_options.connection_string))) {
		goto err;
	}

	new_handle->sock = 0;
	new_handle->state = MARIADB_STATE_INIT;	
	new_handle->affected_rows = 0;
	new_handle->num_retries = DEFAULT_MARIADB_RETRIES;
	new_handle->auto_commit = SWITCH_TRUE;
	new_handle->in_txn = SWITCH_FALSE;
	new_handle->stored_results = 0;

	(*dih)->handle = new_handle;

	if (mariadb_handle_connect(new_handle) != SWITCH_STATUS_SUCCESS) {
		if (mariadb_handle_destroy(dih) != SWITCH_STATUS_SUCCESS) {
			goto err;
		}
	}

	return SWITCH_STATUS_SUCCESS;

err:
	switch_safe_free(*dih);

	if (new_handle) {
		switch_safe_free(new_handle->dsn);
		switch_safe_free(new_handle);
	}

	return SWITCH_STATUS_FALSE;
}

switch_status_t mariadb_handle_destroy(switch_database_interface_handle_t **dih)
{
	mariadb_handle_t *handle = NULL;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = (*dih)->handle;

	if (handle) {
		mariadb_handle_disconnect(handle);

		switch_safe_free(handle->dsn);
		free(handle);
	}

	switch_safe_free(*dih);

	return SWITCH_STATUS_SUCCESS;
}

switch_status_t database_flush(switch_database_interface_handle_t *dih)
{
	mariadb_handle_t *handle;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	return mariadb_flush(handle);
}

switch_status_t mariadb_flush(mariadb_handle_t *handle)
{
	MYSQL_RES *tmp = NULL;
	int x = 0;

	if (!handle) {
		return SWITCH_STATUS_FALSE;
	}

	if (handle->stored_results) {
		if (mysql_next_result(&handle->con) != 0) {
			goto done;
		}
	}

	/* Make sure the query is fully cleared */
	while ((tmp = mysql_store_result(&handle->con)) != NULL) {
		mysql_free_result(tmp);
		x++;

		if (mysql_next_result(&handle->con) != 0)
			break;
	}

	if (x) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG10, "Flushing %d results\n", x);
	}

done:

	return SWITCH_STATUS_SUCCESS;
}

switch_status_t mariadb_send_query(mariadb_handle_t *handle, const char* sql)
{
	char *err_str;
	int ret;
	unsigned retries = 60; /* 60 tries, will take 30 to 60 seconds at worst */

	switch_safe_free(handle->sql);
	handle->sql = strdup(sql);
    again:
	handle->stored_results = 0;
	ret = mysql_real_query(&handle->con, sql, (unsigned long)strlen(sql));	
	if (ret) {
		err_str = mariadb_handle_get_error(handle);
		if (strstr(err_str, "Deadlock found when trying to get lock; try restarting transaction")) {
			if (--retries > 0) {
				switch_safe_free(err_str);
				/* We are waiting for 500 ms and random time is not more than 500 ms.
				  This is necessary so that the delay on the primary and secondary servers does not coincide and deadlock does not occur again. */
				switch_yield(500 + (rand() & 511));
				goto again;
			}

			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "DeadLock. The retries are over.\n");
		}

		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Failed to send query (%s) to database: %s\n", sql, err_str);
		switch_safe_free(err_str);
		mariadb_finish_results(handle);
		goto error;
	}

	return SWITCH_STATUS_SUCCESS;

error:
	return SWITCH_STATUS_FALSE;
}

switch_status_t mariadb_handle_exec_base_detailed(const char *file, const char *func, int line,
	mariadb_handle_t *handle, const char *sql, char **err)
{
	char *err_str = NULL, *er = NULL;

	mariadb_flush(handle);
	handle->affected_rows = 0;

	if (!db_is_up(handle)) {
		er = strdup("Database is not up!");
		goto error;
	}

	if (handle->auto_commit == SWITCH_FALSE && handle->in_txn == SWITCH_FALSE) {
		if (mariadb_send_query(handle, "BEGIN") != SWITCH_STATUS_SUCCESS) {
			er = strdup("Error sending BEGIN!");
			if (mariadb_finish_results(handle) != SWITCH_STATUS_SUCCESS) {
				db_is_up(handle); /* If finish_results failed, maybe the db went dead */
			}
			goto error;
		}

		if (mariadb_finish_results(handle) != SWITCH_STATUS_SUCCESS) {
			db_is_up(handle);
			er = strdup("Error sending BEGIN!");
			goto error;
		}
		handle->in_txn = SWITCH_TRUE;
	}

	if (mariadb_send_query(handle, sql) != SWITCH_STATUS_SUCCESS) {
		er = strdup("Error sending query!");
		if (mariadb_finish_results(handle) != SWITCH_STATUS_SUCCESS) {
			db_is_up(handle);
		}
		goto error;
	}

	return SWITCH_STATUS_SUCCESS;

error:
	err_str = mariadb_handle_get_error(handle);

	if (zstr(err_str)) {
		switch_safe_free(err_str);
		err_str = (er) ? er : strdup((char *)"SQL ERROR!");
	} else {
		switch_safe_free(er);
	}

	if (err_str) {
		if (!switch_stristr("already exists", err_str) && !switch_stristr("duplicate key name", err_str)) {
			switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "ERR: [%s]\n[%s]\n", sql, switch_str_nil(err_str));
		}

		if (err) {
			*err = err_str;
		} else {
			free(err_str);
		}
	}

	return SWITCH_STATUS_FALSE;
}

switch_status_t mariadb_handle_exec_detailed(const char *file, const char *func, int line,
	mariadb_handle_t *handle, const char *sql, char **err)
{
	if (mariadb_handle_exec_base_detailed(file, func, line, handle, sql, err) == SWITCH_STATUS_FALSE) {
		goto error;
	}

	return mariadb_finish_results(handle);

error:
	return SWITCH_STATUS_FALSE;
}

switch_status_t database_handle_exec_detailed(const char *file, const char *func, int line, 
	switch_database_interface_handle_t *dih, const char *sql, char **err)
{
	mariadb_handle_t *handle;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	return mariadb_handle_exec_detailed(file, func, line, handle, sql, err);
}

switch_status_t database_handle_exec_string(switch_database_interface_handle_t *dih, const char *sql, char *resbuf, size_t len, char **err)
{
	mariadb_handle_t *handle;
	switch_status_t sstatus = SWITCH_STATUS_SUCCESS;
	mariadb_result_t *result = NULL;
	MYSQL_ROW row;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	if (!handle)
		return SWITCH_STATUS_FALSE;

	handle->affected_rows = 0;

	if (mariadb_handle_exec_base(handle, sql, err) == SWITCH_STATUS_FALSE) {
		goto error;
	}

	if (mariadb_next_result(handle, &result) == SWITCH_STATUS_FALSE) {
		goto error;
	}

	if (!result) {
		sstatus = SWITCH_STATUS_FALSE;
		goto done;
	}

	if (!result->result) {
		sstatus = SWITCH_STATUS_FALSE;
		goto done;
	}

	if (handle->affected_rows <= 0) {
		goto done;
	}

	row = mysql_fetch_row(result->result);
	if (row) {
		strncpy(resbuf, row[0], len);
	} else {
		resbuf[0] = '\0';
	}

done:

	mariadb_free_result(&result);
	if (mariadb_finish_results(handle) != SWITCH_STATUS_SUCCESS) {
		sstatus = SWITCH_STATUS_FALSE;
	}

	return sstatus;

error:
	return SWITCH_STATUS_FALSE;
}

switch_status_t database_SQLSetAutoCommitAttr(switch_database_interface_handle_t *dih, switch_bool_t on)
{
	mariadb_handle_t *handle;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	if (!handle)
		return SWITCH_STATUS_FALSE;

	if (on) {
		handle->auto_commit = SWITCH_TRUE;
	} else {
		handle->auto_commit = SWITCH_FALSE;
	}

	return SWITCH_STATUS_SUCCESS;
}

switch_status_t mariadb_handle_affected_rows(switch_database_interface_handle_t *dih, int *affected_rows)
{
	mariadb_handle_t *handle = NULL;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	if (!handle)
		return SWITCH_STATUS_FALSE;

	*affected_rows = handle->affected_rows;

	return SWITCH_STATUS_SUCCESS;
}

switch_status_t database_commit(switch_database_interface_handle_t *dih)
{
	switch_status_t result;

	mariadb_handle_t *handle;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	if (!handle)
		return SWITCH_STATUS_FALSE;

	result = mariadb_SQLEndTran(handle, SWITCH_TRUE);
	result = database_SQLSetAutoCommitAttr(dih, SWITCH_TRUE) && result;
	result = mariadb_finish_results(handle) && result;

	return result;
}

switch_status_t database_rollback(switch_database_interface_handle_t *dih)
{
	switch_status_t result;
	mariadb_handle_t *handle;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	if (!handle) {
		return SWITCH_STATUS_FALSE;
	}

	result = mariadb_SQLEndTran(handle, SWITCH_FALSE);
	result = database_SQLSetAutoCommitAttr(dih, SWITCH_TRUE) && result;
	result = mariadb_finish_results(handle) && result;

	return result;
}

switch_status_t mariadb_handle_callback_exec_detailed(const char *file, const char *func, int line,
	switch_database_interface_handle_t *dih, const char *sql, switch_core_db_callback_func_t callback, void *pdata, char **err)
{
	mariadb_handle_t *handle;
	char *err_str = NULL;
	int row = 0, col = 0, err_cnt = 0;
	mariadb_result_t *result = NULL;

	if (!dih) {
		return SWITCH_STATUS_FALSE;
	}

	handle = dih->handle;

	if (!handle) {
		return SWITCH_STATUS_FALSE;
	}

	handle->affected_rows = 0;

	switch_assert(callback != NULL);

	if (mariadb_handle_exec_base(handle, sql, err) == SWITCH_STATUS_FALSE) {
		goto error;
	}

	if (mariadb_next_result(handle, &result) == SWITCH_STATUS_FALSE) {
		err_cnt++;
		err_str = mariadb_handle_get_error(handle);
		if (result && !zstr(result->err)) {
			switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "ERR: [%s]\n[%s]\n", sql, switch_str_nil(result->err));
		}
		if (!zstr(err_str)) {
			switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "ERR: [%s]\n[%s]\n", sql, switch_str_nil(err_str));
		}
		switch_safe_free(err_str);
		err_str = NULL;
	}

	while (result != NULL) {
		for (row = 0; row < result->rows; ++row) {
			char **names;
			char **vals;
			MYSQL_ROW data_row;

			names = calloc(result->cols, sizeof(*names));
			vals = calloc(result->cols, sizeof(*vals));

			switch_assert(names && vals);

			data_row = mysql_fetch_row(result->result);

			for (col = 0; col < result->cols; ++col) {
				unsigned long *lengths;
				MYSQL_FIELD *field = mysql_fetch_field_direct(result->result, col);
				if (field) {
					names[col] = malloc(field->name_length +1);
					names[col][field->name_length] = '\0';
					strncpy(names[col], field->name, field->name_length);
										
					lengths = mysql_fetch_lengths(result->result);
					vals[col] = malloc(lengths[col] + 1);
					vals[col][lengths[col]] = '\0';

					if (data_row) {
						strncpy(vals[col], data_row[col], lengths[col]);
					} else {
						vals[col][0] = '\0';
					}
				} else {
					switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "ERR: Column number %d out of range\n", col);
				}
			}

			if (callback(pdata, result->cols, vals, names)) {
				mariadb_finish_results(handle);
				row = result->rows;
			}

			for (col = 0; col < result->cols; ++col) {
				free(names[col]);
				free(vals[col]);
			}

			free(names);
			free(vals);
		}

		mariadb_free_result(&result);
		if (mariadb_next_result(handle, &result) == SWITCH_STATUS_FALSE) {
			err_cnt++;
			err_str = mariadb_handle_get_error(handle);
			if (result && !zstr(result->err)) {
				switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "ERR: [%s]\n[%s]\n", sql, switch_str_nil(result->err));
			}
			if (!zstr(err_str)) {
				switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, NULL, SWITCH_LOG_ERROR, "ERR: [%s]\n[%s]\n", sql, switch_str_nil(err_str));
			}
			switch_safe_free(err_str);
			err_str = NULL;
		}
	}
	if (err_cnt) {
		goto error;
	}

	return SWITCH_STATUS_SUCCESS;

error:
	return SWITCH_STATUS_FALSE;
}

SWITCH_MODULE_LOAD_FUNCTION(mod_mariadb_load)
{
	switch_database_interface_t *database_interface;

	supported_prefixes[0] = (char *)"mariadb";
	supported_prefixes[1] = (char *)"maria";
	supported_prefixes[2] = (char *)"mysql";

	/* connect my internal structure to the blank pointer passed to me */
	*module_interface = switch_loadable_module_create_module_interface(pool, modname);
	MODULE_INTERFACE = *module_interface;

	database_interface = (switch_database_interface_t *)switch_loadable_module_create_interface(*module_interface, SWITCH_DATABASE_INTERFACE);
	database_interface->interface_name = modname;
	/*
		MariaDB and MySQL both have row size limits
		https://mariadb.com/kb/en/library/innodb-limitations/#limitations-on-size
		https://dev.mysql.com/doc/refman/8.0/en/column-count-limit.html

		Setting database flag to SWITCH_DATABASE_FLAG_ROW_SIZE_LIMIT 
		will allow FreeSWITCH Core to properly create wide tables such as the channel table 
		which size exeeds the limit in the case of a multi-byte charset like utf8 (1-4 bytes per character).
	*/
	database_interface->flags = SWITCH_DATABASE_FLAG_ROW_SIZE_LIMIT;
	database_interface->prefixes = supported_prefixes;
	database_interface->handle_new = mariadb_handle_new;
	database_interface->handle_destroy = mariadb_handle_destroy;
	database_interface->flush = database_flush;
	database_interface->exec_detailed = database_handle_exec_detailed;
	database_interface->exec_string = database_handle_exec_string;
	database_interface->affected_rows = mariadb_handle_affected_rows;
	database_interface->sql_set_auto_commit_attr = database_SQLSetAutoCommitAttr;
	database_interface->commit = database_commit;
	database_interface->rollback = database_rollback;
	database_interface->callback_exec_detailed = mariadb_handle_callback_exec_detailed;
	
	/* indicate that the module should continue to be loaded */
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_mariadb_shutdown)
{
	return SWITCH_STATUS_UNLOAD;
}

/* For Emacs:
 * Local Variables:
 * mode:c
 * indent-tabs-mode:t
 * tab-width:4
 * c-basic-offset:4
 * End:
 * For VIM:
 * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
 */