#ifndef _DCB_H
#define _DCB_H
/*
 * This file is distributed as part of the SkySQL Gateway.  It 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,
 * version 2.
 *
 * This program 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.
 *
 * Copyright SkySQL Ab
 */

struct session;

/*
 * The function pointer table used by descriptors to call relevant functions
 * within the protocol specific code.
 */

struct dcb;

typedef struct gw_protocol {
        /*                              
         * The operations that can be performed on the descriptor
         */                             
	int		(*read)(struct dcb *, int);
	int		(*write)(struct dcb *, int);
	int		(*error)(struct dcb *, int);
	int		(*accept)(struct dcb *, int);
	//int		(*close)(struct dcb *);
} GWPROTOCOL;

/*
 * Descriptor Control Block
 */
typedef struct dcb {
	int		fd;		/* The descriptor */
	int 		state;		/* Current descriptor state */
	void		*protocol;	/* The protocol specific state */
	struct session	*session;	/* The owning session */
	GWPROTOCOL	func;		/* The functions for this descrioptor */

	/* queue buffer for write
	is now a two buffer implementation
	Only used in client write
	*/
	uint8_t buffer[MAX_BUFFER_SIZE];	/* network buffer */
	int buff_bytes;				/* bytes in buffer */
	uint8_t *buffer_ptr;			/* buffer pointer */
	uint8_t second_buffer[MAX_BUFFER_SIZE];	/* 2nd network buffer */
	int second_buff_bytes;			/* 2nd bytes in buffer */
	uint8_t *second_buffer_ptr;		/* 2nd buffer pointer */
} DCB;

/* DCB states */
#define	DCB_STATE_ALLOC		0	/* Memory allocated but not populated */
#define DCB_STATE_IDLE		1	/* Not yet in the poll mask */
#define DCB_STATE_POLLING	2	/* Waiting in the poll loop */
#define DCB_STATE_PROCESSING	4	/* Processing an event */
#define DCB_STATE_LISTENING	5	/* The DCB is for a listening socket */

/* A few useful macros */
#define	DCB_SESSION(x)			(x)->session
#define DCB_PROTOCOL(x, type)		(type *)((x)->protocol)

#endif