/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) NGINX, Inc.
 */

#ifndef _NXT_PORT_H_INCLUDED_
#define _NXT_PORT_H_INCLUDED_


typedef struct nxt_port_s  nxt_port_t;


typedef struct {
    uint32_t            stream;

    uint16_t            type;
    uint8_t             last;      /* 1 bit */
} nxt_port_msg_t;


typedef struct {
    nxt_queue_link_t    link;
    nxt_buf_t           *buf;
    size_t              share;
    nxt_fd_t            fd;
    nxt_port_msg_t      port_msg;
} nxt_port_send_msg_t;


typedef struct nxt_port_recv_msg_s {
    uint32_t            stream;
    uint16_t            type;

    nxt_fd_t            fd;
    nxt_buf_t           *buf;
    nxt_port_t          *port;
} nxt_port_recv_msg_t;


typedef void (*nxt_port_handler_t)(nxt_task_t *task, nxt_port_recv_msg_t *msg);


struct nxt_port_s {
    /* Must be the first field. */
    nxt_fd_event_t      socket;

    nxt_queue_t         messages;   /* of nxt_port_send_msg_t */

    /* Maximum size of message part. */
    uint32_t            max_size;
    /* Maximum interleave of message parts. */
    uint32_t            max_share;

    nxt_port_handler_t  handler;
    void                *data;

    nxt_mem_pool_t      *mem_pool;
    nxt_buf_t           *free_bufs;
    nxt_socket_t        pair[2];

    nxt_pid_t           pid;
    uint32_t            engine;
    uint32_t            generation;
};


#define NXT_PORT_MSG_MAX  NXT_PORT_MSG_DATA

typedef enum {
    NXT_PORT_MSG_QUIT = 0,
    NXT_PORT_MSG_NEW_PORT,
    NXT_PORT_MSG_CHANGE_FILE,
    NXT_PORT_MSG_DATA,
} nxt_port_msg_type_e;


typedef struct {
    nxt_pid_t           pid;
    uint32_t            engine;
    size_t              max_size;
    size_t              max_share;
} nxt_port_msg_new_port_t;


/*
 * nxt_port_data_t size is allocation size
 * which enables effective reuse of memory pool cache.
 */
typedef union {
    nxt_buf_t                buf;
    nxt_port_msg_new_port_t  new_port;
} nxt_port_data_t;


nxt_int_t nxt_port_socket_init(nxt_task_t *task, nxt_port_t *port,
    size_t max_size);
void nxt_port_destroy(nxt_port_t *port);
void nxt_port_write_enable(nxt_task_t *task, nxt_port_t *port);
void nxt_port_write_close(nxt_port_t *port);
void nxt_port_read_enable(nxt_task_t *task, nxt_port_t *port);
void nxt_port_read_close(nxt_port_t *port);
nxt_int_t nxt_port_socket_write(nxt_task_t *task, nxt_port_t *port,
    nxt_uint_t type, nxt_fd_t fd, uint32_t stream, nxt_buf_t *b);

void nxt_port_create(nxt_thread_t *thread, nxt_port_t *port,
    nxt_port_handler_t *handlers);
void nxt_port_write(nxt_task_t *task, nxt_cycle_t *cycle, nxt_uint_t type,
    nxt_fd_t fd, uint32_t stream, nxt_buf_t *b);
void nxt_port_send_new_port(nxt_task_t *task, nxt_cycle_t *cycle,
    nxt_port_t *port);
void nxt_port_change_log_file(nxt_task_t *task, nxt_cycle_t *cycle,
    nxt_uint_t slot, nxt_fd_t fd);

void nxt_port_quit_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg);
void nxt_port_new_port_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg);
void nxt_port_change_log_file_handler(nxt_task_t *task,
    nxt_port_recv_msg_t *msg);
void nxt_port_data_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg);
void nxt_port_empty_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg);


#endif /* _NXT_PORT_H_INCLUDED_ */