#define AOF_REWRITE_ITEMS_PER_CMD 64
#define AOF_READ_DIFF_INTERVAL_BYTES (1024*10)
#define AOF_ANNOTATION_LINE_MAX_LEN 1024

/* AOF states */
#define AOF_OFF 0             /* AOF is off */
#define AOF_ON 1              /* AOF is on */
#define AOF_WAIT_REWRITE 2    /* AOF waits rewrite to start appending */

/* AOF return values for loadAppendOnlyFile() */
#define AOF_OK 0
#define AOF_NOT_EXIST 1
#define AOF_EMPTY 2
#define AOF_OPEN_ERR 3
#define AOF_FAILED 4

#define CLIENT_FORCE_AOF (1<<14)   /* Force AOF propagation of current cmd. */
#define CLIENT_PREVENT_AOF_PROP (1<<19)  /* Don't propagate to AOF. */

/* Append only defines */
#define AOF_FSYNC_NO 0
#define AOF_FSYNC_ALWAYS 1
#define AOF_FSYNC_EVERYSEC 2

size_t stat_aof_cow_bytes;      /* Copy on write bytes during AOF rewrite. */
/* AOF persistence */
    int aof_enabled;                /* AOF configuration */
    int aof_state;                  /* AOF_(ON|OFF|WAIT_REWRITE) */
    int aof_fsync;                  /* Kind of fsync() policy */
    char *aof_filename;             /* Name of the AOF file */
    int aof_no_fsync_on_rewrite;    /* Don't fsync if a rewrite is in prog. */
    int aof_rewrite_perc;           /* Rewrite AOF if % growth is > M and... */
    off_t aof_rewrite_min_size;     /* the AOF file is at least N bytes. */
    off_t aof_rewrite_base_size;    /* AOF size on latest startup or rewrite. */
    off_t aof_current_size;         /* AOF current size. */
    off_t aof_fsync_offset;         /* AOF offset which is already synced to disk. */
    int aof_flush_sleep;            /* Micros to sleep before flush. (used by tests) */
    int aof_rewrite_scheduled;      /* Rewrite once BGSAVE terminates. */
    list *aof_rewrite_buf_blocks;   /* Hold changes during an AOF rewrite. */
    sds aof_buf;      /* AOF buffer, written before entering the event loop */
    int aof_fd;       /* File descriptor of currently selected AOF file */
    int aof_selected_db; /* Currently selected DB in AOF */
    time_t aof_flush_postponed_start; /* UNIX time of postponed AOF flush */
    time_t aof_last_fsync;            /* UNIX time of last fsync() */
    time_t aof_rewrite_time_last;   /* Time used by last AOF rewrite run. */
    time_t aof_rewrite_time_start;  /* Current AOF rewrite start time. */
    time_t aof_cur_timestamp;       /* Current record timestamp in AOF */
    int aof_timestamp_enabled;      /* Enable record timestamp in AOF */
    int aof_lastbgrewrite_status;   /* C_OK or C_ERR */
    unsigned long aof_delayed_fsync;  /* delayed AOF fsync() counter */
    int aof_rewrite_incremental_fsync;/* fsync incrementally while aof rewriting? */
    int rdb_save_incremental_fsync;   /* fsync incrementally while rdb saving? */
    int aof_last_write_status;      /* C_OK or C_ERR */
    int aof_last_write_errno;       /* Valid if aof write/fsync status is ERR */
    int aof_load_truncated;         /* Don't stop on unexpected AOF EOF. */
    int aof_use_rdb_preamble;       /* Use RDB preamble on AOF rewrites. */
    redisAtomic int aof_bio_fsync_status; /* Status of AOF fsync in bio job. */
    redisAtomic int aof_bio_fsync_errno;  /* Errno of AOF fsync in bio job. */
    /* AOF pipes used to communicate between parent and child during rewrite. */
    int aof_pipe_write_data_to_child;
    int aof_pipe_read_data_from_parent;
    int aof_pipe_write_ack_to_parent;
    int aof_pipe_read_ack_from_child;
    int aof_pipe_write_ack_to_child;
    int aof_pipe_read_ack_from_parent;
    int aof_stop_sending_diff;     /* If true stop sending accumulated diffs
                                      to child process. */
    sds aof_child_diff;             /* AOF diff accumulator child side. */