diskquota.h

#ifndef DISK_QUOTA_H
#define DISK_QUOTA_H

#include "storage/lwlock.h"

typedef enum
{
	NAMESPACE_QUOTA,
	ROLE_QUOTA
} QuotaType;

struct DiskQuotaLocks
{
	LWLock *active_table_lock;
	LWLock *black_map_lock;
	LWLock *message_box_lock;
};
typedef struct DiskQuotaLocks DiskQuotaLocks;

/*
 * MessageBox is used to store a message for communication between
 * the diskquota launcher process and backends.
 * When backend create an extension, it send a message to launcher
 * to start the diskquota worker process and write the corresponding
 * dbOid into diskquota database_list table in postgres database.
 * When backend drop an extension, it will send a message to launcher
 * to stop the diskquota worker process and remove the dbOid from diskquota
 * database_list table as well.
 */
struct MessageBox
{
	int launcher_pid;
	int req_pid;		/* pid of the request process */
	int cmd;			/* message command type, see MessageCommand */
	int result;			/* message result writen by launcher, see MessageResult */
	int data[4];		/* for create/drop extension diskquota, data[0] is dbid */
};

enum MessageCommand
{
	CMD_CREATE_EXTENSION = 1,
	CMD_DROP_EXTENSION,
};

enum MessageResult
{
	ERR_PENDING = 0,
	ERR_OK,
	/* the number of database exceeds the maximum */
	ERR_EXCEED,
	/* add the dbid to diskquota_namespace.database_list failed */
	ERR_ADD_TO_DB,
	/* cann't start worker process */
	ERR_START_WORKER,
	/* invalid dbid */
	ERR_INVALID_DBID,
	ERR_UNKNOWN,
};

typedef struct MessageBox MessageBox;
typedef enum MessageCommand MessageCommand;
typedef enum MessageResult MessageResult;

extern DiskQuotaLocks diskquota_locks;
extern volatile MessageBox *message_box;

/* enforcement interface*/
extern void init_disk_quota_enforcement(void);
extern void diskquota_invalidate_db(Oid dbid);

/* quota model interface*/
extern void init_disk_quota_shmem(void);
extern void init_disk_quota_model(void);
extern void refresh_disk_quota_model(bool force);
extern bool quota_check_common(Oid reloid);

/* quotaspi interface */
extern void init_disk_quota_hook(void);

extern int   diskquota_naptime;
extern int   diskquota_max_active_tables;

#endif