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/*
* objectaccess.h
*
* Object access hooks.
*
* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*/
#ifndef OBJECTACCESS_H
#define OBJECTACCESS_H
/*
* Object access hooks are intended to be called just before or just after
* performing certain actions on a SQL object. This is intended as
* infrastructure for security or logging pluggins.
*
* OAT_POST_CREATE should be invoked just after the object is created.
* Typically, this is done after inserting the primary catalog records and
* associated dependencies.
*
* OAT_DROP should be invoked just before deletion of objects; typically
* deleteOneObject(). Its arguments are packed within ObjectAccessDrop.
*
* OAT_POST_ALTER should be invoked just after the object is altered,
* but before the command counter is incremented. An extension using the
* hook can use SnapshotNow and SnapshotSelf to get the old and new
* versions of the tuple.
*
* Other types may be added in the future.
*/
typedef enum ObjectAccessType
{
OAT_POST_CREATE,
OAT_DROP,
OAT_POST_ALTER,
} ObjectAccessType;
/*
* Arguments of OAT_POST_CREATE event
*/
typedef struct
{
/*
* This flag informs extensions whether the context of this creation
* is invoked by user's operations, or not. E.g, it shall be dealt
* as internal stuff on toast tables or indexes due to type changes.
*/
bool is_internal;
} ObjectAccessPostCreate;
/*
* Arguments of OAT_DROP event
*/
typedef struct
{
/*
* Flags to inform extensions the context of this deletion. Also see
* PERFORM_DELETION_* in dependency.h
*/
int dropflags;
} ObjectAccessDrop;
/*
* Arguments of OAT_POST_ALTER event
*/
typedef struct
{
/*
* This identifier is used when system catalog takes two IDs
* to identify a particular tuple of the catalog.
* It is only used when the caller want to identify an entry
* of pg_inherits, pg_db_role_setting or pg_user_mapping.
* Elsewhere, InvalidOid should be set.
*/
Oid auxiliary_id;
/*
* If this flag is set, the user hasn't requested that the object be
* altered, but we're doing it anyway for some internal reason.
* Permissions-checking hooks may want to skip checks if, say, we're
* alter the constraints of a temporary heap during CLUSTER.
*/
bool is_internal;
} ObjectAccessPostAlter;
/* Plugin provides a hook function matching this signature. */
typedef void (*object_access_hook_type) (ObjectAccessType access,
Oid classId,
Oid objectId,
int subId,
void *arg);
/* Plugin sets this variable to a suitable hook function. */
extern PGDLLIMPORT object_access_hook_type object_access_hook;
/* Core code uses these functions to call the hook (see macros below). */
extern void RunObjectPostCreateHook(Oid classId, Oid objectId, int subId,
bool is_internal);
extern void RunObjectDropHook(Oid classId, Oid objectId, int subId,
int dropflags);
extern void RunObjectPostAlterHook(Oid classId, Oid objectId, int subId,
Oid auxiliaryId, bool is_internal);
/*
* The following macros are wrappers around the functions above; these should
* normally be used to invoke the hook in lieu of calling the above functions
* directly.
*/
#define InvokeObjectPostCreateHook(classId,objectId,subId) \
InvokeObjectPostCreateHookArg((classId),(objectId),(subId),false)
#define InvokeObjectPostCreateHookArg(classId,objectId,subId,is_internal) \
do { \
if (object_access_hook) \
RunObjectPostCreateHook((classId),(objectId),(subId), \
(is_internal)); \
} while(0)
#define InvokeObjectDropHook(classId,objectId,subId) \
InvokeObjectDropHookArg((classId),(objectId),(subId),0)
#define InvokeObjectDropHookArg(classId,objectId,subId,dropflags) \
do { \
if (object_access_hook) \
RunObjectDropHook((classId),(objectId),(subId), \
(dropflags)); \
} while(0)
#define InvokeObjectPostAlterHook(classId,objectId,subId) \
InvokeObjectPostAlterHookArg((classId),(objectId),(subId), \
InvalidOid,false)
#define InvokeObjectPostAlterHookArg(classId,objectId,subId, \
auxiliaryId,is_internal) \
do { \
if (object_access_hook) \
RunObjectPostAlterHook((classId),(objectId),(subId), \
(auxiliaryId),(is_internal)); \
} while(0)
#endif /* OBJECTACCESS_H */
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