libpq-events.h

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/*-------------------------------------------------------------------------
 *
 * libpq-events.h
 *    This file contains definitions that are useful to applications
 *    that invoke the libpq "events" API, but are not interesting to
 *    ordinary users of libpq.
 *
 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/interfaces/libpq/libpq-events.h
 *
 *-------------------------------------------------------------------------
 */
 
#ifndef LIBPQ_EVENTS_H
#define LIBPQ_EVENTS_H
 
#include "libpq-fe.h"
 
#ifdef __cplusplus
extern "C"
{
#endif
 
/* Callback Event Ids */
typedef enum
{
    PGEVT_REGISTER,
    PGEVT_CONNRESET,
    PGEVT_CONNDESTROY,
    PGEVT_RESULTCREATE,
    PGEVT_RESULTCOPY,
    PGEVT_RESULTDESTROY
} PGEventId;
 
typedef struct
{
    PGconn     *conn;
} PGEventRegister;
 
typedef struct
{
    PGconn     *conn;
} PGEventConnReset;
 
typedef struct
{
    PGconn     *conn;
} PGEventConnDestroy;
 
typedef struct
{
    PGconn     *conn;
    PGresult   *result;
} PGEventResultCreate;
 
typedef struct
{
    const PGresult *src;
    PGresult   *dest;
} PGEventResultCopy;
 
typedef struct
{
    PGresult   *result;
} PGEventResultDestroy;
 
typedef int (*PGEventProc) (PGEventId evtId, void *evtInfo, void *passThrough);
 
/* Registers an event proc with the given PGconn. */
extern int  PQregisterEventProc(PGconn *conn, PGEventProc proc,
                                const char *name, void *passThrough);
 
/* Sets the PGconn instance data for the provided proc to data. */
extern int  PQsetInstanceData(PGconn *conn, PGEventProc proc, void *data);
 
/* Gets the PGconn instance data for the provided proc. */
extern void *PQinstanceData(const PGconn *conn, PGEventProc proc);
 
/* Sets the PGresult instance data for the provided proc to data. */
extern int  PQresultSetInstanceData(PGresult *result, PGEventProc proc, void *data);
 
/* Gets the PGresult instance data for the provided proc. */
extern void *PQresultInstanceData(const PGresult *result, PGEventProc proc);
 
/* Fires RESULTCREATE events for an application-created PGresult. */
extern int  PQfireResultCreateEvents(PGconn *conn, PGresult *res);
 
#ifdef __cplusplus
}
#endif
 
#endif                          /* LIBPQ_EVENTS_H */