parallel_slot.h

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/*-------------------------------------------------------------------------
 *
 *  parallel_slot.h
 *      Parallel support for bin/scripts/
 *
 *  Copyright (c) 2003-2024, PostgreSQL Global Development Group
 *
 *  src/include/fe_utils/parallel_slot.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PARALLEL_SLOT_H
#define PARALLEL_SLOT_H
 
#include "fe_utils/connect_utils.h"
#include "libpq-fe.h"
 
typedef bool (*ParallelSlotResultHandler) (PGresult *res, PGconn *conn,
                                           void *context);
 
typedef struct ParallelSlot
{
    PGconn     *connection;     /* One connection */
    bool        inUse;          /* Is the slot being used? */
 
    /*
     * Prior to issuing a command or query on 'connection', a handler callback
     * function may optionally be registered to be invoked to process the
     * results, and context information may optionally be registered for use
     * by the handler.  If unset, these fields should be NULL.
     */
    ParallelSlotResultHandler handler;
    void       *handler_context;
} ParallelSlot;
 
typedef struct ParallelSlotArray
{
    int         numslots;
    ConnParams *cparams;
    const char *progname;
    bool        echo;
    const char *initcmd;
    ParallelSlot slots[FLEXIBLE_ARRAY_MEMBER];
} ParallelSlotArray;
 
static inline void
ParallelSlotSetHandler(ParallelSlot *slot, ParallelSlotResultHandler handler,
                       void *context)
{
    slot->handler = handler;
    slot->handler_context = context;
}
 
static inline void
ParallelSlotClearHandler(ParallelSlot *slot)
{
    slot->handler = NULL;
    slot->handler_context = NULL;
}
 
extern ParallelSlot *ParallelSlotsGetIdle(ParallelSlotArray *sa,
                                          const char *dbname);
 
extern ParallelSlotArray *ParallelSlotsSetup(int numslots, ConnParams *cparams,
                                             const char *progname, bool echo,
                                             const char *initcmd);
 
extern void ParallelSlotsAdoptConn(ParallelSlotArray *sa, PGconn *conn);
 
extern void ParallelSlotsTerminate(ParallelSlotArray *sa);
 
extern bool ParallelSlotsWaitCompletion(ParallelSlotArray *sa);
 
extern bool TableCommandResultHandler(PGresult *res, PGconn *conn,
                                      void *context);
 
#endif                          /* PARALLEL_SLOT_H */