72 lines
2.0 KiB
C
72 lines
2.0 KiB
C
/*-------------------------------------------------------------------------
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*
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* portal.h
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* POSTGRES portal definitions.
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*
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*
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* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: portal.h,v 1.28 2001/05/21 14:22:18 wieck Exp $
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*
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*-------------------------------------------------------------------------
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*/
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/*
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* Note:
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* A portal is an abstraction which represents the execution state of
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* a running query (specifically, a CURSOR).
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*/
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#ifndef PORTAL_H
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#define PORTAL_H
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#include "executor/execdesc.h"
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#include "nodes/memnodes.h"
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typedef struct PortalData *Portal;
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typedef struct PortalData
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{
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char *name; /* Portal's name */
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MemoryContext heap; /* subsidiary memory */
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QueryDesc *queryDesc; /* Info about query associated with portal */
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TupleDesc attinfo;
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EState *state; /* Execution state of query */
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bool atStart; /* T => fetch backwards is not allowed */
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bool atEnd; /* T => fetch forwards is not allowed */
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void (*cleanup) (Portal); /* Cleanup routine (optional) */
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} PortalData;
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/*
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* PortalIsValid
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* True iff portal is valid.
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*/
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#define PortalIsValid(p) PointerIsValid(p)
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/*
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* Access macros for Portal ... use these in preference to field access.
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*/
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#define PortalGetQueryDesc(portal) ((portal)->queryDesc)
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#define PortalGetTupleDesc(portal) ((portal)->attinfo)
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#define PortalGetState(portal) ((portal)->state)
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#define PortalGetHeapMemory(portal) ((portal)->heap)
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/*
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* estimate of the maximum number of open portals a user would have,
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* used in initially sizing the PortalHashTable in EnablePortalManager()
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*/
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#define PORTALS_PER_USER 64
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extern void EnablePortalManager(void);
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extern void AtEOXact_portals(void);
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extern Portal CreatePortal(char *name);
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extern void PortalDrop(Portal *portalP);
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extern Portal GetPortalByName(char *name);
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extern void PortalSetQuery(Portal portal, QueryDesc *queryDesc,
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TupleDesc attinfo, EState *state,
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void (*cleanup) (Portal portal));
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#endif /* PORTAL_H */
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