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/*-------------------------------------------------------------------------
*
* tuplestore.h
* Generalized routines for temporary tuple storage.
*
* This module handles temporary storage of tuples for purposes such
* as Materialize nodes, hashjoin batch files, etc. It is essentially
* a dumbed-down version of tuplesort.c; it does no sorting of tuples
* but can only store a sequence of tuples and regurgitate it later.
* A temporary file is used to handle the data if it exceeds the
* space limit specified by the caller.
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: tuplestore.h,v 1.2 2001/01/24 19:43:29 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef TUPLESTORE_H
#define TUPLESTORE_H
#include "access/htup.h"
/* Tuplestorestate is an opaque type whose details are not known outside
* tuplestore.c.
*/
typedef struct Tuplestorestate Tuplestorestate;
/*
* Currently we only need to store HeapTuples, but it would be easy
* to support the same behavior for IndexTuples and/or bare Datums.
*/
extern Tuplestorestate *tuplestore_begin_heap(bool randomAccess,
int maxKBytes);
extern void tuplestore_puttuple(Tuplestorestate *state, void *tuple);
extern void tuplestore_donestoring(Tuplestorestate *state);
extern void *tuplestore_gettuple(Tuplestorestate *state, bool forward,
bool *should_free);
#define tuplestore_getheaptuple(state, forward, should_free) \
((HeapTuple) tuplestore_gettuple(state, forward, should_free))
extern void tuplestore_end(Tuplestorestate *state);
/*
* These routines may only be called if randomAccess was specified 'true'.
* Likewise, backwards scan in gettuple/getdatum is only allowed if
* randomAccess was specified.
*/
extern void tuplestore_rescan(Tuplestorestate *state);
extern void tuplestore_markpos(Tuplestorestate *state);
extern void tuplestore_restorepos(Tuplestorestate *state);
#endif /* TUPLESTORE_H */
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