90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
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/*-------------------------------------------------------------------------
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*
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* tstore_receiver.c
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* an implementation of DestReceiver that stores the result tuples in
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* a Tuplestore
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*
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*
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* Portions Copyright (c) 1996-2002, 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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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/executor/tstoreReceiver.c,v 1.1 2003/03/27 16:53:15 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "executor/tstoreReceiver.h"
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#include "utils/memutils.h"
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#include "utils/portal.h"
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typedef struct
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{
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DestReceiver pub;
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Tuplestorestate *tstore;
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MemoryContext cxt;
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} TStoreState;
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/*
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* Receive a tuple from the executor and store it in the tuplestore.
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*
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* XXX: As currently implemented, this routine is a hack: there should
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* be no tie between this code and the portal system. Instead, the
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* receiver function that is part of DestFunction should be passed a
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* QueryDesc, so that the call site of ExecutorRun can "sub-class"
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* QueryDesc and pass in any necessary addition information (in this
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* case, the Tuplestore to use).
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*/
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static void
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tstoreSetupReceiver(DestReceiver *self, int operation,
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const char *portalname, TupleDesc typeinfo)
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{
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TStoreState *myState = (TStoreState *) self;
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Portal portal;
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if (operation != CMD_SELECT)
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elog(ERROR, "Unexpected operation type: %d", operation);
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portal = GetPortalByName(portalname);
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if (portal == NULL)
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elog(ERROR, "Specified portal does not exist: %s", portalname);
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myState->tstore = portal->holdStore;
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myState->cxt = portal->holdContext;
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}
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static void
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tstoreReceiveTuple(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
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{
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TStoreState *myState = (TStoreState *) self;
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MemoryContext oldcxt = MemoryContextSwitchTo(myState->cxt);
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tuplestore_puttuple(myState->tstore, tuple);
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MemoryContextSwitchTo(oldcxt);
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}
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static void
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tstoreCleanupReceiver(DestReceiver *self)
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{
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; /* do nothing */
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}
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DestReceiver *
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tstoreReceiverCreateDR(void)
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{
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TStoreState *self = (TStoreState *) palloc(sizeof(TStoreState));
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self->pub.receiveTuple = tstoreReceiveTuple;
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self->pub.setup = tstoreSetupReceiver;
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self->pub.cleanup = tstoreCleanupReceiver;
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self->tstore = NULL;
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self->cxt = NULL;
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return (DestReceiver *) self;
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}
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