1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/*-------------------------------------------------------------------------
*
* tstore_receiver.c
* an implementation of DestReceiver that stores the result tuples in
* a Tuplestore
*
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/tstoreReceiver.c,v 1.1 2003/03/27 16:53:15 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "executor/tstoreReceiver.h"
#include "utils/memutils.h"
#include "utils/portal.h"
typedef struct
{
DestReceiver pub;
Tuplestorestate *tstore;
MemoryContext cxt;
} TStoreState;
/*
* Receive a tuple from the executor and store it in the tuplestore.
*
* XXX: As currently implemented, this routine is a hack: there should
* be no tie between this code and the portal system. Instead, the
* receiver function that is part of DestFunction should be passed a
* QueryDesc, so that the call site of ExecutorRun can "sub-class"
* QueryDesc and pass in any necessary addition information (in this
* case, the Tuplestore to use).
*/
static void
tstoreSetupReceiver(DestReceiver *self, int operation,
const char *portalname, TupleDesc typeinfo)
{
TStoreState *myState = (TStoreState *) self;
Portal portal;
if (operation != CMD_SELECT)
elog(ERROR, "Unexpected operation type: %d", operation);
portal = GetPortalByName(portalname);
if (portal == NULL)
elog(ERROR, "Specified portal does not exist: %s", portalname);
myState->tstore = portal->holdStore;
myState->cxt = portal->holdContext;
}
static void
tstoreReceiveTuple(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
{
TStoreState *myState = (TStoreState *) self;
MemoryContext oldcxt = MemoryContextSwitchTo(myState->cxt);
tuplestore_puttuple(myState->tstore, tuple);
MemoryContextSwitchTo(oldcxt);
}
static void
tstoreCleanupReceiver(DestReceiver *self)
{
; /* do nothing */
}
DestReceiver *
tstoreReceiverCreateDR(void)
{
TStoreState *self = (TStoreState *) palloc(sizeof(TStoreState));
self->pub.receiveTuple = tstoreReceiveTuple;
self->pub.setup = tstoreSetupReceiver;
self->pub.cleanup = tstoreCleanupReceiver;
self->tstore = NULL;
self->cxt = NULL;
return (DestReceiver *) self;
}
|
