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/*-------------------------------------------------------------------------
*
* spi_priv.h
* Server Programming Interface private declarations
*
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/executor/spi_priv.h,v 1.35 2010/02/26 02:01:24 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef SPI_PRIV_H
#define SPI_PRIV_H
#include "executor/spi.h"
#define _SPI_PLAN_MAGIC 569278163
typedef struct
{
/* current results */
uint32 processed; /* by Executor */
Oid lastoid;
SPITupleTable *tuptable;
MemoryContext procCxt; /* procedure context */
MemoryContext execCxt; /* executor context */
MemoryContext savedcxt; /* context of SPI_connect's caller */
SubTransactionId connectSubid; /* ID of connecting subtransaction */
} _SPI_connection;
/*
* SPI plans have two states: saved or unsaved.
*
* For an unsaved plan, the _SPI_plan struct and all its subsidiary data are in
* a dedicated memory context identified by plancxt. An unsaved plan is good
* at most for the current transaction, since the locks that protect it from
* schema changes will be lost at end of transaction. Hence the plancxt is
* always a transient one.
*
* For a saved plan, the _SPI_plan struct and the argument type array are in
* the plancxt (which can be really small). All the other subsidiary state
* is in plancache entries identified by plancache_list (note: the list cells
* themselves are in plancxt). We rely on plancache.c to keep the cache
* entries up-to-date as needed. The plancxt is a child of CacheMemoryContext
* since it should persist until explicitly destroyed.
*
* To avoid redundant coding, the representation of unsaved plans matches
* that of saved plans, ie, plancache_list is a list of CachedPlanSource
* structs which in turn point to CachedPlan structs. However, in an unsaved
* plan all these structs are just created by spi.c and are not known to
* plancache.c. We don't try very hard to make all their fields valid,
* only the ones spi.c actually uses.
*
* Note: if the original query string contained only whitespace and comments,
* the plancache_list will be NIL and so there is no place to store the
* query string. We don't care about that, but we do care about the
* argument type array, which is why it's seemingly-redundantly stored.
*/
typedef struct _SPI_plan
{
int magic; /* should equal _SPI_PLAN_MAGIC */
bool saved; /* saved or unsaved plan? */
List *plancache_list; /* one CachedPlanSource per parsetree */
MemoryContext plancxt; /* Context containing _SPI_plan and data */
int cursor_options; /* Cursor options used for planning */
int nargs; /* number of plan arguments */
Oid *argtypes; /* Argument types (NULL if nargs is 0) */
ParserSetupHook parserSetup; /* alternative parameter spec method */
void *parserSetupArg;
} _SPI_plan;
#endif /* SPI_PRIV_H */
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