codekingpro/portable-devtools

1/*-------------------------------------------------------------------------2 *3 * spi_priv.h4 *				Server Programming Interface private declarations5 *6 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group7 * Portions Copyright (c) 1994, Regents of the University of California8 *9 * src/include/executor/spi_priv.h10 *11 *-------------------------------------------------------------------------12 */13#ifndef SPI_PRIV_H14#define SPI_PRIV_H15 16#include "executor/spi.h"17#include "utils/queryenvironment.h"18 19 20#define _SPI_PLAN_MAGIC		56927816321 22typedef struct23{24	/* current results */25	uint64		processed;		/* by Executor */26	SPITupleTable *tuptable;	/* tuptable currently being built */27 28	/* subtransaction in which current Executor call was started */29	SubTransactionId execSubid;30 31	/* resources of this execution context */32	slist_head	tuptables;		/* list of all live SPITupleTables */33	MemoryContext procCxt;		/* procedure context */34	MemoryContext execCxt;		/* executor context */35	MemoryContext savedcxt;		/* context of SPI_connect's caller */36	SubTransactionId connectSubid;	/* ID of connecting subtransaction */37	QueryEnvironment *queryEnv; /* query environment setup for SPI level */38 39	/* transaction management support */40	bool		atomic;			/* atomic execution context, does not allow41								 * transactions */42	bool		internal_xact;	/* SPI-managed transaction boundary, skip43								 * cleanup */44 45	/* saved values of API global variables for previous nesting level */46	uint64		outer_processed;47	SPITupleTable *outer_tuptable;48	int			outer_result;49} _SPI_connection;50 51/*52 * SPI plans have three states: saved, unsaved, or temporary.53 *54 * Ordinarily, the _SPI_plan struct itself as well as the argtypes array55 * are in a dedicated memory context identified by plancxt (which can be56 * really small).  All the other subsidiary state is in plancache entries57 * identified by plancache_list (note: the list cells themselves are in58 * plancxt).59 *60 * In an unsaved plan, the plancxt as well as the plancache entries' contexts61 * are children of the SPI procedure context, so they'll all disappear at62 * function exit.  plancache.c also knows that the plancache entries are63 * "unsaved", so it doesn't link them into its global list; hence they do64 * not respond to inval events.  This is OK since we are presumably holding65 * adequate locks to prevent other backends from messing with the tables.66 *67 * For a saved plan, the plancxt is made a child of CacheMemoryContext68 * since it should persist until explicitly destroyed.  Likewise, the69 * plancache entries will be under CacheMemoryContext since we tell70 * plancache.c to save them.  We rely on plancache.c to keep the cache71 * entries up-to-date as needed in the face of invalidation events.72 *73 * There are also "temporary" SPI plans, in which the _SPI_plan struct is74 * not even palloc'd but just exists in some function's local variable.75 * The plancache entries are unsaved and exist under the SPI executor context,76 * while additional data such as argtypes and list cells is loose in the SPI77 * executor context.  Such plans can be identified by having plancxt == NULL.78 *79 * We can also have "one-shot" SPI plans (which are typically temporary,80 * as described above).  These are meant to be executed once and discarded,81 * and various optimizations are made on the assumption of single use.82 * Note in particular that the CachedPlanSources within such an SPI plan83 * are not "complete" until execution.84 *85 * Note: if the original query string contained only whitespace and comments,86 * the plancache_list will be NIL and so there is no place to store the87 * query string.  We don't care about that, but we do care about the88 * argument type array, which is why it's seemingly-redundantly stored.89 */90typedef struct _SPI_plan91{92	int			magic;			/* should equal _SPI_PLAN_MAGIC */93	bool		saved;			/* saved or unsaved plan? */94	bool		oneshot;		/* one-shot plan? */95	List	   *plancache_list; /* one CachedPlanSource per parsetree */96	MemoryContext plancxt;		/* Context containing _SPI_plan and data */97	RawParseMode parse_mode;	/* raw_parser() mode */98	int			cursor_options; /* Cursor options used for planning */99	int			nargs;			/* number of plan arguments */100	Oid		   *argtypes;		/* Argument types (NULL if nargs is 0) */101	ParserSetupHook parserSetup;	/* alternative parameter spec method */102	void	   *parserSetupArg;103} _SPI_plan;104 105#endif							/* SPI_PRIV_H */106