plpgsql.h

PostgreSQL7.4.6 for Linux

/**********************************************************************
 * plpgsql.h		- Definitions for the PL/pgSQL
 *			  procedural language
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.42 2003/09/28 23:37:45 tgl Exp $
 *
 *	  This software is copyrighted by Jan Wieck - Hamburg.
 *
 *	  The author hereby grants permission  to  use,  copy,	modify,
 *	  distribute,  and	license this software and its documentation
 *	  for any purpose, provided that existing copyright notices are
 *	  retained	in	all  copies  and  that	this notice is included
 *	  verbatim in any distributions. No written agreement, license,
 *	  or  royalty  fee	is required for any of the authorized uses.
 *	  Modifications to this software may be  copyrighted  by  their
 *	  author  and  need  not  follow  the licensing terms described
 *	  here, provided that the new terms are  clearly  indicated  on
 *	  the first page of each file where they apply.
 *
 *	  IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY
 *	  PARTY  FOR  DIRECT,	INDIRECT,	SPECIAL,   INCIDENTAL,	 OR
 *	  CONSEQUENTIAL   DAMAGES  ARISING	OUT  OF  THE  USE  OF  THIS
 *	  SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN
 *	  IF  THE  AUTHOR  HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
 *	  DAMAGE.
 *
 *	  THE  AUTHOR  AND	DISTRIBUTORS  SPECIFICALLY	 DISCLAIM	ANY
 *	  WARRANTIES,  INCLUDING,  BUT	NOT  LIMITED  TO,  THE	IMPLIED
 *	  WARRANTIES  OF  MERCHANTABILITY,	FITNESS  FOR  A  PARTICULAR
 *	  PURPOSE,	AND NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON
 *	  AN "AS IS" BASIS, AND THE AUTHOR	AND  DISTRIBUTORS  HAVE  NO
 *	  OBLIGATION   TO	PROVIDE   MAINTENANCE,	 SUPPORT,  UPDATES,
 *	  ENHANCEMENTS, OR MODIFICATIONS.
 *
 **********************************************************************/
#ifndef PLPGSQL_H
#define PLPGSQL_H

#include "postgres.h"

#include "fmgr.h"
#include "miscadmin.h"
#include "executor/spi.h"
#include "commands/trigger.h"
#include "utils/tuplestore.h"

/**********************************************************************
 * Definitions
 **********************************************************************/

/* ----------
 * Compilers namestack item types
 * ----------
 */
enum
{
	PLPGSQL_NSTYPE_LABEL,
	PLPGSQL_NSTYPE_VAR,
	PLPGSQL_NSTYPE_ROW,
	PLPGSQL_NSTYPE_REC,
	PLPGSQL_NSTYPE_RECFIELD
};

/* ----------
 * Datum array node types
 * ----------
 */
enum
{
	PLPGSQL_DTYPE_VAR,
	PLPGSQL_DTYPE_ROW,
	PLPGSQL_DTYPE_REC,
	PLPGSQL_DTYPE_RECFIELD,
	PLPGSQL_DTYPE_ARRAYELEM,
	PLPGSQL_DTYPE_EXPR,
	PLPGSQL_DTYPE_TRIGARG
};

/* ----------
 * Execution tree node types
 * ----------
 */
enum
{
	PLPGSQL_STMT_BLOCK,
	PLPGSQL_STMT_ASSIGN,
	PLPGSQL_STMT_IF,
	PLPGSQL_STMT_LOOP,
	PLPGSQL_STMT_WHILE,
	PLPGSQL_STMT_FORI,
	PLPGSQL_STMT_FORS,
	PLPGSQL_STMT_SELECT,
	PLPGSQL_STMT_EXIT,
	PLPGSQL_STMT_RETURN,
	PLPGSQL_STMT_RETURN_NEXT,
	PLPGSQL_STMT_RAISE,
	PLPGSQL_STMT_EXECSQL,
	PLPGSQL_STMT_DYNEXECUTE,
	PLPGSQL_STMT_DYNFORS,
	PLPGSQL_STMT_GETDIAG,
	PLPGSQL_STMT_OPEN,
	PLPGSQL_STMT_FETCH,
	PLPGSQL_STMT_CLOSE,
	PLPGSQL_STMT_PERFORM
};


/* ----------
 * Execution node return codes
 * ----------
 */
enum
{
	PLPGSQL_RC_OK,
	PLPGSQL_RC_EXIT,
	PLPGSQL_RC_RETURN
};

/* ----------
 * GET DIAGNOSTICS system attrs
 * ----------
 */
enum
{
	PLPGSQL_GETDIAG_ROW_COUNT,
	PLPGSQL_GETDIAG_RESULT_OID
};


/**********************************************************************
 * Node and structure definitions
 **********************************************************************/


typedef struct
{								/* Dynamic string control structure */
	int			alloc;
	int			used;
	char	   *value;
}	PLpgSQL_dstring;


typedef struct
{								/* Postgres data type		*/
	char	   *typname;
	Oid			typoid;			/* OID of the data type */
	int16		typlen;			/* stuff copied from its pg_type entry */
	bool		typbyval;
	Oid			typrelid;
	Oid			typelem;
	FmgrInfo	typinput;		/* lookup info for typinput function */
	int32		atttypmod;		/* typmod (taken from someplace else) */
}	PLpgSQL_type;


/*
 * PLpgSQL_datum is the common supertype for PLpgSQL_expr, PLpgSQL_var,
 * PLpgSQL_row, PLpgSQL_rec, PLpgSQL_recfield, PLpgSQL_arrayelem, and
 * PLpgSQL_trigarg
 */
typedef struct
{								/* Generic datum array item		*/
	int			dtype;
	int			dno;
}	PLpgSQL_datum;


typedef struct PLpgSQL_expr
{								/* SQL Query to plan and execute	*/
	int			dtype;
	int			exprno;
	char	   *query;
	void	   *plan;
	Oid		   *plan_argtypes;
	/* fields for "simple expression" fast-path execution: */
	Expr	   *expr_simple_expr;	/* NULL means not a simple expr */
	Oid			expr_simple_type;
	/* if expr is simple AND in use in current xact, these fields are set: */
	ExprState  *expr_simple_state;
	struct PLpgSQL_expr *expr_simple_next;
	/* params to pass to expr */
	int			nparams;
	int			params[1];		/* VARIABLE SIZE ARRAY ... must be last */
}	PLpgSQL_expr;


typedef struct
{								/* Local variable			*/
	int			dtype;
	int			varno;
	char	   *refname;
	int			lineno;

	PLpgSQL_type *datatype;
	int			isconst;
	int			notnull;
	PLpgSQL_expr *default_val;
	PLpgSQL_expr *cursor_explicit_expr;
	int			cursor_explicit_argrow;

	Datum		value;
	bool		isnull;
	bool		freeval;
}	PLpgSQL_var;


typedef struct
{								/* Rowtype				*/
	int			dtype;
	int			rowno;
	char	   *refname;
	int			lineno;
	TupleDesc	rowtupdesc;

	/*
	 * Note: TupleDesc is only set up for named rowtypes, else it is NULL.
	 *
	 * Note: if the underlying rowtype contains a dropped column, the
	 * corresponding fieldnames[] entry will be NULL, and there is no
	 * corresponding var (varnos[] will be -1).
	 */
	int			nfields;
	char	  **fieldnames;
	int		   *varnos;
}	PLpgSQL_row;


typedef struct
{								/* Record of non-fixed structure */
	int			dtype;
	int			recno;
	char	   *refname;
	int			lineno;

	HeapTuple	tup;
	TupleDesc	tupdesc;
	bool		freetup;
	bool		freetupdesc;
}	PLpgSQL_rec;


typedef struct
{								/* Field in record */
	int			dtype;
	int			rfno;
	char	   *fieldname;
	int			recparentno;	/* dno of parent record */
}	PLpgSQL_recfield;


typedef struct
{								/* Element of array variable */
	int			dtype;
	int			dno;
	PLpgSQL_expr *subscript;
	int			arrayparentno;	/* dno of parent array variable */
}	PLpgSQL_arrayelem;


typedef struct
{								/* Positional argument to trigger	*/
	int			dtype;
	int			dno;
	PLpgSQL_expr *argnum;
}	PLpgSQL_trigarg;


typedef struct
{								/* Item in the compilers namestack	*/
	int			itemtype;
	int			itemno;
	char		name[1];
}	PLpgSQL_nsitem;


typedef struct PLpgSQL_ns
{								/* Compiler namestack level		*/
	int			items_alloc;
	int			items_used;
	PLpgSQL_nsitem **items;
	struct PLpgSQL_ns *upper;
}	PLpgSQL_ns;


typedef struct
{								/* List of execution nodes		*/
	int			stmts_alloc;
	int			stmts_used;
	struct PLpgSQL_stmt **stmts;
}	PLpgSQL_stmts;


typedef struct
{								/* Generic execution node		*/
	int			cmd_type;
	int			lineno;
}	PLpgSQL_stmt;


typedef struct
{								/* Block of statements			*/
	int			cmd_type;
	int			lineno;
	char	   *label;
	PLpgSQL_stmts *body;
	int			n_initvars;
	int		   *initvarnos;
}	PLpgSQL_stmt_block;


typedef struct
{								/* Assign statement			*/
	int			cmd_type;
	int			lineno;
	int			varno;
	PLpgSQL_expr *expr;
}	PLpgSQL_stmt_assign;

typedef struct
{								/* PERFORM statement		*/
	int			cmd_type;
	int			lineno;
	PLpgSQL_expr *expr;
}	PLpgSQL_stmt_perform;

typedef struct
{								/* Get Diagnostics item		*/
	int			item;			/* id for diagnostic value desired */
	int			target;			/* where to assign it */
}	PLpgSQL_diag_item;

typedef struct
{								/* Get Diagnostics statement		*/
	int			cmd_type;
	int			lineno;
	int			ndtitems;
	PLpgSQL_diag_item *dtitems;
}	PLpgSQL_stmt_getdiag;


typedef struct
{								/* IF statement				*/
	int			cmd_type;
	int			lineno;
	PLpgSQL_expr *cond;
	PLpgSQL_stmts *true_body;
	PLpgSQL_stmts *false_body;
}	PLpgSQL_stmt_if;