postgresql/src/include/tcop/utility.h

102 lines
3.7 KiB
C

/*-------------------------------------------------------------------------
*
* utility.h
* prototypes for utility.c.
*
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/tcop/utility.h
*
*-------------------------------------------------------------------------
*/
#ifndef UTILITY_H
#define UTILITY_H
#include "tcop/tcopprot.h"
typedef enum
{
PROCESS_UTILITY_TOPLEVEL, /* toplevel interactive command */
PROCESS_UTILITY_QUERY, /* a complete query, but not toplevel */
PROCESS_UTILITY_QUERY_NONATOMIC, /* a complete query, nonatomic
* execution context */
PROCESS_UTILITY_SUBCOMMAND /* a portion of a query */
} ProcessUtilityContext;
/* Info needed when recursing from ALTER TABLE */
typedef struct AlterTableUtilityContext
{
PlannedStmt *pstmt; /* PlannedStmt for outer ALTER TABLE command */
const char *queryString; /* its query string */
Oid relid; /* OID of ALTER's target table */
ParamListInfo params; /* any parameters available to ALTER TABLE */
QueryEnvironment *queryEnv; /* execution environment for ALTER TABLE */
} AlterTableUtilityContext;
/*
* These constants are used to describe the extent to which a particular
* command is read-only.
*
* COMMAND_OK_IN_READ_ONLY_TXN means that the command is permissible even when
* XactReadOnly is set. This bit should be set for commands that don't change
* the state of the database (data or schema) in a way that would affect the
* output of pg_dump.
*
* COMMAND_OK_IN_PARALLEL_MODE means that the command is permissible even
* when in parallel mode. Writing tuples is forbidden, as is anything that
* might confuse cooperating processes.
*
* COMMAND_OK_IN_RECOVERY means that the command is permissible even when in
* recovery. It can't write WAL, nor can it do things that would imperil
* replay of future WAL received from the master.
*/
#define COMMAND_OK_IN_READ_ONLY_TXN 0x0001
#define COMMAND_OK_IN_PARALLEL_MODE 0x0002
#define COMMAND_OK_IN_RECOVERY 0x0004
/*
* We say that a command is strictly read-only if it is sufficiently read-only
* for all purposes. For clarity, we also have a constant for commands that are
* in no way read-only.
*/
#define COMMAND_IS_STRICTLY_READ_ONLY \
(COMMAND_OK_IN_READ_ONLY_TXN | COMMAND_OK_IN_RECOVERY | \
COMMAND_OK_IN_PARALLEL_MODE)
#define COMMAND_IS_NOT_READ_ONLY 0
/* Hook for plugins to get control in ProcessUtility() */
typedef void (*ProcessUtility_hook_type) (PlannedStmt *pstmt,
const char *queryString, ProcessUtilityContext context,
ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, char *completionTag);
extern PGDLLIMPORT ProcessUtility_hook_type ProcessUtility_hook;
extern void ProcessUtility(PlannedStmt *pstmt, const char *queryString,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, char *completionTag);
extern void standard_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
ProcessUtilityContext context, ParamListInfo params,
QueryEnvironment *queryEnv,
DestReceiver *dest, char *completionTag);
extern void ProcessUtilityForAlterTable(Node *stmt,
AlterTableUtilityContext *context);
extern bool UtilityReturnsTuples(Node *parsetree);
extern TupleDesc UtilityTupleDescriptor(Node *parsetree);
extern Query *UtilityContainsQuery(Node *parsetree);
extern const char *CreateCommandTag(Node *parsetree);
extern LogStmtLevel GetCommandLogLevel(Node *parsetree);
extern bool CommandIsReadOnly(PlannedStmt *pstmt);
#endif /* UTILITY_H */