1 /*-------------------------------------------------------------------------
2 *
3 * utility.h
4 * prototypes for utility.c.
5 *
6 *
7 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
9 *
10 * src/include/tcop/utility.h
11 *
12 *-------------------------------------------------------------------------
13 */
14 #ifndef UTILITY_H
15 #define UTILITY_H
16
17 #include "tcop/cmdtag.h"
18 #include "tcop/tcopprot.h"
19
20 typedef enum
21 {
22 PROCESS_UTILITY_TOPLEVEL, /* toplevel interactive command */
23 PROCESS_UTILITY_QUERY, /* a complete query, but not toplevel */
24 PROCESS_UTILITY_QUERY_NONATOMIC, /* a complete query, nonatomic
25 * execution context */
26 PROCESS_UTILITY_SUBCOMMAND /* a portion of a query */
27 } ProcessUtilityContext;
28
29 /* Info needed when recursing from ALTER TABLE */
30 typedef struct AlterTableUtilityContext
31 {
32 PlannedStmt *pstmt; /* PlannedStmt for outer ALTER TABLE command */
33 const char *queryString; /* its query string */
34 Oid relid; /* OID of ALTER's target table */
35 ParamListInfo params; /* any parameters available to ALTER TABLE */
36 QueryEnvironment *queryEnv; /* execution environment for ALTER TABLE */
37 } AlterTableUtilityContext;
38
39 /*
40 * These constants are used to describe the extent to which a particular
41 * command is read-only.
42 *
43 * COMMAND_OK_IN_READ_ONLY_TXN means that the command is permissible even when
44 * XactReadOnly is set. This bit should be set for commands that don't change
45 * the state of the database (data or schema) in a way that would affect the
46 * output of pg_dump.
47 *
48 * COMMAND_OK_IN_PARALLEL_MODE means that the command is permissible even
49 * when in parallel mode. Writing tuples is forbidden, as is anything that
50 * might confuse cooperating processes.
51 *
52 * COMMAND_OK_IN_RECOVERY means that the command is permissible even when in
53 * recovery. It can't write WAL, nor can it do things that would imperil
54 * replay of future WAL received from the master.
55 */
56 #define COMMAND_OK_IN_READ_ONLY_TXN 0x0001
57 #define COMMAND_OK_IN_PARALLEL_MODE 0x0002
58 #define COMMAND_OK_IN_RECOVERY 0x0004
59
60 /*
61 * We say that a command is strictly read-only if it is sufficiently read-only
62 * for all purposes. For clarity, we also have a constant for commands that are
63 * in no way read-only.
64 */
65 #define COMMAND_IS_STRICTLY_READ_ONLY \
66 (COMMAND_OK_IN_READ_ONLY_TXN | COMMAND_OK_IN_RECOVERY | \
67 COMMAND_OK_IN_PARALLEL_MODE)
68 #define COMMAND_IS_NOT_READ_ONLY 0
69
70 /* Hook for plugins to get control in ProcessUtility() */
71 typedef void (*ProcessUtility_hook_type) (PlannedStmt *pstmt,
72 const char *queryString, ProcessUtilityContext context,
73 ParamListInfo params,
74 QueryEnvironment *queryEnv,
75 DestReceiver *dest, QueryCompletion *qc);
76 extern PGDLLIMPORT ProcessUtility_hook_type ProcessUtility_hook;
77
78 extern void ProcessUtility(PlannedStmt *pstmt, const char *queryString,
79 ProcessUtilityContext context, ParamListInfo params,
80 QueryEnvironment *queryEnv,
81 DestReceiver *dest, QueryCompletion *qc);
82 extern void standard_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
83 ProcessUtilityContext context, ParamListInfo params,
84 QueryEnvironment *queryEnv,
85 DestReceiver *dest, QueryCompletion *qc);
86
87 extern void ProcessUtilityForAlterTable(Node *stmt,
88 AlterTableUtilityContext *context);
89
90 extern bool UtilityReturnsTuples(Node *parsetree);
91
92 extern TupleDesc UtilityTupleDescriptor(Node *parsetree);
93
94 extern Query *UtilityContainsQuery(Node *parsetree);
95
96 extern CommandTag CreateCommandTag(Node *parsetree);
97
98 static inline const char *
CreateCommandName(Node * parsetree)99 CreateCommandName(Node *parsetree)
100 {
101 return GetCommandTagName(CreateCommandTag(parsetree));
102 }
103
104 extern LogStmtLevel GetCommandLogLevel(Node *parsetree);
105
106 extern bool CommandIsReadOnly(PlannedStmt *pstmt);
107
108 #endif /* UTILITY_H */
109