1 /* -*-pgsql-c-*- */
2 /*
3  *
4  * $Header$
5  *
6  * pgpool: a language independent connection pool server for PostgreSQL
7  * written by Tatsuo Ishii
8  *
9  * Copyright (c) 2003-2017	PgPool Global Development Group
10  *
11  * Permission to use, copy, modify, and distribute this software and
12  * its documentation for any purpose and without fee is hereby
13  * granted, provided that the above copyright notice appear in all
14  * copies and that both that copyright notice and this permission
15  * notice appear in supporting documentation, and that the name of the
16  * author not be used in advertising or publicity pertaining to
17  * distribution of the software without specific, written prior
18  * permission. The author makes no representations about the
19  * suitability of this software for any purpose.  It is provided "as
20  * is" without express or implied warranty.
21  *
22  * pool_process_context.h.: process context information
23  *
24  */
25 
26 #ifndef POOL_QUERY_CONTEXT_H
27 #define POOL_QUERY_CONTEXT_H
28 
29 #include "pool.h"
30 #include "pool_process_context.h"
31 #include "parser/nodes.h"
32 #include "parser/parsenodes.h"
33 #include "utils/palloc.h"
34 #include "query_cache/pool_memqcache.h"
35 
36 /*
37  * Parse state transition.
38  * transition order is:
39  * UNPARSED < PARSE_COMPLETE < BIND_COMPLETE < EXECUTE_COMPLETE
40  */
41 typedef enum
42 {
43 	POOL_UNPARSED,
44 	POOL_PARSE_COMPLETE,
45 	POOL_BIND_COMPLETE,
46 	POOL_EXECUTE_COMPLETE
47 }			POOL_QUERY_STATE;
48 
49 /*
50  * Query context:
51  * Manages per query context
52  */
53 typedef struct
54 {
55 	char	   *original_query; /* original query string */
56 	char	   *rewritten_query;	/* rewritten query string if any */
57 	int			original_length;	/* original query length which contains
58 									 * '\0' */
59 	int			rewritten_length;	/* rewritten query length which contains
60 									 * '\0' if any */
61 	Node	   *parse_tree;		/* raw parser output if any */
62 	Node	   *rewritten_parse_tree;	/* rewritten raw parser output if any */
63 	bool		where_to_send[MAX_NUM_BACKENDS];	/* DB node map to send
64 													 * query */
65 	int         load_balance_node_id;	/* load balance node id per statement */
66 	int			virtual_master_node_id; /* the 1st DB node to send query */
67 	POOL_QUERY_STATE query_state[MAX_NUM_BACKENDS]; /* for extended query
68 													 * protocol */
69 	bool		is_cache_safe;	/* true if SELECT is safe to cache */
70 	POOL_TEMP_QUERY_CACHE *temp_cache;	/* temporary cache */
71 	bool		is_multi_statement; /* true if multi statement query */
72 	int			dboid;			/* DB oid which is used at DROP DATABASE */
73 	char	   *query_w_hex;	/* original_query with bind message hex which
74 								 * used for committing cache of extended query */
75 	bool		is_parse_error; /* if true, we could not parse the original
76 								 * query and parsed node is actually a dummy
77 								 * query. */
78 	int			num_original_params;	/* number of parameters in original
79 										 * query */
80 	ConnectionInfo *pg_terminate_backend_conn;
81 
82 	/*
83 	 * pointer to the shared memory connection info object referred by
84 	 * pg_terminate_backend() function. we need this to reset the flag after
85 	 * executing the pg_terminate_backend query, especially for the case when
86 	 * the query gets fail on the backend.
87 	 */
88 
89 	bool		skip_cache_commit;	/* In streaming replication mode and
90 									 * extended query, do not commit cache if
91 									 * this flag is true. */
92 
93 	MemoryContext memory_context;	/* memory context for query context */
94 }			POOL_QUERY_CONTEXT;
95 
96 extern POOL_QUERY_CONTEXT * pool_init_query_context(void);
97 extern void pool_query_context_destroy(POOL_QUERY_CONTEXT * query_context);
98 extern POOL_QUERY_CONTEXT * pool_query_context_shallow_copy(POOL_QUERY_CONTEXT * query_context);
99 extern void pool_start_query(POOL_QUERY_CONTEXT * query_context, char *query, int len, Node *node);
100 extern void pool_set_node_to_be_sent(POOL_QUERY_CONTEXT * query_context, int node_id);
101 extern bool pool_is_node_to_be_sent(POOL_QUERY_CONTEXT * query_context, int node_id);
102 extern void pool_set_node_to_be_sent(POOL_QUERY_CONTEXT * query_context, int node_id);
103 extern void pool_unset_node_to_be_sent(POOL_QUERY_CONTEXT * query_context, int node_id);
104 extern void pool_clear_node_to_be_sent(POOL_QUERY_CONTEXT * query_context);
105 extern void pool_setall_node_to_be_sent(POOL_QUERY_CONTEXT * query_context);
106 extern bool pool_multi_node_to_be_sent(POOL_QUERY_CONTEXT * query_context);
107 extern void pool_where_to_send(POOL_QUERY_CONTEXT * query_context, char *query, Node *node);
108 extern POOL_STATUS pool_send_and_wait(POOL_QUERY_CONTEXT * query_context, int send_type, int node_id);
109 extern POOL_STATUS pool_extended_send_and_wait(POOL_QUERY_CONTEXT * query_context, char *kind, int len, char *contents, int send_type, int node_id, bool nowait);
110 extern Node *pool_get_parse_tree(void);
111 extern char *pool_get_query_string(void);
112 extern bool is_set_transaction_serializable(Node *node);
113 extern bool is_start_transaction_query(Node *node);
114 extern bool is_read_write(TransactionStmt *node);
115 extern bool is_serializable(TransactionStmt *node);
116 extern bool pool_need_to_treat_as_if_default_transaction(POOL_QUERY_CONTEXT * query_context);
117 extern bool is_savepoint_query(Node *node);
118 extern bool is_2pc_transaction_query(Node *node);
119 extern void pool_set_query_state(POOL_QUERY_CONTEXT * query_context, POOL_QUERY_STATE state);
120 extern int	statecmp(POOL_QUERY_STATE s1, POOL_QUERY_STATE s2);
121 extern bool pool_is_cache_safe(void);
122 extern void pool_set_cache_safe(void);
123 extern void pool_unset_cache_safe(void);
124 extern bool pool_is_cache_exceeded(void);
125 extern void pool_set_cache_exceeded(void);
126 extern void pool_unset_cache_exceeded(void);
127 extern bool pool_is_transaction_read_only(Node *node);
128 extern void pool_force_query_node_to_backend(POOL_QUERY_CONTEXT * query_context, int backend_id);
129 #endif							/* POOL_QUERY_CONTEXT_H */
130