1 /*-------------------------------------------------------------------------
2  *
3  * typcache.h
4  *	  Type cache definitions.
5  *
6  * The type cache exists to speed lookup of certain information about data
7  * types that is not directly available from a type's pg_type row.
8  *
9  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
10  * Portions Copyright (c) 1994, Regents of the University of California
11  *
12  * src/include/utils/typcache.h
13  *
14  *-------------------------------------------------------------------------
15  */
16 #ifndef TYPCACHE_H
17 #define TYPCACHE_H
18 
19 #include "access/tupdesc.h"
20 #include "fmgr.h"
21 #include "storage/dsm.h"
22 #include "utils/dsa.h"
23 
24 
25 /* DomainConstraintCache is an opaque struct known only within typcache.c */
26 typedef struct DomainConstraintCache DomainConstraintCache;
27 
28 /* TypeCacheEnumData is an opaque struct known only within typcache.c */
29 struct TypeCacheEnumData;
30 
31 typedef struct TypeCacheEntry
32 {
33 	/* typeId is the hash lookup key and MUST BE FIRST */
34 	Oid			type_id;		/* OID of the data type */
35 
36 	/* some subsidiary information copied from the pg_type row */
37 	int16		typlen;
38 	bool		typbyval;
39 	char		typalign;
40 	char		typstorage;
41 	char		typtype;
42 	Oid			typrelid;
43 	Oid			typelem;
44 	Oid			typcollation;
45 
46 	/*
47 	 * Information obtained from opfamily entries
48 	 *
49 	 * These will be InvalidOid if no match could be found, or if the
50 	 * information hasn't yet been requested.  Also note that for array and
51 	 * composite types, typcache.c checks that the contained types are
52 	 * comparable or hashable before allowing eq_opr etc to become set.
53 	 */
54 	Oid			btree_opf;		/* the default btree opclass' family */
55 	Oid			btree_opintype; /* the default btree opclass' opcintype */
56 	Oid			hash_opf;		/* the default hash opclass' family */
57 	Oid			hash_opintype;	/* the default hash opclass' opcintype */
58 	Oid			eq_opr;			/* the equality operator */
59 	Oid			lt_opr;			/* the less-than operator */
60 	Oid			gt_opr;			/* the greater-than operator */
61 	Oid			cmp_proc;		/* the btree comparison function */
62 	Oid			hash_proc;		/* the hash calculation function */
63 	Oid			hash_extended_proc; /* the extended hash calculation function */
64 
65 	/*
66 	 * Pre-set-up fmgr call info for the equality operator, the btree
67 	 * comparison function, and the hash calculation function.  These are kept
68 	 * in the type cache to avoid problems with memory leaks in repeated calls
69 	 * to functions such as array_eq, array_cmp, hash_array.  There is not
70 	 * currently a need to maintain call info for the lt_opr or gt_opr.
71 	 */
72 	FmgrInfo	eq_opr_finfo;
73 	FmgrInfo	cmp_proc_finfo;
74 	FmgrInfo	hash_proc_finfo;
75 	FmgrInfo	hash_extended_proc_finfo;
76 
77 	/*
78 	 * Tuple descriptor if it's a composite type (row type).  NULL if not
79 	 * composite or information hasn't yet been requested.  (NOTE: this is a
80 	 * reference-counted tupledesc.)
81 	 *
82 	 * To simplify caching dependent info, tupDesc_identifier is an identifier
83 	 * for this tupledesc that is unique for the life of the process, and
84 	 * changes anytime the tupledesc does.  Zero if not yet determined.
85 	 */
86 	TupleDesc	tupDesc;
87 	uint64		tupDesc_identifier;
88 
89 	/*
90 	 * Fields computed when TYPECACHE_RANGE_INFO is requested.  Zeroes if not
91 	 * a range type or information hasn't yet been requested.  Note that
92 	 * rng_cmp_proc_finfo could be different from the element type's default
93 	 * btree comparison function.
94 	 */
95 	struct TypeCacheEntry *rngelemtype; /* range's element type */
96 	Oid			rng_collation;	/* collation for comparisons, if any */
97 	FmgrInfo	rng_cmp_proc_finfo; /* comparison function */
98 	FmgrInfo	rng_canonical_finfo;	/* canonicalization function, if any */
99 	FmgrInfo	rng_subdiff_finfo;	/* difference function, if any */
100 
101 	/*
102 	 * Domain's base type and typmod if it's a domain type.  Zeroes if not
103 	 * domain, or if information hasn't been requested.
104 	 */
105 	Oid			domainBaseType;
106 	int32		domainBaseTypmod;
107 
108 	/*
109 	 * Domain constraint data if it's a domain type.  NULL if not domain, or
110 	 * if domain has no constraints, or if information hasn't been requested.
111 	 */
112 	DomainConstraintCache *domainData;
113 
114 	/* Private data, for internal use of typcache.c only */
115 	int			flags;			/* flags about what we've computed */
116 
117 	/*
118 	 * Private information about an enum type.  NULL if not enum or
119 	 * information hasn't been requested.
120 	 */
121 	struct TypeCacheEnumData *enumData;
122 
123 	/* We also maintain a list of all known domain-type cache entries */
124 	struct TypeCacheEntry *nextDomain;
125 } TypeCacheEntry;
126 
127 /* Bit flags to indicate which fields a given caller needs to have set */
128 #define TYPECACHE_EQ_OPR			0x0001
129 #define TYPECACHE_LT_OPR			0x0002
130 #define TYPECACHE_GT_OPR			0x0004
131 #define TYPECACHE_CMP_PROC			0x0008
132 #define TYPECACHE_HASH_PROC			0x0010
133 #define TYPECACHE_EQ_OPR_FINFO		0x0020
134 #define TYPECACHE_CMP_PROC_FINFO	0x0040
135 #define TYPECACHE_HASH_PROC_FINFO	0x0080
136 #define TYPECACHE_TUPDESC			0x0100
137 #define TYPECACHE_BTREE_OPFAMILY	0x0200
138 #define TYPECACHE_HASH_OPFAMILY		0x0400
139 #define TYPECACHE_RANGE_INFO		0x0800
140 #define TYPECACHE_DOMAIN_BASE_INFO			0x1000
141 #define TYPECACHE_DOMAIN_CONSTR_INFO		0x2000
142 #define TYPECACHE_HASH_EXTENDED_PROC		0x4000
143 #define TYPECACHE_HASH_EXTENDED_PROC_FINFO	0x8000
144 
145 /* This value will not equal any valid tupledesc identifier, nor 0 */
146 #define INVALID_TUPLEDESC_IDENTIFIER ((uint64) 1)
147 
148 /*
149  * Callers wishing to maintain a long-lived reference to a domain's constraint
150  * set must store it in one of these.  Use InitDomainConstraintRef() and
151  * UpdateDomainConstraintRef() to manage it.  Note: DomainConstraintState is
152  * considered an executable expression type, so it's defined in execnodes.h.
153  */
154 typedef struct DomainConstraintRef
155 {
156 	List	   *constraints;	/* list of DomainConstraintState nodes */
157 	MemoryContext refctx;		/* context holding DomainConstraintRef */
158 	TypeCacheEntry *tcache;		/* typcache entry for domain type */
159 	bool		need_exprstate; /* does caller need check_exprstate? */
160 
161 	/* Management data --- treat these fields as private to typcache.c */
162 	DomainConstraintCache *dcc; /* current constraints, or NULL if none */
163 	MemoryContextCallback callback; /* used to release refcount when done */
164 } DomainConstraintRef;
165 
166 typedef struct SharedRecordTypmodRegistry SharedRecordTypmodRegistry;
167 
168 extern TypeCacheEntry *lookup_type_cache(Oid type_id, int flags);
169 
170 extern void InitDomainConstraintRef(Oid type_id, DomainConstraintRef *ref,
171 									MemoryContext refctx, bool need_exprstate);
172 
173 extern void UpdateDomainConstraintRef(DomainConstraintRef *ref);
174 
175 extern bool DomainHasConstraints(Oid type_id);
176 
177 extern TupleDesc lookup_rowtype_tupdesc(Oid type_id, int32 typmod);
178 
179 extern TupleDesc lookup_rowtype_tupdesc_noerror(Oid type_id, int32 typmod,
180 												bool noError);
181 
182 extern TupleDesc lookup_rowtype_tupdesc_copy(Oid type_id, int32 typmod);
183 
184 extern TupleDesc lookup_rowtype_tupdesc_domain(Oid type_id, int32 typmod,
185 											   bool noError);
186 
187 extern void assign_record_type_typmod(TupleDesc tupDesc);
188 
189 extern uint64 assign_record_type_identifier(Oid type_id, int32 typmod);
190 
191 extern int	compare_values_of_enum(TypeCacheEntry *tcache, Oid arg1, Oid arg2);
192 
193 extern size_t SharedRecordTypmodRegistryEstimate(void);
194 
195 extern void SharedRecordTypmodRegistryInit(SharedRecordTypmodRegistry *,
196 										   dsm_segment *segment, dsa_area *area);
197 
198 extern void SharedRecordTypmodRegistryAttach(SharedRecordTypmodRegistry *);
199 
200 #endif							/* TYPCACHE_H */
201