Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * tupmacs.h
4 : : * Tuple macros used by both index tuples and heap tuples.
5 : : *
6 : : *
7 : : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
8 : : * Portions Copyright (c) 1994, Regents of the University of California
9 : : *
10 : : * src/include/access/tupmacs.h
11 : : *
12 : : *-------------------------------------------------------------------------
13 : : */
14 : : #ifndef TUPMACS_H
15 : : #define TUPMACS_H
16 : :
17 : : #include "catalog/pg_type_d.h" /* for TYPALIGN macros */
18 : :
19 : :
20 : : /*
21 : : * Check a tuple's null bitmap to determine whether the attribute is null.
22 : : * Note that a 0 in the null bitmap indicates a null, while 1 indicates
23 : : * non-null.
24 : : */
25 : : static inline bool
636 peter@eisentraut.org 26 :CBC 301659145 : att_isnull(int ATT, const bits8 *BITS)
27 : : {
28 : 301659145 : return !(BITS[ATT >> 3] & (1 << (ATT & 0x07)));
29 : : }
30 : :
31 : : #ifndef FRONTEND
32 : : /*
33 : : * Given a Form_pg_attribute and a pointer into a tuple's data area,
34 : : * return the correct value or pointer.
35 : : *
36 : : * We return a Datum value in all cases. If the attribute has "byval" false,
37 : : * we return the same pointer into the tuple data area that we're passed.
38 : : * Otherwise, we return the correct number of bytes fetched from the data
39 : : * area and extended to Datum form.
40 : : *
41 : : * On machines where Datum is 8 bytes, we support fetching 8-byte byval
42 : : * attributes; otherwise, only 1, 2, and 4-byte values are supported.
43 : : *
44 : : * Note that T must already be properly aligned for this to work correctly.
45 : : */
46 : : #define fetchatt(A,T) fetch_att(T, (A)->attbyval, (A)->attlen)
47 : :
48 : : /*
49 : : * Same, but work from byval/len parameters rather than Form_pg_attribute.
50 : : */
51 : : static inline Datum
52 : 719450234 : fetch_att(const void *T, bool attbyval, int attlen)
53 : : {
54 [ + + ]: 719450234 : if (attbyval)
55 : : {
56 [ + + + + : 592321164 : switch (attlen)
- ]
57 : : {
58 : 53704089 : case sizeof(char):
59 : 53704089 : return CharGetDatum(*((const char *) T));
60 : 33311148 : case sizeof(int16):
61 : 33311148 : return Int16GetDatum(*((const int16 *) T));
62 : 484387632 : case sizeof(int32):
63 : 484387632 : return Int32GetDatum(*((const int32 *) T));
64 : : #if SIZEOF_DATUM == 8
65 : 20918295 : case sizeof(Datum):
66 : 20918295 : return *((const Datum *) T);
67 : : #endif
636 peter@eisentraut.org 68 :UBC 0 : default:
69 [ # # ]: 0 : elog(ERROR, "unsupported byval length: %d", attlen);
70 : : return 0;
71 : : }
72 : : }
73 : : else
636 peter@eisentraut.org 74 :CBC 127129070 : return PointerGetDatum(T);
75 : : }
76 : : #endif /* FRONTEND */
77 : :
78 : : /*
79 : : * att_align_datum aligns the given offset as needed for a datum of alignment
80 : : * requirement attalign and typlen attlen. attdatum is the Datum variable
81 : : * we intend to pack into a tuple (it's only accessed if we are dealing with
82 : : * a varlena type). Note that this assumes the Datum will be stored as-is;
83 : : * callers that are intending to convert non-short varlena datums to short
84 : : * format have to account for that themselves.
85 : : */
86 : : #define att_align_datum(cur_offset, attalign, attlen, attdatum) \
87 : : ( \
88 : : ((attlen) == -1 && VARATT_IS_SHORT(DatumGetPointer(attdatum))) ? \
89 : : (uintptr_t) (cur_offset) : \
90 : : att_align_nominal(cur_offset, attalign) \
91 : : )
92 : :
93 : : /*
94 : : * att_align_pointer performs the same calculation as att_align_datum,
95 : : * but is used when walking a tuple. attptr is the current actual data
96 : : * pointer; when accessing a varlena field we have to "peek" to see if we
97 : : * are looking at a pad byte or the first byte of a 1-byte-header datum.
98 : : * (A zero byte must be either a pad byte, or the first byte of a correctly
99 : : * aligned 4-byte length word; in either case we can align safely. A non-zero
100 : : * byte must be either a 1-byte length word, or the first byte of a correctly
101 : : * aligned 4-byte length word; in either case we need not align.)
102 : : *
103 : : * Note: some callers pass a "char *" pointer for cur_offset. This is
104 : : * a bit of a hack but should work all right as long as uintptr_t is the
105 : : * correct width.
106 : : */
107 : : #define att_align_pointer(cur_offset, attalign, attlen, attptr) \
108 : : ( \
109 : : ((attlen) == -1 && VARATT_NOT_PAD_BYTE(attptr)) ? \
110 : : (uintptr_t) (cur_offset) : \
111 : : att_align_nominal(cur_offset, attalign) \
112 : : )
113 : :
114 : : /*
115 : : * att_align_nominal aligns the given offset as needed for a datum of alignment
116 : : * requirement attalign, ignoring any consideration of packed varlena datums.
117 : : * There are three main use cases for using this macro directly:
118 : : * * we know that the att in question is not varlena (attlen != -1);
119 : : * in this case it is cheaper than the above macros and just as good.
120 : : * * we need to estimate alignment padding cost abstractly, ie without
121 : : * reference to a real tuple. We must assume the worst case that
122 : : * all varlenas are aligned.
123 : : * * within arrays and multiranges, we unconditionally align varlenas (XXX this
124 : : * should be revisited, probably).
125 : : *
126 : : * The attalign cases are tested in what is hopefully something like their
127 : : * frequency of occurrence.
128 : : */
129 : : #define att_align_nominal(cur_offset, attalign) \
130 : : ( \
131 : : ((attalign) == TYPALIGN_INT) ? INTALIGN(cur_offset) : \
132 : : (((attalign) == TYPALIGN_CHAR) ? (uintptr_t) (cur_offset) : \
133 : : (((attalign) == TYPALIGN_DOUBLE) ? DOUBLEALIGN(cur_offset) : \
134 : : ( \
135 : : AssertMacro((attalign) == TYPALIGN_SHORT), \
136 : : SHORTALIGN(cur_offset) \
137 : : ))) \
138 : : )
139 : :
140 : : /*
141 : : * att_addlength_datum increments the given offset by the space needed for
142 : : * the given Datum variable. attdatum is only accessed if we are dealing
143 : : * with a variable-length attribute.
144 : : */
145 : : #define att_addlength_datum(cur_offset, attlen, attdatum) \
146 : : att_addlength_pointer(cur_offset, attlen, DatumGetPointer(attdatum))
147 : :
148 : : /*
149 : : * att_addlength_pointer performs the same calculation as att_addlength_datum,
150 : : * but is used when walking a tuple --- attptr is the pointer to the field
151 : : * within the tuple.
152 : : *
153 : : * Note: some callers pass a "char *" pointer for cur_offset. This is
154 : : * actually perfectly OK, but probably should be cleaned up along with
155 : : * the same practice for att_align_pointer.
156 : : */
157 : : #define att_addlength_pointer(cur_offset, attlen, attptr) \
158 : : ( \
159 : : ((attlen) > 0) ? \
160 : : ( \
161 : : (cur_offset) + (attlen) \
162 : : ) \
163 : : : (((attlen) == -1) ? \
164 : : ( \
165 : : (cur_offset) + VARSIZE_ANY(attptr) \
166 : : ) \
167 : : : \
168 : : ( \
169 : : AssertMacro((attlen) == -2), \
170 : : (cur_offset) + (strlen((char *) (attptr)) + 1) \
171 : : )) \
172 : : )
173 : :
174 : : #ifndef FRONTEND
175 : : /*
176 : : * store_att_byval is a partial inverse of fetch_att: store a given Datum
177 : : * value into a tuple data area at the specified address. However, it only
178 : : * handles the byval case, because in typical usage the caller needs to
179 : : * distinguish by-val and by-ref cases anyway, and so a do-it-all function
180 : : * wouldn't be convenient.
181 : : */
182 : : static inline void
183 : 85284955 : store_att_byval(void *T, Datum newdatum, int attlen)
184 : : {
185 [ + + + + : 85284955 : switch (attlen)
- ]
186 : : {
187 : 10892051 : case sizeof(char):
188 : 10892051 : *(char *) T = DatumGetChar(newdatum);
189 : 10892051 : break;
190 : 4032491 : case sizeof(int16):
191 : 4032491 : *(int16 *) T = DatumGetInt16(newdatum);
192 : 4032491 : break;
193 : 61757623 : case sizeof(int32):
194 : 61757623 : *(int32 *) T = DatumGetInt32(newdatum);
195 : 61757623 : break;
196 : : #if SIZEOF_DATUM == 8
197 : 8602790 : case sizeof(Datum):
198 : 8602790 : *(Datum *) T = newdatum;
199 : 8602790 : break;
200 : : #endif
636 peter@eisentraut.org 201 :UBC 0 : default:
202 [ # # ]: 0 : elog(ERROR, "unsupported byval length: %d", attlen);
203 : : }
636 peter@eisentraut.org 204 :CBC 85284955 : }
205 : : #endif /* FRONTEND */
206 : :
207 : : #endif /* TUPMACS_H */
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