Remove bitfields, which are just a bit-addressed integer
[babeltrace.git] / include / babeltrace / types.h
1 #ifndef _BABELTRACE_TYPES_H
2 #define _BABELTRACE_TYPES_H
3
4 /*
5 * BabelTrace
6 *
7 * Type Header
8 *
9 * Copyright (c) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
10 *
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2.1 of the License, or (at your option) any later version.
15 *
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this library; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26 #include <babeltrace/format.h>
27 #include <babeltrace/align.h>
28 #include <string.h>
29
30 /*
31 * Always update stream_pos with move_pos and init_pos.
32 */
33 struct stream_pos {
34 unsigned char *base; /* Base address */
35 size_t offset; /* Offset from base, in bits */
36 int dummy; /* Dummy position, for length calculation */
37 };
38
39 static inline
40 void init_pos(struct stream_pos *pos, unsigned char *base)
41 {
42 pos->base = base; /* initial base, page-aligned */
43 pos->offset = 0;
44 pos->dummy = false;
45 }
46
47 /*
48 * move_pos - move position of a relative bit offset
49 *
50 * TODO: allow larger files by updating base too.
51 */
52 static inline
53 void move_pos(struct stream_pos *pos, size_t offset)
54 {
55 pos->offset = pos->offset + offset;
56 }
57
58 /*
59 * align_pos - align position on a bit offset (> 0)
60 *
61 * TODO: allow larger files by updating base too.
62 */
63 static inline
64 void align_pos(struct stream_pos *pos, size_t offset)
65 {
66 pos->offset += offset_align(pos->offset, offset);
67 }
68
69 static inline
70 void copy_pos(struct stream_pos *dest, struct stream_pos *src)
71 {
72 memcpy(dest, src, sizeof(struct stream_pos));
73 }
74
75 static inline
76 unsigned char *get_pos_addr(struct stream_pos *pos)
77 {
78 /* Only makes sense to get the address after aligning on CHAR_BIT */
79 assert(!(pos->alignment % CHAR_BIT));
80 return pos->base + (pos->offset / CHAR_BIT);
81 }
82
83 struct type_class {
84 GQuark name; /* type name */
85 size_t alignment; /* type alignment, in bits */
86 /*
87 * Type copy function. Knows how to find the child type_class from the
88 * parent type_class.
89 */
90 size_t (*copy)(struct stream_pos *dest, const struct format *fdest,
91 struct stream_pos *src, const struct format *fsrc,
92 const struct type_class *type_class);
93 void (*free)(struct type_class *type_class);
94 };
95
96 /*
97 * Because we address in bits, bitfields end up being exactly the same as
98 * integers, except that their read/write functions must be able to deal with
99 * read/write non aligned on CHAR_BIT.
100 */
101 struct type_class_integer {
102 struct type_class p;
103 size_t len; /* length, in bits. */
104 int byte_order; /* byte order */
105 int signedness;
106 };
107
108 struct type_class_float {
109 struct type_class p;
110 struct int_class *sign;
111 struct int_class *mantissa;
112 struct int_class *exp;
113 int byte_order;
114 /* TODO: we might want to express more info about NaN, +inf and -inf */
115 };
116
117 struct enum_table {
118 GHashTable *value_to_quark; /* Tuples (value, GQuark) */
119 GHashTable *quark_to_value; /* Tuples (GQuark, value) */
120 };
121
122 struct type_class_enum {
123 struct type_class_int p; /* inherit from integer */
124 struct enum_table table;
125 };
126
127 struct type_class_string {
128 struct type_class p;
129 };
130
131 struct type_class_struct {
132 struct type_class p;
133 /* TODO */
134 };
135
136 struct type_class *ctf_lookup_type(GQuark qname);
137 int ctf_register_type(struct type_class *type_class);
138
139 /* Nameless types can be created by passing a NULL name */
140
141 struct type_class_integer *integer_type_new(const char *name,
142 size_t len, int byte_order,
143 int signedness,
144 size_t alignment);
145 void integer_type_free(struct type_class_integer *int_class);
146
147 /*
148 * mantissa_len is the length of the number of bytes represented by the mantissa
149 * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
150 */
151 struct type_class_float *float_type_new(const char *name,
152 size_t mantissa_len,
153 size_t exp_len, int byte_order,
154 size_t alignment);
155 void float_type_free(struct type_class_float *float_class);
156
157 /*
158 * A GQuark can be translated to/from strings with g_quark_from_string() and
159 * g_quark_to_string().
160 */
161 GQuark enum_uint_to_quark(const struct type_class_enum *enum_class, uint64_t v);
162 GQuark enum_int_to_quark(const struct type_class_enum *enum_class, uint64_t v);
163 uint64_t enum_quark_to_uint(const struct type_class_enum *enum_class,
164 size_t len, int byte_order, GQuark q);
165 int64_t enum_quark_to_int(const struct type_class_enum *enum_class,
166 size_t len, int byte_order, GQuark q);
167 void enum_signed_insert(struct type_class_enum *enum_class,
168 int64_t v, GQuark q);
169 void enum_unsigned_insert(struct type_class_enum *enum_class,
170 uint64_t v, GQuark q);
171
172 struct type_class_enum *enum_type_new(const char *name,
173 size_t len, int byte_order,
174 int signedness,
175 size_t alignment);
176 void enum_type_free(struct type_class_enum *enum_class);
177
178 #endif /* _BABELTRACE_TYPES_H */
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