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 */