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 /* Preallocate this many fields for structures */
  31 #define DEFAULT_NR_STRUCT_FIELDS 8
  32
  33 /*
  34  * Always update stream_pos with move_pos and init_pos.
  35  */
  36 struct stream_pos {
  37         unsigned char *base;    /* Base address */
  38         size_t offset;          /* Offset from base, in bits */
  39         int dummy;              /* Dummy position, for length calculation */
  40 };
  41
  42 static inline
  43 void init_pos(struct stream_pos *pos, unsigned char *base)
  44 {
  45         pos->base = base;       /* initial base, page-aligned */
  46         pos->offset = 0;
  47         pos->dummy = false;
  48 }
  49
  50 /*
  51  * move_pos - move position of a relative bit offset
  52  *
  53  * TODO: allow larger files by updating base too.
  54  */
  55 static inline
  56 void move_pos(struct stream_pos *pos, size_t offset)
  57 {
  58         pos->offset = pos->offset + offset;
  59 }
  60
  61 /*
  62  * align_pos - align position on a bit offset (> 0)
  63  *
  64  * TODO: allow larger files by updating base too.
  65  */
  66 static inline
  67 void align_pos(struct stream_pos *pos, size_t offset)
  68 {
  69         pos->offset += offset_align(pos->offset, offset);
  70 }
  71
  72 static inline
  73 void copy_pos(struct stream_pos *dest, struct stream_pos *src)
  74 {
  75         memcpy(dest, src, sizeof(struct stream_pos));
  76 }
  77
  78 static inline
  79 unsigned char *get_pos_addr(struct stream_pos *pos)
  80 {
  81         /* Only makes sense to get the address after aligning on CHAR_BIT */
  82         assert(!(pos->alignment % CHAR_BIT));
  83         return pos->base + (pos->offset / CHAR_BIT);
  84 }
  85
  86 struct type_class {
  87         GQuark name;            /* type name */
  88         size_t alignment;       /* type alignment, in bits */
  89         /*
  90          * Type copy function. Knows how to find the child type_class from the
  91          * parent type_class.
  92          */
  93         size_t (*copy)(struct stream_pos *dest, const struct format *fdest,
  94                        struct stream_pos *src, const struct format *fsrc,
  95                        const struct type_class *type_class);
  96         void (*free)(struct type_class *type_class);
  97 };
  98
  99 /*
 100  * Because we address in bits, bitfields end up being exactly the same as
 101  * integers, except that their read/write functions must be able to deal with
 102  * read/write non aligned on CHAR_BIT.
 103  */
 104 struct type_class_integer {
 105         struct type_class p;
 106         size_t len;             /* length, in bits. */
 107         int byte_order;         /* byte order */
 108         int signedness;
 109 };
 110
 111 struct type_class_float {
 112         struct type_class p;
 113         struct int_class *sign;
 114         struct int_class *mantissa;
 115         struct int_class *exp;
 116         int byte_order;
 117         /* TODO: we might want to express more info about NaN, +inf and -inf */
 118 };
 119
 120 struct enum_table {
 121         GHashTable *value_to_quark;     /* Tuples (value, GQuark) */
 122         GHashTable *quark_to_value;     /* Tuples (GQuark, value) */
 123 };
 124
 125 struct type_class_enum {
 126         struct type_class_int p;        /* inherit from integer */
 127         struct enum_table table;
 128 };
 129
 130 struct type_class_string {
 131         struct type_class p;
 132 };
 133
 134 struct field {
 135         GQuark name;
 136         struct type_class *type_class;
 137 };
 138
 139 struct type_class_struct {
 140         struct type_class p;
 141         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 142         GArray *fields;                 /* Array of fields */
 143 };
 144
 145 struct type_class_array {
 146         struct type_class p;
 147         size_t len;
 148         struct type_class *elem;
 149 };
 150
 151 struct type_class_sequence {
 152         struct type_class p;
 153         struct type_class_integer *len;
 154         struct type_class *elem;
 155 };
 156
 157 struct type_class *ctf_lookup_type(GQuark qname);
 158 int ctf_register_type(struct type_class *type_class);
 159
 160 /* Nameless types can be created by passing a NULL name */
 161
 162 struct type_class_integer *integer_type_new(const char *name,
 163                                             size_t len, int byte_order,
 164                                             int signedness,
 165                                             size_t alignment);
 166 void integer_type_free(struct type_class_integer *int_class);
 167
 168 /*
 169  * mantissa_len is the length of the number of bytes represented by the mantissa
 170  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 171  */
 172 struct type_class_float *float_type_new(const char *name,
 173                                         size_t mantissa_len,
 174                                         size_t exp_len, int byte_order,
 175                                         size_t alignment);
 176 void float_type_free(struct type_class_float *float_class);
 177
 178 /*
 179  * A GQuark can be translated to/from strings with g_quark_from_string() and
 180  * g_quark_to_string().
 181  */
 182 GQuark enum_uint_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 183 GQuark enum_int_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 184 uint64_t enum_quark_to_uint(const struct type_class_enum *enum_class,
 185                             size_t len, int byte_order, GQuark q);
 186 int64_t enum_quark_to_int(const struct type_class_enum *enum_class,
 187                           size_t len, int byte_order, GQuark q);
 188 void enum_signed_insert(struct type_class_enum *enum_class,
 189                         int64_t v, GQuark q);
 190 void enum_unsigned_insert(struct type_class_enum *enum_class,
 191                           uint64_t v, GQuark q);
 192
 193 struct type_class_enum *enum_type_new(const char *name,
 194                                       size_t len, int byte_order,
 195                                       int signedness,
 196                                       size_t alignment);
 197 void enum_type_free(struct type_class_enum *enum_class);
 198
 199 struct type_class_struct *struct_type_new(const char *name);
 200 void struct_type_free(struct type_class_struct *struct_class);
 201 void struct_type_add_field(struct type_class_struct *struct_class,
 202                            GQuark field_name,
 203                            struct type_class *type_class);
 204 /*
 205  * Returns the index of a field within a structure.
 206  */
 207 unsigned long
 208 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 209                                GQuark field_name);
 210 /*
 211  * field returned only valid as long as the field structure is not appended to.
 212  */
 213 struct field *
 214 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 215                                  unsigned long index);
 216
 217 /*
 218  * elem_class passed as parameter now belongs to the array. No need to free it
 219  * explicitely.
 220  */
 221 struct type_class_array *array_type_new(const char *name,
 222                                         size_t len,
 223                                         struct type_class *elem_class);
 224 void array_type_free(struct type_class_array *array_class);
 225
 226 /*
 227  * int_class and elem_class passed as parameter now belongs to the sequence. No
 228  * need to free them explicitely.
 229  */
 230 struct type_class_sequence *sequence_type_new(const char *name,
 231                                         struct type_class_integer *int_class,
 232                                         struct type_class *elem_class);
 233 void sequence_type_free(struct type_class_sequence *sequence_class);
 234
 235 #endif /* _BABELTRACE_TYPES_H */