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 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  */
  21
  22 #include <babeltrace/align.h>
  23 #include <stdbool.h>
  24 #include <stdint.h>
  25 #include <limits.h>
  26 #include <string.h>
  27 #include <glib.h>
  28 #include <assert.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->offset % CHAR_BIT));
  83         return pos->base + (pos->offset / CHAR_BIT);
  84 }
  85
  86 struct format;
  87
  88 struct type_class {
  89         GQuark name;            /* type name */
  90         size_t alignment;       /* type alignment, in bits */
  91         int ref;                /* number of references to the type */
  92         /*
  93          * Type copy function. Knows how to find the child type_class from the
  94          * parent type_class.
  95          */
  96         void (*copy)(struct stream_pos *dest, const struct format *fdest,
  97                      struct stream_pos *src, const struct format *fsrc,
  98                      const struct type_class *type_class);
  99         void (*free)(struct type_class *type_class);
 100 };
 101
 102 /*
 103  * Because we address in bits, bitfields end up being exactly the same as
 104  * integers, except that their read/write functions must be able to deal with
 105  * read/write non aligned on CHAR_BIT.
 106  */
 107 struct type_class_integer {
 108         struct type_class p;
 109         size_t len;             /* length, in bits. */
 110         int byte_order;         /* byte order */
 111         int signedness;
 112 };
 113
 114 struct type_class_float {
 115         struct type_class p;
 116         struct type_class_integer *sign;
 117         struct type_class_integer *mantissa;
 118         struct type_class_integer *exp;
 119         int byte_order;
 120         /* TODO: we might want to express more info about NaN, +inf and -inf */
 121 };
 122
 123 struct enum_table {
 124         GHashTable *value_to_quark;     /* Tuples (value, GQuark) */
 125         GHashTable *quark_to_value;     /* Tuples (GQuark, value) */
 126 };
 127
 128 struct type_class_enum {
 129         struct type_class_integer p;    /* inherit from integer */
 130         struct enum_table table;
 131 };
 132
 133 struct type_class_string {
 134         struct type_class p;
 135 };
 136
 137 struct field {
 138         GQuark name;
 139         struct type_class *type_class;
 140 };
 141
 142 struct type_class_struct {
 143         struct type_class p;
 144         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 145         GArray *fields;                 /* Array of fields */
 146 };
 147
 148 struct type_class_array {
 149         struct type_class p;
 150         size_t len;
 151         struct type_class *elem;
 152 };
 153
 154 struct type_class_sequence {
 155         struct type_class p;
 156         struct type_class_integer *len_class;
 157         struct type_class *elem;
 158 };
 159
 160 struct type_class *lookup_type(GQuark qname);
 161 int register_type(struct type_class *type_class);
 162
 163 void type_ref(struct type_class *type_class);
 164 void type_unref(struct type_class *type_class);
 165
 166 /* Nameless types can be created by passing a NULL name */
 167
 168 struct type_class_integer *integer_type_new(const char *name,
 169                                             size_t len, int byte_order,
 170                                             int signedness,
 171                                             size_t alignment);
 172 void integer_type_free(struct type_class_integer *int_class);
 173
 174 /*
 175  * mantissa_len is the length of the number of bytes represented by the mantissa
 176  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 177  */
 178 struct type_class_float *float_type_new(const char *name,
 179                                         size_t mantissa_len,
 180                                         size_t exp_len, int byte_order,
 181                                         size_t alignment);
 182 void float_type_free(struct type_class_float *float_class);
 183
 184 /*
 185  * A GQuark can be translated to/from strings with g_quark_from_string() and
 186  * g_quark_to_string().
 187  */
 188 GQuark enum_uint_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 189 GQuark enum_int_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 190 uint64_t enum_quark_to_uint(const struct type_class_enum *enum_class,
 191                             GQuark q);
 192 int64_t enum_quark_to_int(const struct type_class_enum *enum_class,
 193                           GQuark q);
 194 void enum_signed_insert(struct type_class_enum *enum_class,
 195                         int64_t v, GQuark q);
 196 void enum_unsigned_insert(struct type_class_enum *enum_class,
 197                           uint64_t v, GQuark q);
 198
 199 struct type_class_enum *enum_type_new(const char *name,
 200                                       size_t len, int byte_order,
 201                                       int signedness,
 202                                       size_t alignment);
 203 void enum_type_free(struct type_class_enum *enum_class);
 204
 205 struct type_class_struct *struct_type_new(const char *name);
 206 void struct_type_free(struct type_class_struct *struct_class);
 207 void struct_type_add_field(struct type_class_struct *struct_class,
 208                            const char *field_name,
 209                            struct type_class *type_class);
 210 /*
 211  * Returns the index of a field within a structure.
 212  */
 213 unsigned long
 214 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 215                                GQuark field_name);
 216 /*
 217  * field returned only valid as long as the field structure is not appended to.
 218  */
 219 struct field *
 220 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 221                                  unsigned long index);
 222
 223 /*
 224  * elem_class passed as parameter now belongs to the array. No need to free it
 225  * explicitely.
 226  */
 227 struct type_class_array *array_type_new(const char *name,
 228                                         size_t len,
 229                                         struct type_class *elem_class);
 230 void array_type_free(struct type_class_array *array_class);
 231
 232 /*
 233  * int_class and elem_class passed as parameter now belongs to the sequence. No
 234  * need to free them explicitely.
 235  */
 236 struct type_class_sequence *sequence_type_new(const char *name,
 237                                         struct type_class_integer *len_class,
 238                                         struct type_class *elem_class);
 239 void sequence_type_free(struct type_class_sequence *sequence_class);
 240
 241 #endif /* _BABELTRACE_TYPES_H */