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
  29 /* Preallocate this many fields for structures */
  30 #define DEFAULT_NR_STRUCT_FIELDS 8
  31
  32 /*
  33  * Always update stream_pos with move_pos and init_pos.
  34  */
  35 struct stream_pos {
  36         unsigned char *base;    /* Base address */
  37         size_t offset;          /* Offset from base, in bits */
  38         int dummy;              /* Dummy position, for length calculation */
  39 };
  40
  41 static inline
  42 void init_pos(struct stream_pos *pos, unsigned char *base)
  43 {
  44         pos->base = base;       /* initial base, page-aligned */
  45         pos->offset = 0;
  46         pos->dummy = false;
  47 }
  48
  49 /*
  50  * move_pos - move position of a relative bit offset
  51  *
  52  * TODO: allow larger files by updating base too.
  53  */
  54 static inline
  55 void move_pos(struct stream_pos *pos, size_t offset)
  56 {
  57         pos->offset = pos->offset + offset;
  58 }
  59
  60 /*
  61  * align_pos - align position on a bit offset (> 0)
  62  *
  63  * TODO: allow larger files by updating base too.
  64  */
  65 static inline
  66 void align_pos(struct stream_pos *pos, size_t offset)
  67 {
  68         pos->offset += offset_align(pos->offset, offset);
  69 }
  70
  71 static inline
  72 void copy_pos(struct stream_pos *dest, struct stream_pos *src)
  73 {
  74         memcpy(dest, src, sizeof(struct stream_pos));
  75 }
  76
  77 static inline
  78 unsigned char *get_pos_addr(struct stream_pos *pos)
  79 {
  80         /* Only makes sense to get the address after aligning on CHAR_BIT */
  81         assert(!(pos->offset % CHAR_BIT));
  82         return pos->base + (pos->offset / CHAR_BIT);
  83 }
  84
  85 struct format;
  86
  87 struct type_class {
  88         GQuark name;            /* type name */
  89         size_t alignment;       /* type alignment, in bits */
  90         int ref;                /* number of references to the type */
  91         /*
  92          * Type copy function. Knows how to find the child type_class from the
  93          * parent type_class.
  94          */
  95         void (*copy)(struct stream_pos *dest, const struct format *fdest,
  96                      struct stream_pos *src, const struct format *fsrc,
  97                      const struct type_class *type_class);
  98         void (*free)(struct type_class *type_class);
  99 };
 100
 101 /*
 102  * Because we address in bits, bitfields end up being exactly the same as
 103  * integers, except that their read/write functions must be able to deal with
 104  * read/write non aligned on CHAR_BIT.
 105  */
 106 struct type_class_integer {
 107         struct type_class p;
 108         size_t len;             /* length, in bits. */
 109         int byte_order;         /* byte order */
 110         int signedness;
 111 };
 112
 113 struct type_class_float {
 114         struct type_class p;
 115         struct type_class_integer *sign;
 116         struct type_class_integer *mantissa;
 117         struct type_class_integer *exp;
 118         int byte_order;
 119         /* TODO: we might want to express more info about NaN, +inf and -inf */
 120 };
 121
 122 struct enum_table {
 123         GHashTable *value_to_quark;     /* Tuples (value, GQuark) */
 124         GHashTable *quark_to_value;     /* Tuples (GQuark, value) */
 125 };
 126
 127 struct type_class_enum {
 128         struct type_class_integer p;    /* inherit from integer */
 129         struct enum_table table;
 130 };
 131
 132 struct type_class_string {
 133         struct type_class p;
 134 };
 135
 136 struct field {
 137         GQuark name;
 138         struct type_class *type_class;
 139 };
 140
 141 struct type_class_struct {
 142         struct type_class p;
 143         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 144         GArray *fields;                 /* Array of fields */
 145 };
 146
 147 struct type_class_array {
 148         struct type_class p;
 149         size_t len;
 150         struct type_class *elem;
 151 };
 152
 153 struct type_class_sequence {
 154         struct type_class p;
 155         struct type_class_integer *len_class;
 156         struct type_class *elem;
 157 };
 158
 159 struct type_class *lookup_type(GQuark qname);
 160 int register_type(struct type_class *type_class);
 161
 162 void type_ref(struct type_class *type_class);
 163 void type_unref(struct type_class *type_class);
 164
 165 /* Nameless types can be created by passing a NULL name */
 166
 167 struct type_class_integer *integer_type_new(const char *name,
 168                                             size_t len, int byte_order,
 169                                             int signedness,
 170                                             size_t alignment);
 171 void integer_type_free(struct type_class_integer *int_class);
 172
 173 /*
 174  * mantissa_len is the length of the number of bytes represented by the mantissa
 175  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 176  */
 177 struct type_class_float *float_type_new(const char *name,
 178                                         size_t mantissa_len,
 179                                         size_t exp_len, int byte_order,
 180                                         size_t alignment);
 181 void float_type_free(struct type_class_float *float_class);
 182
 183 /*
 184  * A GQuark can be translated to/from strings with g_quark_from_string() and
 185  * g_quark_to_string().
 186  */
 187 GQuark enum_uint_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 188 GQuark enum_int_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 189 uint64_t enum_quark_to_uint(const struct type_class_enum *enum_class,
 190                             GQuark q);
 191 int64_t enum_quark_to_int(const struct type_class_enum *enum_class,
 192                           GQuark q);
 193 void enum_signed_insert(struct type_class_enum *enum_class,
 194                         int64_t v, GQuark q);
 195 void enum_unsigned_insert(struct type_class_enum *enum_class,
 196                           uint64_t v, GQuark q);
 197
 198 struct type_class_enum *enum_type_new(const char *name,
 199                                       size_t len, int byte_order,
 200                                       int signedness,
 201                                       size_t alignment);
 202 void enum_type_free(struct type_class_enum *enum_class);
 203
 204 struct type_class_struct *struct_type_new(const char *name);
 205 void struct_type_free(struct type_class_struct *struct_class);
 206 void struct_type_add_field(struct type_class_struct *struct_class,
 207                            const char *field_name,
 208                            struct type_class *type_class);
 209 /*
 210  * Returns the index of a field within a structure.
 211  */
 212 unsigned long
 213 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 214                                GQuark field_name);
 215 /*
 216  * field returned only valid as long as the field structure is not appended to.
 217  */
 218 struct field *
 219 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 220                                  unsigned long index);
 221
 222 /*
 223  * elem_class passed as parameter now belongs to the array. No need to free it
 224  * explicitely.
 225  */
 226 struct type_class_array *array_type_new(const char *name,
 227                                         size_t len,
 228                                         struct type_class *elem_class);
 229 void array_type_free(struct type_class_array *array_class);
 230
 231 /*
 232  * int_class and elem_class passed as parameter now belongs to the sequence. No
 233  * need to free them explicitely.
 234  */
 235 struct type_class_sequence *sequence_type_new(const char *name,
 236                                         struct type_class_integer *len_class,
 237                                         struct type_class *elem_class);
 238 void sequence_type_free(struct type_class_sequence *sequence_class);
 239
 240 #endif /* _BABELTRACE_TYPES_H */