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/format.h>
  23 #include <babeltrace/align.h>
  24 #include <string.h>
  25
  26 /* Preallocate this many fields for structures */
  27 #define DEFAULT_NR_STRUCT_FIELDS 8
  28
  29 /*
  30  * Always update stream_pos with move_pos and init_pos.
  31  */
  32 struct stream_pos {
  33         unsigned char *base;    /* Base address */
  34         size_t offset;          /* Offset from base, in bits */
  35         int dummy;              /* Dummy position, for length calculation */
  36 };
  37
  38 static inline
  39 void init_pos(struct stream_pos *pos, unsigned char *base)
  40 {
  41         pos->base = base;       /* initial base, page-aligned */
  42         pos->offset = 0;
  43         pos->dummy = false;
  44 }
  45
  46 /*
  47  * move_pos - move position of a relative bit offset
  48  *
  49  * TODO: allow larger files by updating base too.
  50  */
  51 static inline
  52 void move_pos(struct stream_pos *pos, size_t offset)
  53 {
  54         pos->offset = pos->offset + offset;
  55 }
  56
  57 /*
  58  * align_pos - align position on a bit offset (> 0)
  59  *
  60  * TODO: allow larger files by updating base too.
  61  */
  62 static inline
  63 void align_pos(struct stream_pos *pos, size_t offset)
  64 {
  65         pos->offset += offset_align(pos->offset, offset);
  66 }
  67
  68 static inline
  69 void copy_pos(struct stream_pos *dest, struct stream_pos *src)
  70 {
  71         memcpy(dest, src, sizeof(struct stream_pos));
  72 }
  73
  74 static inline
  75 unsigned char *get_pos_addr(struct stream_pos *pos)
  76 {
  77         /* Only makes sense to get the address after aligning on CHAR_BIT */
  78         assert(!(pos->alignment % CHAR_BIT));
  79         return pos->base + (pos->offset / CHAR_BIT);
  80 }
  81
  82 struct type_class {
  83         GQuark name;            /* type name */
  84         size_t alignment;       /* type alignment, in bits */
  85         /*
  86          * Type copy function. Knows how to find the child type_class from the
  87          * parent type_class.
  88          */
  89         size_t (*copy)(struct stream_pos *dest, const struct format *fdest,
  90                        struct stream_pos *src, const struct format *fsrc,
  91                        const struct type_class *type_class);
  92         void (*free)(struct type_class *type_class);
  93 };
  94
  95 /*
  96  * Because we address in bits, bitfields end up being exactly the same as
  97  * integers, except that their read/write functions must be able to deal with
  98  * read/write non aligned on CHAR_BIT.
  99  */
 100 struct type_class_integer {
 101         struct type_class p;
 102         size_t len;             /* length, in bits. */
 103         int byte_order;         /* byte order */
 104         int signedness;
 105 };
 106
 107 struct type_class_float {
 108         struct type_class p;
 109         struct int_class *sign;
 110         struct int_class *mantissa;
 111         struct int_class *exp;
 112         int byte_order;
 113         /* TODO: we might want to express more info about NaN, +inf and -inf */
 114 };
 115
 116 struct enum_table {
 117         GHashTable *value_to_quark;     /* Tuples (value, GQuark) */
 118         GHashTable *quark_to_value;     /* Tuples (GQuark, value) */
 119 };
 120
 121 struct type_class_enum {
 122         struct type_class_int p;        /* inherit from integer */
 123         struct enum_table table;
 124 };
 125
 126 struct type_class_string {
 127         struct type_class p;
 128 };
 129
 130 struct field {
 131         GQuark name;
 132         struct type_class *type_class;
 133 };
 134
 135 struct type_class_struct {
 136         struct type_class p;
 137         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 138         GArray *fields;                 /* Array of fields */
 139 };
 140
 141 struct type_class_array {
 142         struct type_class p;
 143         size_t len;
 144         struct type_class *elem;
 145 };
 146
 147 struct type_class_sequence {
 148         struct type_class p;
 149         struct type_class_integer *len_class;
 150         struct type_class *elem;
 151 };
 152
 153 struct type_class *ctf_lookup_type(GQuark qname);
 154 int ctf_register_type(struct type_class *type_class);
 155
 156 /* Nameless types can be created by passing a NULL name */
 157
 158 struct type_class_integer *integer_type_new(const char *name,
 159                                             size_t len, int byte_order,
 160                                             int signedness,
 161                                             size_t alignment);
 162 void integer_type_free(struct type_class_integer *int_class);
 163
 164 /*
 165  * mantissa_len is the length of the number of bytes represented by the mantissa
 166  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 167  */
 168 struct type_class_float *float_type_new(const char *name,
 169                                         size_t mantissa_len,
 170                                         size_t exp_len, int byte_order,
 171                                         size_t alignment);
 172 void float_type_free(struct type_class_float *float_class);
 173
 174 /*
 175  * A GQuark can be translated to/from strings with g_quark_from_string() and
 176  * g_quark_to_string().
 177  */
 178 GQuark enum_uint_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 179 GQuark enum_int_to_quark(const struct type_class_enum *enum_class, uint64_t v);
 180 uint64_t enum_quark_to_uint(const struct type_class_enum *enum_class,
 181                             size_t len, int byte_order, GQuark q);
 182 int64_t enum_quark_to_int(const struct type_class_enum *enum_class,
 183                           size_t len, int byte_order, GQuark q);
 184 void enum_signed_insert(struct type_class_enum *enum_class,
 185                         int64_t v, GQuark q);
 186 void enum_unsigned_insert(struct type_class_enum *enum_class,
 187                           uint64_t v, GQuark q);
 188
 189 struct type_class_enum *enum_type_new(const char *name,
 190                                       size_t len, int byte_order,
 191                                       int signedness,
 192                                       size_t alignment);
 193 void enum_type_free(struct type_class_enum *enum_class);
 194
 195 struct type_class_struct *struct_type_new(const char *name);
 196 void struct_type_free(struct type_class_struct *struct_class);
 197 void struct_type_add_field(struct type_class_struct *struct_class,
 198                            GQuark field_name,
 199                            struct type_class *type_class);
 200 /*
 201  * Returns the index of a field within a structure.
 202  */
 203 unsigned long
 204 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 205                                GQuark field_name);
 206 /*
 207  * field returned only valid as long as the field structure is not appended to.
 208  */
 209 struct field *
 210 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 211                                  unsigned long index);
 212
 213 /*
 214  * elem_class passed as parameter now belongs to the array. No need to free it
 215  * explicitely.
 216  */
 217 struct type_class_array *array_type_new(const char *name,
 218                                         size_t len,
 219                                         struct type_class *elem_class);
 220 void array_type_free(struct type_class_array *array_class);
 221
 222 /*
 223  * int_class and elem_class passed as parameter now belongs to the sequence. No
 224  * need to free them explicitely.
 225  */
 226 struct type_class_sequence *sequence_type_new(const char *name,
 227                                         struct type_class_integer *len_class,
 228                                         struct type_class *elem_class);
 229 void sequence_type_free(struct type_class_sequence *sequence_class);
 230
 231 #endif /* _BABELTRACE_TYPES_H */