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 <babeltrace/list.h>
  24 #include <stdbool.h>
  25 #include <stdint.h>
  26 #include <limits.h>
  27 #include <string.h>
  28 #include <glib.h>
  29 #include <assert.h>
  30
  31 /* Preallocate this many fields for structures */
  32 #define DEFAULT_NR_STRUCT_FIELDS 8
  33
  34 /*
  35  * Always update stream_pos with move_pos and init_pos.
  36  */
  37 struct stream_pos {
  38         unsigned char *base;    /* Base address */
  39         size_t offset;          /* Offset from base, in bits */
  40         int dummy;              /* Dummy position, for length calculation */
  41 };
  42
  43 static inline
  44 void init_pos(struct stream_pos *pos, unsigned char *base)
  45 {
  46         pos->base = base;       /* initial base, page-aligned */
  47         pos->offset = 0;
  48         pos->dummy = false;
  49 }
  50
  51 /*
  52  * move_pos - move position of a relative bit offset
  53  *
  54  * TODO: allow larger files by updating base too.
  55  */
  56 static inline
  57 void move_pos(struct stream_pos *pos, size_t offset)
  58 {
  59         pos->offset = pos->offset + offset;
  60 }
  61
  62 /*
  63  * align_pos - align position on a bit offset (> 0)
  64  *
  65  * TODO: allow larger files by updating base too.
  66  */
  67 static inline
  68 void align_pos(struct stream_pos *pos, size_t offset)
  69 {
  70         pos->offset += offset_align(pos->offset, offset);
  71 }
  72
  73 static inline
  74 void copy_pos(struct stream_pos *dest, struct stream_pos *src)
  75 {
  76         memcpy(dest, src, sizeof(struct stream_pos));
  77 }
  78
  79 static inline
  80 unsigned char *get_pos_addr(struct stream_pos *pos)
  81 {
  82         /* Only makes sense to get the address after aligning on CHAR_BIT */
  83         assert(!(pos->offset % CHAR_BIT));
  84         return pos->base + (pos->offset / CHAR_BIT);
  85 }
  86
  87 struct format;
  88
  89 struct type_class {
  90         GQuark name;            /* type name */
  91         size_t alignment;       /* type alignment, in bits */
  92         int ref;                /* number of references to the type */
  93         /*
  94          * Type copy function. Knows how to find the child type_class from the
  95          * parent type_class.
  96          */
  97         void (*copy)(struct stream_pos *dest, const struct format *fdest,
  98                      struct stream_pos *src, const struct format *fsrc,
  99                      const struct type_class *type_class);
 100         void (*free)(struct type_class *type_class);
 101 };
 102
 103 /*
 104  * Because we address in bits, bitfields end up being exactly the same as
 105  * integers, except that their read/write functions must be able to deal with
 106  * read/write non aligned on CHAR_BIT.
 107  */
 108 struct type_class_integer {
 109         struct type_class p;
 110         size_t len;             /* length, in bits. */
 111         int byte_order;         /* byte order */
 112         int signedness;
 113 };
 114
 115 struct type_class_float {
 116         struct type_class p;
 117         struct type_class_integer *sign;
 118         struct type_class_integer *mantissa;
 119         struct type_class_integer *exp;
 120         int byte_order;
 121         /* TODO: we might want to express more info about NaN, +inf and -inf */
 122 };
 123
 124 /*
 125  * enum_val_equal assumes that signed and unsigned memory layout overlap.
 126  */
 127 struct enum_range {
 128         union {
 129                 int64_t _signed;
 130                 uint64_t _unsigned;
 131         } start;        /* lowest range value */
 132         union {
 133                 int64_t _signed;
 134                 uint64_t _unsigned;
 135         } end;          /* highest range value */
 136 };
 137
 138 struct enum_range_to_quark {
 139         struct cds_list_head node;
 140         struct enum_range range;
 141         GQuark quark;
 142 };
 143
 144 /*
 145  * We optimize the common case (range of size 1: single value) by creating a
 146  * hash table mapping values to quark sets. We then lookup the ranges to
 147  * complete the quark set.
 148  *
 149  * TODO: The proper structure to hold the range to quark set mapping would be an
 150  * interval tree, with O(n) size, O(n*log(n)) build time and O(log(n)) query
 151  * time. Using a simple O(n) list search for now for implementation speed and
 152  * given that we can expect to have a _relatively_ small number of enumeration
 153  * ranges. This might become untrue if we are fed with symbol tables often
 154  * required to lookup function names from instruction pointer value.
 155  */
 156 struct enum_table {
 157         GHashTable *value_to_quark_set;         /* (value, GQuark GArray) */
 158         struct cds_list_head range_to_quark;    /* (range, GQuark) */
 159         GHashTable *quark_to_range_set;         /* (GQuark, range GArray) */
 160 };
 161
 162 struct type_class_enum {
 163         struct type_class_integer p;    /* inherit from integer */
 164         struct enum_table table;
 165 };
 166
 167 struct type_class_string {
 168         struct type_class p;
 169 };
 170
 171 struct field {
 172         GQuark name;
 173         struct type_class *type_class;
 174 };
 175
 176 struct type_class_struct {
 177         struct type_class p;
 178         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 179         GArray *fields;                 /* Array of fields */
 180 };
 181
 182 struct type_class_array {
 183         struct type_class p;
 184         size_t len;
 185         struct type_class *elem;
 186 };
 187
 188 struct type_class_sequence {
 189         struct type_class p;
 190         struct type_class_integer *len_class;
 191         struct type_class *elem;
 192 };
 193
 194 struct type_class *lookup_type(GQuark qname);
 195 int register_type(struct type_class *type_class);
 196
 197 void type_ref(struct type_class *type_class);
 198 void type_unref(struct type_class *type_class);
 199
 200 /* Nameless types can be created by passing a NULL name */
 201
 202 struct type_class_integer *integer_type_new(const char *name,
 203                                             size_t len, int byte_order,
 204                                             int signedness,
 205                                             size_t alignment);
 206 void integer_type_free(struct type_class_integer *int_class);
 207
 208 /*
 209  * mantissa_len is the length of the number of bytes represented by the mantissa
 210  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 211  */
 212 struct type_class_float *float_type_new(const char *name,
 213                                         size_t mantissa_len,
 214                                         size_t exp_len, int byte_order,
 215                                         size_t alignment);
 216 void float_type_free(struct type_class_float *float_class);
 217
 218 /*
 219  * A GQuark can be translated to/from strings with g_quark_from_string() and
 220  * g_quark_to_string().
 221  */
 222 GArray *enum_uint_to_quark_set(const struct type_class_enum *enum_class,
 223                                uint64_t v);
 224
 225 /*
 226  * Returns a GArray or NULL.
 227  * Caller must release the GArray with g_array_unref().
 228  */
 229 GArray *enum_int_to_quark_set(const struct type_class_enum *enum_class,
 230                               uint64_t v);
 231 GArray *enum_quark_to_range_set(const struct type_class_enum *enum_class,
 232                                 GQuark q);
 233 void enum_signed_insert(struct type_class_enum *enum_class,
 234                         int64_t start, int64_t end, GQuark q);
 235 void enum_unsigned_insert(struct type_class_enum *enum_class,
 236                           uint64_t start, uint64_t end, GQuark q);
 237
 238 struct type_class_enum *enum_type_new(const char *name,
 239                                       size_t len, int byte_order,
 240                                       int signedness,
 241                                       size_t alignment);
 242 void enum_type_free(struct type_class_enum *enum_class);
 243
 244 struct type_class_struct *struct_type_new(const char *name);
 245 void struct_type_free(struct type_class_struct *struct_class);
 246 void struct_type_add_field(struct type_class_struct *struct_class,
 247                            const char *field_name,
 248                            struct type_class *type_class);
 249 /*
 250  * Returns the index of a field within a structure.
 251  */
 252 unsigned long
 253 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 254                                GQuark field_name);
 255 /*
 256  * field returned only valid as long as the field structure is not appended to.
 257  */
 258 struct field *
 259 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 260                                  unsigned long index);
 261
 262 /*
 263  * elem_class passed as parameter now belongs to the array. No need to free it
 264  * explicitely.
 265  */
 266 struct type_class_array *array_type_new(const char *name,
 267                                         size_t len,
 268                                         struct type_class *elem_class);
 269 void array_type_free(struct type_class_array *array_class);
 270
 271 /*
 272  * int_class and elem_class passed as parameter now belongs to the sequence. No
 273  * need to free them explicitely.
 274  */
 275 struct type_class_sequence *sequence_type_new(const char *name,
 276                                         struct type_class_integer *len_class,
 277                                         struct type_class *elem_class);
 278 void sequence_type_free(struct type_class_sequence *sequence_class);
 279
 280 #endif /* _BABELTRACE_TYPES_H */