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, 2011 - 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         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, 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 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 struct declaration;
  89
  90 /* Type declaration scope */
  91 struct declaration_scope {
  92         /* Hash table mapping type name GQuark to struct type */
  93         GHashTable *types;
  94         /* Hash table mapping field name GQuark to struct declaration */
  95         GHashTable *declarations;
  96         struct declaration_scope *parent_scope;
  97 };
  98
  99 struct type {
 100         GQuark name;            /* type name */
 101         size_t alignment;       /* type alignment, in bits */
 102         int ref;                /* number of references to the type */
 103         /*
 104          * type_free called with type ref is decremented to 0.
 105          */
 106         void (*type_free)(struct type *type);
 107         struct declaration *
 108                 (*declaration_new)(struct type *type,
 109                                    struct declaration_scope *parent_scope);
 110         /*
 111          * declaration_free called with declaration ref is decremented to 0.
 112          */
 113         void (*declaration_free)(struct declaration *declaration);
 114         /*
 115          * Declaration copy function. Knows how to find the child declaration
 116          * from the parent declaration.
 117          */
 118         void (*copy)(struct stream_pos *dest, const struct format *fdest,
 119                      struct stream_pos *src, const struct format *fsrc,
 120                      struct declaration *declaration);
 121 };
 122
 123 struct declaration {
 124         struct type *type;
 125         int ref;                /* number of references to the declaration */
 126 };
 127
 128 /*
 129  * Because we address in bits, bitfields end up being exactly the same as
 130  * integers, except that their read/write functions must be able to deal with
 131  * read/write non aligned on CHAR_BIT.
 132  */
 133 struct type_integer {
 134         struct type p;
 135         size_t len;             /* length, in bits. */
 136         int byte_order;         /* byte order */
 137         int signedness;
 138 };
 139
 140 struct declaration_integer {
 141         struct declaration p;
 142         struct type_integer *type;
 143         /* Last values read */
 144         union {
 145                 uint64_t _unsigned;
 146                 int64_t _signed;
 147         } value;
 148 };
 149
 150 struct type_float {
 151         struct type p;
 152         struct type_integer *sign;
 153         struct type_integer *mantissa;
 154         struct type_integer *exp;
 155         int byte_order;
 156         /* TODO: we might want to express more info about NaN, +inf and -inf */
 157 };
 158
 159 struct declaration_float {
 160         struct declaration p;
 161         struct type_float *type;
 162         /* Last values read */
 163         long double value;
 164 };
 165
 166 /*
 167  * enum_val_equal assumes that signed and unsigned memory layout overlap.
 168  */
 169 struct enum_range {
 170         union {
 171                 int64_t _signed;
 172                 uint64_t _unsigned;
 173         } start;        /* lowest range value */
 174         union {
 175                 int64_t _signed;
 176                 uint64_t _unsigned;
 177         } end;          /* highest range value */
 178 };
 179
 180 struct enum_range_to_quark {
 181         struct cds_list_head node;
 182         struct enum_range range;
 183         GQuark quark;
 184 };
 185
 186 /*
 187  * We optimize the common case (range of size 1: single value) by creating a
 188  * hash table mapping values to quark sets. We then lookup the ranges to
 189  * complete the quark set.
 190  *
 191  * TODO: The proper structure to hold the range to quark set mapping would be an
 192  * interval tree, with O(n) size, O(n*log(n)) build time and O(log(n)) query
 193  * time. Using a simple O(n) list search for now for implementation speed and
 194  * given that we can expect to have a _relatively_ small number of enumeration
 195  * ranges. This might become untrue if we are fed with symbol tables often
 196  * required to lookup function names from instruction pointer value.
 197  */
 198 struct enum_table {
 199         GHashTable *value_to_quark_set;         /* (value, GQuark GArray) */
 200         struct cds_list_head range_to_quark;    /* (range, GQuark) */
 201         GHashTable *quark_to_range_set;         /* (GQuark, range GArray) */
 202 };
 203
 204 struct type_enum {
 205         struct type p;
 206         struct type_integer *integer_type;
 207         struct enum_table table;
 208 };
 209
 210 struct declaration_enum {
 211         struct declaration p;
 212         struct declaration_integer *integer;
 213         struct type_enum *type;
 214         /* Last GQuark values read. Keeping a reference on the GQuark array. */
 215         GArray *value;
 216 };
 217
 218 struct type_string {
 219         struct type p;
 220 };
 221
 222 struct declaration_string {
 223         struct declaration p;
 224         struct type_string *type;
 225         char *value;    /* freed at declaration_string teardown */
 226 };
 227
 228 struct type_field {
 229         GQuark name;
 230         struct type *type;
 231 };
 232
 233 struct field {
 234         GQuark name;
 235         struct declaration *declaration;
 236 };
 237
 238 struct type_struct {
 239         struct type p;
 240         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 241         GArray *fields;                 /* Array of type_field */
 242 };
 243
 244 struct declaration_struct {
 245         struct declaration p;
 246         struct type_struct *type;
 247         struct declaration_scope *scope;
 248         GArray *fields;                 /* Array of struct field */
 249 };
 250
 251 struct type_variant {
 252         struct type p;
 253         GHashTable *fields_by_tag;      /* Tuples (field tag, field index) */
 254         GArray *fields;                 /* Array of type_field */
 255 };
 256
 257 struct declaration_variant {
 258         struct declaration p;
 259         struct type_variant *type;
 260         struct declaration_scope *scope;
 261         struct declaration *enum_tag;
 262         GArray *fields;                 /* Array of struct field */
 263         struct field *current_field;    /* Last field read */
 264 };
 265
 266 struct type_array {
 267         struct type p;
 268         size_t len;
 269         struct type *elem;
 270 };
 271
 272 struct declaration_array {
 273         struct declaration p;
 274         struct type_array *type;
 275         struct declaration_scope *scope;
 276         struct field current_element;           /* struct field */
 277 };
 278
 279 struct type_sequence {
 280         struct type p;
 281         struct type_integer *len_type;
 282         struct type *elem;
 283 };
 284
 285 struct declaration_sequence {
 286         struct declaration p;
 287         struct type_sequence *type;
 288         struct declaration_scope *scope;
 289         struct declaration_integer *len;
 290         struct field current_element;           /* struct field */
 291 };
 292
 293 struct type *lookup_type(GQuark type_name, struct declaration_scope *scope);
 294 int register_type(struct type *type, struct declaration_scope *scope);
 295
 296 struct declaration *
 297         lookup_declaration(GQuark field_name, struct declaration_scope *scope);
 298 int register_declaration(GQuark field_name, struct declaration *declaration,
 299                          struct declaration_scope *scope);
 300
 301 void type_ref(struct type *type);
 302 void type_unref(struct type *type);
 303
 304 struct declaration_scope *
 305         new_declaration_scope(struct declaration_scope *parent_scope);
 306 void free_declaration_scope(struct declaration_scope *scope);
 307
 308 void declaration_ref(struct declaration *declaration);
 309 void declaration_unref(struct declaration *declaration);
 310
 311 /* Nameless types can be created by passing a NULL name */
 312
 313 struct type_integer *integer_type_new(const char *name,
 314                                       size_t len, int byte_order,
 315                                       int signedness, size_t alignment);
 316
 317 /*
 318  * mantissa_len is the length of the number of bytes represented by the mantissa
 319  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 320  */
 321 struct type_float *float_type_new(const char *name,
 322                                   size_t mantissa_len,
 323                                   size_t exp_len, int byte_order,
 324                                   size_t alignment);
 325
 326 /*
 327  * A GQuark can be translated to/from strings with g_quark_from_string() and
 328  * g_quark_to_string().
 329  */
 330
 331 /*
 332  * Returns a GArray of GQuark or NULL.
 333  * Caller must release the GArray with g_array_unref().
 334  */
 335 GArray *enum_uint_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 336
 337 /*
 338  * Returns a GArray of GQuark or NULL.
 339  * Caller must release the GArray with g_array_unref().
 340  */
 341 GArray *enum_int_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 342
 343 /*
 344  * Returns a GArray of struct enum_range or NULL.
 345  * Callers do _not_ own the returned GArray (and therefore _don't_ need to
 346  * release it).
 347  */
 348 GArray *enum_quark_to_range_set(const struct type_enum *enum_type, GQuark q);
 349 void enum_signed_insert(struct type_enum *enum_type,
 350                         int64_t start, int64_t end, GQuark q);
 351 void enum_unsigned_insert(struct type_enum *enum_type,
 352                           uint64_t start, uint64_t end, GQuark q);
 353 size_t enum_get_nr_enumerators(struct type_enum *enum_type);
 354
 355 struct type_enum *enum_type_new(const char *name,
 356                                 struct type_integer *integer_type);
 357
 358 struct type_struct *struct_type_new(const char *name);
 359 void struct_type_add_field(struct type_struct *struct_type,
 360                            const char *field_name, struct type *field_type);
 361 /*
 362  * Returns the index of a field within a structure.
 363  */
 364 unsigned long struct_type_lookup_field_index(struct type_struct *struct_type,
 365                                              GQuark field_name);
 366 /*
 367  * field returned only valid as long as the field structure is not appended to.
 368  */
 369 struct type_field *
 370 struct_type_get_field_from_index(struct type_struct *struct_type,
 371                                  unsigned long index);
 372 struct field *
 373 struct_get_field_from_index(struct declaration_struct *struct_declaration,
 374                             unsigned long index);
 375
 376 /*
 377  * The tag enumeration is validated to ensure that it contains only mappings
 378  * from numeric values to a single tag. Overlapping tag value ranges are
 379  * therefore forbidden.
 380  */
 381 struct type_variant *variant_type_new(const char *name);
 382 void variant_type_add_field(struct type_variant *variant_type,
 383                             const char *tag_name, struct type *tag_type);
 384 struct type_field *
 385 variant_type_get_field_from_tag(struct type_variant *variant_type, GQuark tag);
 386 /*
 387  * Returns 0 on success, -EPERM on error.
 388  */
 389 int variant_declaration_set_tag(struct declaration_variant *variant,
 390                                 struct declaration *enum_tag);
 391 /*
 392  * Returns the field selected by the current tag value.
 393  * field returned only valid as long as the variant structure is not appended
 394  * to.
 395  */
 396 struct field *
 397 variant_get_current_field(struct declaration_variant *variant);
 398
 399 /*
 400  * elem_type passed as parameter now belongs to the array. No need to free it
 401  * explicitly. "len" is the number of elements in the array.
 402  */
 403 struct type_array *array_type_new(const char *name,
 404                                   size_t len, struct type *elem_type);
 405
 406 /*
 407  * int_type and elem_type passed as parameter now belong to the sequence. No
 408  * need to free them explicitly.
 409  */
 410 struct type_sequence *sequence_type_new(const char *name,
 411                                         struct type_integer *len_type,
 412                                         struct type *elem_type);
 413
 414 #endif /* _BABELTRACE_TYPES_H */