types/struct.c

   1 /*
   2  * BabelTrace - Structure Type Converter
   3  *
   4  * Copyright (c) 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <babeltrace/compiler.h>
  22 #include <babeltrace/types.h>
  23
  24 void struct_copy(struct stream_pos *dest, const struct format *fdest,
  25                  struct stream_pos *src, const struct format *fsrc,
  26                  const struct type_class *type_class)
  27 {
  28         struct type_class_struct *struct_class =
  29                 container_of(type_class, struct type_class_struct, p);
  30         unsigned int i;
  31
  32         fsrc->struct_begin(src, struct_class);
  33         fdest->struct_begin(dest, struct_class);
  34
  35         for (i = 0; i < struct_class->fields->len; i++) {
  36                 struct field *field = &g_array_index(struct_class->fields,
  37                                                      struct field, i);
  38                 struct type_class *field_class = field->type_class;
  39
  40                 field_class->copy(dest, fdest, src, fsrc, type_class);
  41
  42         }
  43         fsrc->struct_end(src, struct_class);
  44         fdest->struct_end(dest, struct_class);
  45 }
  46
  47 void struct_type_free(struct type_class_struct *struct_class)
  48 {
  49         g_hash_table_destroy(struct_class->fields_by_name);
  50         g_array_free(struct_class->fields, true);
  51         g_free(struct_class);
  52 }
  53
  54 static void _struct_type_free(struct type_class *type_class)
  55 {
  56         struct type_class_struct *struct_class =
  57                 container_of(type_class, struct type_class_struct, p);
  58         struct_type_free(struct_class);
  59 }
  60
  61 struct type_class_struct *struct_type_new(const char *name)
  62 {
  63         struct type_class_struct *struct_class;
  64         int ret;
  65
  66         struct_class = g_new(struct type_class_struct, 1);
  67         type_class = &float_class->p;
  68
  69         struct_class->fields_by_name = g_hash_table_new(g_direct_hash,
  70                                                         g_direct_equal);
  71         struct_class->fields = g_array_sized_new(false, false,
  72                                                  sizeof(struct field),
  73                                                  DEFAULT_NR_STRUCT_FIELDS)
  74         type_class->name = g_quark_from_string(name);
  75         type_class->alignment = 1;
  76         type_class->copy = struct_copy;
  77         type_class->free = _struct_type_free;
  78
  79         if (type_class->name) {
  80                 ret = ctf_register_type(type_class);
  81                 if (ret)
  82                         goto error_register;
  83         }
  84         return struct_class;
  85
  86 error_register:
  87         g_free(struct_class);
  88         return NULL;
  89 }
  90
  91 void struct_type_add_field(struct type_class_struct *struct_class,
  92                            const char *field_name,
  93                            struct type_class *type_class)
  94 {
  95         struct field *field;
  96         unsigned long index;
  97
  98         g_array_set_size(struct_class->fields, struct_class->fields->len + 1);
  99         index = struct_class->fields->len - 1;  /* last field (new) */
 100         field = &g_array_index(struct_class->fields, struct field, index);
 101         field->name = g_quark_from_string(field_name);
 102         field->type_class = type_class;
 103         /* Keep index in hash rather than pointer, because array can relocate */
 104         g_hash_table_insert(struct_class->fields_by_name,
 105                             (gpointer) (unsigned long) field->name,
 106                             (gpointer) index);
 107         /*
 108          * Alignment of structure is the max alignment of types contained
 109          * therein.
 110          */
 111         struct_class->p.alignment = max(struct_class->p.alignment,
 112                                         type_class->alignment);
 113 }
 114
 115 unsigned long
 116 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 117                                GQuark field_name)
 118 {
 119         unsigned long index;
 120
 121         index = (unsigned long) g_hash_table_lookup(struct_class->fields_by_name,
 122                                                     field_name);
 123         return index;
 124 }
 125
 126 /*
 127  * field returned only valid as long as the field structure is not appended to.
 128  */
 129 struct field *
 130 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 131                                  unsigned long index)
 132 {
 133         return &g_array_index(struct_class->fields, struct field, index);
 134 }