types/struct.c

   1 /*
   2  * struct.c
   3  *
   4  * BabelTrace - Structure Type Converter
   5  *
   6  * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
   7  *
   8  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26  * SOFTWARE.
  27  */
  28
  29 #include <babeltrace/compiler.h>
  30 #include <babeltrace/format.h>
  31 #include <babeltrace/types.h>
  32 #include <errno.h>
  33
  34 #ifndef max
  35 #define max(a, b)       ((a) < (b) ? (b) : (a))
  36 #endif
  37
  38 static
  39 struct bt_definition *_struct_definition_new(struct bt_declaration *declaration,
  40                                 struct definition_scope *parent_scope,
  41                                 GQuark field_name, int index,
  42                                 const char *root_name);
  43 static
  44 void _struct_definition_free(struct bt_definition *definition);
  45
  46 int bt_struct_rw(struct bt_stream_pos *ppos, struct bt_definition *definition)
  47 {
  48         struct definition_struct *struct_definition =
  49                 container_of(definition, struct definition_struct, p);
  50         unsigned long i;
  51         int ret;
  52
  53         for (i = 0; i < struct_definition->fields->len; i++) {
  54                 struct bt_definition *field =
  55                         g_ptr_array_index(struct_definition->fields, i);
  56                 ret = generic_rw(ppos, field);
  57                 if (ret)
  58                         return ret;
  59         }
  60         return 0;
  61 }
  62
  63 static
  64 void _struct_declaration_free(struct bt_declaration *declaration)
  65 {
  66         struct declaration_struct *struct_declaration =
  67                 container_of(declaration, struct declaration_struct, p);
  68         unsigned long i;
  69
  70         bt_free_declaration_scope(struct_declaration->scope);
  71         g_hash_table_destroy(struct_declaration->fields_by_name);
  72
  73         for (i = 0; i < struct_declaration->fields->len; i++) {
  74                 struct declaration_field *declaration_field =
  75                         &g_array_index(struct_declaration->fields,
  76                                        struct declaration_field, i);
  77                 bt_declaration_unref(declaration_field->declaration);
  78         }
  79         g_array_free(struct_declaration->fields, true);
  80         g_free(struct_declaration);
  81 }
  82
  83 struct declaration_struct *
  84         bt_struct_declaration_new(struct declaration_scope *parent_scope,
  85                                uint64_t min_align)
  86 {
  87         struct declaration_struct *struct_declaration;
  88         struct bt_declaration *declaration;
  89
  90         struct_declaration = g_new(struct declaration_struct, 1);
  91         declaration = &struct_declaration->p;
  92         struct_declaration->fields_by_name = g_hash_table_new(g_direct_hash,
  93                                                        g_direct_equal);
  94         struct_declaration->fields = g_array_sized_new(FALSE, TRUE,
  95                                                 sizeof(struct declaration_field),
  96                                                 DEFAULT_NR_STRUCT_FIELDS);
  97         struct_declaration->scope = bt_new_declaration_scope(parent_scope);
  98         declaration->id = CTF_TYPE_STRUCT;
  99         declaration->alignment = max(1, min_align);
 100         declaration->declaration_free = _struct_declaration_free;
 101         declaration->definition_new = _struct_definition_new;
 102         declaration->definition_free = _struct_definition_free;
 103         declaration->ref = 1;
 104         return struct_declaration;
 105 }
 106
 107 static
 108 struct bt_definition *
 109         _struct_definition_new(struct bt_declaration *declaration,
 110                                struct definition_scope *parent_scope,
 111                                GQuark field_name, int index,
 112                                const char *root_name)
 113 {
 114         struct declaration_struct *struct_declaration =
 115                 container_of(declaration, struct declaration_struct, p);
 116         struct definition_struct *_struct;
 117         int i;
 118         int ret;
 119
 120         _struct = g_new(struct definition_struct, 1);
 121         bt_declaration_ref(&struct_declaration->p);
 122         _struct->p.declaration = declaration;
 123         _struct->declaration = struct_declaration;
 124         _struct->p.ref = 1;
 125         /*
 126          * Use INT_MAX order to ensure that all fields of the parent
 127          * scope are seen as being prior to this scope.
 128          */
 129         _struct->p.index = root_name ? INT_MAX : index;
 130         _struct->p.name = field_name;
 131         _struct->p.path = bt_new_definition_path(parent_scope, field_name, root_name);
 132         _struct->p.scope = bt_new_definition_scope(parent_scope, field_name, root_name);
 133
 134         ret = bt_register_field_definition(field_name, &_struct->p,
 135                                         parent_scope);
 136         assert(!ret || ret == -EPERM);
 137
 138         _struct->fields = g_ptr_array_sized_new(DEFAULT_NR_STRUCT_FIELDS);
 139         g_ptr_array_set_size(_struct->fields, struct_declaration->fields->len);
 140         for (i = 0; i < struct_declaration->fields->len; i++) {
 141                 struct declaration_field *declaration_field =
 142                         &g_array_index(struct_declaration->fields,
 143                                        struct declaration_field, i);
 144                 struct bt_definition **field =
 145                         (struct bt_definition **) &g_ptr_array_index(_struct->fields, i);
 146
 147                 *field = declaration_field->declaration->definition_new(declaration_field->declaration,
 148                                                           _struct->p.scope,
 149                                                           declaration_field->name, i, NULL);
 150                 if (!*field)
 151                         goto error;
 152         }
 153         return &_struct->p;
 154
 155 error:
 156         for (i--; i >= 0; i--) {
 157                 struct bt_definition *field = g_ptr_array_index(_struct->fields, i);
 158                 bt_definition_unref(field);
 159         }
 160         bt_free_definition_scope(_struct->p.scope);
 161         bt_declaration_unref(&struct_declaration->p);
 162         g_free(_struct);
 163         return NULL;
 164 }
 165
 166 static
 167 void _struct_definition_free(struct bt_definition *definition)
 168 {
 169         struct definition_struct *_struct =
 170                 container_of(definition, struct definition_struct, p);
 171         unsigned long i;
 172
 173         assert(_struct->fields->len == _struct->declaration->fields->len);
 174         for (i = 0; i < _struct->fields->len; i++) {
 175                 struct bt_definition *field = g_ptr_array_index(_struct->fields, i);
 176                 bt_definition_unref(field);
 177         }
 178         bt_free_definition_scope(_struct->p.scope);
 179         bt_declaration_unref(_struct->p.declaration);
 180         g_ptr_array_free(_struct->fields, TRUE);
 181         g_free(_struct);
 182 }
 183
 184 void bt_struct_declaration_add_field(struct declaration_struct *struct_declaration,
 185                            const char *field_name,
 186                            struct bt_declaration *field_declaration)
 187 {
 188         struct declaration_field *field;
 189         unsigned long index;
 190
 191         g_array_set_size(struct_declaration->fields, struct_declaration->fields->len + 1);
 192         index = struct_declaration->fields->len - 1;    /* last field (new) */
 193         field = &g_array_index(struct_declaration->fields, struct declaration_field, index);
 194         field->name = g_quark_from_string(field_name);
 195         bt_declaration_ref(field_declaration);
 196         field->declaration = field_declaration;
 197         /* Keep index in hash rather than pointer, because array can relocate */
 198         g_hash_table_insert(struct_declaration->fields_by_name,
 199                             (gpointer) (unsigned long) field->name,
 200                             (gpointer) index);
 201         /*
 202          * Alignment of structure is the max alignment of declarations contained
 203          * therein.
 204          */
 205         struct_declaration->p.alignment = max(struct_declaration->p.alignment,
 206                                        field_declaration->alignment);
 207 }
 208
 209 /*
 210  * bt_struct_declaration_lookup_field_index - returns field index
 211  *
 212  * Returns the index of a field in a structure, or -1 if it does not
 213  * exist.
 214  */
 215 int bt_struct_declaration_lookup_field_index(struct declaration_struct *struct_declaration,
 216                                        GQuark field_name)
 217 {
 218         gpointer index;
 219         gboolean found;
 220
 221         found = g_hash_table_lookup_extended(struct_declaration->fields_by_name,
 222                                     (gconstpointer) (unsigned long) field_name,
 223                                     NULL, &index);
 224         if (!found)
 225                 return -1;
 226         return (int) (unsigned long) index;
 227 }
 228
 229 /*
 230  * field returned only valid as long as the field structure is not appended to.
 231  */
 232 struct declaration_field *
 233         bt_struct_declaration_get_field_from_index(struct declaration_struct *struct_declaration,
 234                                          int index)
 235 {
 236         if (index < 0)
 237                 return NULL;
 238         return &g_array_index(struct_declaration->fields, struct declaration_field, index);
 239 }
 240
 241 /*
 242  * field returned only valid as long as the field structure is not appended to.
 243  */
 244 struct bt_definition *
 245 bt_struct_definition_get_field_from_index(const struct definition_struct *_struct,
 246                                         int index)
 247 {
 248         if (index < 0)
 249                 return NULL;
 250         return g_ptr_array_index(_struct->fields, index);
 251 }
 252
 253 uint64_t bt_struct_declaration_len(const struct declaration_struct *struct_declaration)
 254 {
 255         return struct_declaration->fields->len;
 256 }