src/lib/trace-ir/attributes.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2015 EfficiOS Inc. and Linux Foundation
   5  * Copyright (c) 2015 Philippe Proulx <pproulx@efficios.com>
   6  */
   7
   8 #define BT_LOG_TAG "LIB/ATTRS"
   9 #include "lib/logging.h"
  10
  11 #include "common/macros.h"
  12 #include <babeltrace2/value.h>
  13 #include "lib/assert-pre.h"
  14 #include "lib/object.h"
  15 #include <babeltrace2/value.h>
  16 #include "lib/value.h"
  17 #include "attributes.h"
  18 #include <inttypes.h>
  19 #include "compat/string.h"
  20 #include "common/assert.h"
  21
  22 #define BT_ATTR_NAME_INDEX              0
  23 #define BT_ATTR_VALUE_INDEX             1
  24
  25 BT_HIDDEN
  26 struct bt_value *bt_attributes_create(void)
  27 {
  28         struct bt_value *attr_obj;
  29
  30         /*
  31          * Attributes: array value object of array value objects, each one
  32          * containing two entries: a string value object (attributes
  33          * field name), and a value object (attributes field value).
  34          *
  35          * Example (JSON representation):
  36          *
  37          *     [
  38          *         ["hostname", "eeppdesk"],
  39          *         ["sysname", "Linux"],
  40          *         ["tracer_major", 2],
  41          *         ["tracer_minor", 5]
  42          *     ]
  43          */
  44         BT_LOGD_STR("Creating attributes object.");
  45         attr_obj = bt_value_array_create();
  46         if (!attr_obj) {
  47                 BT_LIB_LOGE_APPEND_CAUSE("Failed to create array value.");
  48         } else {
  49                 BT_LOGD("Created attributes object: addr=%p",
  50                         attr_obj);
  51         }
  52
  53         return attr_obj;
  54 }
  55
  56 BT_HIDDEN
  57 void bt_attributes_destroy(struct bt_value *attr_obj)
  58 {
  59         BT_LOGD("Destroying attributes object: addr=%p", attr_obj);
  60         BT_OBJECT_PUT_REF_AND_RESET(attr_obj);
  61 }
  62
  63 BT_HIDDEN
  64 uint64_t bt_attributes_get_count(const struct bt_value *attr_obj)
  65 {
  66         return bt_value_array_get_length(attr_obj);
  67 }
  68
  69 BT_HIDDEN
  70 const char *bt_attributes_get_field_name(const struct bt_value *attr_obj,
  71                 uint64_t index)
  72 {
  73         const struct bt_value *attr_field_obj = NULL;
  74         const struct bt_value *attr_field_name_obj = NULL;
  75
  76         BT_ASSERT_DBG(attr_obj);
  77         BT_ASSERT_DBG(index < bt_value_array_get_length(attr_obj));
  78         attr_field_obj = bt_value_array_borrow_element_by_index_const(
  79                 attr_obj, index);
  80
  81         attr_field_name_obj =
  82                 bt_value_array_borrow_element_by_index_const(attr_field_obj,
  83                         BT_ATTR_NAME_INDEX);
  84
  85         return bt_value_string_get(attr_field_name_obj);
  86 }
  87
  88 BT_HIDDEN
  89 struct bt_value *bt_attributes_borrow_field_value(
  90                 struct bt_value *attr_obj, uint64_t index)
  91 {
  92         struct bt_value *attr_field_obj = NULL;
  93
  94         BT_ASSERT_DBG(attr_obj);
  95         BT_ASSERT_DBG(index < bt_value_array_get_length(attr_obj));
  96
  97         attr_field_obj =
  98                 bt_value_array_borrow_element_by_index(attr_obj, index);
  99
 100         return bt_value_array_borrow_element_by_index( attr_field_obj,
 101                 BT_ATTR_VALUE_INDEX);
 102 }
 103
 104 static
 105 struct bt_value *bt_attributes_borrow_field_by_name(
 106                 struct bt_value *attr_obj, const char *name)
 107 {
 108         uint64_t i, attr_size;
 109         struct bt_value *value_obj = NULL;
 110         struct bt_value *attr_field_name_obj = NULL;
 111
 112         attr_size = bt_value_array_get_length(attr_obj);
 113         for (i = 0; i < attr_size; ++i) {
 114                 const char *field_name;
 115
 116                 value_obj = bt_value_array_borrow_element_by_index(
 117                         attr_obj, i);
 118
 119                 attr_field_name_obj =
 120                         bt_value_array_borrow_element_by_index(
 121                                 value_obj, BT_ATTR_NAME_INDEX);
 122
 123                 field_name = bt_value_string_get(attr_field_name_obj);
 124
 125                 if (strcmp(field_name, name) == 0) {
 126                         break;
 127                 }
 128
 129                 value_obj = NULL;
 130         }
 131
 132         return value_obj;
 133 }
 134
 135 BT_HIDDEN
 136 int bt_attributes_set_field_value(struct bt_value *attr_obj,
 137                 const char *name, struct bt_value *value_obj)
 138 {
 139         int ret = 0;
 140         struct bt_value *attr_field_obj = NULL;
 141
 142         BT_ASSERT(attr_obj);
 143         BT_ASSERT(name);
 144         BT_ASSERT(value_obj);
 145         attr_field_obj = bt_attributes_borrow_field_by_name(attr_obj, name);
 146         if (attr_field_obj) {
 147                 ret = bt_value_array_set_element_by_index(
 148                         attr_field_obj, BT_ATTR_VALUE_INDEX,
 149                         value_obj);
 150                 attr_field_obj = NULL;
 151                 goto end;
 152         }
 153
 154         attr_field_obj = bt_value_array_create();
 155         if (!attr_field_obj) {
 156                 BT_LIB_LOGE_APPEND_CAUSE("Failed to create empty array value.");
 157                 ret = -1;
 158                 goto end;
 159         }
 160
 161         ret = bt_value_array_append_string_element(attr_field_obj,
 162                 name);
 163         ret |= bt_value_array_append_element(attr_field_obj,
 164                 value_obj);
 165         if (ret) {
 166                 BT_LIB_LOGE_APPEND_CAUSE(
 167                         "Cannot append elements to array value: %!+v",
 168                         attr_field_obj);
 169                 goto end;
 170         }
 171
 172         ret = bt_value_array_append_element(attr_obj,
 173                 attr_field_obj);
 174         if (ret) {
 175                 BT_LIB_LOGE_APPEND_CAUSE(
 176                         "Cannot append element to array value: "
 177                         "%![array-value-]+v, %![element-value-]+v",
 178                         attr_obj, attr_field_obj);
 179         }
 180
 181 end:
 182         bt_object_put_ref(attr_field_obj);
 183         return ret;
 184 }
 185
 186 BT_HIDDEN
 187 struct bt_value *bt_attributes_borrow_field_value_by_name(
 188                 struct bt_value *attr_obj, const char *name)
 189 {
 190         struct bt_value *value_obj = NULL;
 191         struct bt_value *attr_field_obj = NULL;
 192
 193         BT_ASSERT_DBG(attr_obj);
 194         BT_ASSERT_DBG(name);
 195         attr_field_obj = bt_attributes_borrow_field_by_name(attr_obj, name);
 196         if (!attr_field_obj) {
 197                 BT_LOGD("Cannot find attributes object's field by name: "
 198                         "value-addr=%p, name=\"%s\"", attr_obj, name);
 199                 goto end;
 200         }
 201
 202         value_obj = bt_value_array_borrow_element_by_index(
 203                 attr_field_obj, BT_ATTR_VALUE_INDEX);
 204
 205 end:
 206         return value_obj;
 207 }
 208
 209 BT_HIDDEN
 210 int bt_attributes_freeze(const struct bt_value *attr_obj)
 211 {
 212         uint64_t i, count;
 213         int ret = 0;
 214
 215         BT_ASSERT(attr_obj);
 216         BT_LOGD("Freezing attributes object: value-addr=%p", attr_obj);
 217
 218         count = bt_value_array_get_length(attr_obj);
 219
 220         /*
 221          * We do not freeze the array value object itself here, since
 222          * internal stuff could need to modify/add attributes. Each
 223          * attribute is frozen one by one.
 224          */
 225         for (i = 0; i < count; ++i) {
 226                 struct bt_value *obj = NULL;
 227
 228                 obj = bt_attributes_borrow_field_value(
 229                         (void *) attr_obj, i);
 230                 if (!obj) {
 231                         BT_LIB_LOGE_APPEND_CAUSE(
 232                                 "Cannot get attributes object's field value by index: "
 233                                 "%![value-]+v, index=%" PRIu64,
 234                                 attr_obj, i);
 235                         ret = -1;
 236                         goto end;
 237                 }
 238
 239                 bt_value_freeze(obj);
 240         }
 241
 242 end:
 243         return ret;
 244 }