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