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