1 #ifndef _BABELTRACE_VALUES_H
2 #define _BABELTRACE_VALUES_H
5 * Babeltrace - Value objects
7 * Copyright (c) 2015-2016 EfficiOS Inc. and Linux Foundation
8 * Copyright (c) 2015-2016 Philippe Proulx <pproulx@efficios.com>
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:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
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
32 #include <babeltrace/ref.h>
39 @defgroup values Value objects
43 This is a set of <strong><em>value objects</em></strong>. With the
44 functions documented here, you can create and modify:
46 - \link bt_value_bool_create() Boolean value objects\endlink.
47 - \link bt_value_integer_create() Integer value objects\endlink.
48 - \link bt_value_float_create() Floating point number
49 value objects\endlink.
50 - \link bt_value_string_create() String value objects\endlink.
51 - \link bt_value_array_create() Array value objects\endlink,
52 containing zero or more value objects.
53 - \link bt_value_map_create() Map value objects\endlink, mapping
54 string keys to value objects.
56 As with any Babeltrace object, value objects have
57 <a href="https://en.wikipedia.org/wiki/Reference_counting">reference
58 counts</a>. When you \link bt_value_array_append() append a value object
59 to an array value object\endlink, or when you \link bt_value_map_insert()
60 insert a value object into a map value object\endlink, its reference
61 count is incremented, as well as when you get a value object back from
62 those objects. See \ref refs to learn more about the reference counting
63 management of Babeltrace objects.
65 Most functions of this API return a <em>status code</em>, one of the
66 values of #bt_value_status.
68 You can create a deep copy of any value object with bt_value_copy(). You
69 can compare two value objects with bt_value_compare().
71 You can \em freeze a value object with bt_value_freeze(). You can get
72 the raw value of a frozen value object, but you cannot modify it.
73 Reference counting still works on frozen value objects. You can copy
74 a frozen value object: the returned copy is not frozen. You can also
75 compare a frozen value object to another value object (frozen or not).
76 Freezing a value object is typically used to make it immutable after
77 it's built by its initial owner.
79 The following matrix shows some categorized value object functions
80 to use for each value object type:
84 <th>Function role →<br>
85 Value object type ↓
93 <td>Use the \ref bt_value_null variable
94 <td>bt_value_is_null()
100 <td>bt_value_bool_create()<br>
101 bt_value_bool_create_init()
102 <td>bt_value_is_bool()
103 <td>bt_value_bool_get()
104 <td>bt_value_bool_set()
108 <td>bt_value_integer_create()<br>
109 bt_value_integer_create_init()
110 <td>bt_value_is_integer()
111 <td>bt_value_integer_get()
112 <td>bt_value_integer_set()
115 <th>Floating point<br>number
116 <td>bt_value_float_create()<br>
117 bt_value_float_create_init()
118 <td>bt_value_is_float()
119 <td>bt_value_float_get()
120 <td>bt_value_float_set()
124 <td>bt_value_string_create()<br>
125 bt_value_string_create_init()
126 <td>bt_value_is_string()
127 <td>bt_value_string_get()
128 <td>bt_value_string_set()
132 <td>bt_value_array_create()
133 <td>bt_value_is_array()
134 <td>bt_value_array_get()
135 <td>bt_value_array_append()<br>
136 bt_value_array_append_bool()<br>
137 bt_value_array_append_integer()<br>
138 bt_value_array_append_float()<br>
139 bt_value_array_append_string()<br>
140 bt_value_array_append_empty_array()<br>
141 bt_value_array_append_empty_map()<br>
146 <td>bt_value_map_create()<br>
147 bt_value_map_extend()
148 <td>bt_value_is_map()
149 <td>bt_value_map_get()<br>
150 bt_value_map_foreach()
151 <td>bt_value_map_insert()<br>
152 bt_value_map_insert_bool()<br>
153 bt_value_map_insert_integer()<br>
154 bt_value_map_insert_float()<br>
155 bt_value_map_insert_string()<br>
156 bt_value_map_insert_empty_array()<br>
157 bt_value_map_insert_empty_map()
162 @brief Value object types and functions.
172 enum bt_value_status
{
173 /// Value object cannot be altered because it's frozen.
174 BT_VALUE_STATUS_FROZEN
= -4,
176 /// Operation cancelled.
177 BT_VALUE_STATUS_CANCELLED
= -3,
179 /* -22 for compatibility with -EINVAL */
180 /// Invalid arguments.
181 BT_VALUE_STATUS_INVAL
= -22,
184 BT_VALUE_STATUS_ERROR
= -1,
187 BT_VALUE_STATUS_OK
= 0,
192 @brief A value object.
198 @brief The null value object singleton.
200 You \em must use this variable when you need the null value object.
202 The null value object singleton has no reference count: there is only
203 one. You can compare any value object address to the null value object
204 singleton to check if it's the null value object, or otherwise with
207 You can pass \ref bt_value_null to bt_get() or bt_put(): it has
210 The null value object singleton is <em>always frozen</em> (see
211 bt_value_is_frozen()).
213 The functions of this API return this variable when the value object
214 is actually the null value object (of type #BT_VALUE_TYPE_NULL),
215 whereas \c NULL means an error of some sort.
217 extern struct bt_value
*bt_value_null
;
220 @name Type information
225 @brief Value object type.
228 /// Unknown value object, used as an error code.
229 BT_VALUE_TYPE_UNKNOWN
= -1,
231 /// Null value object.
232 BT_VALUE_TYPE_NULL
= 0,
234 /// Boolean value object (holds \c true or \c false).
235 BT_VALUE_TYPE_BOOL
= 1,
237 /// Integer value object (holds a signed 64-bit integer raw value).
238 BT_VALUE_TYPE_INTEGER
= 2,
240 /// Floating point number value object (holds a \c double raw value).
241 BT_VALUE_TYPE_FLOAT
= 3,
243 /// String value object.
244 BT_VALUE_TYPE_STRING
= 4,
246 /// Array value object.
247 BT_VALUE_TYPE_ARRAY
= 5,
249 /// Map value object.
250 BT_VALUE_TYPE_MAP
= 6,
254 @brief Returns the type of the value object \p object.
256 @param[in] object Value object of which to get the type.
257 @returns Type of value object \p object,
258 or #BT_VALUE_TYPE_UNKNOWN on error.
261 @postrefcountsame{object}
263 @sa #bt_value_type: Value object types.
264 @sa bt_value_is_null(): Returns whether or not a given value object
265 is the null value object.
266 @sa bt_value_is_bool(): Returns whether or not a given value object
267 is a boolean value object.
268 @sa bt_value_is_integer(): Returns whether or not a given value
269 object is an integer value object.
270 @sa bt_value_is_float(): Returns whether or not a given value object
271 is a floating point number value object.
272 @sa bt_value_is_string(): Returns whether or not a given value object
273 is a string value object.
274 @sa bt_value_is_array(): Returns whether or not a given value object
275 is an array value object.
276 @sa bt_value_is_map(): Returns whether or not a given value object
277 is a map value object.
279 extern enum bt_value_type
bt_value_get_type(const struct bt_value
*object
);
282 @brief Returns whether or not the value object \p object is the null
285 The only valid null value object is \ref bt_value_null.
287 An alternative to calling this function is to directly compare the value
288 object pointer to the \ref bt_value_null variable.
290 @param[in] object Value object to check.
291 @returns \c true if \p object is the null value object.
294 @postrefcountsame{object}
296 @sa bt_value_get_type(): Returns the type of a given value object.
299 bool bt_value_is_null(const struct bt_value
*object
)
301 return bt_value_get_type(object
) == BT_VALUE_TYPE_NULL
;
305 @brief Returns whether or not the value object \p object is a boolean
308 @param[in] object Value object to check.
309 @returns \c true if \p object is a boolean value object.
312 @postrefcountsame{object}
314 @sa bt_value_get_type(): Returns the type of a given value object.
317 bool bt_value_is_bool(const struct bt_value
*object
)
319 return bt_value_get_type(object
) == BT_VALUE_TYPE_BOOL
;
323 @brief Returns whether or not the value object \p object is an integer
326 @param[in] object Value object to check.
327 @returns \c true if \p object is an integer value object.
329 @sa bt_value_get_type(): Returns the type of a given value object.
332 bool bt_value_is_integer(const struct bt_value
*object
)
334 return bt_value_get_type(object
) == BT_VALUE_TYPE_INTEGER
;
338 @brief Returns whether or not the value object \p object is a floating
339 point number value object.
341 @param[in] object Value object to check.
342 @returns \c true if \p object is a floating point
346 @postrefcountsame{object}
348 @sa bt_value_get_type(): Returns the type of a given value object.
351 bool bt_value_is_float(const struct bt_value
*object
)
353 return bt_value_get_type(object
) == BT_VALUE_TYPE_FLOAT
;
357 @brief Returns whether or not the value object \p object is a string
360 @param[in] object Value object to check.
361 @returns \c true if \p object is a string value object.
364 @postrefcountsame{object}
366 @sa bt_value_get_type(): Returns the type of a given value object.
369 bool bt_value_is_string(const struct bt_value
*object
)
371 return bt_value_get_type(object
) == BT_VALUE_TYPE_STRING
;
375 @brief Returns whether or not the value object \p object is an array
378 @param[in] object Value object to check.
379 @returns \c true if \p object is an array value object.
382 @postrefcountsame{object}
384 @sa bt_value_get_type(): Returns the type of a given value object.
387 bool bt_value_is_array(const struct bt_value
*object
)
389 return bt_value_get_type(object
) == BT_VALUE_TYPE_ARRAY
;
393 @brief Returns whether or not the value object \p object is a map value
396 @param[in] object Value object to check.
397 @returns \c true if \p object is a map value object.
400 @postrefcountsame{object}
402 @sa bt_value_get_type(): Returns the type of a given value object.
405 bool bt_value_is_map(const struct bt_value
*object
)
407 return bt_value_get_type(object
) == BT_VALUE_TYPE_MAP
;
413 @name Common value object functions
418 @brief Recursively freezes the value object \p object.
420 You cannot modify a frozen value object: it is considered immutable.
421 Reference counting still works on a frozen value object, however: you
422 can pass a frozen value object to bt_get() and bt_put().
424 If \p object is an array value object or a map value object, this
425 function also freezes all its children recursively.
427 Freezing a value object is typically used to make it immutable after
428 it's built by its initial owner.
430 @param[in] object Value object to freeze.
431 @returns Status code. If \p object
432 is already frozen, however, #BT_VALUE_STATUS_OK
433 is returned anyway (that is, this function never
434 returns #BT_VALUE_STATUS_FROZEN).
437 @postrefcountsame{object}
438 @post <strong>On success</strong>, \p object and all its children
441 @sa bt_value_is_frozen(): Returns whether or not a value object is
444 extern enum bt_value_status
bt_value_freeze(struct bt_value
*object
);
447 @brief Returns whether or not the value object \p object is frozen.
449 @param[in] object Value object to check.
450 @returns \c true if \p object is frozen.
453 @postrefcountsame{object}
455 extern bool bt_value_is_frozen(const struct bt_value
*object
);
458 @brief Creates a \em deep copy of the value object \p object.
460 You can copy a frozen value object: the resulting copy is
463 @param[in] object Value object to copy.
464 @returns Deep copy of \p object on success, or \c NULL
468 @post <strong>On success, if the returned value object is not
469 \ref bt_value_null</strong>, its reference count is 1.
470 @postrefcountsame{object}
472 extern struct bt_value
*bt_value_copy(const struct bt_value
*object
);
475 @brief Recursively compares the value objects \p object_a and
476 \p object_b and returns \c true if they have the same
477 \em content (raw values).
479 @param[in] object_a Value object A to compare to \p object_b.
480 @param[in] object_b Value object B to compare to \p object_a.
481 @returns \c true if \p object_a and \p object_b have the
482 same \em content, or \c false if they differ
485 @postrefcountsame{object_a}
486 @postrefcountsame{object_b}
488 extern bool bt_value_compare(const struct bt_value
*object_a
,
489 const struct bt_value
*object_b
);
494 @name Boolean value object functions
499 @brief Creates a default boolean value object.
501 The created boolean value object's initial raw value is \c false.
503 @returns Created boolean value object on success, or \c NULL
506 @postsuccessrefcountret1
508 @sa bt_value_bool_create_init(): Creates an initialized boolean
511 extern struct bt_value
*bt_value_bool_create(void);
514 @brief Creates a boolean value object with its initial raw value set to
517 @param[in] val Initial raw value.
518 @returns Created boolean value object on success, or
521 @postsuccessrefcountret1
523 @sa bt_value_bool_create(): Creates a default boolean value object.
525 extern struct bt_value
*bt_value_bool_create_init(bool val
);
528 @brief Returns the boolean raw value of the boolean value object
531 @param[in] bool_obj Boolean value object of which to get the
533 @param[out] val Returned boolean raw value.
534 @returns Status code.
536 @prenotnull{bool_obj}
538 @pre \p bool_obj is a boolean value object.
539 @postrefcountsame{bool_obj}
541 @sa bt_value_bool_set(): Sets the raw value of a boolean value object.
543 extern enum bt_value_status
bt_value_bool_get(
544 const struct bt_value
*bool_obj
, bool *val
);
547 @brief Sets the boolean raw value of the boolean value object
548 \p bool_obj to \p val.
550 @param[in] bool_obj Boolean value object of which to set
552 @param[in] val New boolean raw value.
553 @returns Status code.
555 @prenotnull{bool_obj}
556 @pre \p bool_obj is a boolean value object.
558 @postrefcountsame{bool_obj}
560 @sa bt_value_bool_get(): Returns the raw value of a given boolean
563 extern enum bt_value_status
bt_value_bool_set(struct bt_value
*bool_obj
,
569 @name Integer value object functions
574 @brief Creates a default integer value object.
576 The created integer value object's initial raw value is 0.
578 @returns Created integer value object on success, or \c NULL
581 @postsuccessrefcountret1
583 @sa bt_value_integer_create_init(): Creates an initialized integer
586 extern struct bt_value
*bt_value_integer_create(void);
589 @brief Creates an integer value object with its initial raw value set to
592 @param[in] val Initial raw value.
593 @returns Created integer value object on success, or
596 @postsuccessrefcountret1
598 @sa bt_value_integer_create(): Creates a default integer
601 extern struct bt_value
*bt_value_integer_create_init(int64_t val
);
604 @brief Returns the integer raw value of the integer value object
607 @param[in] integer_obj Integer value object of which to get the
609 @param[out] val Returned integer raw value.
610 @returns Status code.
612 @prenotnull{integer_obj}
614 @pre \p integer_obj is an integer value object.
615 @postrefcountsame{integer_obj}
617 @sa bt_value_integer_set(): Sets the raw value of an integer value
620 extern enum bt_value_status
bt_value_integer_get(
621 const struct bt_value
*integer_obj
, int64_t *val
);
624 @brief Sets the integer raw value of the integer value object
625 \p integer_obj to \p val.
627 @param[in] integer_obj Integer value object of which to set
629 @param[in] val New integer raw value.
630 @returns Status code.
632 @prenotnull{integer_obj}
633 @pre \p integer_obj is an integer value object.
635 @postrefcountsame{integer_obj}
637 @sa bt_value_integer_get(): Returns the raw value of a given integer
640 extern enum bt_value_status
bt_value_integer_set(
641 struct bt_value
*integer_obj
, int64_t val
);
646 @name Floating point number value object functions
651 @brief Creates a default floating point number value object.
653 The created floating point number value object's initial raw value is 0.
655 @returns Created floating point number value object on success,
658 @postsuccessrefcountret1
660 @sa bt_value_float_create_init(): Creates an initialized floating
661 point number value object.
663 extern struct bt_value
*bt_value_float_create(void);
666 @brief Creates a floating point number value object with its initial raw
669 @param[in] val Initial raw value.
670 @returns Created floating point number value object on
671 success, or \c NULL on error.
673 @postsuccessrefcountret1
675 @sa bt_value_float_create(): Creates a default floating point number
678 extern struct bt_value
*bt_value_float_create_init(double val
);
681 @brief Returns the floating point number raw value of the floating point
682 number value object \p float_obj.
684 @param[in] float_obj Floating point number value object of which to
686 @param[out] val Returned floating point number raw value
687 @returns Status code.
689 @prenotnull{float_obj}
691 @pre \p float_obj is a floating point number value object.
692 @postrefcountsame{float_obj}
694 @sa bt_value_float_set(): Sets the raw value of a given floating
695 point number value object.
697 extern enum bt_value_status
bt_value_float_get(
698 const struct bt_value
*float_obj
, double *val
);
701 @brief Sets the floating point number raw value of the floating point
702 number value object \p float_obj to \p val.
704 @param[in] float_obj Floating point number value object of which to set
706 @param[in] val New floating point number raw value.
707 @returns Status code.
709 @prenotnull{float_obj}
710 @pre \p float_obj is a floating point number value object.
712 @postrefcountsame{float_obj}
714 @sa bt_value_float_get(): Returns the raw value of a floating point
717 extern enum bt_value_status
bt_value_float_set(
718 struct bt_value
*float_obj
, double val
);
723 @name String value object functions
728 @brief Creates a default string value object.
730 The string value object is initially empty.
732 @returns Created string value object on success, or \c NULL
735 @postsuccessrefcountret1
737 @sa bt_value_string_create_init(): Creates an initialized string
740 extern struct bt_value
*bt_value_string_create(void);
743 @brief Creates a string value object with its initial raw value set to
746 On success, \p val is copied.
748 @param[in] val Initial raw value (copied on success).
749 @returns Created string value object on success, or
753 @postsuccessrefcountret1
755 @sa bt_value_float_create(): Creates a default string value object.
757 extern struct bt_value
*bt_value_string_create_init(const char *val
);
760 @brief Returns the string raw value of the string value object
763 The returned string is placed in \p *val. It is valid as long as this
764 value object exists and is \em not modified. The ownership of the
765 returned string is \em not transferred to the caller.
767 @param[in] string_obj String value object of which to get the
769 @param[out] val Returned string raw value.
770 @returns Status code.
772 @prenotnull{string_obj}
774 @pre \p string_obj is a string value object.
775 @postrefcountsame{string_obj}
777 @sa bt_value_string_set(): Sets the raw value of a string
780 extern enum bt_value_status
bt_value_string_get(
781 const struct bt_value
*string_obj
, const char **val
);
784 @brief Sets the string raw value of the string value object
785 \p string_obj to \p val.
787 On success, \p val is copied.
789 @param[in] string_obj String value object of which to set
791 @param[in] val New string raw value (copied on success).
792 @returns Status code.
794 @prenotnull{string_obj}
796 @pre \p string_obj is a string value object.
798 @postrefcountsame{string_obj}
800 @sa bt_value_string_get(): Returns the raw value of a given string
803 extern enum bt_value_status
bt_value_string_set(struct bt_value
*string_obj
,
811 * @name Array value object functions
816 @brief Creates an empty array value object.
818 @returns Created array value object on success, or \c NULL
821 @postsuccessrefcountret1
823 extern struct bt_value
*bt_value_array_create(void);
826 @brief Returns the size of the array value object \p array_obj, that is,
827 the number of value objects contained in \p array_obj.
829 @param[in] array_obj Array value object of which to get the size.
830 @returns Number of value objects contained in
831 \p array_obj if the return value is 0 (empty)
832 or a positive value, or one of
833 #bt_value_status negative values otherwise.
835 @prenotnull{array_obj}
836 @pre \p array_obj is an array value object.
837 @postrefcountsame{array_obj}
839 @sa bt_value_array_is_empty(): Checks whether or not a given array
840 value object is empty.
842 extern int bt_value_array_size(const struct bt_value
*array_obj
);
845 @brief Checks whether or not the array value object \p array_obj
848 @param[in] array_obj Array value object to check.
849 @returns \c true if \p array_obj is empty.
851 @prenotnull{array_obj}
852 @pre \p array_obj is an array value object.
853 @postrefcountsame{array_obj}
855 @sa bt_value_array_size(): Returns the size of a given array value
858 extern bool bt_value_array_is_empty(const struct bt_value
*array_obj
);
861 @brief Returns the value object contained in the array value object
862 \p array_obj at the index \p index.
864 @param[in] array_obj Array value object of which to get an element.
865 @param[in] index Index of value object to get.
866 @returns Value object at index \p index on
867 success, or \c NULL on error.
869 @prenotnull{array_obj}
870 @pre \p array_obj is an array value object.
871 @pre \p index is lesser than the size of \p array_obj (see
872 bt_value_array_size()).
873 @post <strong>On success, if the returned value object is not
874 \ref bt_value_null</strong>, its reference count is incremented.
875 @postrefcountsame{array_obj}
877 extern struct bt_value
*bt_value_array_get(const struct bt_value
*array_obj
,
881 @brief Appends the value object \p element_obj to the array value
884 @param[in] array_obj Array value object in which to append
886 @param[in] element_obj Value object to append.
887 @returns Status code.
889 @prenotnull{array_obj}
890 @prenotnull{element_obj}
891 @pre \p array_obj is an array value object.
893 @post <strong>On success, if \p element_obj is not
894 \ref bt_value_null</strong>, its reference count is incremented.
895 @postrefcountsame{array_obj}
897 @sa bt_value_array_append_bool(): Appends a boolean raw value to a
898 given array value object.
899 @sa bt_value_array_append_integer(): Appends an integer raw value
900 to a given array value object.
901 @sa bt_value_array_append_float(): Appends a floating point number
902 raw value to a given array value object.
903 @sa bt_value_array_append_string(): Appends a string raw value to a
904 given array value object.
905 @sa bt_value_array_append_empty_array(): Appends an empty array value
906 object to a given array value object.
907 @sa bt_value_array_append_empty_map(): Appends an empty map value
908 object to a given array value object.
910 extern enum bt_value_status
bt_value_array_append(struct bt_value
*array_obj
,
911 struct bt_value
*element_obj
);
914 @brief Appends the boolean raw value \p val to the array value object
917 This is a convenience function which creates the underlying boolean
918 value object before appending it.
920 @param[in] array_obj Array value object in which to append \p val.
921 @param[in] val Boolean raw value to append to \p array_obj.
922 @returns Status code.
924 @prenotnull{array_obj}
925 @pre \p array_obj is an array value object.
927 @postrefcountsame{array_obj}
929 @sa bt_value_array_append(): Appends a value object to a given
932 extern enum bt_value_status
bt_value_array_append_bool(
933 struct bt_value
*array_obj
, bool val
);
936 @brief Appends the integer raw value \p val to the array value object
939 This is a convenience function which creates the underlying integer
940 value object before appending it.
942 @param[in] array_obj Array value object in which to append \p val.
943 @param[in] val Integer raw value to append to \p array_obj.
944 @returns Status code.
946 @prenotnull{array_obj}
947 @pre \p array_obj is an array value object.
949 @postrefcountsame{array_obj}
951 @sa bt_value_array_append(): Appends a value object to a given
954 extern enum bt_value_status
bt_value_array_append_integer(
955 struct bt_value
*array_obj
, int64_t val
);
958 @brief Appends the floating point number raw value \p val to the array
959 value object \p array_obj.
961 This is a convenience function which creates the underlying floating
962 point number value object before appending it.
964 @param[in] array_obj Array value object in which to append \p val.
965 @param[in] val Floating point number raw value to append
967 @returns Status code.
969 @prenotnull{array_obj}
970 @pre \p array_obj is an array value object.
972 @postrefcountsame{array_obj}
974 @sa bt_value_array_append(): Appends a value object to a given
977 extern enum bt_value_status
bt_value_array_append_float(
978 struct bt_value
*array_obj
, double val
);
981 @brief Appends the string raw value \p val to the array value object
984 This is a convenience function which creates the underlying string value
985 object before appending it.
987 On success, \p val is copied.
989 @param[in] array_obj Array value object in which to append \p val.
990 @param[in] val String raw value to append to \p array_obj
992 @returns Status code.
994 @prenotnull{array_obj}
995 @pre \p array_obj is an array value object.
998 @postrefcountsame{array_obj}
1000 @sa bt_value_array_append(): Appends a value object to a given
1003 extern enum bt_value_status
bt_value_array_append_string(
1004 struct bt_value
*array_obj
, const char *val
);
1007 @brief Appends an empty array value object to the array value object
1010 This is a convenience function which creates the underlying array value
1011 object before appending it.
1013 @param[in] array_obj Array value object in which to append an
1014 empty array value object
1015 @returns Status code.
1017 @prenotnull{array_obj}
1018 @pre \p array_obj is an array value object.
1020 @postrefcountsame{array_obj}
1022 @sa bt_value_array_append(): Appends a value object to a given
1025 extern enum bt_value_status
bt_value_array_append_empty_array(
1026 struct bt_value
*array_obj
);
1029 @brief Appends an empty map value object to the array value object
1032 This is a convenience function which creates the underlying map value
1033 object before appending it.
1035 @param[in] array_obj Array value object in which to append an empty
1037 @returns Status code.
1039 @prenotnull{array_obj}
1040 @pre \p array_obj is an array value object.
1042 @postrefcountsame{array_obj}
1044 @sa bt_value_array_append(): Appends a value object to a given
1047 extern enum bt_value_status
bt_value_array_append_empty_map(
1048 struct bt_value
*array_obj
);
1051 @brief Replaces the value object contained in the array value object
1052 \p array_obj at the index \p index by \p element_obj.
1054 @param[in] array_obj Array value object in which to replace
1056 @param[in] index Index of value object to replace in
1058 @param[in] element_obj New value object at position \p index of
1060 @returns Status code.
1062 @prenotnull{array_obj}
1063 @prenotnull{element_obj}
1064 @pre \p array_obj is an array value object.
1065 @pre \p index is lesser than the size of \p array_obj (see
1066 bt_value_array_size()).
1068 @post <strong>On success, if the replaced value object is not
1069 \ref bt_value_null</strong>, its reference count is decremented.
1070 @post <strong>On success, if \p element_obj is not
1071 \ref bt_value_null</strong>, its reference count is incremented.
1072 @postrefcountsame{array_obj}
1074 extern enum bt_value_status
bt_value_array_set(struct bt_value
*array_obj
,
1075 size_t index
, struct bt_value
*element_obj
);
1080 @name Map value object functions
1085 @brief Creates an empty map value object.
1087 @returns Created map value object on success, or \c NULL on error.
1089 @postsuccessrefcountret1
1091 extern struct bt_value
*bt_value_map_create(void);
1094 @brief Returns the size of the map value object \p map_obj, that is, the
1095 number of entries contained in \p map_obj.
1097 @param[in] map_obj Map value object of which to get the size.
1098 @returns Number of entries contained in \p map_obj if the
1099 return value is 0 (empty) or a positive value,
1100 or one of #bt_value_status negative values
1103 @prenotnull{map_obj}
1104 @pre \p map_obj is a map value object.
1105 @postrefcountsame{map_obj}
1107 @sa bt_value_map_is_empty(): Checks whether or not a given map value
1110 extern int bt_value_map_size(const struct bt_value
*map_obj
);
1113 @brief Checks whether or not the map value object \p map_obj is empty.
1115 @param[in] map_obj Map value object to check.
1116 @returns \c true if \p map_obj is empty.
1118 @prenotnull{map_obj}
1119 @pre \p map_obj is a map value object.
1120 @postrefcountsame{map_obj}
1122 @sa bt_value_map_size(): Returns the size of a given map value object.
1124 extern bool bt_value_map_is_empty(const struct bt_value
*map_obj
);
1127 @brief Returns the value object associated with the key \p key within
1128 the map value object \p map_obj.
1130 @param[in] map_obj Map value object of which to get an entry.
1131 @param[in] key Key of the value object to get.
1132 @returns Value object associated with the key \p key
1133 on success, or \c NULL on error.
1135 @prenotnull{map_obj}
1137 @pre \p map_obj is a map value object.
1138 @postrefcountsame{map_obj}
1139 @post <strong>On success, if the returned value object is not
1140 \ref bt_value_null</strong>, its reference count is incremented.
1142 extern struct bt_value
*bt_value_map_get(const struct bt_value
*map_obj
,
1146 @brief User function type to use with bt_value_map_foreach().
1148 \p object is a <em>weak reference</em>: you \em must pass it to bt_get()
1149 if you need your own reference.
1151 This function \em must return \c true to continue the map value object
1152 traversal, or \c false to break it.
1154 @param[in] key Key of map entry.
1155 @param[in] object Value object of map entry (weak reference).
1156 @param[in] data User data.
1157 @returns \c true to continue the loop, or \c false to break it.
1161 @post The reference count of \p object is not lesser than what it is
1162 when the function is called.
1164 typedef bool (* bt_value_map_foreach_cb
)(const char *key
,
1165 struct bt_value
*object
, void *data
);
1168 @brief Calls a provided user function \p cb for each value object of the
1169 map value object \p map_obj.
1171 The value object passed to the user function is a <b>weak reference</b>:
1172 you \em must pass it to bt_get() if you need your own reference.
1174 The key passed to the user function is only valid in the scope of
1175 this user function call.
1177 The user function \em must return \c true to continue the traversal of
1178 \p map_obj, or \c false to break it.
1180 @param[in] map_obj Map value object on which to iterate.
1181 @param[in] cb User function to call back.
1182 @param[in] data User data passed to the user function.
1183 @returns Status code. More
1184 specifically, #BT_VALUE_STATUS_CANCELLED is
1185 returned if the loop was cancelled by the user
1188 @prenotnull{map_obj}
1190 @pre \p map_obj is a map value object.
1191 @postrefcountsame{map_obj}
1193 extern enum bt_value_status
bt_value_map_foreach(
1194 const struct bt_value
*map_obj
, bt_value_map_foreach_cb cb
,
1198 @brief Returns whether or not the map value object \p map_obj contains
1199 an entry mapped to the key \p key.
1201 @param[in] map_obj Map value object to check.
1202 @param[in] key Key to check.
1203 @returns \c true if \p map_obj has an entry mapped to the
1204 key \p key, or \c false if it does not or
1207 @prenotnull{map_obj}
1209 @pre \p map_obj is a map value object.
1210 @postrefcountsame{map_obj}
1212 extern bool bt_value_map_has_key(const struct bt_value
*map_obj
,
1216 @brief Inserts the value object \p element_obj mapped to the key
1217 \p key into the map value object \p map_obj.
1219 If a value object is already mapped to \p key in \p map_obj, the
1220 associated value object is first put, and then replaced by
1223 On success, \p key is copied.
1225 @param[in] map_obj Map value object in which to insert
1227 @param[in] key Key (copied on success) to which the
1228 value object to insert is mapped.
1229 @param[in] element_obj Value object to insert, mapped to the
1231 @returns Status code.
1233 @prenotnull{map_obj}
1235 @prenotnull{element_obj}
1236 @pre \p map_obj is a map value object.
1238 @post <strong>On success, if \p element_obj is not
1239 \ref bt_value_null</strong>, its reference count is incremented.
1240 @postrefcountsame{map_obj}
1242 @sa bt_value_map_insert_bool(): Inserts a boolean raw value into a
1243 given map value object.
1244 @sa bt_value_map_insert_integer(): Inserts an integer raw value into
1245 a given map value object.
1246 @sa bt_value_map_insert_float(): Inserts a floating point number raw
1247 value into a given map value object.
1248 @sa bt_value_map_insert_string(): Inserts a string raw value into a
1249 given map value object.
1250 @sa bt_value_map_insert_empty_array(): Inserts an empty array value
1251 object into a given map value object.
1252 @sa bt_value_map_insert_empty_map(): Inserts an empty map value
1253 object into a given map value object.
1255 extern enum bt_value_status
bt_value_map_insert(
1256 struct bt_value
*map_obj
, const char *key
,
1257 struct bt_value
*element_obj
);
1260 @brief Inserts the boolean raw value \p val mapped to the key \p key
1261 into the map value object \p map_obj.
1263 This is a convenience function which creates the underlying boolean
1264 value object before inserting it.
1266 On success, \p key is copied.
1268 @param[in] map_obj Map value object in which to insert \p val.
1269 @param[in] key Key (copied on success) to which the boolean
1270 value object to insert is mapped.
1271 @param[in] val Boolean raw value to insert, mapped to
1273 @returns Status code.
1275 @prenotnull{map_obj}
1277 @pre \p map_obj is a map value object.
1279 @postrefcountsame{map_obj}
1281 @sa bt_value_map_insert(): Inserts a value object into a given map
1284 extern enum bt_value_status
bt_value_map_insert_bool(
1285 struct bt_value
*map_obj
, const char *key
, bool val
);
1288 @brief Inserts the integer raw value \p val mapped to the key \p key
1289 into the map value object \p map_obj.
1291 This is a convenience function which creates the underlying integer
1292 value object before inserting it.
1294 On success, \p key is copied.
1296 @param[in] map_obj Map value object in which to insert \p val.
1297 @param[in] key Key (copied on success) to which the integer
1298 value object to insert is mapped.
1299 @param[in] val Integer raw value to insert, mapped to
1301 @returns Status code.
1303 @prenotnull{map_obj}
1305 @pre \p map_obj is a map value object.
1307 @postrefcountsame{map_obj}
1309 @sa bt_value_map_insert(): Inserts a value object into a given map
1312 extern enum bt_value_status
bt_value_map_insert_integer(
1313 struct bt_value
*map_obj
, const char *key
, int64_t val
);
1316 @brief Inserts the floating point number raw value \p val mapped to
1317 the key \p key into the map value object \p map_obj.
1319 This is a convenience function which creates the underlying floating
1320 point number value object before inserting it.
1322 On success, \p key is copied.
1324 @param[in] map_obj Map value object in which to insert \p val.
1325 @param[in] key Key (copied on success) to which the floating
1326 point number value object to insert is mapped.
1327 @param[in] val Floating point number raw value to insert,
1328 mapped to the key \p key.
1329 @returns Status code.
1331 @prenotnull{map_obj}
1333 @pre \p map_obj is a map value object.
1335 @postrefcountsame{map_obj}
1337 @sa bt_value_map_insert(): Inserts a value object into a given map
1340 extern enum bt_value_status
bt_value_map_insert_float(
1341 struct bt_value
*map_obj
, const char *key
, double val
);
1344 @brief Inserts the string raw value \p val mapped to the key \p key
1345 into the map value object \p map_obj.
1347 This is a convenience function which creates the underlying string value
1348 object before inserting it.
1350 On success, \p val and \p key are copied.
1352 @param[in] map_obj Map value object in which to insert \p val.
1353 @param[in] key Key (copied on success) to which the string
1354 value object to insert is mapped.
1355 @param[in] val String raw value to insert (copied on success),
1356 mapped to the key \p key.
1357 @returns Status code.
1359 @prenotnull{map_obj}
1362 @pre \p map_obj is a map value object.
1364 @postrefcountsame{map_obj}
1366 @sa bt_value_map_insert(): Inserts a value object into a given map
1369 extern enum bt_value_status
bt_value_map_insert_string(
1370 struct bt_value
*map_obj
, const char *key
, const char *val
);
1373 @brief Inserts an empty array value object mapped to the key \p key
1374 into the map value object \p map_obj.
1376 This is a convenience function which creates the underlying array value
1377 object before inserting it.
1379 On success, \p key is copied.
1381 @param[in] map_obj Map value object in which to insert an empty
1383 @param[in] key Key (copied on success) to which the empty array
1384 value object to insert is mapped.
1385 @returns Status code.
1387 @prenotnull{map_obj}
1389 @pre \p map_obj is a map value object.
1391 @postrefcountsame{map_obj}
1393 @sa bt_value_map_insert(): Inserts a value object into a given map
1396 extern enum bt_value_status
bt_value_map_insert_empty_array(
1397 struct bt_value
*map_obj
, const char *key
);
1400 @brief Inserts an empty map value object mapped to the key \p key into
1401 the map value object \p map_obj.
1403 This is a convenience function which creates the underlying map value
1404 object before inserting it.
1406 On success, \p key is copied.
1408 @param[in] map_obj Map value object in which to insert an empty
1410 @param[in] key Key (copied on success) to which the empty map
1411 value object to insert is mapped.
1412 @returns Status code.
1414 @prenotnull{map_obj}
1416 @pre \p map_obj is a map value object.
1418 @postrefcountsame{map_obj}
1420 @sa bt_value_map_insert(): Inserts a value object into a given map
1423 extern enum bt_value_status
bt_value_map_insert_empty_map(
1424 struct bt_value
*map_obj
, const char *key
);
1427 @brief Creates a copy of the base map value object \p base_map_obj
1428 superficially extended with the entries of the extension map
1429 value object \p extension_map_obj.
1431 This function creates a superficial extension of \p base_map_obj with
1432 \p extension_map_obj by adding new entries to it and replacing the
1433 ones that share the keys in the extension object. The extension is
1434 \em superficial because it does not merge internal array and map
1437 For example, consider the following \p base_map_obj (JSON representation):
1444 "return": [5, 6, null]
1448 and the following \p extension_map_obj (JSON representation):
1458 The extended object is (JSON representation):
1470 @param[in] base_map_obj Base map value object with initial
1472 @param[in] extension_map_obj Extension map value object containing
1473 the entries to add to or replace in
1475 @returns Created extended map value object, or
1478 @prenotnull{base_map_obj}
1479 @prenotnull{extension_map_obj}
1480 @pre \p base_map_obj is a map value object.
1481 @pre \p extension_map_obj is a map value object.
1482 @postrefcountsame{base_map_obj}
1483 @postrefcountsame{extension_map_obj}
1484 @postsuccessrefcountret1
1486 extern struct bt_value
*bt_value_map_extend(struct bt_value
*base_map_obj
,
1487 struct bt_value
*extension_map_obj
);
1497 #endif /* _BABELTRACE_VALUES_H */