src/common/mi-lttng.h

   1 /*
   2  * Copyright (C) 2014 - Jonathan Rajotte <jonathan.r.julien@gmail.com>
   3  *                    - Olivier Cotte <olivier.cotte@polymtl.ca>
   4  * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifndef _MI_LTTNG_H
  21 #define _MI_LTTNG_H
  22
  23 #include <stdint.h>
  24
  25 #include <common/error.h>
  26 #include <common/macros.h>
  27 #include <common/config/session-config.h>
  28 #include <lttng/lttng.h>
  29
  30 /* Don't want to reference snapshot-internal.h here */
  31 struct lttng_snapshot_output;
  32
  33 /* Instance of a machine interface writer. */
  34 struct mi_writer {
  35         struct config_writer *writer;
  36         enum lttng_mi_output_type type;
  37 };
  38
  39 /*
  40  * Version information for the machine interface.
  41  */
  42 struct mi_lttng_version {
  43         char version[LTTNG_NAME_MAX]; /* Version number of package */
  44         uint32_t version_major; /* LTTng-Tools major version number */
  45         uint32_t version_minor; /* LTTng-Tools minor version number */
  46         uint32_t version_patchlevel; /* LTTng-Tools patchlevel version number */
  47         char version_commit[LTTNG_NAME_MAX]; /* Commit hash of the current version */
  48         char version_name[LTTNG_NAME_MAX];
  49         char package_url[LTTNG_NAME_MAX]; /* Define to the home page for this package. */
  50 };
  51
  52 /* Strings related to command */
  53 extern const char * const mi_lttng_element_command;
  54 extern const char * const mi_lttng_element_command_action;
  55 extern const char * const mi_lttng_element_command_add_context;
  56 extern const char * const mi_lttng_element_command_calibrate;
  57 extern const char * const mi_lttng_element_command_create;
  58 extern const char * const mi_lttng_element_command_destroy;
  59 extern const char * const mi_lttng_element_command_disable_channel;
  60 extern const char * const mi_lttng_element_command_disable_event;
  61 extern const char * const mi_lttng_element_command_enable_channels;
  62 extern const char * const mi_lttng_element_command_enable_event;
  63 extern const char * const mi_lttng_element_command_list;
  64 extern const char * const mi_lttng_element_command_load;
  65 extern const char * const mi_lttng_element_command_metadata;
  66 extern const char * const mi_lttng_element_command_metadata_action;
  67 extern const char * const mi_lttng_element_command_name;
  68 extern const char * const mi_lttng_element_command_output;
  69 extern const char * const mi_lttng_element_command_save;
  70 extern const char * const mi_lttng_element_command_set_session;
  71 extern const char * const mi_lttng_element_command_snapshot;
  72 extern const char * const mi_lttng_element_command_snapshot_add;
  73 extern const char * const mi_lttng_element_command_snapshot_del;
  74 extern const char * const mi_lttng_element_command_snapshot_list;
  75 extern const char * const mi_lttng_element_command_snapshot_record;
  76 extern const char * const mi_lttng_element_command_start;
  77 extern const char * const mi_lttng_element_command_stop;
  78 extern const char * const mi_lttng_element_command_success;
  79 extern const char * const mi_lttng_element_command_track;
  80 extern const char * const mi_lttng_element_command_untrack;
  81 extern const char * const mi_lttng_element_command_version;
  82
  83 /* Strings related to version command */
  84 extern const char * const mi_lttng_element_version;
  85 extern const char * const mi_lttng_element_version_commit;
  86 extern const char * const mi_lttng_element_version_description;
  87 extern const char * const mi_lttng_element_version_license;
  88 extern const char * const mi_lttng_element_version_major;
  89 extern const char * const mi_lttng_element_version_minor;
  90 extern const char * const mi_lttng_element_version_patch_level;
  91 extern const char * const mi_lttng_element_version_str;
  92 extern const char * const mi_lttng_element_version_web;
  93
  94 /* String related to a lttng_event_field */
  95 extern const char * const mi_lttng_element_event_field;
  96 extern const char * const mi_lttng_element_event_fields;
  97
  98 /* String related to lttng_event_perf_counter_ctx */
  99 extern const char * const mi_lttng_element_perf_counter_context;
 100
 101 /* Strings related to pid */
 102 extern const char * const mi_lttng_element_pid_id;
 103
 104 /* Strings related to save command */
 105 extern const char * const mi_lttng_element_save;
 106
 107 /* Strings related to load command */
 108 extern const char * const mi_lttng_element_load;
 109
 110 /* General element of mi_lttng */
 111 extern const char * const mi_lttng_element_empty;
 112 extern const char * const mi_lttng_element_id;
 113 extern const char * const mi_lttng_element_nowrite;
 114 extern const char * const mi_lttng_element_success;
 115 extern const char * const mi_lttng_element_type_enum;
 116 extern const char * const mi_lttng_element_type_float;
 117 extern const char * const mi_lttng_element_type_integer;
 118 extern const char * const mi_lttng_element_type_other;
 119 extern const char * const mi_lttng_element_type_string;
 120
 121 /* String related to loglevel */
 122 extern const char * const mi_lttng_loglevel_str_alert;
 123 extern const char * const mi_lttng_loglevel_str_crit;
 124 extern const char * const mi_lttng_loglevel_str_debug;
 125 extern const char * const mi_lttng_loglevel_str_debug_function;
 126 extern const char * const mi_lttng_loglevel_str_debug_line;
 127 extern const char * const mi_lttng_loglevel_str_debug_module;
 128 extern const char * const mi_lttng_loglevel_str_debug_process;
 129 extern const char * const mi_lttng_loglevel_str_debug_program;
 130 extern const char * const mi_lttng_loglevel_str_debug_system;
 131 extern const char * const mi_lttng_loglevel_str_debug_unit;
 132 extern const char * const mi_lttng_loglevel_str_emerg;
 133 extern const char * const mi_lttng_loglevel_str_err;
 134 extern const char * const mi_lttng_loglevel_str_info;
 135 extern const char * const mi_lttng_loglevel_str_notice;
 136 extern const char * const mi_lttng_loglevel_str_unknown;
 137 extern const char * const mi_lttng_loglevel_str_warning;
 138
 139 /* String related to loglevel JUL */
 140 extern const char * const mi_lttng_loglevel_str_jul_all;
 141 extern const char * const mi_lttng_loglevel_str_jul_config;
 142 extern const char * const mi_lttng_loglevel_str_jul_fine;
 143 extern const char * const mi_lttng_loglevel_str_jul_finer;
 144 extern const char * const mi_lttng_loglevel_str_jul_finest;
 145 extern const char * const mi_lttng_loglevel_str_jul_info;
 146 extern const char * const mi_lttng_loglevel_str_jul_off;
 147 extern const char * const mi_lttng_loglevel_str_jul_severe;
 148 extern const char * const mi_lttng_loglevel_str_jul_warning;
 149
 150 /* String related to loglevel Log4j */
 151 extern const char * const mi_lttng_loglevel_str_log4j_off;
 152 extern const char * const mi_lttng_loglevel_str_log4j_fatal;
 153 extern const char * const mi_lttng_loglevel_str_log4j_error;
 154 extern const char * const mi_lttng_loglevel_str_log4j_warn;
 155 extern const char * const mi_lttng_loglevel_str_log4j_info;
 156 extern const char * const mi_lttng_loglevel_str_log4j_debug;
 157 extern const char * const mi_lttng_loglevel_str_log4j_trace;
 158 extern const char * const mi_lttng_loglevel_str_log4j_all;
 159
 160 /* String related to loglevel Python */
 161 extern const char * const mi_lttng_loglevel_str_python_critical;
 162 extern const char * const mi_lttng_loglevel_str_python_error;
 163 extern const char * const mi_lttng_loglevel_str_python_warning;
 164 extern const char * const mi_lttng_loglevel_str_python_info;
 165 extern const char * const mi_lttng_loglevel_str_python_debug;
 166 extern const char * const mi_lttng_loglevel_str_python_notset;
 167
 168 /* String related to loglevel type */
 169 extern const char * const mi_lttng_loglevel_type_all;
 170 extern const char * const mi_lttng_loglevel_type_range;
 171 extern const char * const mi_lttng_loglevel_type_single;
 172 extern const char * const mi_lttng_loglevel_type_unknown;
 173
 174 /* Sting related to lttng_calibrate */
 175 extern const char * const mi_lttng_element_calibrate;
 176 extern const char * const mi_lttng_element_calibrate_function;
 177
 178 /* String related to a lttng_snapshot */
 179 extern const char * const mi_lttng_element_snapshot_ctrl_url;
 180 extern const char * const mi_lttng_element_snapshot_data_url;
 181 extern const char * const mi_lttng_element_snapshot_max_size;
 182 extern const char * const mi_lttng_element_snapshot_n_ptr;
 183 extern const char * const mi_lttng_element_snapshot_session_name;
 184 extern const char * const mi_lttng_element_snapshots;
 185
 186 /* String related to track/untrack command */
 187 const char * const mi_lttng_element_track_untrack_all_wildcard;
 188
 189 /* Utility string function  */
 190 const char *mi_lttng_loglevel_string(int value, enum lttng_domain_type domain);
 191 const char *mi_lttng_logleveltype_string(enum lttng_loglevel_type value);
 192 const char *mi_lttng_eventfieldtype_string(enum lttng_event_field_type value);
 193 const char *mi_lttng_domaintype_string(enum lttng_domain_type value);
 194 const char *mi_lttng_buffertype_string(enum lttng_buffer_type value);
 195 const char *mi_lttng_calibratetype_string(enum lttng_calibrate_type val);
 196
 197 /*
 198  * Create an instance of a machine interface writer.
 199  *
 200  * fd_output File to which the XML content must be written. The file will be
 201  * closed once the mi_writer has been destroyed.
 202  *
 203  * Returns an instance of a machine interface writer on success, NULL on
 204  * error.
 205  */
 206 struct mi_writer *mi_lttng_writer_create(int fd_output, int mi_output_type);
 207
 208 /*
 209  * Destroy an instance of a machine interface writer.
 210  *
 211  * writer An instance of a machine interface writer.
 212  *
 213  * Returns zero if the XML document could be closed cleanly. Negative values
 214  * indicate an error.
 215  */
 216 int mi_lttng_writer_destroy(struct mi_writer *writer);
 217
 218 /*
 219  * Open a command tag and add it's name node.
 220  *
 221  * writer An instance of a machine interface writer.
 222  * command The command name.
 223  *
 224  * Returns zero if the XML document could be closed cleanly.
 225  * Negative values indicate an error.
 226  */
 227 int mi_lttng_writer_command_open(struct mi_writer *writer, const char *command);
 228
 229 /*
 230  * Close a command tag.
 231  *
 232  * writer An instance of a machine interface writer.
 233  *
 234  * Returns zero if the XML document could be closed cleanly.
 235  * Negative values indicate an error.
 236  */
 237 int mi_lttng_writer_command_close(struct mi_writer *writer);
 238
 239 /*
 240  * Open an element tag.
 241  *
 242  * writer An instance of a machine interface writer.
 243  * element_name Element tag name.
 244  *
 245  * Returns zero if the XML document could be closed cleanly.
 246  * Negative values indicate an error.
 247  */
 248 int mi_lttng_writer_open_element(struct mi_writer *writer,
 249                 const char *element_name);
 250
 251 /*
 252  * Close the current element tag.
 253  *
 254  * writer An instance of a machine interface writer.
 255  *
 256  * Returns zero if the XML document could be closed cleanly.
 257  * Negative values indicate an error.
 258  */
 259 int mi_lttng_writer_close_element(struct mi_writer *writer);
 260
 261 /*
 262  * Close multiple element.
 263  *
 264  * writer An instance of a machine interface writer.
 265  * nb_element Number of elements.
 266  *
 267  * Returns zero if the XML document could be closed cleanly.
 268  * Negative values indicate an error.
 269  */
 270 int mi_lttng_close_multi_element(struct mi_writer *writer,
 271                 unsigned int nb_element);
 272
 273 /*
 274  * Write an element of type unsigned int.
 275  *
 276  * writer An instance of a machine interface writer.
 277  * element_name Element name.
 278  * value Unsigned int value of the element
 279  *
 280  * Returns zero if the element's value could be written.
 281  * Negative values indicate an error.
 282  */
 283 int mi_lttng_writer_write_element_unsigned_int(struct mi_writer *writer,
 284                 const char *element_name, uint64_t value);
 285
 286 /*
 287  * Write an element of type signed int.
 288  *
 289  * writer An instance of a machine interface writer.
 290  * element_name Element name.
 291  * value Signed int value of the element.
 292  *
 293  * Returns zero if the element's value could be written.
 294  * Negative values indicate an error.
 295  */
 296 int mi_lttng_writer_write_element_signed_int(struct mi_writer *writer,
 297                 const char *element_name, int64_t value);
 298
 299 /*
 300  * Write an element of type boolean.
 301  *
 302  * writer An instance of a machine interface writer.
 303  * element_name Element name.
 304  * value Boolean value of the element.
 305  *
 306  * Returns zero if the element's value could be written.
 307  * Negative values indicate an error.
 308  */
 309 int mi_lttng_writer_write_element_bool(struct mi_writer *writer,
 310                 const char *element_name, int value);
 311
 312 /*
 313  * Write an element of type string.
 314  *
 315  * writer An instance of a machine interface writer.
 316  * element_name Element name.
 317  * value String value of the element.
 318  *
 319  * Returns zero if the element's value could be written.
 320  * Negative values indicate an error.
 321  */
 322 int mi_lttng_writer_write_element_string(struct mi_writer *writer,
 323                 const char *element_name, const char *value);
 324
 325 /*
 326  * Machine interface of struct version.
 327  *
 328  * writer An instance of a machine interface writer.
 329  * version Version struct.
 330  * lttng_description String value of the version description.
 331  * lttng_license String value of the version license.
 332  *
 333  * Returns zero if the element's value could be written.
 334  * Negative values indicate an error.
 335  */
 336 int mi_lttng_version(struct mi_writer *writer, struct mi_lttng_version *version,
 337                 const char *lttng_description, const char *lttng_license);
 338
 339 /*
 340  * Machine interface: open a sessions element.
 341  *
 342  * writer An instance of a machine interface writer.
 343  *
 344  * Returns zero if the element's value could be written.
 345  * Negative values indicate an error.
 346  */
 347 int mi_lttng_sessions_open(struct mi_writer *writer);
 348
 349 /*
 350  * Machine interface of struct session.
 351  *
 352  * writer An instance of a machine interface writer.
 353  * session An instance of a session.
 354  * is_open Defines whether or not the session element shall be closed.
 355  *         This should be used carefully and the client
 356  *         must close the session element.
 357  *         Use case: nested additional information on a session
 358  *                  ex: domain,channel event.
 359  *
 360  * Returns zero if the element's value could be written.
 361  * Negative values indicate an error.
 362  */
 363 int mi_lttng_session(struct mi_writer *writer,
 364                 struct lttng_session *session, int is_open);
 365
 366 /*
 367  * Machine interface: open a domains element.
 368  *
 369  * writer An instance of a machine interface writer.
 370  *
 371  * Returns zero if the element's value could be written.
 372  * Negative values indicate an error.
 373  */
 374 int mi_lttng_domains_open(struct mi_writer *writer);
 375
 376 /*
 377  * Machine interface of struct domain.
 378  *
 379  * writer An instance of a machine interface writer.
 380  * domain An instance of a domain.
 381  *
 382  * is_open Defines whether or not the session element shall be closed.
 383  *         This should be used carefully and the client
 384  *         must close the domain element.
 385  *         Use case: nested addition information on a domain
 386  *                  ex: channel event.
 387  *
 388  * Returns zero if the element's value could be written.
 389  * Negative values indicate an error.
 390  */
 391 int mi_lttng_domain(struct mi_writer *writer,
 392                 struct lttng_domain *domain, int is_open);
 393
 394 /*
 395  * Machine interface: open a channels element.
 396  *
 397  * writer An instance of a machine interface writer.
 398  *
 399  * Returns zero if the element's value could be written.
 400  * Negative values indicate an error.
 401  */
 402 int mi_lttng_channels_open(struct mi_writer *writer);
 403
 404 /*
 405  * Machine interface of struct channel.
 406  *
 407  * writer An instance of a machine interface writer.
 408  * channel An instance of a channel.
 409  *
 410  * is_open Defines whether or not the session element shall be closed.
 411  *         This should be used carefully and the client
 412  *         must close the channel element.
 413  *         Use case: nested addition information on a channel.
 414  *                  ex: channel event.
 415  *
 416  * Returns zero if the element's value could be written.
 417  * Negative values indicate an error.
 418  */
 419 int mi_lttng_channel(struct mi_writer *writer,
 420                 struct lttng_channel *channel, int is_open);
 421
 422 /*
 423  * Machine interface of struct channel_attr.
 424  *
 425  * writer An instance of a machine interface writer.
 426  * attr An instance of a channel_attr struct.
 427  *
 428  * Returns zero if the element's value could be written.
 429  * Negative values indicate an error.
 430  */
 431 int mi_lttng_channel_attr(struct mi_writer *writer,
 432                 struct lttng_channel_attr *attr);
 433
 434 /*
 435 * Machine interface for event common attributes.
 436 *
 437 * writer An instance of a mi writer.
 438 * event single trace event.
 439 *
 440 * The common attribute are:
 441 * - mi event element
 442 * - event name
 443 * - event type
 444 * - enabled tag
 445 * - event filter
 446 *
 447 * Returns zero if the element's value could be written.
 448 * Negative values indicate an error.
 449 */
 450 int mi_lttng_event_common_attributes(struct mi_writer *writer,
 451                 struct lttng_event *event);
 452
 453 /*
 454  * Machine interface for kernel tracepoint event with a loglevel.
 455  *
 456  * writer An instance of a mi writer.
 457  * event single trace event.
 458  * domain Event's domain
 459  *
 460  * Returns zero if the element's value could be written.
 461  * Negative values indicate an error.
 462  */
 463 int mi_lttng_event_tracepoint_loglevel(struct mi_writer *writer,
 464                 struct lttng_event *event, enum lttng_domain_type domain);
 465
 466 /*
 467  * Machine interface for kernel tracepoint event with no loglevel.
 468  *
 469  * writer An instance of a mi writer.
 470  * event single trace event.
 471  *
 472  * Returns zero if the element's value could be written.
 473  * Negative values indicate an error.
 474  */
 475 int mi_lttng_event_tracepoint_no_loglevel(struct mi_writer *writer,
 476                 struct lttng_event *event);
 477
 478 /*
 479  * Machine interface for kernel function and probe event.
 480  *
 481  * writer An instance of a mi writer.
 482  * event single trace event.
 483  *
 484  * Returns zero if the element's value could be written.
 485  * Negative values indicate an error.
 486  */
 487 int mi_lttng_event_function_probe(struct mi_writer *writer,
 488                 struct lttng_event *event);
 489
 490 /*
 491  * Machine interface for kernel function entry event.
 492  *
 493  * writer An instance of a mi writer.
 494  * event single trace event.
 495  *
 496  * Returns zero if the element's value could be written.
 497  * Negative values indicate an error.
 498  */
 499 int mi_lttng_event_function_entry(struct mi_writer *writer,
 500                 struct lttng_event *event);
 501
 502 /*
 503  * Machine interface: open an events element.
 504  *
 505  * writer An instance of a machine interface writer.
 506  *
 507  * Returns zero if the element's value could be written.
 508  * Negative values indicate an error.
 509  */
 510 int mi_lttng_events_open(struct mi_writer *writer);
 511
 512 /*
 513  * Machine interface for printing an event.
 514  * The trace event type currently supported are:
 515  *  TRACEPOINT,
 516  *  PROBE,
 517  *  FUNCTION,
 518  *  FUNCTION_ENTRY,
 519  *  SYSCALL
 520  *
 521  * writer An instance of a mi writer.
 522  * event single trace event.
 523  * is_open Defines whether or not the session element shall be closed.
 524  *         This should be used carefully and the client
 525  *         must close the event element.
 526  *         Use case: nested additional information
 527  * domain Event's domain
 528  *
 529  * Returns zero if the element's value could be written.
 530  * Negative values indicate an error.
 531  */
 532 int mi_lttng_event(struct mi_writer *writer, struct lttng_event *event,
 533                 int is_open, enum lttng_domain_type domain);
 534
 535 /*
 536  * Machine interface for struct lttng_event_field.
 537  *
 538  * writer An instance of a mi writer.
 539  * field An event_field instance.
 540  *
 541  * Returns zero if the element's value could be written.
 542  * Negative values indicate an error.
 543  */
 544 int mi_lttng_event_field(struct mi_writer *writer,
 545                 struct lttng_event_field *field);
 546
 547 /*
 548  * Machine interface: open a event_fields element.
 549  *
 550  * writer An instance of a machine interface writer.
 551  *
 552  * Returns zero if the element have be written.
 553  * Negative values indicate an error.
 554  */
 555 int mi_lttng_event_fields_open(struct mi_writer *writer);
 556
 557 /*
 558  * Machine interface: open a trackers element.
 559  *
 560  * writer An instance of a machine interface writer.
 561  *
 562  * Returns zero if the element's value could be written.
 563  * Negative values indicate an error.
 564  */
 565 int mi_lttng_trackers_open(struct mi_writer *writer);
 566
 567 /*
 568  * Machine interface: open a pid_tracker element.
 569  *
 570  * writer An instance of a machine interface writer.
 571  *
 572  * Returns zero if the element's value could be written.
 573  * Negative values indicate an error.
 574  *
 575  * Note: A targets element is also opened for each tracker definition
 576  */
 577 int mi_lttng_pid_tracker_open(struct mi_writer *writer);
 578
 579 /*
 580  * Machine interface: open a PIDs element.
 581  *
 582  * writer An instance of a machine interface writer.
 583  *
 584  * Returns zero if the element's value could be written.
 585  * Negative values indicate an error.
 586  */
 587 int mi_lttng_pids_open(struct mi_writer *writer);
 588
 589 /*
 590  * Machine interface: open a processes element.
 591  *
 592  * writer An instance of a machine interface writer.
 593  *
 594  * Returns zero if the element's value could be written.
 595  * Negative values indicate an error.
 596  */
 597 int mi_lttng_processes_open(struct mi_writer *writer);
 598
 599 /*
 600  * Machine interface of a Process.
 601  *
 602  * writer An instance of a machine interface writer.
 603  * pid A PID.
 604  *
 605  * is_open Defines whether or not the session element shall be closed.
 606  *         This should be used carefully and the client
 607  *         must close the pid element.
 608  *         Use case: nested addition information on a domain
 609  *                  ex: channel event.
 610  *
 611  * Returns zero if the element's value could be written.
 612  * Negative values indicate an error.
 613  */
 614 int mi_lttng_process(struct mi_writer *writer, pid_t pid , const char *name,
 615                 int is_open);
 616
 617 /*
 618  * TODO: move pid of lttng list -u to process semantic on mi api bump
 619  * Machine interface of a Process.
 620  *
 621  * writer An instance of a machine interface writer.
 622  * pid A PID.
 623  *
 624  * is_open Defines whether or not the session element shall be closed.
 625  *         This should be used carefully and the client
 626  *         must close the pid element.
 627  *         Use case: nested addition information on a domain
 628  *                  ex: channel event.
 629  *
 630  * Returns zero if the element's value could be written.
 631  * Negative values indicate an error.
 632  */
 633 int mi_lttng_pid(struct mi_writer *writer, pid_t pid , const char *name,
 634                 int is_open);
 635 /*
 636  * Machine interface: open a targets element.
 637  *
 638  * writer An instance of a machine interface writer.
 639  *
 640  * Returns zero if the element's value could be written.
 641  * Negative values indicate an error.
 642  */
 643 int mi_lttng_targets_open(struct mi_writer *writer);
 644
 645 /*
 646  * Machine interface for track/untrack a pid_target
 647  *
 648  * writer An instance of a machine interface writer.
 649  *
 650  * Returns zero if the element's value could be written.
 651  * Negative values indicate an error.
 652  */
 653 int mi_lttng_pid_target(struct mi_writer *writer, pid_t pid, int is_open);
 654
 655 /*
 656  * Machine interface for struct lttng_calibrate.
 657  *
 658  * writer An instance of a machine interface writer.
 659  *
 660  * calibrate A lttng_calibrate instance.
 661  *
 662  * Returns zero if the element's value could be written.
 663  * Negative values indicate an error.
 664  */
 665 int mi_lttng_calibrate(struct mi_writer *writer,
 666                 struct lttng_calibrate *calibrate);
 667
 668 /*
 669  * Machine interface of a context.
 670  *
 671  * writer An instance of a machine interface writer
 672  *
 673  * context An instance of a lttng_event_context
 674  *
 675  * is_open Define if we close the context element
 676  *         This should be used carefully and the client
 677  *         need to close the context element.
 678  * Returns zero if the element's value could be written.
 679  * Negative values indicate an error.
 680  */
 681 int mi_lttng_context(struct mi_writer *writer,
 682                 struct lttng_event_context *context, int is_open);
 683
 684 /*
 685  * Machine interface of a perf_counter_context.
 686  *
 687  * writer An instance of a machine interface writer
 688  *
 689  * contest An instance of a lttng_event_perf_counter_ctx
 690  *
 691  * Returns zero if the element's value could be written.
 692  * Negative values indicate an error.
 693  */
 694 int mi_lttng_perf_counter_context(struct mi_writer *writer,
 695                 struct lttng_event_perf_counter_ctx  *perf_context);
 696
 697 /*
 698  * Machine interface of the snapshot list_output.
 699  * It specifies the session for which we are listing snapshots,
 700  * and it opens a snapshots element to list a sequence
 701  * of snapshots.
 702  *
 703  * writer An instance of a machine interface writer.
 704  *
 705  * session_name: Snapshot output for session "session_name".
 706  *
 707  * Note: The client has to close the session and the snapshots elements after
 708  * having listed every lttng_snapshot_output.
 709  *
 710  * Returns zero if the element's value could be written.
 711  * Negative values indicate an error.
 712  */
 713 int mi_lttng_snapshot_output_session_name(struct mi_writer *writer,
 714                 const char *session_name);
 715
 716 /*
 717  * Machine interface of the snapshot output.
 718  * The machine interface serializes the following attributes:
 719  * - id: ID of the snapshot output.
 720  * - name: Name of the output.
 721  * - data_url : Destination of the output.
 722  * - ctrl_url: Destination of the output.
 723  * - max_size: total size of all stream combined.
 724  *
 725  * writer An instance of a machine interface writer.
 726  *
 727  * output: A list of snapshot_output.
 728  *
 729  * Returns zero if the element's value could be written.
 730  * Negative values indicate an error.
 731  */
 732 int mi_lttng_snapshot_list_output(struct mi_writer *writer,
 733                 struct lttng_snapshot_output *output);
 734
 735 /*
 736  * Machine interface of the output of the command snapshot del output
 737  * when deleting a snapshot either by id or by name.
 738  * If the snapshot was found and successfully deleted using its id,
 739  * it return the id of the snapshot and the current session name on which it
 740  * was attached.
 741  *
 742  * Otherwise, it do the same process with the name of the snapshot, if the
 743  * snapshot output id is undefined.
 744  *
 745  * writer An instance of a machine interface writer.
 746  *
 747  * id: ID of the snapshot output.
 748  *
 749  * name: Name of the snapshot.
 750  *
 751  * current_session_name: Session to which the snapshot belongs.
 752  *
 753  * Returns zero if the element's value could be written.
 754  * Negative values indicate an error.
 755  */
 756 int mi_lttng_snapshot_del_output(struct mi_writer *writer, int id,
 757                 const char *name, const char *current_session_name);
 758
 759 /*
 760  * Machine interface of the output of the command snapshot add output
 761  * when adding a snapshot from a user URL.
 762  *
 763  * If the snapshot was successfully added, the machine interface lists
 764  * these information:
 765  * - id: ID of the newly add snapshot output.
 766  * - current_session_name: Name of the session to which the output was added.
 767  * - ctrl_url: Destination of the output.
 768  * - max_size: total size of all stream combined.
 769  *
 770  * writer An instance of a machine interface writer.
 771  *
 772  * current_session_name: Session to which the snapshot belongs.
 773  *
 774  * n_ptr:
 775  *
 776  * output: iterator over a lttng_snapshot_output_list which contain
 777  * the snapshot output informations.
 778  *
 779  * Returns zero if the element's value could be written.
 780  * Negative values indicate an error.
 781  */
 782 int mi_lttng_snapshot_add_output(struct mi_writer *writer,
 783                 const char *current_session_name, const char *n_ptr,
 784                 struct lttng_snapshot_output *output);
 785
 786 /*
 787  * Machine interface of the output of the command snapshot
 788  * record  from a URL (if given).
 789  *
 790  * If the snapshot is successfully recorded from a url, the machine interface
 791  * output the following information:
 792  * - url: Destination of the output stored in the snapshot.
 793  *
 794  * Otherwise, the machine interface output the data and ctrl url received
 795  * from the command-line.
 796  *
 797  * writer An instance of a machine interface writer.
 798  *
 799  * current_session_name: Snapshot record for session "current_session_name".
 800  *
 801  * ctrl_url, data_url: Destination of the output receive from the command-line.
 802  *
 803  * Returns zero if the element's value could be written.
 804  * Negative values indicate an error.
 805  */
 806 int mi_lttng_snapshot_record(struct mi_writer *writer,
 807                 const char *current_session_name, const char *url,
 808                 const char *cmdline_ctrl_url, const char *cmdline_data_url);
 809
 810 #endif /* _MI_LTTNG_H */