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