| 1 | #include <stdlib.h> |
| 2 | #include <stdio.h> |
| 3 | #include <stdint.h> |
| 4 | #include <inttypes.h> |
| 5 | #include <string.h> |
| 6 | #include <babeltrace2/babeltrace.h> |
| 7 | |
| 8 | /* Source component's private data */ |
| 9 | struct dust_in { |
| 10 | /* Input file path parameter value (owned by this) */ |
| 11 | const bt_value *path_value; |
| 12 | |
| 13 | /* Stream (owned by this) */ |
| 14 | bt_stream *stream; |
| 15 | |
| 16 | /* Event classes for each type of event (owned by this) */ |
| 17 | bt_event_class *send_msg_event_class; |
| 18 | bt_event_class *recv_msg_event_class; |
| 19 | }; |
| 20 | |
| 21 | /* |
| 22 | * Creates an event class within `stream_class` named `name`. |
| 23 | */ |
| 24 | static |
| 25 | bt_event_class *create_event_class(bt_stream_class *stream_class, |
| 26 | const char *name) |
| 27 | { |
| 28 | /* Borrow trace class from stream class */ |
| 29 | bt_trace_class *trace_class = |
| 30 | bt_stream_class_borrow_trace_class(stream_class); |
| 31 | |
| 32 | /* Create a default event class */ |
| 33 | bt_event_class *event_class = bt_event_class_create(stream_class); |
| 34 | |
| 35 | /* Name the event class */ |
| 36 | bt_event_class_set_name(event_class, name); |
| 37 | |
| 38 | /* |
| 39 | * Create an empty structure field class to be used as the |
| 40 | * event class's payload field class. |
| 41 | */ |
| 42 | bt_field_class *payload_field_class = |
| 43 | bt_field_class_structure_create(trace_class); |
| 44 | |
| 45 | /* |
| 46 | * Create a string field class to be used as the payload field |
| 47 | * class's `msg` member. |
| 48 | */ |
| 49 | bt_field_class *msg_field_class = |
| 50 | bt_field_class_string_create(trace_class); |
| 51 | |
| 52 | /* |
| 53 | * Append the string field class to the structure field class as the |
| 54 | * `msg` member. |
| 55 | */ |
| 56 | bt_field_class_structure_append_member(payload_field_class, "msg", |
| 57 | msg_field_class); |
| 58 | |
| 59 | /* Set the event class's payload field class */ |
| 60 | bt_event_class_set_payload_field_class(event_class, payload_field_class); |
| 61 | |
| 62 | /* Put the references we don't need anymore */ |
| 63 | bt_field_class_put_ref(payload_field_class); |
| 64 | bt_field_class_put_ref(msg_field_class); |
| 65 | |
| 66 | return event_class; |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * Creates the source component's metadata and stream objects. |
| 71 | */ |
| 72 | static |
| 73 | void create_metadata_and_stream(bt_self_component *self_component, |
| 74 | struct dust_in *dust_in) |
| 75 | { |
| 76 | /* Create a default trace class */ |
| 77 | bt_trace_class *trace_class = bt_trace_class_create(self_component); |
| 78 | |
| 79 | /* Create a stream trace class within `trace_class` */ |
| 80 | bt_stream_class *stream_class = bt_stream_class_create(trace_class); |
| 81 | |
| 82 | /* Create a default clock class (1 GHz frequency) */ |
| 83 | bt_clock_class *clock_class = bt_clock_class_create(self_component); |
| 84 | |
| 85 | /* |
| 86 | * Set `clock_class` as the default clock class of `stream_class`. |
| 87 | * |
| 88 | * This means all the streams created from `stream_class` have a |
| 89 | * conceptual default clock which is an instance of `clock_class`. |
| 90 | * Any event message created for such a stream has a snapshot of the |
| 91 | * stream's default clock. |
| 92 | */ |
| 93 | bt_stream_class_set_default_clock_class(stream_class, clock_class); |
| 94 | |
| 95 | /* Create the two event classes we need */ |
| 96 | dust_in->send_msg_event_class = create_event_class(stream_class, |
| 97 | "send-msg"); |
| 98 | dust_in->recv_msg_event_class = create_event_class(stream_class, |
| 99 | "recv-msg"); |
| 100 | |
| 101 | /* Create a default trace from (instance of `trace_class`) */ |
| 102 | bt_trace *trace = bt_trace_create(trace_class); |
| 103 | |
| 104 | /* |
| 105 | * Create the source component's stream (instance of `stream_class` |
| 106 | * within `trace`). |
| 107 | */ |
| 108 | dust_in->stream = bt_stream_create(stream_class, trace); |
| 109 | |
| 110 | /* Put the references we don't need anymore */ |
| 111 | bt_trace_put_ref(trace); |
| 112 | bt_clock_class_put_ref(clock_class); |
| 113 | bt_stream_class_put_ref(stream_class); |
| 114 | bt_trace_class_put_ref(trace_class); |
| 115 | } |
| 116 | |
| 117 | /* |
| 118 | * Initializes the source component. |
| 119 | */ |
| 120 | static |
| 121 | bt_component_class_initialize_method_status dust_in_initialize( |
| 122 | bt_self_component_source *self_component_source, |
| 123 | bt_self_component_source_configuration *configuration, |
| 124 | const bt_value *params, void *initialize_method_data) |
| 125 | { |
| 126 | /* Allocate a private data structure */ |
| 127 | struct dust_in *dust_in = malloc(sizeof(*dust_in)); |
| 128 | |
| 129 | /* |
| 130 | * Keep a reference of the `path` string value parameter so that the |
| 131 | * initialization method of a message iterator can read its string |
| 132 | * value to open the file. |
| 133 | */ |
| 134 | dust_in->path_value = |
| 135 | bt_value_map_borrow_entry_value_const(params, "path"); |
| 136 | bt_value_get_ref(dust_in->path_value); |
| 137 | |
| 138 | /* Upcast `self_component_source` to the `bt_self_component` type */ |
| 139 | bt_self_component *self_component = |
| 140 | bt_self_component_source_as_self_component(self_component_source); |
| 141 | |
| 142 | /* Create the source component's metadata and stream objects */ |
| 143 | create_metadata_and_stream(self_component, dust_in); |
| 144 | |
| 145 | /* Set the component's user data to our private data structure */ |
| 146 | bt_self_component_set_data(self_component, dust_in); |
| 147 | |
| 148 | /* |
| 149 | * Add an output port named `out` to the source component. |
| 150 | * |
| 151 | * This is needed so that this source component can be connected to |
| 152 | * a filter or a sink component. Once a downstream component is |
| 153 | * connected, it can create our message iterator. |
| 154 | */ |
| 155 | bt_self_component_source_add_output_port(self_component_source, |
| 156 | "out", NULL, NULL); |
| 157 | |
| 158 | return BT_COMPONENT_CLASS_INITIALIZE_METHOD_STATUS_OK; |
| 159 | } |
| 160 | |
| 161 | /* |
| 162 | * Finalizes the source component. |
| 163 | */ |
| 164 | static |
| 165 | void dust_in_finalize(bt_self_component_source *self_component_source) |
| 166 | { |
| 167 | /* Retrieve our private data from the component's user data */ |
| 168 | struct dust_in *dust_in = bt_self_component_get_data( |
| 169 | bt_self_component_source_as_self_component(self_component_source)); |
| 170 | |
| 171 | /* Put all references */ |
| 172 | bt_value_put_ref(dust_in->path_value); |
| 173 | bt_event_class_put_ref(dust_in->send_msg_event_class); |
| 174 | bt_event_class_put_ref(dust_in->recv_msg_event_class); |
| 175 | bt_stream_put_ref(dust_in->stream); |
| 176 | |
| 177 | /* Free the allocated structure */ |
| 178 | free(dust_in); |
| 179 | } |
| 180 | |
| 181 | /* State of a message iterator */ |
| 182 | enum dust_in_message_iterator_state { |
| 183 | /* Emit a stream beginning message */ |
| 184 | DUST_IN_MESSAGE_ITERATOR_STATE_STREAM_BEGINNING, |
| 185 | |
| 186 | /* Emit an event message */ |
| 187 | DUST_IN_MESSAGE_ITERATOR_STATE_EVENT, |
| 188 | |
| 189 | /* Message iterator is ended */ |
| 190 | DUST_IN_MESSAGE_ITERATOR_STATE_ENDED, |
| 191 | }; |
| 192 | |
| 193 | /* Message iterator's private data */ |
| 194 | struct dust_in_message_iterator { |
| 195 | /* (Weak) link to the component's private data */ |
| 196 | struct dust_in *dust_in; |
| 197 | |
| 198 | /* Current message iterator's state */ |
| 199 | enum dust_in_message_iterator_state state; |
| 200 | |
| 201 | /* Input file */ |
| 202 | FILE *file; |
| 203 | |
| 204 | /* Buffers to read data from the input file */ |
| 205 | char name_buffer[32]; |
| 206 | char msg_buffer[1024]; |
| 207 | }; |
| 208 | |
| 209 | /* |
| 210 | * Initializes the message iterator. |
| 211 | */ |
| 212 | static |
| 213 | bt_message_iterator_class_initialize_method_status |
| 214 | dust_in_message_iterator_initialize( |
| 215 | bt_self_message_iterator *self_message_iterator, |
| 216 | bt_self_message_iterator_configuration *configuration, |
| 217 | bt_self_component_port_output *self_port) |
| 218 | { |
| 219 | /* Allocate a private data structure */ |
| 220 | struct dust_in_message_iterator *dust_in_iter = |
| 221 | malloc(sizeof(*dust_in_iter)); |
| 222 | |
| 223 | /* Retrieve the component's private data from its user data */ |
| 224 | struct dust_in *dust_in = bt_self_component_get_data( |
| 225 | bt_self_message_iterator_borrow_component(self_message_iterator)); |
| 226 | |
| 227 | /* Keep a link to the component's private data */ |
| 228 | dust_in_iter->dust_in = dust_in; |
| 229 | |
| 230 | /* Set the message iterator's initial state */ |
| 231 | dust_in_iter->state = DUST_IN_MESSAGE_ITERATOR_STATE_STREAM_BEGINNING; |
| 232 | |
| 233 | /* Get the raw value of the input file path string value */ |
| 234 | const char *path = bt_value_string_get(dust_in->path_value); |
| 235 | |
| 236 | /* Open the input file in text mode */ |
| 237 | dust_in_iter->file = fopen(path, "r"); |
| 238 | |
| 239 | /* Set the message iterator's user data to our private data structure */ |
| 240 | bt_self_message_iterator_set_data(self_message_iterator, dust_in_iter); |
| 241 | |
| 242 | return BT_MESSAGE_ITERATOR_CLASS_INITIALIZE_METHOD_STATUS_OK; |
| 243 | } |
| 244 | |
| 245 | /* |
| 246 | * Finalizes the message iterator. |
| 247 | */ |
| 248 | static |
| 249 | void dust_in_message_iterator_finalize( |
| 250 | bt_self_message_iterator *self_message_iterator) |
| 251 | { |
| 252 | /* Retrieve our private data from the message iterator's user data */ |
| 253 | struct dust_in_message_iterator *dust_in_iter = |
| 254 | bt_self_message_iterator_get_data(self_message_iterator); |
| 255 | |
| 256 | /* Close the input file */ |
| 257 | fclose(dust_in_iter->file); |
| 258 | |
| 259 | /* Free the allocated structure */ |
| 260 | free(dust_in_iter); |
| 261 | } |
| 262 | |
| 263 | /* |
| 264 | * Creates a message from the message iterator's input file's current |
| 265 | * line. |
| 266 | * |
| 267 | * If there's a line to process, this function creates an event message. |
| 268 | * Otherwise it creates a stream end message and sets the message |
| 269 | * iterator's state accordingly. |
| 270 | */ |
| 271 | static |
| 272 | bt_message *create_message_from_line( |
| 273 | struct dust_in_message_iterator *dust_in_iter, |
| 274 | bt_self_message_iterator *self_message_iterator) |
| 275 | { |
| 276 | uint64_t timestamp; |
| 277 | uint64_t extra_us; |
| 278 | bt_message *message; |
| 279 | |
| 280 | /* Try to read a line from the input file into individual tokens */ |
| 281 | int count = fscanf(dust_in_iter->file, "%" PRIu64 " %" PRIu64 " %s %[^\n]", |
| 282 | ×tamp, &extra_us, &dust_in_iter->name_buffer[0], |
| 283 | &dust_in_iter->msg_buffer[0]); |
| 284 | |
| 285 | /* Reached the end of the file? */ |
| 286 | if (count == EOF || feof(dust_in_iter->file)) { |
| 287 | /* |
| 288 | * Reached the end of the file: create a stream end message and |
| 289 | * set the message iterator's state to |
| 290 | * `DUST_IN_MESSAGE_ITERATOR_STATE_ENDED` so that the next call |
| 291 | * to dust_in_message_iterator_next() returns |
| 292 | * `BT_MESSAGE_ITERATOR_CLASS_NEXT_METHOD_STATUS_END` (end of |
| 293 | * iteration). |
| 294 | */ |
| 295 | message = bt_message_stream_end_create(self_message_iterator, |
| 296 | dust_in_iter->dust_in->stream); |
| 297 | dust_in_iter->state = DUST_IN_MESSAGE_ITERATOR_STATE_ENDED; |
| 298 | goto end; |
| 299 | } |
| 300 | |
| 301 | /* Choose the correct event class, depending on the event name token */ |
| 302 | bt_event_class *event_class; |
| 303 | |
| 304 | if (strcmp(dust_in_iter->name_buffer, "send-msg") == 0) { |
| 305 | event_class = dust_in_iter->dust_in->send_msg_event_class; |
| 306 | } else { |
| 307 | event_class = dust_in_iter->dust_in->recv_msg_event_class; |
| 308 | } |
| 309 | |
| 310 | /* |
| 311 | * At this point `timestamp` contains seconds since the Unix epoch. |
| 312 | * Multiply it by 1,000,000,000 to get nanoseconds since the Unix |
| 313 | * epoch because the stream's clock's frequency is 1 GHz. |
| 314 | */ |
| 315 | timestamp *= UINT64_C(1000000000); |
| 316 | |
| 317 | /* Add the extra microseconds (as nanoseconds) to `timestamp` */ |
| 318 | timestamp += extra_us * UINT64_C(1000); |
| 319 | |
| 320 | /* Create the event message */ |
| 321 | message = bt_message_event_create_with_default_clock_snapshot( |
| 322 | self_message_iterator, event_class, dust_in_iter->dust_in->stream, |
| 323 | timestamp); |
| 324 | |
| 325 | /* |
| 326 | * At this point `message` is an event message which contains |
| 327 | * an empty event object. |
| 328 | * |
| 329 | * We need to fill its fields. |
| 330 | * |
| 331 | * The only field to fill is the payload field's `msg` field |
| 332 | * which is the event record's message. |
| 333 | * |
| 334 | * All the references below are borrowed references, therefore we |
| 335 | * don't need to put them. |
| 336 | */ |
| 337 | bt_event *event = bt_message_event_borrow_event(message); |
| 338 | bt_field *payload_field = bt_event_borrow_payload_field(event); |
| 339 | bt_field *msg_field = bt_field_structure_borrow_member_field_by_index( |
| 340 | payload_field, 0); |
| 341 | |
| 342 | bt_field_string_set_value(msg_field, dust_in_iter->msg_buffer); |
| 343 | |
| 344 | end: |
| 345 | return message; |
| 346 | } |
| 347 | |
| 348 | /* |
| 349 | * Returns the next message to the message iterator's user. |
| 350 | * |
| 351 | * This method can fill the `messages` array with up to `capacity` |
| 352 | * messages. |
| 353 | * |
| 354 | * To keep this example simple, we put a single message into `messages` |
| 355 | * and set `*count` to 1 (if the message iterator is not ended). |
| 356 | */ |
| 357 | static |
| 358 | bt_message_iterator_class_next_method_status dust_in_message_iterator_next( |
| 359 | bt_self_message_iterator *self_message_iterator, |
| 360 | bt_message_array_const messages, uint64_t capacity, |
| 361 | uint64_t *count) |
| 362 | { |
| 363 | /* Retrieve our private data from the message iterator's user data */ |
| 364 | struct dust_in_message_iterator *dust_in_iter = |
| 365 | bt_self_message_iterator_get_data(self_message_iterator); |
| 366 | |
| 367 | /* |
| 368 | * This is the message to return (by moving it to the `messages` |
| 369 | * array). |
| 370 | * |
| 371 | * We initialize it to `NULL`. If it's not `NULL` after the |
| 372 | * processing below, then we move it to the message array. |
| 373 | */ |
| 374 | bt_message *message = NULL; |
| 375 | |
| 376 | /* Initialize the return status to a success */ |
| 377 | bt_message_iterator_class_next_method_status status = |
| 378 | BT_MESSAGE_ITERATOR_CLASS_NEXT_METHOD_STATUS_OK; |
| 379 | |
| 380 | switch (dust_in_iter->state) { |
| 381 | case DUST_IN_MESSAGE_ITERATOR_STATE_STREAM_BEGINNING: |
| 382 | /* Create a stream beginning message */ |
| 383 | message = bt_message_stream_beginning_create(self_message_iterator, |
| 384 | dust_in_iter->dust_in->stream); |
| 385 | |
| 386 | /* Next state: an event message */ |
| 387 | dust_in_iter->state = DUST_IN_MESSAGE_ITERATOR_STATE_EVENT; |
| 388 | break; |
| 389 | case DUST_IN_MESSAGE_ITERATOR_STATE_EVENT: |
| 390 | /* |
| 391 | * Create an event or a stream end message from the message |
| 392 | * iterator's input file's current line. |
| 393 | * |
| 394 | * This function also updates the message iterator's state if |
| 395 | * needed. |
| 396 | */ |
| 397 | message = create_message_from_line(dust_in_iter, |
| 398 | self_message_iterator); |
| 399 | break; |
| 400 | case DUST_IN_MESSAGE_ITERATOR_STATE_ENDED: |
| 401 | /* Message iterator is ended: return the corresponding status */ |
| 402 | status = |
| 403 | BT_MESSAGE_ITERATOR_CLASS_NEXT_METHOD_STATUS_END; |
| 404 | goto end; |
| 405 | } |
| 406 | |
| 407 | if (message) { |
| 408 | /* |
| 409 | * We created a message above: move it to the beginning of the |
| 410 | * `messages` array, setting `*count` to 1 to indicate that the |
| 411 | * array contains a single message. |
| 412 | */ |
| 413 | messages[0] = message; |
| 414 | *count = 1; |
| 415 | } |
| 416 | |
| 417 | end: |
| 418 | return status; |
| 419 | } |
| 420 | |
| 421 | /* Mandatory */ |
| 422 | BT_PLUGIN_MODULE(); |
| 423 | |
| 424 | /* Define the `dust` plugin */ |
| 425 | BT_PLUGIN(dust); |
| 426 | |
| 427 | /* Define the `input` source component class */ |
| 428 | BT_PLUGIN_SOURCE_COMPONENT_CLASS(input, dust_in_message_iterator_next); |
| 429 | |
| 430 | /* Set some of the `input` source component class's optional methods */ |
| 431 | BT_PLUGIN_SOURCE_COMPONENT_CLASS_INITIALIZE_METHOD(input, dust_in_initialize); |
| 432 | BT_PLUGIN_SOURCE_COMPONENT_CLASS_FINALIZE_METHOD(input, dust_in_finalize); |
| 433 | BT_PLUGIN_SOURCE_COMPONENT_CLASS_MESSAGE_ITERATOR_CLASS_INITIALIZE_METHOD(input, |
| 434 | dust_in_message_iterator_initialize); |
| 435 | BT_PLUGIN_SOURCE_COMPONENT_CLASS_MESSAGE_ITERATOR_CLASS_FINALIZE_METHOD(input, |
| 436 | dust_in_message_iterator_finalize); |