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1 | /* |
2 | * SPDX-License-Identifier: MIT | |
3 | * | |
4 | * Copyright 2017-2023 Philippe Proulx <pproulx@efficios.com> | |
5 | */ | |
6 | ||
7 | #include <algorithm> | |
8 | ||
9 | #include <glib.h> | |
10 | ||
11 | #include <babeltrace2/babeltrace.h> | |
12 | ||
13 | #include "common/common.h" | |
14 | #include "cpp-common/bt2c/call.hpp" | |
15 | #include "cpp-common/bt2s/make-unique.hpp" | |
16 | #include "cpp-common/vendor/fmt/format.h" | |
17 | ||
18 | #include "plugins/common/muxing/muxing.h" | |
19 | ||
20 | #include "comp.hpp" | |
21 | #include "msg-iter.hpp" | |
22 | ||
23 | namespace bt2mux { | |
24 | ||
25 | MsgIter::MsgIter(const bt2::SelfMessageIterator selfMsgIter, | |
26 | const bt2::SelfMessageIteratorConfiguration cfg, bt2::SelfComponentOutputPort) : | |
27 | bt2::UserMessageIterator<MsgIter, Comp> {selfMsgIter, "MSG-ITER"}, | |
28 | _mHeap {_HeapComparator {_mLogger}} | |
29 | { | |
30 | /* | |
31 | * Create one upstream message iterator for each connected | |
32 | * input port. | |
33 | */ | |
34 | auto canSeekForward = true; | |
35 | ||
36 | for (const auto inputPort : this->_component()._inputPorts()) { | |
37 | if (!inputPort.isConnected()) { | |
38 | BT_CPPLOGI("Ignoring disconnected port: name={}", inputPort.name()); | |
39 | continue; | |
40 | } | |
41 | ||
42 | /* | |
43 | * Create new upstream message iterator and immediately make it | |
44 | * part of `_mUpstreamMsgItersToReload` (_ensureFullHeap() will | |
45 | * deal with it when downstream calls next()). | |
46 | */ | |
47 | auto upstreamMsgIter = bt2s::make_unique<UpstreamMsgIter>( | |
48 | this->_createMessageIterator(inputPort), inputPort.name(), _mLogger); | |
49 | ||
50 | canSeekForward = canSeekForward && upstreamMsgIter->canSeekForward(); | |
51 | _mUpstreamMsgItersToReload.emplace_back(upstreamMsgIter.get()); | |
52 | _mUpstreamMsgIters.push_back(std::move(upstreamMsgIter)); | |
53 | } | |
54 | ||
55 | /* Set the "can seek forward" configuration */ | |
56 | cfg.canSeekForward(canSeekForward); | |
57 | } | |
58 | ||
59 | namespace { | |
60 | ||
61 | std::string optMsgTsStr(const bt2s::optional<std::int64_t>& ts) | |
62 | { | |
63 | if (ts) { | |
64 | return fmt::to_string(*ts); | |
65 | } | |
66 | ||
67 | return "none"; | |
68 | } | |
69 | ||
70 | } /* namespace */ | |
71 | ||
72 | void MsgIter::_next(bt2::ConstMessageArray& msgs) | |
73 | { | |
74 | /* Make sure all upstream message iterators are part of the heap */ | |
75 | this->_ensureFullHeap(); | |
76 | ||
77 | while (msgs.length() < msgs.capacity()) { | |
78 | /* Empty heap? */ | |
79 | if (G_UNLIKELY(_mHeap.isEmpty())) { | |
80 | /* No more upstream messages! */ | |
81 | return; | |
82 | } | |
83 | ||
84 | /* | |
85 | * Retrieve the upstream message iterator having the oldest message. | |
86 | */ | |
87 | auto& oldestUpstreamMsgIter = *_mHeap.top(); | |
88 | ||
89 | /* Validate the clock class of the oldest message */ | |
90 | this->_validateMsgClkCls(oldestUpstreamMsgIter.msg()); | |
91 | ||
92 | /* Append the oldest message and discard it */ | |
93 | msgs.append(oldestUpstreamMsgIter.msg().shared()); | |
94 | ||
95 | if (_mLogger.wouldLogD()) { | |
96 | BT_CPPLOGD("Appended message to array: port-name={}, ts={}", | |
97 | oldestUpstreamMsgIter.portName(), | |
98 | optMsgTsStr(oldestUpstreamMsgIter.msgTs())); | |
99 | } | |
100 | ||
101 | oldestUpstreamMsgIter.discard(); | |
102 | ||
103 | /* | |
104 | * Immediately try to reload `oldestUpstreamMsgIter`. | |
105 | * | |
106 | * The possible outcomes are: | |
107 | * | |
108 | * There's an available message: | |
109 | * Call `_mHeap.replaceTop()` to bring | |
110 | * `oldestUpstreamMsgIter` back to the heap, performing a | |
111 | * single heap rebalance. | |
112 | * | |
113 | * There isn't an available message (ended): | |
114 | * Remove `oldestUpstreamMsgIter` from the heap. | |
115 | * | |
116 | * `bt2::TryAgain` is thrown: | |
117 | * Remove `oldestUpstreamMsgIter` from the heap. | |
118 | * | |
119 | * Add `oldestUpstreamMsgIter` to the set of upstream | |
120 | * message iterators to reload. The next call to _next() | |
121 | * will move it to the heap again (if not ended) after | |
122 | * having successfully called reload(). | |
123 | */ | |
124 | BT_CPPLOGD( | |
125 | "Trying to reload upstream message iterator having the oldest message: port-name={}", | |
126 | oldestUpstreamMsgIter.portName()); | |
127 | ||
128 | try { | |
129 | if (G_LIKELY(oldestUpstreamMsgIter.reload() == UpstreamMsgIter::ReloadStatus::MORE)) { | |
130 | /* New current message: update heap */ | |
131 | _mHeap.replaceTop(&oldestUpstreamMsgIter); | |
132 | BT_CPPLOGD("More messages available; updated heap: port-name={}, heap-len={}", | |
133 | oldestUpstreamMsgIter.portName(), _mHeap.len()); | |
134 | } else { | |
135 | _mHeap.removeTop(); | |
136 | BT_CPPLOGD("Upstream message iterator has no more messages; removed from heap: " | |
137 | "port-name{}, heap-len={}", | |
138 | oldestUpstreamMsgIter.portName(), _mHeap.len()); | |
139 | } | |
140 | } catch (const bt2::TryAgain&) { | |
141 | _mHeap.removeTop(); | |
142 | _mUpstreamMsgItersToReload.push_back(&oldestUpstreamMsgIter); | |
143 | BT_CPPLOGD("Moved upstream message iterator from heap to \"to reload\" set: " | |
144 | "port-name={}, heap-len={}, to-reload-len={}", | |
145 | oldestUpstreamMsgIter.portName(), _mHeap.len(), | |
146 | _mUpstreamMsgItersToReload.size()); | |
147 | throw; | |
148 | } | |
149 | } | |
150 | } | |
151 | ||
152 | void MsgIter::_ensureFullHeap() | |
153 | { | |
154 | /* | |
155 | * Always remove from `_mUpstreamMsgItersToReload` when reload() | |
156 | * doesn't throw. | |
157 | * | |
158 | * If reload() returns `UpstreamMsgIter::ReloadStatus::NO_MORE`, | |
159 | * then we don't need it anymore (remains alive in | |
160 | * `_mUpstreamMsgIters`). | |
161 | */ | |
162 | for (auto it = _mUpstreamMsgItersToReload.begin(); it != _mUpstreamMsgItersToReload.end(); | |
163 | it = _mUpstreamMsgItersToReload.erase(it)) { | |
164 | auto& upstreamMsgIter = **it; | |
165 | ||
166 | BT_CPPLOGD("Handling upstream message iterator to reload: " | |
167 | "port-name={}, heap-len={}, to-reload-len={}", | |
168 | upstreamMsgIter.portName(), _mHeap.len(), _mUpstreamMsgItersToReload.size()); | |
169 | ||
170 | if (G_LIKELY(upstreamMsgIter.reload() == UpstreamMsgIter::ReloadStatus::MORE)) { | |
171 | /* New current message: move to heap */ | |
172 | _mHeap.insert(&upstreamMsgIter); | |
173 | BT_CPPLOGD("More messages available; " | |
174 | "inserted upstream message iterator into heap from \"to reload\" set: " | |
175 | "port-name={}, heap-len={}", | |
176 | upstreamMsgIter.portName(), _mHeap.len()); | |
177 | } else { | |
178 | BT_CPPLOGD("Not inserting upstream message iterator into heap (no more messages): " | |
179 | "port-name={}", | |
180 | upstreamMsgIter.portName()); | |
181 | } | |
182 | } | |
183 | } | |
184 | ||
185 | bool MsgIter::_canSeekBeginning() | |
186 | { | |
187 | /* | |
188 | * We can only seek our beginning if all our upstream message | |
189 | * iterators also can. | |
190 | */ | |
191 | return std::all_of(_mUpstreamMsgIters.begin(), _mUpstreamMsgIters.end(), | |
192 | [](UpstreamMsgIter::UP& upstreamMsgIter) { | |
193 | return upstreamMsgIter->canSeekBeginning(); | |
194 | }); | |
195 | } | |
196 | ||
197 | void MsgIter::_seekBeginning() | |
198 | { | |
199 | /* | |
200 | * The current approach is that this operation is either successful | |
201 | * (all upstream message iterators seek) or not. If it's not, then | |
202 | * we don't keep any state that some sought and some didn't: we'll | |
203 | * restart the whole process when the user tries to seek again. | |
204 | * | |
205 | * The first step is to clear all the containers of upstream message | |
206 | * iterator pointers so that we can process what's in | |
207 | * `_mUpstreamMsgIters` only. This is irreversible, but it's okay: | |
208 | * if any seeking fails below, the downstream user is required to | |
209 | * try the "seek beginning" operation again and only call | |
210 | * bt_message_iterator_next() if it was successful. | |
211 | * | |
212 | * This means if the first four upstream message iterators seek, and | |
213 | * then the fifth one throws `bt2::TryAgain`, then the next time | |
214 | * this method executes, the first four upstream message iterators | |
215 | * will seek again. That being said, it's such an unlikely scenario | |
216 | * that the simplicity outweighs performance concerns here. | |
217 | */ | |
218 | _mHeap.clear(); | |
219 | _mUpstreamMsgItersToReload.clear(); | |
220 | ||
221 | /* Also reset clock class expectation */ | |
222 | _mClkClsExpectation = _ClkClsExpectation::ANY; | |
223 | _mExpectedClkClsUuid.reset(); | |
224 | ||
225 | /* Make each upstream message iterator seek */ | |
226 | for (auto& upstreamMsgIter : _mUpstreamMsgIters) { | |
227 | /* This may throw! */ | |
228 | upstreamMsgIter->seekBeginning(); | |
229 | } | |
230 | ||
231 | /* | |
232 | * All sought successfully: fill `_mUpstreamMsgItersToReload`; the | |
233 | * next call to _next() will deal with those. | |
234 | */ | |
235 | for (auto& upstreamMsgIter : _mUpstreamMsgIters) { | |
236 | _mUpstreamMsgItersToReload.push_back(upstreamMsgIter.get()); | |
237 | } | |
238 | } | |
239 | ||
240 | namespace { | |
241 | ||
242 | const char *msgTypeStr(const bt2::ConstMessage msg) noexcept | |
243 | { | |
244 | return bt_common_message_type_string(static_cast<bt_message_type>(msg.type())); | |
245 | } | |
246 | ||
247 | std::string optLogStr(const char * const str) noexcept | |
248 | { | |
249 | return str ? fmt::format("\"{}\"", str) : "(none)"; | |
250 | } | |
251 | ||
252 | } /* namespace */ | |
253 | ||
254 | void MsgIter::_setClkClsExpectation( | |
255 | const bt2::OptionalBorrowedObject<bt2::ConstClockClass> clkCls) noexcept | |
256 | { | |
257 | BT_ASSERT_DBG(_mClkClsExpectation == _ClkClsExpectation::ANY); | |
258 | ||
259 | /* No initial clock class: also expect none afterwards */ | |
260 | if (!clkCls) { | |
261 | _mClkClsExpectation = _ClkClsExpectation::NONE; | |
262 | return; | |
263 | } | |
264 | ||
265 | /* | |
266 | * This is the first clock class that this message iterator | |
267 | * encounters. Its properties determine what to expect for the whole | |
268 | * lifetime of the iterator. | |
269 | */ | |
270 | if (clkCls->originIsUnixEpoch()) { | |
271 | /* Expect clock classes having a Unix epoch origin*/ | |
272 | _mClkClsExpectation = _ClkClsExpectation::ORIG_IS_UNIX_EPOCH; | |
273 | } else { | |
274 | if (clkCls->uuid()) { | |
275 | /* | |
276 | * Expect clock classes not having a Unix epoch origin and | |
277 | * with a specific UUID. | |
278 | */ | |
279 | _mClkClsExpectation = _ClkClsExpectation::ORIG_ISNT_UNIX_EPOCH_AND_SPEC_UUID; | |
280 | _mExpectedClkClsUuid = *clkCls->uuid(); | |
281 | } else { | |
282 | /* | |
283 | * Expect clock classes not having a Unix epoch origin and | |
284 | * without a UUID. | |
285 | */ | |
286 | _mClkClsExpectation = _ClkClsExpectation::ORIG_ISNT_UNIX_EPOCH_AND_NO_UUID; | |
287 | } | |
288 | } | |
289 | } | |
290 | ||
291 | void MsgIter::_makeSureClkClsIsExpected( | |
292 | const bt2::ConstMessage msg, | |
293 | const bt2::OptionalBorrowedObject<bt2::ConstClockClass> clkCls) const | |
294 | { | |
295 | BT_ASSERT_DBG(_mClkClsExpectation != _ClkClsExpectation::ANY); | |
296 | ||
297 | if (!clkCls) { | |
298 | if (_mClkClsExpectation != _ClkClsExpectation::NONE) { | |
299 | /* | |
300 | * `msg` is a stream beginning message because a message | |
301 | * iterator inactivity message always has a clock class. | |
302 | */ | |
303 | const auto streamCls = msg.asStreamBeginning().stream().cls(); | |
304 | ||
305 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW(bt2::Error, | |
306 | "Expecting a clock class, but got none: " | |
307 | "stream-class-addr={}, stream-class-name=\"{}\", " | |
308 | "stream-class-id={}", | |
309 | static_cast<const void *>(streamCls.libObjPtr()), | |
310 | optLogStr(streamCls.name()), streamCls.id()); | |
311 | } | |
312 | ||
313 | return; | |
314 | } | |
315 | ||
316 | const auto clkClsAddr = static_cast<const void *>(clkCls->libObjPtr()); | |
317 | ||
318 | switch (_mClkClsExpectation) { | |
319 | case _ClkClsExpectation::ORIG_IS_UNIX_EPOCH: | |
320 | if (!clkCls->originIsUnixEpoch()) { | |
321 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW(bt2::Error, | |
322 | "Expecting a clock class having a Unix epoch origin, " | |
323 | "but got one not having a Unix epoch origin: " | |
324 | "clock-class-addr={}, clock-class-name={}", | |
325 | clkClsAddr, optLogStr(clkCls->name())); | |
326 | } | |
327 | ||
328 | break; | |
329 | case _ClkClsExpectation::ORIG_ISNT_UNIX_EPOCH_AND_NO_UUID: | |
330 | BT_ASSERT_DBG(!_mExpectedClkClsUuid); | |
331 | ||
332 | if (clkCls->originIsUnixEpoch()) { | |
333 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW( | |
334 | bt2::Error, | |
335 | "Expecting a clock class not having a Unix epoch origin, " | |
336 | "but got one having a Unix epoch origin: " | |
337 | "clock-class-addr={}, clock-class-name={}", | |
338 | clkClsAddr, optLogStr(clkCls->name())); | |
339 | } | |
340 | ||
341 | if (clkCls->uuid()) { | |
342 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW( | |
343 | bt2::Error, | |
344 | "Expecting a clock class without a UUID, but got one with a UUID: " | |
345 | "clock-class-addr={}, clock-class-name={}, uuid={}", | |
346 | clkClsAddr, optLogStr(clkCls->name()), clkCls->uuid()->str()); | |
347 | } | |
348 | ||
349 | break; | |
350 | case _ClkClsExpectation::ORIG_ISNT_UNIX_EPOCH_AND_SPEC_UUID: | |
351 | BT_ASSERT_DBG(_mExpectedClkClsUuid); | |
352 | ||
353 | if (clkCls->originIsUnixEpoch()) { | |
354 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW( | |
355 | bt2::Error, | |
356 | "Expecting a clock class not having a Unix epoch origin, " | |
357 | "but got one having a Unix epoch origin: " | |
358 | "clock-class-addr={}, clock-class-name={}", | |
359 | clkClsAddr, optLogStr(clkCls->name())); | |
360 | } | |
361 | ||
362 | if (!clkCls->uuid()) { | |
363 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW( | |
364 | bt2::Error, | |
365 | "Expecting a clock class with a UUID, but got one without a UUID: " | |
366 | "clock-class-addr={}, clock-class-name={}", | |
367 | clkClsAddr, optLogStr(clkCls->name())); | |
368 | } | |
369 | ||
370 | if (*clkCls->uuid() != bt2c::UuidView {*_mExpectedClkClsUuid}) { | |
371 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW(bt2::Error, | |
372 | "Expecting a clock class with a specific UUID, " | |
373 | "but got one with a different UUID: " | |
374 | "clock-class-addr={}, clock-class-name={}, " | |
375 | "expected-uuid=\"{}\", uuid=\"{}\"", | |
376 | clkClsAddr, optLogStr(clkCls->name()), | |
377 | _mExpectedClkClsUuid->str(), clkCls->uuid()->str()); | |
378 | } | |
379 | ||
380 | break; | |
381 | case _ClkClsExpectation::NONE: | |
382 | BT_CPPLOGE_APPEND_CAUSE_AND_THROW(bt2::Error, | |
383 | "Expecting no clock class, but got one: " | |
384 | "clock-class-addr={}, clock-class-name={}", | |
385 | clkClsAddr, optLogStr(clkCls->name())); | |
386 | break; | |
387 | default: | |
388 | bt_common_abort(); | |
389 | } | |
390 | } | |
391 | ||
392 | void MsgIter::_validateMsgClkCls(const bt2::ConstMessage msg) | |
393 | { | |
394 | if (G_LIKELY(!msg.isStreamBeginning() && !msg.isMessageIteratorInactivity())) { | |
395 | /* | |
396 | * We don't care about the other types: all the messages related | |
397 | * to a given stream shared the same default clock class, if | |
398 | * any. | |
399 | */ | |
400 | return; | |
401 | } | |
402 | ||
403 | BT_CPPLOGD("Validating the clock class of a message: msg-type={}", msgTypeStr(msg)); | |
404 | ||
405 | /* Get the clock class, if any, of `msg` */ | |
406 | const auto clkCls = bt2c::call([msg]() -> bt2::OptionalBorrowedObject<bt2::ConstClockClass> { | |
407 | if (msg.isStreamBeginning()) { | |
408 | return msg.asStreamBeginning().stream().cls().defaultClockClass(); | |
409 | } else { | |
410 | BT_ASSERT(msg.isMessageIteratorInactivity()); | |
411 | return msg.asMessageIteratorInactivity().clockSnapshot().clockClass(); | |
412 | } | |
413 | }); | |
414 | ||
415 | /* Set the expectation or check it */ | |
416 | if (_mClkClsExpectation == _ClkClsExpectation::ANY) { | |
417 | /* First message: set the expectation */ | |
418 | this->_setClkClsExpectation(clkCls); | |
419 | } else { | |
420 | /* Make sure clock class is expected */ | |
421 | this->_makeSureClkClsIsExpected(msg, clkCls); | |
422 | } | |
423 | } | |
424 | ||
425 | MsgIter::_HeapComparator::_HeapComparator(const bt2c::Logger& logger) : _mLogger {logger} | |
426 | { | |
427 | } | |
428 | ||
429 | bool MsgIter::_HeapComparator::operator()( | |
430 | const UpstreamMsgIter * const upstreamMsgIterA, | |
431 | const UpstreamMsgIter * const upstreamMsgIterB) const noexcept | |
432 | { | |
433 | /* The two messages to compare */ | |
434 | const auto msgA = upstreamMsgIterA->msg(); | |
435 | const auto msgB = upstreamMsgIterB->msg(); | |
436 | auto& msgTsA = upstreamMsgIterA->msgTs(); | |
437 | auto& msgTsB = upstreamMsgIterB->msgTs(); | |
438 | ||
439 | if (_mLogger.wouldLogT()) { | |
440 | BT_CPPLOGT("Comparing two messages: " | |
441 | "port-name-a={}, msg-a-type={}, msg-a-ts={}, " | |
442 | "port-name-b={}, msg-b-type={}, msg-b-ts={}", | |
443 | upstreamMsgIterA->portName(), msgTypeStr(msgA), optMsgTsStr(msgTsA), | |
444 | upstreamMsgIterB->portName(), msgTypeStr(msgB), optMsgTsStr(msgTsB)); | |
445 | } | |
446 | ||
447 | /* | |
448 | * Try to compare using timestamps. | |
449 | * | |
450 | * If both timestamps are set and their values are different, then | |
451 | * use this to establish the ordering of the two messages. | |
452 | * | |
453 | * If one timestamp is set, but not the other, the latter always | |
454 | * wins. This is because, for a given upstream message iterator, we | |
455 | * need to consume all the messages having no timestamp so that we | |
456 | * can reach a message with a timestamp to compare it. | |
457 | * | |
458 | * Otherwise, we'll fall back to using | |
459 | * common_muxing_compare_messages(). | |
460 | */ | |
461 | if (G_LIKELY(msgTsA && msgTsB)) { | |
462 | if (*msgTsA < *msgTsB) { | |
463 | /* | |
464 | * Return `true` because `_mHeap.top()` provides the | |
465 | * "greatest" element. For us, the "greatest" message is | |
466 | * the oldest one, that is, the one having the smallest | |
467 | * timestamp. | |
468 | */ | |
469 | BT_CPPLOGT_STR("Timestamp of message A is less than timestamp of message B: oldest=A"); | |
470 | return true; | |
471 | } else if (*msgTsA > *msgTsB) { | |
472 | BT_CPPLOGT_STR( | |
473 | "Timestamp of message A is greater than timestamp of message B: oldest=B"); | |
474 | return false; | |
475 | } | |
476 | } else if (msgTsA && !msgTsB) { | |
477 | BT_CPPLOGT_STR("Message A has a timestamp, but message B has none: oldest=B"); | |
478 | return false; | |
479 | } else if (!msgTsA && msgTsB) { | |
480 | BT_CPPLOGT_STR("Message B has a timestamp, but message A has none: oldest=A"); | |
481 | return true; | |
482 | } | |
483 | ||
484 | /* | |
485 | * Comparison failed using timestamps: determine an ordering using | |
486 | * arbitrary properties, but in a deterministic way. | |
487 | * | |
488 | * common_muxing_compare_messages() returns less than 0 if the first | |
489 | * message is considered older than the second, which corresponds to | |
490 | * this comparator returning `true`. | |
491 | */ | |
492 | const auto res = common_muxing_compare_messages(msgA.libObjPtr(), msgB.libObjPtr()) < 0; | |
493 | ||
494 | BT_CPPLOGT("Timestamps are considered equal; comparing other properties: oldest={}", | |
495 | res ? "A" : "B"); | |
496 | return res; | |
497 | } | |
498 | ||
499 | } /* namespace bt2mux */ |