source: trip-planner-front/node_modules/readable-stream/lib/_stream_writable.js

Last change on this file was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

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1// Copyright Joyent, Inc. and other Node contributors.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a
4// copy of this software and associated documentation files (the
5// "Software"), to deal in the Software without restriction, including
6// without limitation the rights to use, copy, modify, merge, publish,
7// distribute, sublicense, and/or sell copies of the Software, and to permit
8// persons to whom the Software is furnished to do so, subject to the
9// following conditions:
10//
11// The above copyright notice and this permission notice shall be included
12// in all copies or substantial portions of the Software.
13//
14// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
17// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
18// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
19// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20// USE OR OTHER DEALINGS IN THE SOFTWARE.
21// A bit simpler than readable streams.
22// Implement an async ._write(chunk, encoding, cb), and it'll handle all
23// the drain event emission and buffering.
24'use strict';
25
26module.exports = Writable;
27/* <replacement> */
28
29function WriteReq(chunk, encoding, cb) {
30 this.chunk = chunk;
31 this.encoding = encoding;
32 this.callback = cb;
33 this.next = null;
34} // It seems a linked list but it is not
35// there will be only 2 of these for each stream
36
37
38function CorkedRequest(state) {
39 var _this = this;
40
41 this.next = null;
42 this.entry = null;
43
44 this.finish = function () {
45 onCorkedFinish(_this, state);
46 };
47}
48/* </replacement> */
49
50/*<replacement>*/
51
52
53var Duplex;
54/*</replacement>*/
55
56Writable.WritableState = WritableState;
57/*<replacement>*/
58
59var internalUtil = {
60 deprecate: require('util-deprecate')
61};
62/*</replacement>*/
63
64/*<replacement>*/
65
66var Stream = require('./internal/streams/stream');
67/*</replacement>*/
68
69
70var Buffer = require('buffer').Buffer;
71
72var OurUint8Array = global.Uint8Array || function () {};
73
74function _uint8ArrayToBuffer(chunk) {
75 return Buffer.from(chunk);
76}
77
78function _isUint8Array(obj) {
79 return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
80}
81
82var destroyImpl = require('./internal/streams/destroy');
83
84var _require = require('./internal/streams/state'),
85 getHighWaterMark = _require.getHighWaterMark;
86
87var _require$codes = require('../errors').codes,
88 ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
89 ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
90 ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
91 ERR_STREAM_CANNOT_PIPE = _require$codes.ERR_STREAM_CANNOT_PIPE,
92 ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED,
93 ERR_STREAM_NULL_VALUES = _require$codes.ERR_STREAM_NULL_VALUES,
94 ERR_STREAM_WRITE_AFTER_END = _require$codes.ERR_STREAM_WRITE_AFTER_END,
95 ERR_UNKNOWN_ENCODING = _require$codes.ERR_UNKNOWN_ENCODING;
96
97var errorOrDestroy = destroyImpl.errorOrDestroy;
98
99require('inherits')(Writable, Stream);
100
101function nop() {}
102
103function WritableState(options, stream, isDuplex) {
104 Duplex = Duplex || require('./_stream_duplex');
105 options = options || {}; // Duplex streams are both readable and writable, but share
106 // the same options object.
107 // However, some cases require setting options to different
108 // values for the readable and the writable sides of the duplex stream,
109 // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
110
111 if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex; // object stream flag to indicate whether or not this stream
112 // contains buffers or objects.
113
114 this.objectMode = !!options.objectMode;
115 if (isDuplex) this.objectMode = this.objectMode || !!options.writableObjectMode; // the point at which write() starts returning false
116 // Note: 0 is a valid value, means that we always return false if
117 // the entire buffer is not flushed immediately on write()
118
119 this.highWaterMark = getHighWaterMark(this, options, 'writableHighWaterMark', isDuplex); // if _final has been called
120
121 this.finalCalled = false; // drain event flag.
122
123 this.needDrain = false; // at the start of calling end()
124
125 this.ending = false; // when end() has been called, and returned
126
127 this.ended = false; // when 'finish' is emitted
128
129 this.finished = false; // has it been destroyed
130
131 this.destroyed = false; // should we decode strings into buffers before passing to _write?
132 // this is here so that some node-core streams can optimize string
133 // handling at a lower level.
134
135 var noDecode = options.decodeStrings === false;
136 this.decodeStrings = !noDecode; // Crypto is kind of old and crusty. Historically, its default string
137 // encoding is 'binary' so we have to make this configurable.
138 // Everything else in the universe uses 'utf8', though.
139
140 this.defaultEncoding = options.defaultEncoding || 'utf8'; // not an actual buffer we keep track of, but a measurement
141 // of how much we're waiting to get pushed to some underlying
142 // socket or file.
143
144 this.length = 0; // a flag to see when we're in the middle of a write.
145
146 this.writing = false; // when true all writes will be buffered until .uncork() call
147
148 this.corked = 0; // a flag to be able to tell if the onwrite cb is called immediately,
149 // or on a later tick. We set this to true at first, because any
150 // actions that shouldn't happen until "later" should generally also
151 // not happen before the first write call.
152
153 this.sync = true; // a flag to know if we're processing previously buffered items, which
154 // may call the _write() callback in the same tick, so that we don't
155 // end up in an overlapped onwrite situation.
156
157 this.bufferProcessing = false; // the callback that's passed to _write(chunk,cb)
158
159 this.onwrite = function (er) {
160 onwrite(stream, er);
161 }; // the callback that the user supplies to write(chunk,encoding,cb)
162
163
164 this.writecb = null; // the amount that is being written when _write is called.
165
166 this.writelen = 0;
167 this.bufferedRequest = null;
168 this.lastBufferedRequest = null; // number of pending user-supplied write callbacks
169 // this must be 0 before 'finish' can be emitted
170
171 this.pendingcb = 0; // emit prefinish if the only thing we're waiting for is _write cbs
172 // This is relevant for synchronous Transform streams
173
174 this.prefinished = false; // True if the error was already emitted and should not be thrown again
175
176 this.errorEmitted = false; // Should close be emitted on destroy. Defaults to true.
177
178 this.emitClose = options.emitClose !== false; // Should .destroy() be called after 'finish' (and potentially 'end')
179
180 this.autoDestroy = !!options.autoDestroy; // count buffered requests
181
182 this.bufferedRequestCount = 0; // allocate the first CorkedRequest, there is always
183 // one allocated and free to use, and we maintain at most two
184
185 this.corkedRequestsFree = new CorkedRequest(this);
186}
187
188WritableState.prototype.getBuffer = function getBuffer() {
189 var current = this.bufferedRequest;
190 var out = [];
191
192 while (current) {
193 out.push(current);
194 current = current.next;
195 }
196
197 return out;
198};
199
200(function () {
201 try {
202 Object.defineProperty(WritableState.prototype, 'buffer', {
203 get: internalUtil.deprecate(function writableStateBufferGetter() {
204 return this.getBuffer();
205 }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003')
206 });
207 } catch (_) {}
208})(); // Test _writableState for inheritance to account for Duplex streams,
209// whose prototype chain only points to Readable.
210
211
212var realHasInstance;
213
214if (typeof Symbol === 'function' && Symbol.hasInstance && typeof Function.prototype[Symbol.hasInstance] === 'function') {
215 realHasInstance = Function.prototype[Symbol.hasInstance];
216 Object.defineProperty(Writable, Symbol.hasInstance, {
217 value: function value(object) {
218 if (realHasInstance.call(this, object)) return true;
219 if (this !== Writable) return false;
220 return object && object._writableState instanceof WritableState;
221 }
222 });
223} else {
224 realHasInstance = function realHasInstance(object) {
225 return object instanceof this;
226 };
227}
228
229function Writable(options) {
230 Duplex = Duplex || require('./_stream_duplex'); // Writable ctor is applied to Duplexes, too.
231 // `realHasInstance` is necessary because using plain `instanceof`
232 // would return false, as no `_writableState` property is attached.
233 // Trying to use the custom `instanceof` for Writable here will also break the
234 // Node.js LazyTransform implementation, which has a non-trivial getter for
235 // `_writableState` that would lead to infinite recursion.
236 // Checking for a Stream.Duplex instance is faster here instead of inside
237 // the WritableState constructor, at least with V8 6.5
238
239 var isDuplex = this instanceof Duplex;
240 if (!isDuplex && !realHasInstance.call(Writable, this)) return new Writable(options);
241 this._writableState = new WritableState(options, this, isDuplex); // legacy.
242
243 this.writable = true;
244
245 if (options) {
246 if (typeof options.write === 'function') this._write = options.write;
247 if (typeof options.writev === 'function') this._writev = options.writev;
248 if (typeof options.destroy === 'function') this._destroy = options.destroy;
249 if (typeof options.final === 'function') this._final = options.final;
250 }
251
252 Stream.call(this);
253} // Otherwise people can pipe Writable streams, which is just wrong.
254
255
256Writable.prototype.pipe = function () {
257 errorOrDestroy(this, new ERR_STREAM_CANNOT_PIPE());
258};
259
260function writeAfterEnd(stream, cb) {
261 var er = new ERR_STREAM_WRITE_AFTER_END(); // TODO: defer error events consistently everywhere, not just the cb
262
263 errorOrDestroy(stream, er);
264 process.nextTick(cb, er);
265} // Checks that a user-supplied chunk is valid, especially for the particular
266// mode the stream is in. Currently this means that `null` is never accepted
267// and undefined/non-string values are only allowed in object mode.
268
269
270function validChunk(stream, state, chunk, cb) {
271 var er;
272
273 if (chunk === null) {
274 er = new ERR_STREAM_NULL_VALUES();
275 } else if (typeof chunk !== 'string' && !state.objectMode) {
276 er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer'], chunk);
277 }
278
279 if (er) {
280 errorOrDestroy(stream, er);
281 process.nextTick(cb, er);
282 return false;
283 }
284
285 return true;
286}
287
288Writable.prototype.write = function (chunk, encoding, cb) {
289 var state = this._writableState;
290 var ret = false;
291
292 var isBuf = !state.objectMode && _isUint8Array(chunk);
293
294 if (isBuf && !Buffer.isBuffer(chunk)) {
295 chunk = _uint8ArrayToBuffer(chunk);
296 }
297
298 if (typeof encoding === 'function') {
299 cb = encoding;
300 encoding = null;
301 }
302
303 if (isBuf) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding;
304 if (typeof cb !== 'function') cb = nop;
305 if (state.ending) writeAfterEnd(this, cb);else if (isBuf || validChunk(this, state, chunk, cb)) {
306 state.pendingcb++;
307 ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb);
308 }
309 return ret;
310};
311
312Writable.prototype.cork = function () {
313 this._writableState.corked++;
314};
315
316Writable.prototype.uncork = function () {
317 var state = this._writableState;
318
319 if (state.corked) {
320 state.corked--;
321 if (!state.writing && !state.corked && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state);
322 }
323};
324
325Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
326 // node::ParseEncoding() requires lower case.
327 if (typeof encoding === 'string') encoding = encoding.toLowerCase();
328 if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new ERR_UNKNOWN_ENCODING(encoding);
329 this._writableState.defaultEncoding = encoding;
330 return this;
331};
332
333Object.defineProperty(Writable.prototype, 'writableBuffer', {
334 // making it explicit this property is not enumerable
335 // because otherwise some prototype manipulation in
336 // userland will fail
337 enumerable: false,
338 get: function get() {
339 return this._writableState && this._writableState.getBuffer();
340 }
341});
342
343function decodeChunk(state, chunk, encoding) {
344 if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') {
345 chunk = Buffer.from(chunk, encoding);
346 }
347
348 return chunk;
349}
350
351Object.defineProperty(Writable.prototype, 'writableHighWaterMark', {
352 // making it explicit this property is not enumerable
353 // because otherwise some prototype manipulation in
354 // userland will fail
355 enumerable: false,
356 get: function get() {
357 return this._writableState.highWaterMark;
358 }
359}); // if we're already writing something, then just put this
360// in the queue, and wait our turn. Otherwise, call _write
361// If we return false, then we need a drain event, so set that flag.
362
363function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) {
364 if (!isBuf) {
365 var newChunk = decodeChunk(state, chunk, encoding);
366
367 if (chunk !== newChunk) {
368 isBuf = true;
369 encoding = 'buffer';
370 chunk = newChunk;
371 }
372 }
373
374 var len = state.objectMode ? 1 : chunk.length;
375 state.length += len;
376 var ret = state.length < state.highWaterMark; // we must ensure that previous needDrain will not be reset to false.
377
378 if (!ret) state.needDrain = true;
379
380 if (state.writing || state.corked) {
381 var last = state.lastBufferedRequest;
382 state.lastBufferedRequest = {
383 chunk: chunk,
384 encoding: encoding,
385 isBuf: isBuf,
386 callback: cb,
387 next: null
388 };
389
390 if (last) {
391 last.next = state.lastBufferedRequest;
392 } else {
393 state.bufferedRequest = state.lastBufferedRequest;
394 }
395
396 state.bufferedRequestCount += 1;
397 } else {
398 doWrite(stream, state, false, len, chunk, encoding, cb);
399 }
400
401 return ret;
402}
403
404function doWrite(stream, state, writev, len, chunk, encoding, cb) {
405 state.writelen = len;
406 state.writecb = cb;
407 state.writing = true;
408 state.sync = true;
409 if (state.destroyed) state.onwrite(new ERR_STREAM_DESTROYED('write'));else if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite);
410 state.sync = false;
411}
412
413function onwriteError(stream, state, sync, er, cb) {
414 --state.pendingcb;
415
416 if (sync) {
417 // defer the callback if we are being called synchronously
418 // to avoid piling up things on the stack
419 process.nextTick(cb, er); // this can emit finish, and it will always happen
420 // after error
421
422 process.nextTick(finishMaybe, stream, state);
423 stream._writableState.errorEmitted = true;
424 errorOrDestroy(stream, er);
425 } else {
426 // the caller expect this to happen before if
427 // it is async
428 cb(er);
429 stream._writableState.errorEmitted = true;
430 errorOrDestroy(stream, er); // this can emit finish, but finish must
431 // always follow error
432
433 finishMaybe(stream, state);
434 }
435}
436
437function onwriteStateUpdate(state) {
438 state.writing = false;
439 state.writecb = null;
440 state.length -= state.writelen;
441 state.writelen = 0;
442}
443
444function onwrite(stream, er) {
445 var state = stream._writableState;
446 var sync = state.sync;
447 var cb = state.writecb;
448 if (typeof cb !== 'function') throw new ERR_MULTIPLE_CALLBACK();
449 onwriteStateUpdate(state);
450 if (er) onwriteError(stream, state, sync, er, cb);else {
451 // Check if we're actually ready to finish, but don't emit yet
452 var finished = needFinish(state) || stream.destroyed;
453
454 if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) {
455 clearBuffer(stream, state);
456 }
457
458 if (sync) {
459 process.nextTick(afterWrite, stream, state, finished, cb);
460 } else {
461 afterWrite(stream, state, finished, cb);
462 }
463 }
464}
465
466function afterWrite(stream, state, finished, cb) {
467 if (!finished) onwriteDrain(stream, state);
468 state.pendingcb--;
469 cb();
470 finishMaybe(stream, state);
471} // Must force callback to be called on nextTick, so that we don't
472// emit 'drain' before the write() consumer gets the 'false' return
473// value, and has a chance to attach a 'drain' listener.
474
475
476function onwriteDrain(stream, state) {
477 if (state.length === 0 && state.needDrain) {
478 state.needDrain = false;
479 stream.emit('drain');
480 }
481} // if there's something in the buffer waiting, then process it
482
483
484function clearBuffer(stream, state) {
485 state.bufferProcessing = true;
486 var entry = state.bufferedRequest;
487
488 if (stream._writev && entry && entry.next) {
489 // Fast case, write everything using _writev()
490 var l = state.bufferedRequestCount;
491 var buffer = new Array(l);
492 var holder = state.corkedRequestsFree;
493 holder.entry = entry;
494 var count = 0;
495 var allBuffers = true;
496
497 while (entry) {
498 buffer[count] = entry;
499 if (!entry.isBuf) allBuffers = false;
500 entry = entry.next;
501 count += 1;
502 }
503
504 buffer.allBuffers = allBuffers;
505 doWrite(stream, state, true, state.length, buffer, '', holder.finish); // doWrite is almost always async, defer these to save a bit of time
506 // as the hot path ends with doWrite
507
508 state.pendingcb++;
509 state.lastBufferedRequest = null;
510
511 if (holder.next) {
512 state.corkedRequestsFree = holder.next;
513 holder.next = null;
514 } else {
515 state.corkedRequestsFree = new CorkedRequest(state);
516 }
517
518 state.bufferedRequestCount = 0;
519 } else {
520 // Slow case, write chunks one-by-one
521 while (entry) {
522 var chunk = entry.chunk;
523 var encoding = entry.encoding;
524 var cb = entry.callback;
525 var len = state.objectMode ? 1 : chunk.length;
526 doWrite(stream, state, false, len, chunk, encoding, cb);
527 entry = entry.next;
528 state.bufferedRequestCount--; // if we didn't call the onwrite immediately, then
529 // it means that we need to wait until it does.
530 // also, that means that the chunk and cb are currently
531 // being processed, so move the buffer counter past them.
532
533 if (state.writing) {
534 break;
535 }
536 }
537
538 if (entry === null) state.lastBufferedRequest = null;
539 }
540
541 state.bufferedRequest = entry;
542 state.bufferProcessing = false;
543}
544
545Writable.prototype._write = function (chunk, encoding, cb) {
546 cb(new ERR_METHOD_NOT_IMPLEMENTED('_write()'));
547};
548
549Writable.prototype._writev = null;
550
551Writable.prototype.end = function (chunk, encoding, cb) {
552 var state = this._writableState;
553
554 if (typeof chunk === 'function') {
555 cb = chunk;
556 chunk = null;
557 encoding = null;
558 } else if (typeof encoding === 'function') {
559 cb = encoding;
560 encoding = null;
561 }
562
563 if (chunk !== null && chunk !== undefined) this.write(chunk, encoding); // .end() fully uncorks
564
565 if (state.corked) {
566 state.corked = 1;
567 this.uncork();
568 } // ignore unnecessary end() calls.
569
570
571 if (!state.ending) endWritable(this, state, cb);
572 return this;
573};
574
575Object.defineProperty(Writable.prototype, 'writableLength', {
576 // making it explicit this property is not enumerable
577 // because otherwise some prototype manipulation in
578 // userland will fail
579 enumerable: false,
580 get: function get() {
581 return this._writableState.length;
582 }
583});
584
585function needFinish(state) {
586 return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;
587}
588
589function callFinal(stream, state) {
590 stream._final(function (err) {
591 state.pendingcb--;
592
593 if (err) {
594 errorOrDestroy(stream, err);
595 }
596
597 state.prefinished = true;
598 stream.emit('prefinish');
599 finishMaybe(stream, state);
600 });
601}
602
603function prefinish(stream, state) {
604 if (!state.prefinished && !state.finalCalled) {
605 if (typeof stream._final === 'function' && !state.destroyed) {
606 state.pendingcb++;
607 state.finalCalled = true;
608 process.nextTick(callFinal, stream, state);
609 } else {
610 state.prefinished = true;
611 stream.emit('prefinish');
612 }
613 }
614}
615
616function finishMaybe(stream, state) {
617 var need = needFinish(state);
618
619 if (need) {
620 prefinish(stream, state);
621
622 if (state.pendingcb === 0) {
623 state.finished = true;
624 stream.emit('finish');
625
626 if (state.autoDestroy) {
627 // In case of duplex streams we need a way to detect
628 // if the readable side is ready for autoDestroy as well
629 var rState = stream._readableState;
630
631 if (!rState || rState.autoDestroy && rState.endEmitted) {
632 stream.destroy();
633 }
634 }
635 }
636 }
637
638 return need;
639}
640
641function endWritable(stream, state, cb) {
642 state.ending = true;
643 finishMaybe(stream, state);
644
645 if (cb) {
646 if (state.finished) process.nextTick(cb);else stream.once('finish', cb);
647 }
648
649 state.ended = true;
650 stream.writable = false;
651}
652
653function onCorkedFinish(corkReq, state, err) {
654 var entry = corkReq.entry;
655 corkReq.entry = null;
656
657 while (entry) {
658 var cb = entry.callback;
659 state.pendingcb--;
660 cb(err);
661 entry = entry.next;
662 } // reuse the free corkReq.
663
664
665 state.corkedRequestsFree.next = corkReq;
666}
667
668Object.defineProperty(Writable.prototype, 'destroyed', {
669 // making it explicit this property is not enumerable
670 // because otherwise some prototype manipulation in
671 // userland will fail
672 enumerable: false,
673 get: function get() {
674 if (this._writableState === undefined) {
675 return false;
676 }
677
678 return this._writableState.destroyed;
679 },
680 set: function set(value) {
681 // we ignore the value if the stream
682 // has not been initialized yet
683 if (!this._writableState) {
684 return;
685 } // backward compatibility, the user is explicitly
686 // managing destroyed
687
688
689 this._writableState.destroyed = value;
690 }
691});
692Writable.prototype.destroy = destroyImpl.destroy;
693Writable.prototype._undestroy = destroyImpl.undestroy;
694
695Writable.prototype._destroy = function (err, cb) {
696 cb(err);
697};
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