All files / lib/internal/streams writable.js

98.24% Statements 896/912
95.98% Branches 287/299
94.11% Functions 48/51
98.24% Lines 896/912

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 91332x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 32x 249040x 32x 32x 32x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 88642x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 93866x 32x 112998x 112998x 112998x 112998x 112998x 112998x 32x 32x 63x 32x 32x 32x 32x 11x 11x 32x 32x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93886x 93866x 93866x 93866x 93886x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 71202x 93859x 93859x 93859x 93859x 67x 67x 67x 67x 67x 67x 67x 93859x 93886x 32x 32x 32x 866x 19x 5x 866x 32x 32x 32x 32x 32x 1x 32x 32x 392733x 392733x 392733x 392733x 55590x 55590x 389146x 337143x 337143x 37969x 37969x 337141x 337141x 337143x 392731x 392733x 7x 392733x 389508x 118756x 51404x 51404x 51404x 389489x 270701x 270752x 30x 30x 51x 21x 21x 21x 389508x 392703x 392703x 392714x 23x 392720x 15x 15x 392703x 392714x 38x 38x 38x 38x 392665x 392665x 392733x 32x 32x 388777x 32x 32x 32x 44703x 32x 32x 32x 47471x 47471x 47471x 44791x 44791x 44791x 44791x 44791x 32x 32x 32x 8x 8x 8x 8x 8x 7x 7x 32x 32x 32x 32x 32x 392663x 392663x 392663x 392663x 392663x 392663x 392663x 392663x 392663x 392663x 392663x 392663x 133251x 133251x 16832x 16832x 133251x 17815x 17815x 392601x 259412x 259412x 259412x 259412x 259412x 259412x 259412x 392512x 392512x 392512x 392663x 392663x 32x 24336x 24336x 24336x 24336x 24336x 24336x 24336x 24335x 24335x 10595x 10595x 24328x 24336x 32x 57x 57x 57x 57x 57x 57x 57x 57x 57x 57x 57x 57x 32x 282575x 282575x 282575x 282575x 282575x 282575x 6x 6x 6x 282569x 282569x 282569x 282569x 282569x 282569x 282575x 57x 57x 57x 57x 55x 55x 57x 57x 57x 57x 25x 25x 57x 57x 33x 49x 24x 24x 282575x 282512x 19763x 19763x 282510x 282511x 251642x 251642x 251642x 251642x 251642x 251642x 193763x 251388x 57879x 57879x 57879x 282511x 30868x 30868x 282512x 282575x 32x 57712x 57712x 57712x 57712x 32x 88580x 88580x 88580x 88580x 26976x 26976x 26976x 88580x 88580x 282064x 282064x 282064x 88577x 88579x 103x 103x 88577x 88577x 88580x 32x 32x 169x 169x 5x 5x 164x 169x 15x 15x 15x 15x 15x 164x 164x 168x 11x 11x 164x 164x 169x 32x 32x 64592x 64592x 64592x 64592x 64592x 13556x 13556x 51036x 51036x 51036x 51036x 64591x 26725x 26725x 24311x 24311x 24311x 24311x 64592x 13741x 13741x 13741x 13265x 75137x 75137x 13741x 13741x 13741x 13741x 13741x 13741x 13741x 13741x 13741x 13741x 43528x 10570x 10596x 10596x 10596x 10596x 10570x 10570x 10570x 5235x 10562x     5327x 5327x 5327x 10570x 24302x 64592x 32x 32x 5996x 5995x 5996x 1x 1x 32x 32x 32x 32x 32x 39816x 39816x 39816x 669x 669x 669x 39638x 1025x 1025x 1025x 39816x 39816x 39816x 39816x 3957x 3957x 2x 2x 3957x 39665x 39665x 39815x 2611x 2611x 2611x 39665x 39816x 2x 39816x 37144x 37144x 37144x 37144x 37144x 37144x 37144x 37144x 37144x 39651x 29x 2516x 86x 86x 39664x 39816x 1696x 4x 1696x 1692x 1692x 1696x 39664x 39664x 32x 32x 162427x 162427x 162427x 162427x 162427x 162427x 162427x 162427x 162427x 162427x 162427x 162427x 32x 36464x 36464x 36464x 36464x 36427x       36427x 36427x 36427x 36427x 6x 6x     6x 36427x 36399x 36399x 36399x 36399x 36399x 36399x 36399x 36399x 36427x 36464x 36464x 36464x 36464x 36464x 36464x 36464x 1x 1x 36464x 36464x 36464x 32x 39939x 39939x 36680x 36464x 36464x 36672x 216x 216x 216x 36680x 39939x 32x 125787x 125787x 39939x 39939x 219x 89x 89x 89x 72x 86x 17x 17x 89x 217x 129x 129x 129x 219x 39939x 125787x 32x 36593x 36593x 36593x 36593x 36593x 36593x 1671x 1671x 36593x 36593x 36593x 36593x 11152x 11152x 11152x 11152x 10968x 10968x 10968x 10968x 11152x 11152x 5814x 5814x 11152x 36593x 32x 32x 32x 32x 32x 216x 216x 32x 32x 32x 32x 41910x 32x 32x 2x 2x 1x 1x 2x 32x 32x 32x 32x 125103x 125103x 125103x 125103x 125103x 125103x 125103x 32x 32x 10998x 10998x 10998x 10998x 10998x 32x 32x 32x 32x 57661x 57661x 32x 32x 32x 32x 53x 53x 32x 32x 32x 32x 64x 64x 32x 32x 32x 32x 13799x 13799x 32x 32x 32x 32x 2842x 2842x 2842x 2842x 32x 32x 32x 32x 57673x 57673x 32x 32x 32x 32x 7157x 7157x 32x 32x 32x 32x 7433x 7433x 32x 32x 32x 32x 32x 2x 2x 32x 32x 32x 32x 32x 4x 4x 4x 2x 4x 4x 32x 32x 32x 32x 32x 330x 330x 330x 330x 311x 330x 9x 9x 330x 330x 330x 32x 32x 32x 32x 220x 32x 32x 32x 2x 32x 32x 32x 32x 32x           32x 32x       32x 32x 32x   32x  
// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
 
// A bit simpler than readable streams.
// Implement an async ._write(chunk, encoding, cb), and it'll handle all
// the drain event emission and buffering.
 
'use strict';
 
const {
  ArrayPrototypeSlice,
  Error,
  FunctionPrototypeSymbolHasInstance,
  ObjectDefineProperty,
  ObjectDefineProperties,
  ObjectSetPrototypeOf,
  StringPrototypeToLowerCase,
  Symbol,
  SymbolHasInstance,
} = primordials;
 
module.exports = Writable;
Writable.WritableState = WritableState;
 
const EE = require('events');
const Stream = require('internal/streams/legacy').Stream;
const { Buffer } = require('buffer');
const destroyImpl = require('internal/streams/destroy');
 
const {
  addAbortSignal,
} = require('internal/streams/add-abort-signal');
 
const {
  getHighWaterMark,
  getDefaultHighWaterMark
} = require('internal/streams/state');
const {
  ERR_INVALID_ARG_TYPE,
  ERR_METHOD_NOT_IMPLEMENTED,
  ERR_MULTIPLE_CALLBACK,
  ERR_STREAM_CANNOT_PIPE,
  ERR_STREAM_DESTROYED,
  ERR_STREAM_ALREADY_FINISHED,
  ERR_STREAM_NULL_VALUES,
  ERR_STREAM_WRITE_AFTER_END,
  ERR_UNKNOWN_ENCODING
} = require('internal/errors').codes;
 
const { errorOrDestroy } = destroyImpl;
 
ObjectSetPrototypeOf(Writable.prototype, Stream.prototype);
ObjectSetPrototypeOf(Writable, Stream);
 
function nop() {}
 
const kOnFinished = Symbol('kOnFinished');
 
function WritableState(options, stream, isDuplex) {
  // Duplex streams are both readable and writable, but share
  // the same options object.
  // However, some cases require setting options to different
  // values for the readable and the writable sides of the duplex stream,
  // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
  if (typeof isDuplex !== 'boolean')
    isDuplex = stream instanceof Stream.Duplex;
 
  // Object stream flag to indicate whether or not this stream
  // contains buffers or objects.
  this.objectMode = !!(options && options.objectMode);
 
  if (isDuplex)
    this.objectMode = this.objectMode ||
      !!(options && options.writableObjectMode);
 
  // The point at which write() starts returning false
  // Note: 0 is a valid value, means that we always return false if
  // the entire buffer is not flushed immediately on write().
  this.highWaterMark = options ?
    getHighWaterMark(this, options, 'writableHighWaterMark', isDuplex) :
    getDefaultHighWaterMark(false);
 
  // if _final has been called.
  this.finalCalled = false;
 
  // drain event flag.
  this.needDrain = false;
  // At the start of calling end()
  this.ending = false;
  // When end() has been called, and returned.
  this.ended = false;
  // When 'finish' is emitted.
  this.finished = false;
 
  // Has it been destroyed
  this.destroyed = false;
 
  // Should we decode strings into buffers before passing to _write?
  // this is here so that some node-core streams can optimize string
  // handling at a lower level.
  const noDecode = !!(options && options.decodeStrings === false);
  this.decodeStrings = !noDecode;
 
  // Crypto is kind of old and crusty.  Historically, its default string
  // encoding is 'binary' so we have to make this configurable.
  // Everything else in the universe uses 'utf8', though.
  this.defaultEncoding = (options && options.defaultEncoding) || 'utf8';
 
  // Not an actual buffer we keep track of, but a measurement
  // of how much we're waiting to get pushed to some underlying
  // socket or file.
  this.length = 0;
 
  // A flag to see when we're in the middle of a write.
  this.writing = false;
 
  // When true all writes will be buffered until .uncork() call.
  this.corked = 0;
 
  // A flag to be able to tell if the onwrite cb is called immediately,
  // or on a later tick.  We set this to true at first, because any
  // actions that shouldn't happen until "later" should generally also
  // not happen before the first write call.
  this.sync = true;
 
  // A flag to know if we're processing previously buffered items, which
  // may call the _write() callback in the same tick, so that we don't
  // end up in an overlapped onwrite situation.
  this.bufferProcessing = false;
 
  // The callback that's passed to _write(chunk, cb).
  this.onwrite = onwrite.bind(undefined, stream);
 
  // The callback that the user supplies to write(chunk, encoding, cb).
  this.writecb = null;
 
  // The amount that is being written when _write is called.
  this.writelen = 0;
 
  // Storage for data passed to the afterWrite() callback in case of
  // synchronous _write() completion.
  this.afterWriteTickInfo = null;
 
  resetBuffer(this);
 
  // Number of pending user-supplied write callbacks
  // this must be 0 before 'finish' can be emitted.
  this.pendingcb = 0;
 
  // Stream is still being constructed and cannot be
  // destroyed until construction finished or failed.
  // Async construction is opt in, therefore we start as
  // constructed.
  this.constructed = true;
 
  // Emit prefinish if the only thing we're waiting for is _write cbs
  // This is relevant for synchronous Transform streams.
  this.prefinished = false;
 
  // True if the error was already emitted and should not be thrown again.
  this.errorEmitted = false;
 
  // Should close be emitted on destroy. Defaults to true.
  this.emitClose = !options || options.emitClose !== false;
 
  // Should .destroy() be called after 'finish' (and potentially 'end').
  this.autoDestroy = !options || options.autoDestroy !== false;
 
  // Indicates whether the stream has errored. When true all write() calls
  // should return false. This is needed since when autoDestroy
  // is disabled we need a way to tell whether the stream has failed.
  this.errored = null;
 
  // Indicates whether the stream has finished destroying.
  this.closed = false;
 
  // True if close has been emitted or would have been emitted
  // depending on emitClose.
  this.closeEmitted = false;
 
  this[kOnFinished] = [];
}
 
function resetBuffer(state) {
  state.buffered = [];
  state.bufferedIndex = 0;
  state.allBuffers = true;
  state.allNoop = true;
}
 
WritableState.prototype.getBuffer = function getBuffer() {
  return ArrayPrototypeSlice(this.buffered, this.bufferedIndex);
};
 
ObjectDefineProperty(WritableState.prototype, 'bufferedRequestCount', {
  get() {
    return this.buffered.length - this.bufferedIndex;
  }
});
 
function Writable(options) {
  // Writable ctor is applied to Duplexes, too.
  // `realHasInstance` is necessary because using plain `instanceof`
  // would return false, as no `_writableState` property is attached.
 
  // Trying to use the custom `instanceof` for Writable here will also break the
  // Node.js LazyTransform implementation, which has a non-trivial getter for
  // `_writableState` that would lead to infinite recursion.
 
  // Checking for a Stream.Duplex instance is faster here instead of inside
  // the WritableState constructor, at least with V8 6.5.
  const isDuplex = (this instanceof Stream.Duplex);
 
  if (!isDuplex && !FunctionPrototypeSymbolHasInstance(Writable, this))
    return new Writable(options);
 
  this._writableState = new WritableState(options, this, isDuplex);
 
  if (options) {
    if (typeof options.write === 'function')
      this._write = options.write;
 
    if (typeof options.writev === 'function')
      this._writev = options.writev;
 
    if (typeof options.destroy === 'function')
      this._destroy = options.destroy;
 
    if (typeof options.final === 'function')
      this._final = options.final;
 
    if (typeof options.construct === 'function')
      this._construct = options.construct;
 
    if (options.signal)
      addAbortSignal(options.signal, this);
  }
 
  Stream.call(this, options);
 
  destroyImpl.construct(this, () => {
    const state = this._writableState;
 
    if (!state.writing) {
      clearBuffer(this, state);
    }
 
    finishMaybe(this, state);
  });
}
 
ObjectDefineProperty(Writable, SymbolHasInstance, {
  value: function(object) {
    if (FunctionPrototypeSymbolHasInstance(this, object)) return true;
    if (this !== Writable) return false;
 
    return object && object._writableState instanceof WritableState;
  },
});
 
// Otherwise people can pipe Writable streams, which is just wrong.
Writable.prototype.pipe = function() {
  errorOrDestroy(this, new ERR_STREAM_CANNOT_PIPE());
};
 
function _write(stream, chunk, encoding, cb) {
  const state = stream._writableState;
 
  if (typeof encoding === 'function') {
    cb = encoding;
    encoding = state.defaultEncoding;
  } else {
    if (!encoding)
      encoding = state.defaultEncoding;
    else if (encoding !== 'buffer' && !Buffer.isEncoding(encoding))
      throw new ERR_UNKNOWN_ENCODING(encoding);
    if (typeof cb !== 'function')
      cb = nop;
  }
 
  if (chunk === null) {
    throw new ERR_STREAM_NULL_VALUES();
  } else if (!state.objectMode) {
    if (typeof chunk === 'string') {
      if (state.decodeStrings !== false) {
        chunk = Buffer.from(chunk, encoding);
        encoding = 'buffer';
      }
    } else if (chunk instanceof Buffer) {
      encoding = 'buffer';
    } else if (Stream._isUint8Array(chunk)) {
      chunk = Stream._uint8ArrayToBuffer(chunk);
      encoding = 'buffer';
    } else {
      throw new ERR_INVALID_ARG_TYPE(
        'chunk', ['string', 'Buffer', 'Uint8Array'], chunk);
    }
  }
 
  let err;
  if (state.ending) {
    err = new ERR_STREAM_WRITE_AFTER_END();
  } else if (state.destroyed) {
    err = new ERR_STREAM_DESTROYED('write');
  }
 
  if (err) {
    process.nextTick(cb, err);
    errorOrDestroy(stream, err, true);
    return err;
  }
  state.pendingcb++;
  return writeOrBuffer(stream, state, chunk, encoding, cb);
}
 
Writable.prototype.write = function(chunk, encoding, cb) {
  return _write(this, chunk, encoding, cb) === true;
};
 
Writable.prototype.cork = function() {
  this._writableState.corked++;
};
 
Writable.prototype.uncork = function() {
  const state = this._writableState;
 
  if (state.corked) {
    state.corked--;
 
    if (!state.writing)
      clearBuffer(this, state);
  }
};
 
Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
  // node::ParseEncoding() requires lower case.
  if (typeof encoding === 'string')
    encoding = StringPrototypeToLowerCase(encoding);
  if (!Buffer.isEncoding(encoding))
    throw new ERR_UNKNOWN_ENCODING(encoding);
  this._writableState.defaultEncoding = encoding;
  return this;
};
 
// If we're already writing something, then just put this
// in the queue, and wait our turn.  Otherwise, call _write
// If we return false, then we need a drain event, so set that flag.
function writeOrBuffer(stream, state, chunk, encoding, callback) {
  const len = state.objectMode ? 1 : chunk.length;
 
  state.length += len;
 
  // stream._write resets state.length
  const ret = state.length < state.highWaterMark;
  // We must ensure that previous needDrain will not be reset to false.
  if (!ret)
    state.needDrain = true;
 
  if (state.writing || state.corked || state.errored || !state.constructed) {
    state.buffered.push({ chunk, encoding, callback });
    if (state.allBuffers && encoding !== 'buffer') {
      state.allBuffers = false;
    }
    if (state.allNoop && callback !== nop) {
      state.allNoop = false;
    }
  } else {
    state.writelen = len;
    state.writecb = callback;
    state.writing = true;
    state.sync = true;
    stream._write(chunk, encoding, state.onwrite);
    state.sync = false;
  }
 
  // Return false if errored or destroyed in order to break
  // any synchronous while(stream.write(data)) loops.
  return ret && !state.errored && !state.destroyed;
}
 
function doWrite(stream, state, writev, len, chunk, encoding, cb) {
  state.writelen = len;
  state.writecb = cb;
  state.writing = true;
  state.sync = true;
  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);
  state.sync = false;
}
 
function onwriteError(stream, state, er, cb) {
  --state.pendingcb;
 
  cb(er);
  // Ensure callbacks are invoked even when autoDestroy is
  // not enabled. Passing `er` here doesn't make sense since
  // it's related to one specific write, not to the buffered
  // writes.
  errorBuffer(state);
  // This can emit error, but error must always follow cb.
  errorOrDestroy(stream, er);
}
 
function onwrite(stream, er) {
  const state = stream._writableState;
  const sync = state.sync;
  const cb = state.writecb;
 
  if (typeof cb !== 'function') {
    errorOrDestroy(stream, new ERR_MULTIPLE_CALLBACK());
    return;
  }
 
  state.writing = false;
  state.writecb = null;
  state.length -= state.writelen;
  state.writelen = 0;
 
  if (er) {
    // Avoid V8 leak, https://github.com/nodejs/node/pull/34103#issuecomment-652002364
    er.stack; // eslint-disable-line no-unused-expressions
 
    if (!state.errored) {
      state.errored = er;
    }
 
    // In case of duplex streams we need to notify the readable side of the
    // error.
    if (stream._readableState && !stream._readableState.errored) {
      stream._readableState.errored = er;
    }
 
    if (sync) {
      process.nextTick(onwriteError, stream, state, er, cb);
    } else {
      onwriteError(stream, state, er, cb);
    }
  } else {
    if (state.buffered.length > state.bufferedIndex) {
      clearBuffer(stream, state);
    }
 
    if (sync) {
      // It is a common case that the callback passed to .write() is always
      // the same. In that case, we do not schedule a new nextTick(), but
      // rather just increase a counter, to improve performance and avoid
      // memory allocations.
      if (state.afterWriteTickInfo !== null &&
          state.afterWriteTickInfo.cb === cb) {
        state.afterWriteTickInfo.count++;
      } else {
        state.afterWriteTickInfo = { count: 1, cb, stream, state };
        process.nextTick(afterWriteTick, state.afterWriteTickInfo);
      }
    } else {
      afterWrite(stream, state, 1, cb);
    }
  }
}
 
function afterWriteTick({ stream, state, count, cb }) {
  state.afterWriteTickInfo = null;
  return afterWrite(stream, state, count, cb);
}
 
function afterWrite(stream, state, count, cb) {
  const needDrain = !state.ending && !stream.destroyed && state.length === 0 &&
    state.needDrain;
  if (needDrain) {
    state.needDrain = false;
    stream.emit('drain');
  }
 
  while (count-- > 0) {
    state.pendingcb--;
    cb();
  }
 
  if (state.destroyed) {
    errorBuffer(state);
  }
 
  finishMaybe(stream, state);
}
 
// If there's something in the buffer waiting, then invoke callbacks.
function errorBuffer(state) {
  if (state.writing) {
    return;
  }
 
  for (let n = state.bufferedIndex; n < state.buffered.length; ++n) {
    const { chunk, callback } = state.buffered[n];
    const len = state.objectMode ? 1 : chunk.length;
    state.length -= len;
    callback(state.errored ?? new ERR_STREAM_DESTROYED('write'));
  }
 
  const onfinishCallbacks = state[kOnFinished].splice(0);
  for (let i = 0; i < onfinishCallbacks.length; i++) {
    onfinishCallbacks[i](state.errored ?? new ERR_STREAM_DESTROYED('end'));
  }
 
  resetBuffer(state);
}
 
// If there's something in the buffer waiting, then process it.
function clearBuffer(stream, state) {
  if (state.corked ||
      state.bufferProcessing ||
      state.destroyed ||
      !state.constructed) {
    return;
  }
 
  const { buffered, bufferedIndex, objectMode } = state;
  const bufferedLength = buffered.length - bufferedIndex;
 
  if (!bufferedLength) {
    return;
  }
 
  let i = bufferedIndex;
 
  state.bufferProcessing = true;
  if (bufferedLength > 1 && stream._writev) {
    state.pendingcb -= bufferedLength - 1;
 
    const callback = state.allNoop ? nop : (err) => {
      for (let n = i; n < buffered.length; ++n) {
        buffered[n].callback(err);
      }
    };
    // Make a copy of `buffered` if it's going to be used by `callback` above,
    // since `doWrite` will mutate the array.
    const chunks = state.allNoop && i === 0 ?
      buffered : ArrayPrototypeSlice(buffered, i);
    chunks.allBuffers = state.allBuffers;
 
    doWrite(stream, state, true, state.length, chunks, '', callback);
 
    resetBuffer(state);
  } else {
    do {
      const { chunk, encoding, callback } = buffered[i];
      buffered[i++] = null;
      const len = objectMode ? 1 : chunk.length;
      doWrite(stream, state, false, len, chunk, encoding, callback);
    } while (i < buffered.length && !state.writing);
 
    if (i === buffered.length) {
      resetBuffer(state);
    } else if (i > 256) {
      buffered.splice(0, i);
      state.bufferedIndex = 0;
    } else {
      state.bufferedIndex = i;
    }
  }
  state.bufferProcessing = false;
}
 
Writable.prototype._write = function(chunk, encoding, cb) {
  if (this._writev) {
    this._writev([{ chunk, encoding }], cb);
  } else {
    throw new ERR_METHOD_NOT_IMPLEMENTED('_write()');
  }
};
 
Writable.prototype._writev = null;
 
Writable.prototype.end = function(chunk, encoding, cb) {
  const state = this._writableState;
 
  if (typeof chunk === 'function') {
    cb = chunk;
    chunk = null;
    encoding = null;
  } else if (typeof encoding === 'function') {
    cb = encoding;
    encoding = null;
  }
 
  let err;
 
  if (chunk !== null && chunk !== undefined) {
    const ret = _write(this, chunk, encoding);
    if (ret instanceof Error) {
      err = ret;
    }
  }
 
  // .end() fully uncorks.
  if (state.corked) {
    state.corked = 1;
    this.uncork();
  }
 
  if (err) {
    // Do nothing...
  } else if (!state.errored && !state.ending) {
    // This is forgiving in terms of unnecessary calls to end() and can hide
    // logic errors. However, usually such errors are harmless and causing a
    // hard error can be disproportionately destructive. It is not always
    // trivial for the user to determine whether end() needs to be called
    // or not.
 
    state.ending = true;
    finishMaybe(this, state, true);
    state.ended = true;
  } else if (state.finished) {
    err = new ERR_STREAM_ALREADY_FINISHED('end');
  } else if (state.destroyed) {
    err = new ERR_STREAM_DESTROYED('end');
  }
 
  if (typeof cb === 'function') {
    if (err || state.finished) {
      process.nextTick(cb, err);
    } else {
      state[kOnFinished].push(cb);
    }
  }
 
  return this;
};
 
function needFinish(state) {
  return (state.ending &&
          !state.destroyed &&
          state.constructed &&
          state.length === 0 &&
          !state.errored &&
          state.buffered.length === 0 &&
          !state.finished &&
          !state.writing &&
          !state.errorEmitted &&
          !state.closeEmitted);
}
 
function callFinal(stream, state) {
  let called = false;
 
  function onFinish(err) {
    if (called) {
      errorOrDestroy(stream, err ?? ERR_MULTIPLE_CALLBACK());
      return;
    }
    called = true;
 
    state.pendingcb--;
    if (err) {
      const onfinishCallbacks = state[kOnFinished].splice(0);
      for (let i = 0; i < onfinishCallbacks.length; i++) {
        onfinishCallbacks[i](err);
      }
      errorOrDestroy(stream, err, state.sync);
    } else if (needFinish(state)) {
      state.prefinished = true;
      stream.emit('prefinish');
      // Backwards compat. Don't check state.sync here.
      // Some streams assume 'finish' will be emitted
      // asynchronously relative to _final callback.
      state.pendingcb++;
      process.nextTick(finish, stream, state);
    }
  }
 
  state.sync = true;
  state.pendingcb++;
 
  try {
    stream._final(onFinish);
  } catch (err) {
    onFinish(err);
  }
 
  state.sync = false;
}
 
function prefinish(stream, state) {
  if (!state.prefinished && !state.finalCalled) {
    if (typeof stream._final === 'function' && !state.destroyed) {
      state.finalCalled = true;
      callFinal(stream, state);
    } else {
      state.prefinished = true;
      stream.emit('prefinish');
    }
  }
}
 
function finishMaybe(stream, state, sync) {
  if (needFinish(state)) {
    prefinish(stream, state);
    if (state.pendingcb === 0) {
      if (sync) {
        state.pendingcb++;
        process.nextTick((stream, state) => {
          if (needFinish(state)) {
            finish(stream, state);
          } else {
            state.pendingcb--;
          }
        }, stream, state);
      } else if (needFinish(state)) {
        state.pendingcb++;
        finish(stream, state);
      }
    }
  }
}
 
function finish(stream, state) {
  state.pendingcb--;
  state.finished = true;
 
  const onfinishCallbacks = state[kOnFinished].splice(0);
  for (let i = 0; i < onfinishCallbacks.length; i++) {
    onfinishCallbacks[i]();
  }
 
  stream.emit('finish');
 
  if (state.autoDestroy) {
    // In case of duplex streams we need a way to detect
    // if the readable side is ready for autoDestroy as well.
    const rState = stream._readableState;
    const autoDestroy = !rState || (
      rState.autoDestroy &&
      // We don't expect the readable to ever 'end'
      // if readable is explicitly set to false.
      (rState.endEmitted || rState.readable === false)
    );
    if (autoDestroy) {
      stream.destroy();
    }
  }
}
 
ObjectDefineProperties(Writable.prototype, {
 
  closed: {
    get() {
      return this._writableState ? this._writableState.closed : false;
    }
  },
 
  destroyed: {
    get() {
      return this._writableState ? this._writableState.destroyed : false;
    },
    set(value) {
      // Backward compatibility, the user is explicitly managing destroyed.
      if (this._writableState) {
        this._writableState.destroyed = value;
      }
    }
  },
 
  writable: {
    get() {
      const w = this._writableState;
      // w.writable === false means that this is part of a Duplex stream
      // where the writable side was disabled upon construction.
      // Compat. The user might manually disable writable side through
      // deprecated setter.
      return !!w && w.writable !== false && !w.destroyed && !w.errored &&
        !w.ending && !w.ended;
    },
    set(val) {
      // Backwards compatible.
      if (this._writableState) {
        this._writableState.writable = !!val;
      }
    }
  },
 
  writableFinished: {
    get() {
      return this._writableState ? this._writableState.finished : false;
    }
  },
 
  writableObjectMode: {
    get() {
      return this._writableState ? this._writableState.objectMode : false;
    }
  },
 
  writableBuffer: {
    get() {
      return this._writableState && this._writableState.getBuffer();
    }
  },
 
  writableEnded: {
    get() {
      return this._writableState ? this._writableState.ending : false;
    }
  },
 
  writableNeedDrain: {
    get() {
      const wState = this._writableState;
      if (!wState) return false;
      return !wState.destroyed && !wState.ending && wState.needDrain;
    }
  },
 
  writableHighWaterMark: {
    get() {
      return this._writableState && this._writableState.highWaterMark;
    }
  },
 
  writableCorked: {
    get() {
      return this._writableState ? this._writableState.corked : 0;
    }
  },
 
  writableLength: {
    get() {
      return this._writableState && this._writableState.length;
    }
  },
 
  errored: {
    enumerable: false,
    get() {
      return this._writableState ? this._writableState.errored : null;
    }
  },
 
  writableAborted: {
    enumerable: false,
    get: function() {
      return !!(
        this._writableState.writable !== false &&
        (this._writableState.destroyed || this._writableState.errored) &&
        !this._writableState.finished
      );
    }
  },
});
 
const destroy = destroyImpl.destroy;
Writable.prototype.destroy = function(err, cb) {
  const state = this._writableState;
 
  // Invoke pending callbacks.
  if (!state.destroyed &&
    (state.bufferedIndex < state.buffered.length ||
      state[kOnFinished].length)) {
    process.nextTick(errorBuffer, state);
  }
 
  destroy.call(this, err, cb);
  return this;
};
 
Writable.prototype._undestroy = destroyImpl.undestroy;
Writable.prototype._destroy = function(err, cb) {
  cb(err);
};
 
Writable.prototype[EE.captureRejectionSymbol] = function(err) {
  this.destroy(err);
};
 
let webStreamsAdapters;
 
// Lazy to avoid circular references
function lazyWebStreams() {
  if (webStreamsAdapters === undefined)
    webStreamsAdapters = require('internal/webstreams/adapters');
  return webStreamsAdapters;
}
 
Writable.fromWeb = function(writableStream, options) {
  return lazyWebStreams().newStreamWritableFromWritableStream(
    writableStream,
    options);
};
 
Writable.toWeb = function(streamWritable) {
  return lazyWebStreams().newWritableStreamFromStreamWritable(streamWritable);
};