LukasMeine / vigilance

'use strict';

/*<replacement>*/

var pna = require('process-nextick-args');

/*</replacement>*/

module.exports = Writable;

/* <replacement> */

function WriteReq(chunk, encoding, cb) {

  this.chunk = chunk;

  this.encoding = encoding;

  this.callback = cb;

  this.next = null;

}

// It seems a linked list but it is not

// there will be only 2 of these for each stream

function CorkedRequest(state) {

  var _this = this;

  this.next = null;

  this.entry = null;

  this.finish = function () {

    onCorkedFinish(_this, state);

  };

}

/* </replacement> */

/*<replacement>*/

/*</replacement>*/

/*<replacement>*/

var Duplex;

/*</replacement>*/

Writable.WritableState = WritableState;

/*<replacement>*/

var util = require('core-util-is');

util.inherits = require('inherits');

/*</replacement>*/

/*<replacement>*/

var internalUtil = {

  deprecate: require('util-deprecate')

};

/*</replacement>*/

/*<replacement>*/

var Stream = require('./internal/streams/stream');

/*</replacement>*/

/*<replacement>*/

var Buffer = require('safe-buffer').Buffer;

var OurUint8Array = global.Uint8Array || function () {};

function _uint8ArrayToBuffer(chunk) {

  return Buffer.from(chunk);

}

function _isUint8Array(obj) {

  return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;

}

/*</replacement>*/

var destroyImpl = require('./internal/streams/destroy');

util.inherits(Writable, Stream);

function nop() {}

  Duplex = Duplex || require('./_stream_duplex');

  options = options || {};

  // 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.

  // These options can be provided separately as readableXXX and writableXXX.

  var isDuplex = stream instanceof Duplex;

  // object stream flag to indicate whether or not this stream

  // contains buffers or objects.

  this.objectMode = !!options.objectMode;

  // 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()

  var hwm = options.highWaterMark;

  var writableHwm = options.writableHighWaterMark;

  var defaultHwm = this.objectMode ? 16 : 16 * 1024;

  // cast to ints.

  this.highWaterMark = Math.floor(this.highWaterMark);

  // 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.

  var noDecode = 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.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 = function (er) {

    onwrite(stream, er);

  };

  // 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;

  this.bufferedRequest = null;

  this.lastBufferedRequest = null;

  // number of pending user-supplied write callbacks

  // this must be 0 before 'finish' can be emitted

  this.pendingcb = 0;

  // 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;

  // count buffered requests

  this.bufferedRequestCount = 0;

  // allocate the first CorkedRequest, there is always

  // one allocated and free to use, and we maintain at most two

  this.corkedRequestsFree = new CorkedRequest(this);

}

WritableState.prototype.getBuffer = function getBuffer() {

  var current = this.bufferedRequest;

  var out = [];

  while (current) {

    out.push(current);

    current = current.next;

  }

  return out;

};

(function () {

  try {

    Object.defineProperty(WritableState.prototype, 'buffer', {

      get: internalUtil.deprecate(function () {

        return this.getBuffer();

      }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003')

    });

})();

// Test _writableState for inheritance to account for Duplex streams,

// whose prototype chain only points to Readable.

var realHasInstance;

  realHasInstance = Function.prototype[Symbol.hasInstance];

  Object.defineProperty(Writable, Symbol.hasInstance, {

    value: function (object) {

      return object && object._writableState instanceof WritableState;

    }

  });

} else {

  realHasInstance = function (object) {

    return object instanceof this;

  };

}

  Duplex = Duplex || require('./_stream_duplex');

  // 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.

  if (!realHasInstance.call(Writable, this) && !(this instanceof Duplex)) {

    return new Writable(options);

  }

  this._writableState = new WritableState(options, this);

  // legacy.

  this.writable = true;

  if (options) {

  }

}

// Otherwise people can pipe Writable streams, which is just wrong.

Writable.prototype.pipe = function () {

  this.emit('error', new Error('Cannot pipe, not readable'));

};

function writeAfterEnd(stream, cb) {

  var er = new Error('write after end');

  // TODO: defer error events consistently everywhere, not just the cb

  stream.emit('error', er);

  pna.nextTick(cb, er);

}

// Checks that a user-supplied chunk is valid, especially for the particular

// mode the stream is in. Currently this means that `null` is never accepted

// and undefined/non-string values are only allowed in object mode.

function validChunk(stream, state, chunk, cb) {

  var valid = true;

  var er = false;

  if (chunk === null) {

    er = new TypeError('May not write null values to stream');

  } else if (typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {

    er = new TypeError('Invalid non-string/buffer chunk');

  }

  if (er) {

    stream.emit('error', er);

    pna.nextTick(cb, er);

    valid = false;

  }

  return valid;

}

  var state = this._writableState;

  var ret = false;

  var isBuf = !state.objectMode && _isUint8Array(chunk);

  if (isBuf && !Buffer.isBuffer(chunk)) {

    chunk = _uint8ArrayToBuffer(chunk);

  }

  if (typeof encoding === 'function') {

    cb = encoding;

    encoding = null;

  }

    state.pendingcb++;

    ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb);

  }

  return ret;

};

Writable.prototype.cork = function () {

  var state = this._writableState;

  state.corked++;

};

Writable.prototype.uncork = function () {

  var state = this._writableState;

  if (state.corked) {

    state.corked--;

  }

};

  // node::ParseEncoding() requires lower case.

  this._writableState.defaultEncoding = encoding;

  return this;

};

function decodeChunk(state, chunk, encoding) {

  if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') {

    chunk = Buffer.from(chunk, encoding);

  }

  return chunk;

}

// 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.

  if (!isBuf) {

    var newChunk = decodeChunk(state, chunk, encoding);

    if (chunk !== newChunk) {

      isBuf = true;

      encoding = 'buffer';

      chunk = newChunk;

    }

  }

  var len = state.objectMode ? 1 : chunk.length;

  state.length += len;

  var ret = state.length < state.highWaterMark;

  // we must ensure that previous needDrain will not be reset to false.

  if (state.writing || state.corked) {

    var last = state.lastBufferedRequest;

    state.lastBufferedRequest = {

      chunk: chunk,

      encoding: encoding,

      isBuf: isBuf,

      callback: cb,

      next: null

    };

    if (last) {

      last.next = state.lastBufferedRequest;

    } else {

      state.bufferedRequest = state.lastBufferedRequest;

    }

    state.bufferedRequestCount += 1;

  } else {

    doWrite(stream, state, false, len, chunk, encoding, cb);

  }

  return ret;

}

function doWrite(stream, state, writev, len, chunk, encoding, cb) {

  state.writelen = len;

  state.writecb = cb;

  state.writing = true;

  state.sync = true;

  state.sync = false;

}

function onwriteError(stream, state, sync, er, cb) {

  --state.pendingcb;

  if (sync) {

    // defer the callback if we are being called synchronously

    // to avoid piling up things on the stack

    pna.nextTick(cb, er);

    // this can emit finish, and it will always happen

    // after error

    pna.nextTick(finishMaybe, stream, state);

    stream._writableState.errorEmitted = true;

    stream.emit('error', er);

  } else {

    // the caller expect this to happen before if

    // it is async

    cb(er);

    stream._writableState.errorEmitted = true;

    stream.emit('error', er);

    // this can emit finish, but finish must

    // always follow error

    finishMaybe(stream, state);

  }

}

function onwriteStateUpdate(state) {

  state.writing = false;

  state.writecb = null;

  state.length -= state.writelen;

  state.writelen = 0;

}

function onwrite(stream, er) {

  var state = stream._writableState;

  var sync = state.sync;

  var cb = state.writecb;

  onwriteStateUpdate(state);

    // Check if we're actually ready to finish, but don't emit yet

    var finished = needFinish(state);

    if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) {

      clearBuffer(stream, state);

    }

    if (sync) {

      /*<replacement>*/

      asyncWrite(afterWrite, stream, state, finished, cb);

      /*</replacement>*/

    } else {

      afterWrite(stream, state, finished, cb);

    }

  }

}

function afterWrite(stream, state, finished, cb) {

  state.pendingcb--;

  cb();

  finishMaybe(stream, state);

}

// Must force callback to be called on nextTick, so that we don't

// emit 'drain' before the write() consumer gets the 'false' return

// value, and has a chance to attach a 'drain' listener.

function onwriteDrain(stream, state) {

  if (state.length === 0 && state.needDrain) {

    state.needDrain = false;

    stream.emit('drain');

  }

}

// if there's something in the buffer waiting, then process it

  state.bufferProcessing = true;

  var entry = state.bufferedRequest;

  if (stream._writev && entry && entry.next) {

    // Fast case, write everything using _writev()

    var l = state.bufferedRequestCount;

    var buffer = new Array(l);

    var holder = state.corkedRequestsFree;

    holder.entry = entry;

    var count = 0;

    var allBuffers = true;

    while (entry) {

      buffer[count] = entry;

      entry = entry.next;

      count += 1;

    }

    buffer.allBuffers = allBuffers;

    doWrite(stream, state, true, state.length, buffer, '', holder.finish);

    // doWrite is almost always async, defer these to save a bit of time

    // as the hot path ends with doWrite

    state.pendingcb++;

    state.lastBufferedRequest = null;

    if (holder.next) {

      state.corkedRequestsFree = holder.next;

      holder.next = null;

    } else {

      state.corkedRequestsFree = new CorkedRequest(state);

    }

    state.bufferedRequestCount = 0;

  } else {

    // Slow case, write chunks one-by-one

    while (entry) {

      var chunk = entry.chunk;

      var encoding = entry.encoding;

      var cb = entry.callback;

      var len = state.objectMode ? 1 : chunk.length;

      doWrite(stream, state, false, len, chunk, encoding, cb);

      entry = entry.next;

      state.bufferedRequestCount--;

      // if we didn't call the onwrite immediately, then

      // it means that we need to wait until it does.

      // also, that means that the chunk and cb are currently

      // being processed, so move the buffer counter past them.

      if (state.writing) {

        break;

      }

    }

  }

  state.bufferedRequest = entry;

  state.bufferProcessing = false;

}

Writable.prototype._write = function (chunk, encoding, cb) {

  cb(new Error('_write() is not implemented'));

};

Writable.prototype._writev = null;

  var state = this._writableState;

  if (typeof chunk === 'function') {

    cb = chunk;

    chunk = null;

    encoding = null;

  } else if (typeof encoding === 'function') {

    cb = encoding;

    encoding = null;

  }

  // .end() fully uncorks

  if (state.corked) {

    state.corked = 1;

    this.uncork();

  }

  // ignore unnecessary end() calls.

};

function needFinish(state) {

  return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;

}

function callFinal(stream, state) {

  stream._final(function (err) {

    state.pendingcb--;

    if (err) {

      stream.emit('error', err);

    }

    state.prefinished = true;

    stream.emit('prefinish');

    finishMaybe(stream, state);

  });

}

function prefinish(stream, state) {

  if (!state.prefinished && !state.finalCalled) {

    if (typeof stream._final === 'function') {

      state.pendingcb++;

      state.finalCalled = true;

      pna.nextTick(callFinal, stream, state);

    } else {

      state.prefinished = true;

      stream.emit('prefinish');

    }

  }

}

function finishMaybe(stream, state) {

  var need = needFinish(state);

  if (need) {

    prefinish(stream, state);

    if (state.pendingcb === 0) {

      state.finished = true;

      stream.emit('finish');

    }

  }

  return need;

}

function endWritable(stream, state, cb) {

  state.ending = true;

  finishMaybe(stream, state);

  if (cb) {