Initial commit (by create-cloudflare CLI)

node_modules/rollup-plugin-node-polyfills/polyfills/readable-stream/writable.js

@@ -0,0 +1,483 @@
+// A bit simpler than readable streams.
+// Implement an async ._write(chunk, encoding, cb), and it'll handle all
+// the drain event emission and buffering.
+
+
+import {inherits, deprecate} from 'util';
+import {Buffer} from 'buffer';
+Writable.WritableState = WritableState;
+import {EventEmitter} from 'events';
+import {Duplex} from './duplex';
+import {nextTick} from 'process';
+inherits(Writable, EventEmitter);
+
+function nop() {}
+
+function WriteReq(chunk, encoding, cb) {
+  this.chunk = chunk;
+  this.encoding = encoding;
+  this.callback = cb;
+  this.next = null;
+}
+
+function WritableState(options, stream) {
+  Object.defineProperty(this, 'buffer', {
+    get: deprecate(function () {
+      return this.getBuffer();
+    }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.')
+  });
+  options = options || {};
+
+  // object stream flag to indicate whether or not this stream
+  // contains buffers or objects.
+  this.objectMode = !!options.objectMode;
+
+  if (stream instanceof Duplex) this.objectMode = this.objectMode || !!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()
+  var hwm = options.highWaterMark;
+  var defaultHwm = this.objectMode ? 16 : 16 * 1024;
+  this.highWaterMark = hwm || hwm === 0 ? hwm : defaultHwm;
+
+  // cast to ints.
+  this.highWaterMark = ~ ~this.highWaterMark;
+
+  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;
+
+  // 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 writableStateGetBuffer() {
+  var current = this.bufferedRequest;
+  var out = [];
+  while (current) {
+    out.push(current);
+    current = current.next;
+  }
+  return out;
+};
+
+export default Writable;
+export function Writable(options) {
+
+  // Writable ctor is applied to Duplexes, though they're not
+  // instanceof Writable, they're instanceof Readable.
+  if (!(this instanceof Writable) && !(this instanceof Duplex)) return new Writable(options);
+
+  this._writableState = new WritableState(options, this);
+
+  // legacy.
+  this.writable = true;
+
+  if (options) {
+    if (typeof options.write === 'function') this._write = options.write;
+
+    if (typeof options.writev === 'function') this._writev = options.writev;
+  }
+
+  EventEmitter.call(this);
+}
+
+// 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);
+  nextTick(cb, er);
+}
+
+// If we get something that is not a buffer, string, null, or undefined,
+// and we're not in objectMode, then that's an error.
+// Otherwise stream chunks are all considered to be of length=1, and the
+// watermarks determine how many objects to keep in the buffer, rather than
+// how many bytes or characters.
+function validChunk(stream, state, chunk, cb) {
+  var valid = true;
+  var er = false;
+  // Always throw error if a null is written
+  // if we are not in object mode then throw
+  // if it is not a buffer, string, or undefined.
+  if (chunk === null) {
+    er = new TypeError('May not write null values to stream');
+  } else if (!Buffer.isBuffer(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
+    er = new TypeError('Invalid non-string/buffer chunk');
+  }
+  if (er) {
+    stream.emit('error', er);
+    nextTick(cb, er);
+    valid = false;
+  }
+  return valid;
+}
+
+Writable.prototype.write = function (chunk, encoding, cb) {
+  var state = this._writableState;
+  var ret = false;
+
+  if (typeof encoding === 'function') {
+    cb = encoding;
+    encoding = null;
+  }
+
+  if (Buffer.isBuffer(chunk)) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding;
+
+  if (typeof cb !== 'function') cb = nop;
+
+  if (state.ended) writeAfterEnd(this, cb);else if (validChunk(this, state, chunk, cb)) {
+    state.pendingcb++;
+    ret = writeOrBuffer(this, state, 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--;
+
+    if (!state.writing && !state.corked && !state.finished && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state);
+  }
+};
+
+Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
+  // node::ParseEncoding() requires lower case.
+  if (typeof encoding === 'string') encoding = encoding.toLowerCase();
+  if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new TypeError('Unknown encoding: ' + encoding);
+  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.
+function writeOrBuffer(stream, state, chunk, encoding, cb) {
+  chunk = decodeChunk(state, chunk, encoding);
+
+  if (Buffer.isBuffer(chunk)) encoding = 'buffer';
+  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 (!ret) state.needDrain = true;
+
+  if (state.writing || state.corked) {
+    var last = state.lastBufferedRequest;
+    state.lastBufferedRequest = new WriteReq(chunk, encoding, cb);
+    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;
+  if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite);
+  state.sync = false;
+}
+
+function onwriteError(stream, state, sync, er, cb) {
+  --state.pendingcb;
+  if (sync) nextTick(cb, er);else cb(er);
+
+  stream._writableState.errorEmitted = true;
+  stream.emit('error', er);
+}
+
+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);
+
+  if (er) onwriteError(stream, state, sync, er, cb);else {
+    // 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>*/
+        nextTick(afterWrite, stream, state, finished, cb);
+      /*</replacement>*/
+    } else {
+        afterWrite(stream, state, finished, cb);
+      }
+  }
+}
+
+function afterWrite(stream, state, finished, cb) {
+  if (!finished) onwriteDrain(stream, state);
+  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
+function clearBuffer(stream, state) {
+  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;
+    while (entry) {
+      buffer[count] = entry;
+      entry = entry.next;
+      count += 1;
+    }
+
+    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);
+    }
+  } 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;
+      // 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;
+      }
+    }
+
+    if (entry === null) state.lastBufferedRequest = null;
+  }
+
+  state.bufferedRequestCount = 0;
+  state.bufferedRequest = entry;
+  state.bufferProcessing = false;
+}
+
+Writable.prototype._write = function (chunk, encoding, cb) {
+  cb(new Error('not implemented'));
+};
+
+Writable.prototype._writev = null;
+
+Writable.prototype.end = function (chunk, encoding, cb) {
+  var state = this._writableState;
+
+  if (typeof chunk === 'function') {
+    cb = chunk;
+    chunk = null;
+    encoding = null;
+  } else if (typeof encoding === 'function') {
+    cb = encoding;
+    encoding = null;
+  }
+
+  if (chunk !== null && chunk !== undefined) this.write(chunk, encoding);
+
+  // .end() fully uncorks
+  if (state.corked) {
+    state.corked = 1;
+    this.uncork();
+  }
+
+  // ignore unnecessary end() calls.
+  if (!state.ending && !state.finished) endWritable(this, state, cb);
+};
+
+function needFinish(state) {
+  return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;
+}
+
+function prefinish(stream, state) {
+  if (!state.prefinished) {
+    state.prefinished = true;
+    stream.emit('prefinish');
+  }
+}
+
+function finishMaybe(stream, state) {
+  var need = needFinish(state);
+  if (need) {
+    if (state.pendingcb === 0) {
+      prefinish(stream, state);
+      state.finished = true;
+      stream.emit('finish');
+    } else {
+      prefinish(stream, state);
+    }
+  }
+  return need;
+}
+
+function endWritable(stream, state, cb) {
+  state.ending = true;
+  finishMaybe(stream, state);
+  if (cb) {
+    if (state.finished) nextTick(cb);else stream.once('finish', cb);
+  }
+  state.ended = true;
+  stream.writable = false;
+}
+
+// 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 (err) {
+    var entry = _this.entry;
+    _this.entry = null;
+    while (entry) {
+      var cb = entry.callback;
+      state.pendingcb--;
+      cb(err);
+      entry = entry.next;
+    }
+    if (state.corkedRequestsFree) {
+      state.corkedRequestsFree.next = _this;
+    } else {
+      state.corkedRequestsFree = _this;
+    }
+  };
+}