--- /dev/null
+// 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.
+
+'use strict';
+
+/*<replacement>*/
+
+var pna = require('process-nextick-args');
+/*</replacement>*/
+
+module.exports = Readable;
+
+/*<replacement>*/
+var isArray = require('isarray');
+/*</replacement>*/
+
+/*<replacement>*/
+var Duplex;
+/*</replacement>*/
+
+Readable.ReadableState = ReadableState;
+
+/*<replacement>*/
+var EE = require('events').EventEmitter;
+
+var EElistenerCount = function (emitter, type) {
+ return emitter.listeners(type).length;
+};
+/*</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>*/
+
+/*<replacement>*/
+var util = require('core-util-is');
+util.inherits = require('inherits');
+/*</replacement>*/
+
+/*<replacement>*/
+var debugUtil = require('util');
+var debug = void 0;
+if (debugUtil && debugUtil.debuglog) {
+ debug = debugUtil.debuglog('stream');
+} else {
+ debug = function () {};
+}
+/*</replacement>*/
+
+var BufferList = require('./internal/streams/BufferList');
+var destroyImpl = require('./internal/streams/destroy');
+var StringDecoder;
+
+util.inherits(Readable, Stream);
+
+var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
+
+function prependListener(emitter, event, fn) {
+ // Sadly this is not cacheable as some libraries bundle their own
+ // event emitter implementation with them.
+ if (typeof emitter.prependListener === 'function') return emitter.prependListener(event, fn);
+
+ // This is a hack to make sure that our error handler is attached before any
+ // userland ones. NEVER DO THIS. This is here only because this code needs
+ // to continue to work with older versions of Node.js that do not include
+ // the prependListener() method. The goal is to eventually remove this hack.
+ if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
+}
+
+function ReadableState(options, stream) {
+ 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. Used to make read(n) ignore n and to
+ // make all the buffer merging and length checks go away
+ this.objectMode = !!options.objectMode;
+
+ if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode;
+
+ // the point at which it stops calling _read() to fill the buffer
+ // Note: 0 is a valid value, means "don't call _read preemptively ever"
+ var hwm = options.highWaterMark;
+ var readableHwm = options.readableHighWaterMark;
+ var defaultHwm = this.objectMode ? 16 : 16 * 1024;
+
+ if (hwm || hwm === 0) this.highWaterMark = hwm;else if (isDuplex && (readableHwm || readableHwm === 0)) this.highWaterMark = readableHwm;else this.highWaterMark = defaultHwm;
+
+ // cast to ints.
+ this.highWaterMark = Math.floor(this.highWaterMark);
+
+ // A linked list is used to store data chunks instead of an array because the
+ // linked list can remove elements from the beginning faster than
+ // array.shift()
+ this.buffer = new BufferList();
+ this.length = 0;
+ this.pipes = null;
+ this.pipesCount = 0;
+ this.flowing = null;
+ this.ended = false;
+ this.endEmitted = false;
+ this.reading = false;
+
+ // a flag to be able to tell if the event 'readable'/'data' is emitted
+ // 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 read call.
+ this.sync = true;
+
+ // whenever we return null, then we set a flag to say
+ // that we're awaiting a 'readable' event emission.
+ this.needReadable = false;
+ this.emittedReadable = false;
+ this.readableListening = false;
+ this.resumeScheduled = false;
+
+ // has it been destroyed
+ this.destroyed = false;
+
+ // 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';
+
+ // the number of writers that are awaiting a drain event in .pipe()s
+ this.awaitDrain = 0;
+
+ // if true, a maybeReadMore has been scheduled
+ this.readingMore = false;
+
+ this.decoder = null;
+ this.encoding = null;
+ if (options.encoding) {
+ if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
+ this.decoder = new StringDecoder(options.encoding);
+ this.encoding = options.encoding;
+ }
+}
+
+function Readable(options) {
+ Duplex = Duplex || require('./_stream_duplex');
+
+ if (!(this instanceof Readable)) return new Readable(options);
+
+ this._readableState = new ReadableState(options, this);
+
+ // legacy
+ this.readable = true;
+
+ if (options) {
+ if (typeof options.read === 'function') this._read = options.read;
+
+ if (typeof options.destroy === 'function') this._destroy = options.destroy;
+ }
+
+ Stream.call(this);
+}
+
+Object.defineProperty(Readable.prototype, 'destroyed', {
+ get: function () {
+ if (this._readableState === undefined) {
+ return false;
+ }
+ return this._readableState.destroyed;
+ },
+ set: function (value) {
+ // we ignore the value if the stream
+ // has not been initialized yet
+ if (!this._readableState) {
+ return;
+ }
+
+ // backward compatibility, the user is explicitly
+ // managing destroyed
+ this._readableState.destroyed = value;
+ }
+});
+
+Readable.prototype.destroy = destroyImpl.destroy;
+Readable.prototype._undestroy = destroyImpl.undestroy;
+Readable.prototype._destroy = function (err, cb) {
+ this.push(null);
+ cb(err);
+};
+
+// Manually shove something into the read() buffer.
+// This returns true if the highWaterMark has not been hit yet,
+// similar to how Writable.write() returns true if you should
+// write() some more.
+Readable.prototype.push = function (chunk, encoding) {
+ var state = this._readableState;
+ var skipChunkCheck;
+
+ if (!state.objectMode) {
+ if (typeof chunk === 'string') {
+ encoding = encoding || state.defaultEncoding;
+ if (encoding !== state.encoding) {
+ chunk = Buffer.from(chunk, encoding);
+ encoding = '';
+ }
+ skipChunkCheck = true;
+ }
+ } else {
+ skipChunkCheck = true;
+ }
+
+ return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
+};
+
+// Unshift should *always* be something directly out of read()
+Readable.prototype.unshift = function (chunk) {
+ return readableAddChunk(this, chunk, null, true, false);
+};
+
+function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
+ var state = stream._readableState;
+ if (chunk === null) {
+ state.reading = false;
+ onEofChunk(stream, state);
+ } else {
+ var er;
+ if (!skipChunkCheck) er = chunkInvalid(state, chunk);
+ if (er) {
+ stream.emit('error', er);
+ } else if (state.objectMode || chunk && chunk.length > 0) {
+ if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
+ chunk = _uint8ArrayToBuffer(chunk);
+ }
+
+ if (addToFront) {
+ if (state.endEmitted) stream.emit('error', new Error('stream.unshift() after end event'));else addChunk(stream, state, chunk, true);
+ } else if (state.ended) {
+ stream.emit('error', new Error('stream.push() after EOF'));
+ } else {
+ state.reading = false;
+ if (state.decoder && !encoding) {
+ chunk = state.decoder.write(chunk);
+ if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
+ } else {
+ addChunk(stream, state, chunk, false);
+ }
+ }
+ } else if (!addToFront) {
+ state.reading = false;
+ }
+ }
+
+ return needMoreData(state);
+}
+
+function addChunk(stream, state, chunk, addToFront) {
+ if (state.flowing && state.length === 0 && !state.sync) {
+ stream.emit('data', chunk);
+ stream.read(0);
+ } else {
+ // update the buffer info.
+ state.length += state.objectMode ? 1 : chunk.length;
+ if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
+
+ if (state.needReadable) emitReadable(stream);
+ }
+ maybeReadMore(stream, state);
+}
+
+function chunkInvalid(state, chunk) {
+ var er;
+ if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
+ er = new TypeError('Invalid non-string/buffer chunk');
+ }
+ return er;
+}
+
+// if it's past the high water mark, we can push in some more.
+// Also, if we have no data yet, we can stand some
+// more bytes. This is to work around cases where hwm=0,
+// such as the repl. Also, if the push() triggered a
+// readable event, and the user called read(largeNumber) such that
+// needReadable was set, then we ought to push more, so that another
+// 'readable' event will be triggered.
+function needMoreData(state) {
+ return !state.ended && (state.needReadable || state.length < state.highWaterMark || state.length === 0);
+}
+
+Readable.prototype.isPaused = function () {
+ return this._readableState.flowing === false;
+};
+
+// backwards compatibility.
+Readable.prototype.setEncoding = function (enc) {
+ if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
+ this._readableState.decoder = new StringDecoder(enc);
+ this._readableState.encoding = enc;
+ return this;
+};
+
+// Don't raise the hwm > 8MB
+var MAX_HWM = 0x800000;
+function computeNewHighWaterMark(n) {
+ if (n >= MAX_HWM) {
+ n = MAX_HWM;
+ } else {
+ // Get the next highest power of 2 to prevent increasing hwm excessively in
+ // tiny amounts
+ n--;
+ n |= n >>> 1;
+ n |= n >>> 2;
+ n |= n >>> 4;
+ n |= n >>> 8;
+ n |= n >>> 16;
+ n++;
+ }
+ return n;
+}
+
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function howMuchToRead(n, state) {
+ if (n <= 0 || state.length === 0 && state.ended) return 0;
+ if (state.objectMode) return 1;
+ if (n !== n) {
+ // Only flow one buffer at a time
+ if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
+ }
+ // If we're asking for more than the current hwm, then raise the hwm.
+ if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
+ if (n <= state.length) return n;
+ // Don't have enough
+ if (!state.ended) {
+ state.needReadable = true;
+ return 0;
+ }
+ return state.length;
+}
+
+// you can override either this method, or the async _read(n) below.
+Readable.prototype.read = function (n) {
+ debug('read', n);
+ n = parseInt(n, 10);
+ var state = this._readableState;
+ var nOrig = n;
+
+ if (n !== 0) state.emittedReadable = false;
+
+ // if we're doing read(0) to trigger a readable event, but we
+ // already have a bunch of data in the buffer, then just trigger
+ // the 'readable' event and move on.
+ if (n === 0 && state.needReadable && (state.length >= state.highWaterMark || state.ended)) {
+ debug('read: emitReadable', state.length, state.ended);
+ if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
+ return null;
+ }
+
+ n = howMuchToRead(n, state);
+
+ // if we've ended, and we're now clear, then finish it up.
+ if (n === 0 && state.ended) {
+ if (state.length === 0) endReadable(this);
+ return null;
+ }
+
+ // All the actual chunk generation logic needs to be
+ // *below* the call to _read. The reason is that in certain
+ // synthetic stream cases, such as passthrough streams, _read
+ // may be a completely synchronous operation which may change
+ // the state of the read buffer, providing enough data when
+ // before there was *not* enough.
+ //
+ // So, the steps are:
+ // 1. Figure out what the state of things will be after we do
+ // a read from the buffer.
+ //
+ // 2. If that resulting state will trigger a _read, then call _read.
+ // Note that this may be asynchronous, or synchronous. Yes, it is
+ // deeply ugly to write APIs this way, but that still doesn't mean
+ // that the Readable class should behave improperly, as streams are
+ // designed to be sync/async agnostic.
+ // Take note if the _read call is sync or async (ie, if the read call
+ // has returned yet), so that we know whether or not it's safe to emit
+ // 'readable' etc.
+ //
+ // 3. Actually pull the requested chunks out of the buffer and return.
+
+ // if we need a readable event, then we need to do some reading.
+ var doRead = state.needReadable;
+ debug('need readable', doRead);
+
+ // if we currently have less than the highWaterMark, then also read some
+ if (state.length === 0 || state.length - n < state.highWaterMark) {
+ doRead = true;
+ debug('length less than watermark', doRead);
+ }
+
+ // however, if we've ended, then there's no point, and if we're already
+ // reading, then it's unnecessary.
+ if (state.ended || state.reading) {
+ doRead = false;
+ debug('reading or ended', doRead);
+ } else if (doRead) {
+ debug('do read');
+ state.reading = true;
+ state.sync = true;
+ // if the length is currently zero, then we *need* a readable event.
+ if (state.length === 0) state.needReadable = true;
+ // call internal read method
+ this._read(state.highWaterMark);
+ state.sync = false;
+ // If _read pushed data synchronously, then `reading` will be false,
+ // and we need to re-evaluate how much data we can return to the user.
+ if (!state.reading) n = howMuchToRead(nOrig, state);
+ }
+
+ var ret;
+ if (n > 0) ret = fromList(n, state);else ret = null;
+
+ if (ret === null) {
+ state.needReadable = true;
+ n = 0;
+ } else {
+ state.length -= n;
+ }
+
+ if (state.length === 0) {
+ // If we have nothing in the buffer, then we want to know
+ // as soon as we *do* get something into the buffer.
+ if (!state.ended) state.needReadable = true;
+
+ // If we tried to read() past the EOF, then emit end on the next tick.
+ if (nOrig !== n && state.ended) endReadable(this);
+ }
+
+ if (ret !== null) this.emit('data', ret);
+
+ return ret;
+};
+
+function onEofChunk(stream, state) {
+ if (state.ended) return;
+ if (state.decoder) {
+ var chunk = state.decoder.end();
+ if (chunk && chunk.length) {
+ state.buffer.push(chunk);
+ state.length += state.objectMode ? 1 : chunk.length;
+ }
+ }
+ state.ended = true;
+
+ // emit 'readable' now to make sure it gets picked up.
+ emitReadable(stream);
+}
+
+// Don't emit readable right away in sync mode, because this can trigger
+// another read() call => stack overflow. This way, it might trigger
+// a nextTick recursion warning, but that's not so bad.
+function emitReadable(stream) {
+ var state = stream._readableState;
+ state.needReadable = false;
+ if (!state.emittedReadable) {
+ debug('emitReadable', state.flowing);
+ state.emittedReadable = true;
+ if (state.sync) pna.nextTick(emitReadable_, stream);else emitReadable_(stream);
+ }
+}
+
+function emitReadable_(stream) {
+ debug('emit readable');
+ stream.emit('readable');
+ flow(stream);
+}
+
+// at this point, the user has presumably seen the 'readable' event,
+// and called read() to consume some data. that may have triggered
+// in turn another _read(n) call, in which case reading = true if
+// it's in progress.
+// However, if we're not ended, or reading, and the length < hwm,
+// then go ahead and try to read some more preemptively.
+function maybeReadMore(stream, state) {
+ if (!state.readingMore) {
+ state.readingMore = true;
+ pna.nextTick(maybeReadMore_, stream, state);
+ }
+}
+
+function maybeReadMore_(stream, state) {
+ var len = state.length;
+ while (!state.reading && !state.flowing && !state.ended && state.length < state.highWaterMark) {
+ debug('maybeReadMore read 0');
+ stream.read(0);
+ if (len === state.length)
+ // didn't get any data, stop spinning.
+ break;else len = state.length;
+ }
+ state.readingMore = false;
+}
+
+// abstract method. to be overridden in specific implementation classes.
+// call cb(er, data) where data is <= n in length.
+// for virtual (non-string, non-buffer) streams, "length" is somewhat
+// arbitrary, and perhaps not very meaningful.
+Readable.prototype._read = function (n) {
+ this.emit('error', new Error('_read() is not implemented'));
+};
+
+Readable.prototype.pipe = function (dest, pipeOpts) {
+ var src = this;
+ var state = this._readableState;
+
+ switch (state.pipesCount) {
+ case 0:
+ state.pipes = dest;
+ break;
+ case 1:
+ state.pipes = [state.pipes, dest];
+ break;
+ default:
+ state.pipes.push(dest);
+ break;
+ }
+ state.pipesCount += 1;
+ debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
+
+ var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
+
+ var endFn = doEnd ? onend : unpipe;
+ if (state.endEmitted) pna.nextTick(endFn);else src.once('end', endFn);
+
+ dest.on('unpipe', onunpipe);
+ function onunpipe(readable, unpipeInfo) {
+ debug('onunpipe');
+ if (readable === src) {
+ if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
+ unpipeInfo.hasUnpiped = true;
+ cleanup();
+ }
+ }
+ }
+
+ function onend() {
+ debug('onend');
+ dest.end();
+ }
+
+ // when the dest drains, it reduces the awaitDrain counter
+ // on the source. This would be more elegant with a .once()
+ // handler in flow(), but adding and removing repeatedly is
+ // too slow.
+ var ondrain = pipeOnDrain(src);
+ dest.on('drain', ondrain);
+
+ var cleanedUp = false;
+ function cleanup() {
+ debug('cleanup');
+ // cleanup event handlers once the pipe is broken
+ dest.removeListener('close', onclose);
+ dest.removeListener('finish', onfinish);
+ dest.removeListener('drain', ondrain);
+ dest.removeListener('error', onerror);
+ dest.removeListener('unpipe', onunpipe);
+ src.removeListener('end', onend);
+ src.removeListener('end', unpipe);
+ src.removeListener('data', ondata);
+
+ cleanedUp = true;
+
+ // if the reader is waiting for a drain event from this
+ // specific writer, then it would cause it to never start
+ // flowing again.
+ // So, if this is awaiting a drain, then we just call it now.
+ // If we don't know, then assume that we are waiting for one.
+ if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
+ }
+
+ // If the user pushes more data while we're writing to dest then we'll end up
+ // in ondata again. However, we only want to increase awaitDrain once because
+ // dest will only emit one 'drain' event for the multiple writes.
+ // => Introduce a guard on increasing awaitDrain.
+ var increasedAwaitDrain = false;
+ src.on('data', ondata);
+ function ondata(chunk) {
+ debug('ondata');
+ increasedAwaitDrain = false;
+ var ret = dest.write(chunk);
+ if (false === ret && !increasedAwaitDrain) {
+ // If the user unpiped during `dest.write()`, it is possible
+ // to get stuck in a permanently paused state if that write
+ // also returned false.
+ // => Check whether `dest` is still a piping destination.
+ if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
+ debug('false write response, pause', src._readableState.awaitDrain);
+ src._readableState.awaitDrain++;
+ increasedAwaitDrain = true;
+ }
+ src.pause();
+ }
+ }
+
+ // if the dest has an error, then stop piping into it.
+ // however, don't suppress the throwing behavior for this.
+ function onerror(er) {
+ debug('onerror', er);
+ unpipe();
+ dest.removeListener('error', onerror);
+ if (EElistenerCount(dest, 'error') === 0) dest.emit('error', er);
+ }
+
+ // Make sure our error handler is attached before userland ones.
+ prependListener(dest, 'error', onerror);
+
+ // Both close and finish should trigger unpipe, but only once.
+ function onclose() {
+ dest.removeListener('finish', onfinish);
+ unpipe();
+ }
+ dest.once('close', onclose);
+ function onfinish() {
+ debug('onfinish');
+ dest.removeListener('close', onclose);
+ unpipe();
+ }
+ dest.once('finish', onfinish);
+
+ function unpipe() {
+ debug('unpipe');
+ src.unpipe(dest);
+ }
+
+ // tell the dest that it's being piped to
+ dest.emit('pipe', src);
+
+ // start the flow if it hasn't been started already.
+ if (!state.flowing) {
+ debug('pipe resume');
+ src.resume();
+ }
+
+ return dest;
+};
+
+function pipeOnDrain(src) {
+ return function () {
+ var state = src._readableState;
+ debug('pipeOnDrain', state.awaitDrain);
+ if (state.awaitDrain) state.awaitDrain--;
+ if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
+ state.flowing = true;
+ flow(src);
+ }
+ };
+}
+
+Readable.prototype.unpipe = function (dest) {
+ var state = this._readableState;
+ var unpipeInfo = { hasUnpiped: false };
+
+ // if we're not piping anywhere, then do nothing.
+ if (state.pipesCount === 0) return this;
+
+ // just one destination. most common case.
+ if (state.pipesCount === 1) {
+ // passed in one, but it's not the right one.
+ if (dest && dest !== state.pipes) return this;
+
+ if (!dest) dest = state.pipes;
+
+ // got a match.
+ state.pipes = null;
+ state.pipesCount = 0;
+ state.flowing = false;
+ if (dest) dest.emit('unpipe', this, unpipeInfo);
+ return this;
+ }
+
+ // slow case. multiple pipe destinations.
+
+ if (!dest) {
+ // remove all.
+ var dests = state.pipes;
+ var len = state.pipesCount;
+ state.pipes = null;
+ state.pipesCount = 0;
+ state.flowing = false;
+
+ for (var i = 0; i < len; i++) {
+ dests[i].emit('unpipe', this, unpipeInfo);
+ }return this;
+ }
+
+ // try to find the right one.
+ var index = indexOf(state.pipes, dest);
+ if (index === -1) return this;
+
+ state.pipes.splice(index, 1);
+ state.pipesCount -= 1;
+ if (state.pipesCount === 1) state.pipes = state.pipes[0];
+
+ dest.emit('unpipe', this, unpipeInfo);
+
+ return this;
+};
+
+// set up data events if they are asked for
+// Ensure readable listeners eventually get something
+Readable.prototype.on = function (ev, fn) {
+ var res = Stream.prototype.on.call(this, ev, fn);
+
+ if (ev === 'data') {
+ // Start flowing on next tick if stream isn't explicitly paused
+ if (this._readableState.flowing !== false) this.resume();
+ } else if (ev === 'readable') {
+ var state = this._readableState;
+ if (!state.endEmitted && !state.readableListening) {
+ state.readableListening = state.needReadable = true;
+ state.emittedReadable = false;
+ if (!state.reading) {
+ pna.nextTick(nReadingNextTick, this);
+ } else if (state.length) {
+ emitReadable(this);
+ }
+ }
+ }
+
+ return res;
+};
+Readable.prototype.addListener = Readable.prototype.on;
+
+function nReadingNextTick(self) {
+ debug('readable nexttick read 0');
+ self.read(0);
+}
+
+// pause() and resume() are remnants of the legacy readable stream API
+// If the user uses them, then switch into old mode.
+Readable.prototype.resume = function () {
+ var state = this._readableState;
+ if (!state.flowing) {
+ debug('resume');
+ state.flowing = true;
+ resume(this, state);
+ }
+ return this;
+};
+
+function resume(stream, state) {
+ if (!state.resumeScheduled) {
+ state.resumeScheduled = true;
+ pna.nextTick(resume_, stream, state);
+ }
+}
+
+function resume_(stream, state) {
+ if (!state.reading) {
+ debug('resume read 0');
+ stream.read(0);
+ }
+
+ state.resumeScheduled = false;
+ state.awaitDrain = 0;
+ stream.emit('resume');
+ flow(stream);
+ if (state.flowing && !state.reading) stream.read(0);
+}
+
+Readable.prototype.pause = function () {
+ debug('call pause flowing=%j', this._readableState.flowing);
+ if (false !== this._readableState.flowing) {
+ debug('pause');
+ this._readableState.flowing = false;
+ this.emit('pause');
+ }
+ return this;
+};
+
+function flow(stream) {
+ var state = stream._readableState;
+ debug('flow', state.flowing);
+ while (state.flowing && stream.read() !== null) {}
+}
+
+// wrap an old-style stream as the async data source.
+// This is *not* part of the readable stream interface.
+// It is an ugly unfortunate mess of history.
+Readable.prototype.wrap = function (stream) {
+ var _this = this;
+
+ var state = this._readableState;
+ var paused = false;
+
+ stream.on('end', function () {
+ debug('wrapped end');
+ if (state.decoder && !state.ended) {
+ var chunk = state.decoder.end();
+ if (chunk && chunk.length) _this.push(chunk);
+ }
+
+ _this.push(null);
+ });
+
+ stream.on('data', function (chunk) {
+ debug('wrapped data');
+ if (state.decoder) chunk = state.decoder.write(chunk);
+
+ // don't skip over falsy values in objectMode
+ if (state.objectMode && (chunk === null || chunk === undefined)) return;else if (!state.objectMode && (!chunk || !chunk.length)) return;
+
+ var ret = _this.push(chunk);
+ if (!ret) {
+ paused = true;
+ stream.pause();
+ }
+ });
+
+ // proxy all the other methods.
+ // important when wrapping filters and duplexes.
+ for (var i in stream) {
+ if (this[i] === undefined && typeof stream[i] === 'function') {
+ this[i] = function (method) {
+ return function () {
+ return stream[method].apply(stream, arguments);
+ };
+ }(i);
+ }
+ }
+
+ // proxy certain important events.
+ for (var n = 0; n < kProxyEvents.length; n++) {
+ stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
+ }
+
+ // when we try to consume some more bytes, simply unpause the
+ // underlying stream.
+ this._read = function (n) {
+ debug('wrapped _read', n);
+ if (paused) {
+ paused = false;
+ stream.resume();
+ }
+ };
+
+ return this;
+};
+
+Object.defineProperty(Readable.prototype, 'readableHighWaterMark', {
+ // making it explicit this property is not enumerable
+ // because otherwise some prototype manipulation in
+ // userland will fail
+ enumerable: false,
+ get: function () {
+ return this._readableState.highWaterMark;
+ }
+});
+
+// exposed for testing purposes only.
+Readable._fromList = fromList;
+
+// Pluck off n bytes from an array of buffers.
+// Length is the combined lengths of all the buffers in the list.
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function fromList(n, state) {
+ // nothing buffered
+ if (state.length === 0) return null;
+
+ var ret;
+ if (state.objectMode) ret = state.buffer.shift();else if (!n || n >= state.length) {
+ // read it all, truncate the list
+ if (state.decoder) ret = state.buffer.join('');else if (state.buffer.length === 1) ret = state.buffer.head.data;else ret = state.buffer.concat(state.length);
+ state.buffer.clear();
+ } else {
+ // read part of list
+ ret = fromListPartial(n, state.buffer, state.decoder);
+ }
+
+ return ret;
+}
+
+// Extracts only enough buffered data to satisfy the amount requested.
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function fromListPartial(n, list, hasStrings) {
+ var ret;
+ if (n < list.head.data.length) {
+ // slice is the same for buffers and strings
+ ret = list.head.data.slice(0, n);
+ list.head.data = list.head.data.slice(n);
+ } else if (n === list.head.data.length) {
+ // first chunk is a perfect match
+ ret = list.shift();
+ } else {
+ // result spans more than one buffer
+ ret = hasStrings ? copyFromBufferString(n, list) : copyFromBuffer(n, list);
+ }
+ return ret;
+}
+
+// Copies a specified amount of characters from the list of buffered data
+// chunks.
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function copyFromBufferString(n, list) {
+ var p = list.head;
+ var c = 1;
+ var ret = p.data;
+ n -= ret.length;
+ while (p = p.next) {
+ var str = p.data;
+ var nb = n > str.length ? str.length : n;
+ if (nb === str.length) ret += str;else ret += str.slice(0, n);
+ n -= nb;
+ if (n === 0) {
+ if (nb === str.length) {
+ ++c;
+ if (p.next) list.head = p.next;else list.head = list.tail = null;
+ } else {
+ list.head = p;
+ p.data = str.slice(nb);
+ }
+ break;
+ }
+ ++c;
+ }
+ list.length -= c;
+ return ret;
+}
+
+// Copies a specified amount of bytes from the list of buffered data chunks.
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function copyFromBuffer(n, list) {
+ var ret = Buffer.allocUnsafe(n);
+ var p = list.head;
+ var c = 1;
+ p.data.copy(ret);
+ n -= p.data.length;
+ while (p = p.next) {
+ var buf = p.data;
+ var nb = n > buf.length ? buf.length : n;
+ buf.copy(ret, ret.length - n, 0, nb);
+ n -= nb;
+ if (n === 0) {
+ if (nb === buf.length) {
+ ++c;
+ if (p.next) list.head = p.next;else list.head = list.tail = null;
+ } else {
+ list.head = p;
+ p.data = buf.slice(nb);
+ }
+ break;
+ }
+ ++c;
+ }
+ list.length -= c;
+ return ret;
+}
+
+function endReadable(stream) {
+ var state = stream._readableState;
+
+ // If we get here before consuming all the bytes, then that is a
+ // bug in node. Should never happen.
+ if (state.length > 0) throw new Error('"endReadable()" called on non-empty stream');
+
+ if (!state.endEmitted) {
+ state.ended = true;
+ pna.nextTick(endReadableNT, state, stream);
+ }
+}
+
+function endReadableNT(state, stream) {
+ // Check that we didn't get one last unshift.
+ if (!state.endEmitted && state.length === 0) {
+ state.endEmitted = true;
+ stream.readable = false;
+ stream.emit('end');
+ }
+}
+
+function indexOf(xs, x) {
+ for (var i = 0, l = xs.length; i < l; i++) {
+ if (xs[i] === x) return i;
+ }
+ return -1;
+}
\ No newline at end of file
git://repos.xcallymotion.com / motion2.git / blobdiff