| // 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; |
| } |