[6a3a178] | 1 | // Copyright Joyent, Inc. and other Node contributors.
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| 2 | //
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| 3 | // Permission is hereby granted, free of charge, to any person obtaining a
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| 4 | // copy of this software and associated documentation files (the
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| 5 | // "Software"), to deal in the Software without restriction, including
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| 6 | // without limitation the rights to use, copy, modify, merge, publish,
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| 7 | // distribute, sublicense, and/or sell copies of the Software, and to permit
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| 8 | // persons to whom the Software is furnished to do so, subject to the
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| 9 | // following conditions:
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| 10 | //
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| 11 | // The above copyright notice and this permission notice shall be included
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| 12 | // in all copies or substantial portions of the Software.
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| 13 | //
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| 14 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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| 15 | // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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| 16 | // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
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| 17 | // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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| 18 | // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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| 19 | // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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| 20 | // USE OR OTHER DEALINGS IN THE SOFTWARE.
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| 21 | 'use strict';
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| 22 |
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| 23 | module.exports = Readable;
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| 24 | /*<replacement>*/
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| 25 |
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| 26 | var Duplex;
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| 27 | /*</replacement>*/
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| 28 |
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| 29 | Readable.ReadableState = ReadableState;
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| 30 | /*<replacement>*/
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| 31 |
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| 32 | var EE = require('events').EventEmitter;
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| 33 |
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| 34 | var EElistenerCount = function EElistenerCount(emitter, type) {
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| 35 | return emitter.listeners(type).length;
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| 36 | };
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| 37 | /*</replacement>*/
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| 38 |
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| 39 | /*<replacement>*/
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| 40 |
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| 41 |
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| 42 | var Stream = require('./internal/streams/stream');
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| 43 | /*</replacement>*/
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| 44 |
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| 45 |
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| 46 | var Buffer = require('buffer').Buffer;
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| 47 |
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| 48 | var OurUint8Array = global.Uint8Array || function () {};
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| 49 |
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| 50 | function _uint8ArrayToBuffer(chunk) {
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| 51 | return Buffer.from(chunk);
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| 52 | }
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| 53 |
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| 54 | function _isUint8Array(obj) {
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| 55 | return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
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| 56 | }
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| 57 | /*<replacement>*/
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| 58 |
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| 59 |
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| 60 | var debugUtil = require('util');
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| 61 |
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| 62 | var debug;
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| 63 |
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| 64 | if (debugUtil && debugUtil.debuglog) {
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| 65 | debug = debugUtil.debuglog('stream');
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| 66 | } else {
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| 67 | debug = function debug() {};
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| 68 | }
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| 69 | /*</replacement>*/
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| 70 |
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| 71 |
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| 72 | var BufferList = require('./internal/streams/buffer_list');
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| 73 |
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| 74 | var destroyImpl = require('./internal/streams/destroy');
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| 75 |
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| 76 | var _require = require('./internal/streams/state'),
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| 77 | getHighWaterMark = _require.getHighWaterMark;
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| 78 |
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| 79 | var _require$codes = require('../errors').codes,
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| 80 | ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
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| 81 | ERR_STREAM_PUSH_AFTER_EOF = _require$codes.ERR_STREAM_PUSH_AFTER_EOF,
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| 82 | ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
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| 83 | ERR_STREAM_UNSHIFT_AFTER_END_EVENT = _require$codes.ERR_STREAM_UNSHIFT_AFTER_END_EVENT; // Lazy loaded to improve the startup performance.
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| 84 |
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| 85 |
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| 86 | var StringDecoder;
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| 87 | var createReadableStreamAsyncIterator;
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| 88 | var from;
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| 89 |
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| 90 | require('inherits')(Readable, Stream);
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| 91 |
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| 92 | var errorOrDestroy = destroyImpl.errorOrDestroy;
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| 93 | var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
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| 94 |
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| 95 | function prependListener(emitter, event, fn) {
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| 96 | // Sadly this is not cacheable as some libraries bundle their own
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| 97 | // event emitter implementation with them.
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| 98 | 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
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| 99 | // userland ones. NEVER DO THIS. This is here only because this code needs
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| 100 | // to continue to work with older versions of Node.js that do not include
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| 101 | // the prependListener() method. The goal is to eventually remove this hack.
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| 102 |
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| 103 | if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (Array.isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
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| 104 | }
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| 105 |
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| 106 | function ReadableState(options, stream, isDuplex) {
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| 107 | Duplex = Duplex || require('./_stream_duplex');
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| 108 | options = options || {}; // Duplex streams are both readable and writable, but share
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| 109 | // the same options object.
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| 110 | // However, some cases require setting options to different
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| 111 | // values for the readable and the writable sides of the duplex stream.
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| 112 | // These options can be provided separately as readableXXX and writableXXX.
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| 113 |
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| 114 | if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex; // object stream flag. Used to make read(n) ignore n and to
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| 115 | // make all the buffer merging and length checks go away
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| 116 |
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| 117 | this.objectMode = !!options.objectMode;
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| 118 | if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode; // the point at which it stops calling _read() to fill the buffer
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| 119 | // Note: 0 is a valid value, means "don't call _read preemptively ever"
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| 120 |
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| 121 | this.highWaterMark = getHighWaterMark(this, options, 'readableHighWaterMark', isDuplex); // A linked list is used to store data chunks instead of an array because the
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| 122 | // linked list can remove elements from the beginning faster than
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| 123 | // array.shift()
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| 124 |
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| 125 | this.buffer = new BufferList();
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| 126 | this.length = 0;
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| 127 | this.pipes = null;
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| 128 | this.pipesCount = 0;
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| 129 | this.flowing = null;
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| 130 | this.ended = false;
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| 131 | this.endEmitted = false;
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| 132 | this.reading = false; // a flag to be able to tell if the event 'readable'/'data' is emitted
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| 133 | // immediately, or on a later tick. We set this to true at first, because
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| 134 | // any actions that shouldn't happen until "later" should generally also
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| 135 | // not happen before the first read call.
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| 136 |
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| 137 | this.sync = true; // whenever we return null, then we set a flag to say
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| 138 | // that we're awaiting a 'readable' event emission.
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| 139 |
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| 140 | this.needReadable = false;
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| 141 | this.emittedReadable = false;
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| 142 | this.readableListening = false;
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| 143 | this.resumeScheduled = false;
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| 144 | this.paused = true; // Should close be emitted on destroy. Defaults to true.
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| 145 |
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| 146 | this.emitClose = options.emitClose !== false; // Should .destroy() be called after 'end' (and potentially 'finish')
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| 147 |
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| 148 | this.autoDestroy = !!options.autoDestroy; // has it been destroyed
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| 149 |
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| 150 | this.destroyed = false; // Crypto is kind of old and crusty. Historically, its default string
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| 151 | // encoding is 'binary' so we have to make this configurable.
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| 152 | // Everything else in the universe uses 'utf8', though.
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| 153 |
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| 154 | this.defaultEncoding = options.defaultEncoding || 'utf8'; // the number of writers that are awaiting a drain event in .pipe()s
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| 155 |
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| 156 | this.awaitDrain = 0; // if true, a maybeReadMore has been scheduled
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| 157 |
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| 158 | this.readingMore = false;
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| 159 | this.decoder = null;
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| 160 | this.encoding = null;
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| 161 |
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| 162 | if (options.encoding) {
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| 163 | if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
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| 164 | this.decoder = new StringDecoder(options.encoding);
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| 165 | this.encoding = options.encoding;
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| 166 | }
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| 167 | }
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| 168 |
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| 169 | function Readable(options) {
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| 170 | Duplex = Duplex || require('./_stream_duplex');
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| 171 | if (!(this instanceof Readable)) return new Readable(options); // Checking for a Stream.Duplex instance is faster here instead of inside
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| 172 | // the ReadableState constructor, at least with V8 6.5
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| 173 |
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| 174 | var isDuplex = this instanceof Duplex;
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| 175 | this._readableState = new ReadableState(options, this, isDuplex); // legacy
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| 176 |
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| 177 | this.readable = true;
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| 178 |
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| 179 | if (options) {
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| 180 | if (typeof options.read === 'function') this._read = options.read;
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| 181 | if (typeof options.destroy === 'function') this._destroy = options.destroy;
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| 182 | }
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| 183 |
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| 184 | Stream.call(this);
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| 185 | }
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| 186 |
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| 187 | Object.defineProperty(Readable.prototype, 'destroyed', {
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| 188 | // making it explicit this property is not enumerable
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| 189 | // because otherwise some prototype manipulation in
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| 190 | // userland will fail
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| 191 | enumerable: false,
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| 192 | get: function get() {
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| 193 | if (this._readableState === undefined) {
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| 194 | return false;
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| 195 | }
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| 196 |
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| 197 | return this._readableState.destroyed;
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| 198 | },
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| 199 | set: function set(value) {
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| 200 | // we ignore the value if the stream
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| 201 | // has not been initialized yet
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| 202 | if (!this._readableState) {
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| 203 | return;
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| 204 | } // backward compatibility, the user is explicitly
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| 205 | // managing destroyed
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| 206 |
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| 207 |
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| 208 | this._readableState.destroyed = value;
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| 209 | }
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| 210 | });
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| 211 | Readable.prototype.destroy = destroyImpl.destroy;
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| 212 | Readable.prototype._undestroy = destroyImpl.undestroy;
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| 213 |
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| 214 | Readable.prototype._destroy = function (err, cb) {
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| 215 | cb(err);
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| 216 | }; // Manually shove something into the read() buffer.
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| 217 | // This returns true if the highWaterMark has not been hit yet,
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| 218 | // similar to how Writable.write() returns true if you should
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| 219 | // write() some more.
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| 220 |
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| 221 |
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| 222 | Readable.prototype.push = function (chunk, encoding) {
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| 223 | var state = this._readableState;
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| 224 | var skipChunkCheck;
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| 225 |
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| 226 | if (!state.objectMode) {
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| 227 | if (typeof chunk === 'string') {
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| 228 | encoding = encoding || state.defaultEncoding;
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| 229 |
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| 230 | if (encoding !== state.encoding) {
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| 231 | chunk = Buffer.from(chunk, encoding);
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| 232 | encoding = '';
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| 233 | }
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| 234 |
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| 235 | skipChunkCheck = true;
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| 236 | }
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| 237 | } else {
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| 238 | skipChunkCheck = true;
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| 239 | }
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| 240 |
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| 241 | return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
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| 242 | }; // Unshift should *always* be something directly out of read()
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| 243 |
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| 244 |
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| 245 | Readable.prototype.unshift = function (chunk) {
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| 246 | return readableAddChunk(this, chunk, null, true, false);
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| 247 | };
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| 248 |
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| 249 | function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
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| 250 | debug('readableAddChunk', chunk);
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| 251 | var state = stream._readableState;
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| 252 |
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| 253 | if (chunk === null) {
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| 254 | state.reading = false;
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| 255 | onEofChunk(stream, state);
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| 256 | } else {
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| 257 | var er;
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| 258 | if (!skipChunkCheck) er = chunkInvalid(state, chunk);
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| 259 |
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| 260 | if (er) {
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| 261 | errorOrDestroy(stream, er);
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| 262 | } else if (state.objectMode || chunk && chunk.length > 0) {
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| 263 | if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
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| 264 | chunk = _uint8ArrayToBuffer(chunk);
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| 265 | }
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| 266 |
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| 267 | if (addToFront) {
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| 268 | if (state.endEmitted) errorOrDestroy(stream, new ERR_STREAM_UNSHIFT_AFTER_END_EVENT());else addChunk(stream, state, chunk, true);
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| 269 | } else if (state.ended) {
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| 270 | errorOrDestroy(stream, new ERR_STREAM_PUSH_AFTER_EOF());
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| 271 | } else if (state.destroyed) {
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| 272 | return false;
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| 273 | } else {
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| 274 | state.reading = false;
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| 275 |
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| 276 | if (state.decoder && !encoding) {
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| 277 | chunk = state.decoder.write(chunk);
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| 278 | if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
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| 279 | } else {
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| 280 | addChunk(stream, state, chunk, false);
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| 281 | }
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| 282 | }
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| 283 | } else if (!addToFront) {
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| 284 | state.reading = false;
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| 285 | maybeReadMore(stream, state);
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| 286 | }
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| 287 | } // We can push more data if we are below the highWaterMark.
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| 288 | // Also, if we have no data yet, we can stand some more bytes.
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| 289 | // This is to work around cases where hwm=0, such as the repl.
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| 290 |
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| 291 |
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| 292 | return !state.ended && (state.length < state.highWaterMark || state.length === 0);
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| 293 | }
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| 294 |
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| 295 | function addChunk(stream, state, chunk, addToFront) {
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| 296 | if (state.flowing && state.length === 0 && !state.sync) {
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| 297 | state.awaitDrain = 0;
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| 298 | stream.emit('data', chunk);
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| 299 | } else {
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| 300 | // update the buffer info.
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| 301 | state.length += state.objectMode ? 1 : chunk.length;
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| 302 | if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
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| 303 | if (state.needReadable) emitReadable(stream);
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| 304 | }
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| 305 |
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| 306 | maybeReadMore(stream, state);
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| 307 | }
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| 308 |
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| 309 | function chunkInvalid(state, chunk) {
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| 310 | var er;
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| 311 |
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| 312 | if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
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| 313 | er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer', 'Uint8Array'], chunk);
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| 314 | }
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| 315 |
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| 316 | return er;
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| 317 | }
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| 318 |
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| 319 | Readable.prototype.isPaused = function () {
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| 320 | return this._readableState.flowing === false;
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| 321 | }; // backwards compatibility.
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| 322 |
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| 323 |
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| 324 | Readable.prototype.setEncoding = function (enc) {
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| 325 | if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
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| 326 | var decoder = new StringDecoder(enc);
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| 327 | this._readableState.decoder = decoder; // If setEncoding(null), decoder.encoding equals utf8
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| 328 |
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| 329 | this._readableState.encoding = this._readableState.decoder.encoding; // Iterate over current buffer to convert already stored Buffers:
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| 330 |
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| 331 | var p = this._readableState.buffer.head;
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| 332 | var content = '';
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| 333 |
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| 334 | while (p !== null) {
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| 335 | content += decoder.write(p.data);
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| 336 | p = p.next;
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| 337 | }
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| 338 |
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| 339 | this._readableState.buffer.clear();
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| 340 |
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| 341 | if (content !== '') this._readableState.buffer.push(content);
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| 342 | this._readableState.length = content.length;
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| 343 | return this;
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| 344 | }; // Don't raise the hwm > 1GB
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| 345 |
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| 346 |
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| 347 | var MAX_HWM = 0x40000000;
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| 348 |
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| 349 | function computeNewHighWaterMark(n) {
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| 350 | if (n >= MAX_HWM) {
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| 351 | // TODO(ronag): Throw ERR_VALUE_OUT_OF_RANGE.
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| 352 | n = MAX_HWM;
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| 353 | } else {
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| 354 | // Get the next highest power of 2 to prevent increasing hwm excessively in
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| 355 | // tiny amounts
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| 356 | n--;
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| 357 | n |= n >>> 1;
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| 358 | n |= n >>> 2;
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| 359 | n |= n >>> 4;
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| 360 | n |= n >>> 8;
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| 361 | n |= n >>> 16;
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| 362 | n++;
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| 363 | }
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| 364 |
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| 365 | return n;
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| 366 | } // This function is designed to be inlinable, so please take care when making
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| 367 | // changes to the function body.
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| 368 |
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| 369 |
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| 370 | function howMuchToRead(n, state) {
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| 371 | if (n <= 0 || state.length === 0 && state.ended) return 0;
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| 372 | if (state.objectMode) return 1;
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| 373 |
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| 374 | if (n !== n) {
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| 375 | // Only flow one buffer at a time
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| 376 | if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
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| 377 | } // If we're asking for more than the current hwm, then raise the hwm.
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| 378 |
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| 379 |
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| 380 | if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
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| 381 | if (n <= state.length) return n; // Don't have enough
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| 382 |
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| 383 | if (!state.ended) {
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| 384 | state.needReadable = true;
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| 385 | return 0;
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| 386 | }
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| 387 |
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| 388 | return state.length;
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| 389 | } // you can override either this method, or the async _read(n) below.
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| 390 |
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| 391 |
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| 392 | Readable.prototype.read = function (n) {
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| 393 | debug('read', n);
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| 394 | n = parseInt(n, 10);
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| 395 | var state = this._readableState;
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| 396 | var nOrig = n;
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| 397 | if (n !== 0) state.emittedReadable = false; // if we're doing read(0) to trigger a readable event, but we
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| 398 | // already have a bunch of data in the buffer, then just trigger
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| 399 | // the 'readable' event and move on.
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| 400 |
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| 401 | if (n === 0 && state.needReadable && ((state.highWaterMark !== 0 ? state.length >= state.highWaterMark : state.length > 0) || state.ended)) {
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| 402 | debug('read: emitReadable', state.length, state.ended);
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| 403 | if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
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| 404 | return null;
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| 405 | }
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| 406 |
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| 407 | n = howMuchToRead(n, state); // if we've ended, and we're now clear, then finish it up.
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| 408 |
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| 409 | if (n === 0 && state.ended) {
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| 410 | if (state.length === 0) endReadable(this);
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| 411 | return null;
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| 412 | } // All the actual chunk generation logic needs to be
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| 413 | // *below* the call to _read. The reason is that in certain
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| 414 | // synthetic stream cases, such as passthrough streams, _read
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| 415 | // may be a completely synchronous operation which may change
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| 416 | // the state of the read buffer, providing enough data when
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| 417 | // before there was *not* enough.
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| 418 | //
|
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| 419 | // So, the steps are:
|
---|
| 420 | // 1. Figure out what the state of things will be after we do
|
---|
| 421 | // a read from the buffer.
|
---|
| 422 | //
|
---|
| 423 | // 2. If that resulting state will trigger a _read, then call _read.
|
---|
| 424 | // Note that this may be asynchronous, or synchronous. Yes, it is
|
---|
| 425 | // deeply ugly to write APIs this way, but that still doesn't mean
|
---|
| 426 | // that the Readable class should behave improperly, as streams are
|
---|
| 427 | // designed to be sync/async agnostic.
|
---|
| 428 | // Take note if the _read call is sync or async (ie, if the read call
|
---|
| 429 | // has returned yet), so that we know whether or not it's safe to emit
|
---|
| 430 | // 'readable' etc.
|
---|
| 431 | //
|
---|
| 432 | // 3. Actually pull the requested chunks out of the buffer and return.
|
---|
| 433 | // if we need a readable event, then we need to do some reading.
|
---|
| 434 |
|
---|
| 435 |
|
---|
| 436 | var doRead = state.needReadable;
|
---|
| 437 | debug('need readable', doRead); // if we currently have less than the highWaterMark, then also read some
|
---|
| 438 |
|
---|
| 439 | if (state.length === 0 || state.length - n < state.highWaterMark) {
|
---|
| 440 | doRead = true;
|
---|
| 441 | debug('length less than watermark', doRead);
|
---|
| 442 | } // however, if we've ended, then there's no point, and if we're already
|
---|
| 443 | // reading, then it's unnecessary.
|
---|
| 444 |
|
---|
| 445 |
|
---|
| 446 | if (state.ended || state.reading) {
|
---|
| 447 | doRead = false;
|
---|
| 448 | debug('reading or ended', doRead);
|
---|
| 449 | } else if (doRead) {
|
---|
| 450 | debug('do read');
|
---|
| 451 | state.reading = true;
|
---|
| 452 | state.sync = true; // if the length is currently zero, then we *need* a readable event.
|
---|
| 453 |
|
---|
| 454 | if (state.length === 0) state.needReadable = true; // call internal read method
|
---|
| 455 |
|
---|
| 456 | this._read(state.highWaterMark);
|
---|
| 457 |
|
---|
| 458 | state.sync = false; // If _read pushed data synchronously, then `reading` will be false,
|
---|
| 459 | // and we need to re-evaluate how much data we can return to the user.
|
---|
| 460 |
|
---|
| 461 | if (!state.reading) n = howMuchToRead(nOrig, state);
|
---|
| 462 | }
|
---|
| 463 |
|
---|
| 464 | var ret;
|
---|
| 465 | if (n > 0) ret = fromList(n, state);else ret = null;
|
---|
| 466 |
|
---|
| 467 | if (ret === null) {
|
---|
| 468 | state.needReadable = state.length <= state.highWaterMark;
|
---|
| 469 | n = 0;
|
---|
| 470 | } else {
|
---|
| 471 | state.length -= n;
|
---|
| 472 | state.awaitDrain = 0;
|
---|
| 473 | }
|
---|
| 474 |
|
---|
| 475 | if (state.length === 0) {
|
---|
| 476 | // If we have nothing in the buffer, then we want to know
|
---|
| 477 | // as soon as we *do* get something into the buffer.
|
---|
| 478 | if (!state.ended) state.needReadable = true; // If we tried to read() past the EOF, then emit end on the next tick.
|
---|
| 479 |
|
---|
| 480 | if (nOrig !== n && state.ended) endReadable(this);
|
---|
| 481 | }
|
---|
| 482 |
|
---|
| 483 | if (ret !== null) this.emit('data', ret);
|
---|
| 484 | return ret;
|
---|
| 485 | };
|
---|
| 486 |
|
---|
| 487 | function onEofChunk(stream, state) {
|
---|
| 488 | debug('onEofChunk');
|
---|
| 489 | if (state.ended) return;
|
---|
| 490 |
|
---|
| 491 | if (state.decoder) {
|
---|
| 492 | var chunk = state.decoder.end();
|
---|
| 493 |
|
---|
| 494 | if (chunk && chunk.length) {
|
---|
| 495 | state.buffer.push(chunk);
|
---|
| 496 | state.length += state.objectMode ? 1 : chunk.length;
|
---|
| 497 | }
|
---|
| 498 | }
|
---|
| 499 |
|
---|
| 500 | state.ended = true;
|
---|
| 501 |
|
---|
| 502 | if (state.sync) {
|
---|
| 503 | // if we are sync, wait until next tick to emit the data.
|
---|
| 504 | // Otherwise we risk emitting data in the flow()
|
---|
| 505 | // the readable code triggers during a read() call
|
---|
| 506 | emitReadable(stream);
|
---|
| 507 | } else {
|
---|
| 508 | // emit 'readable' now to make sure it gets picked up.
|
---|
| 509 | state.needReadable = false;
|
---|
| 510 |
|
---|
| 511 | if (!state.emittedReadable) {
|
---|
| 512 | state.emittedReadable = true;
|
---|
| 513 | emitReadable_(stream);
|
---|
| 514 | }
|
---|
| 515 | }
|
---|
| 516 | } // Don't emit readable right away in sync mode, because this can trigger
|
---|
| 517 | // another read() call => stack overflow. This way, it might trigger
|
---|
| 518 | // a nextTick recursion warning, but that's not so bad.
|
---|
| 519 |
|
---|
| 520 |
|
---|
| 521 | function emitReadable(stream) {
|
---|
| 522 | var state = stream._readableState;
|
---|
| 523 | debug('emitReadable', state.needReadable, state.emittedReadable);
|
---|
| 524 | state.needReadable = false;
|
---|
| 525 |
|
---|
| 526 | if (!state.emittedReadable) {
|
---|
| 527 | debug('emitReadable', state.flowing);
|
---|
| 528 | state.emittedReadable = true;
|
---|
| 529 | process.nextTick(emitReadable_, stream);
|
---|
| 530 | }
|
---|
| 531 | }
|
---|
| 532 |
|
---|
| 533 | function emitReadable_(stream) {
|
---|
| 534 | var state = stream._readableState;
|
---|
| 535 | debug('emitReadable_', state.destroyed, state.length, state.ended);
|
---|
| 536 |
|
---|
| 537 | if (!state.destroyed && (state.length || state.ended)) {
|
---|
| 538 | stream.emit('readable');
|
---|
| 539 | state.emittedReadable = false;
|
---|
| 540 | } // The stream needs another readable event if
|
---|
| 541 | // 1. It is not flowing, as the flow mechanism will take
|
---|
| 542 | // care of it.
|
---|
| 543 | // 2. It is not ended.
|
---|
| 544 | // 3. It is below the highWaterMark, so we can schedule
|
---|
| 545 | // another readable later.
|
---|
| 546 |
|
---|
| 547 |
|
---|
| 548 | state.needReadable = !state.flowing && !state.ended && state.length <= state.highWaterMark;
|
---|
| 549 | flow(stream);
|
---|
| 550 | } // at this point, the user has presumably seen the 'readable' event,
|
---|
| 551 | // and called read() to consume some data. that may have triggered
|
---|
| 552 | // in turn another _read(n) call, in which case reading = true if
|
---|
| 553 | // it's in progress.
|
---|
| 554 | // However, if we're not ended, or reading, and the length < hwm,
|
---|
| 555 | // then go ahead and try to read some more preemptively.
|
---|
| 556 |
|
---|
| 557 |
|
---|
| 558 | function maybeReadMore(stream, state) {
|
---|
| 559 | if (!state.readingMore) {
|
---|
| 560 | state.readingMore = true;
|
---|
| 561 | process.nextTick(maybeReadMore_, stream, state);
|
---|
| 562 | }
|
---|
| 563 | }
|
---|
| 564 |
|
---|
| 565 | function maybeReadMore_(stream, state) {
|
---|
| 566 | // Attempt to read more data if we should.
|
---|
| 567 | //
|
---|
| 568 | // The conditions for reading more data are (one of):
|
---|
| 569 | // - Not enough data buffered (state.length < state.highWaterMark). The loop
|
---|
| 570 | // is responsible for filling the buffer with enough data if such data
|
---|
| 571 | // is available. If highWaterMark is 0 and we are not in the flowing mode
|
---|
| 572 | // we should _not_ attempt to buffer any extra data. We'll get more data
|
---|
| 573 | // when the stream consumer calls read() instead.
|
---|
| 574 | // - No data in the buffer, and the stream is in flowing mode. In this mode
|
---|
| 575 | // the loop below is responsible for ensuring read() is called. Failing to
|
---|
| 576 | // call read here would abort the flow and there's no other mechanism for
|
---|
| 577 | // continuing the flow if the stream consumer has just subscribed to the
|
---|
| 578 | // 'data' event.
|
---|
| 579 | //
|
---|
| 580 | // In addition to the above conditions to keep reading data, the following
|
---|
| 581 | // conditions prevent the data from being read:
|
---|
| 582 | // - The stream has ended (state.ended).
|
---|
| 583 | // - There is already a pending 'read' operation (state.reading). This is a
|
---|
| 584 | // case where the the stream has called the implementation defined _read()
|
---|
| 585 | // method, but they are processing the call asynchronously and have _not_
|
---|
| 586 | // called push() with new data. In this case we skip performing more
|
---|
| 587 | // read()s. The execution ends in this method again after the _read() ends
|
---|
| 588 | // up calling push() with more data.
|
---|
| 589 | while (!state.reading && !state.ended && (state.length < state.highWaterMark || state.flowing && state.length === 0)) {
|
---|
| 590 | var len = state.length;
|
---|
| 591 | debug('maybeReadMore read 0');
|
---|
| 592 | stream.read(0);
|
---|
| 593 | if (len === state.length) // didn't get any data, stop spinning.
|
---|
| 594 | break;
|
---|
| 595 | }
|
---|
| 596 |
|
---|
| 597 | state.readingMore = false;
|
---|
| 598 | } // abstract method. to be overridden in specific implementation classes.
|
---|
| 599 | // call cb(er, data) where data is <= n in length.
|
---|
| 600 | // for virtual (non-string, non-buffer) streams, "length" is somewhat
|
---|
| 601 | // arbitrary, and perhaps not very meaningful.
|
---|
| 602 |
|
---|
| 603 |
|
---|
| 604 | Readable.prototype._read = function (n) {
|
---|
| 605 | errorOrDestroy(this, new ERR_METHOD_NOT_IMPLEMENTED('_read()'));
|
---|
| 606 | };
|
---|
| 607 |
|
---|
| 608 | Readable.prototype.pipe = function (dest, pipeOpts) {
|
---|
| 609 | var src = this;
|
---|
| 610 | var state = this._readableState;
|
---|
| 611 |
|
---|
| 612 | switch (state.pipesCount) {
|
---|
| 613 | case 0:
|
---|
| 614 | state.pipes = dest;
|
---|
| 615 | break;
|
---|
| 616 |
|
---|
| 617 | case 1:
|
---|
| 618 | state.pipes = [state.pipes, dest];
|
---|
| 619 | break;
|
---|
| 620 |
|
---|
| 621 | default:
|
---|
| 622 | state.pipes.push(dest);
|
---|
| 623 | break;
|
---|
| 624 | }
|
---|
| 625 |
|
---|
| 626 | state.pipesCount += 1;
|
---|
| 627 | debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
|
---|
| 628 | var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
|
---|
| 629 | var endFn = doEnd ? onend : unpipe;
|
---|
| 630 | if (state.endEmitted) process.nextTick(endFn);else src.once('end', endFn);
|
---|
| 631 | dest.on('unpipe', onunpipe);
|
---|
| 632 |
|
---|
| 633 | function onunpipe(readable, unpipeInfo) {
|
---|
| 634 | debug('onunpipe');
|
---|
| 635 |
|
---|
| 636 | if (readable === src) {
|
---|
| 637 | if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
|
---|
| 638 | unpipeInfo.hasUnpiped = true;
|
---|
| 639 | cleanup();
|
---|
| 640 | }
|
---|
| 641 | }
|
---|
| 642 | }
|
---|
| 643 |
|
---|
| 644 | function onend() {
|
---|
| 645 | debug('onend');
|
---|
| 646 | dest.end();
|
---|
| 647 | } // when the dest drains, it reduces the awaitDrain counter
|
---|
| 648 | // on the source. This would be more elegant with a .once()
|
---|
| 649 | // handler in flow(), but adding and removing repeatedly is
|
---|
| 650 | // too slow.
|
---|
| 651 |
|
---|
| 652 |
|
---|
| 653 | var ondrain = pipeOnDrain(src);
|
---|
| 654 | dest.on('drain', ondrain);
|
---|
| 655 | var cleanedUp = false;
|
---|
| 656 |
|
---|
| 657 | function cleanup() {
|
---|
| 658 | debug('cleanup'); // cleanup event handlers once the pipe is broken
|
---|
| 659 |
|
---|
| 660 | dest.removeListener('close', onclose);
|
---|
| 661 | dest.removeListener('finish', onfinish);
|
---|
| 662 | dest.removeListener('drain', ondrain);
|
---|
| 663 | dest.removeListener('error', onerror);
|
---|
| 664 | dest.removeListener('unpipe', onunpipe);
|
---|
| 665 | src.removeListener('end', onend);
|
---|
| 666 | src.removeListener('end', unpipe);
|
---|
| 667 | src.removeListener('data', ondata);
|
---|
| 668 | cleanedUp = true; // if the reader is waiting for a drain event from this
|
---|
| 669 | // specific writer, then it would cause it to never start
|
---|
| 670 | // flowing again.
|
---|
| 671 | // So, if this is awaiting a drain, then we just call it now.
|
---|
| 672 | // If we don't know, then assume that we are waiting for one.
|
---|
| 673 |
|
---|
| 674 | if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
|
---|
| 675 | }
|
---|
| 676 |
|
---|
| 677 | src.on('data', ondata);
|
---|
| 678 |
|
---|
| 679 | function ondata(chunk) {
|
---|
| 680 | debug('ondata');
|
---|
| 681 | var ret = dest.write(chunk);
|
---|
| 682 | debug('dest.write', ret);
|
---|
| 683 |
|
---|
| 684 | if (ret === false) {
|
---|
| 685 | // If the user unpiped during `dest.write()`, it is possible
|
---|
| 686 | // to get stuck in a permanently paused state if that write
|
---|
| 687 | // also returned false.
|
---|
| 688 | // => Check whether `dest` is still a piping destination.
|
---|
| 689 | if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
|
---|
| 690 | debug('false write response, pause', state.awaitDrain);
|
---|
| 691 | state.awaitDrain++;
|
---|
| 692 | }
|
---|
| 693 |
|
---|
| 694 | src.pause();
|
---|
| 695 | }
|
---|
| 696 | } // if the dest has an error, then stop piping into it.
|
---|
| 697 | // however, don't suppress the throwing behavior for this.
|
---|
| 698 |
|
---|
| 699 |
|
---|
| 700 | function onerror(er) {
|
---|
| 701 | debug('onerror', er);
|
---|
| 702 | unpipe();
|
---|
| 703 | dest.removeListener('error', onerror);
|
---|
| 704 | if (EElistenerCount(dest, 'error') === 0) errorOrDestroy(dest, er);
|
---|
| 705 | } // Make sure our error handler is attached before userland ones.
|
---|
| 706 |
|
---|
| 707 |
|
---|
| 708 | prependListener(dest, 'error', onerror); // Both close and finish should trigger unpipe, but only once.
|
---|
| 709 |
|
---|
| 710 | function onclose() {
|
---|
| 711 | dest.removeListener('finish', onfinish);
|
---|
| 712 | unpipe();
|
---|
| 713 | }
|
---|
| 714 |
|
---|
| 715 | dest.once('close', onclose);
|
---|
| 716 |
|
---|
| 717 | function onfinish() {
|
---|
| 718 | debug('onfinish');
|
---|
| 719 | dest.removeListener('close', onclose);
|
---|
| 720 | unpipe();
|
---|
| 721 | }
|
---|
| 722 |
|
---|
| 723 | dest.once('finish', onfinish);
|
---|
| 724 |
|
---|
| 725 | function unpipe() {
|
---|
| 726 | debug('unpipe');
|
---|
| 727 | src.unpipe(dest);
|
---|
| 728 | } // tell the dest that it's being piped to
|
---|
| 729 |
|
---|
| 730 |
|
---|
| 731 | dest.emit('pipe', src); // start the flow if it hasn't been started already.
|
---|
| 732 |
|
---|
| 733 | if (!state.flowing) {
|
---|
| 734 | debug('pipe resume');
|
---|
| 735 | src.resume();
|
---|
| 736 | }
|
---|
| 737 |
|
---|
| 738 | return dest;
|
---|
| 739 | };
|
---|
| 740 |
|
---|
| 741 | function pipeOnDrain(src) {
|
---|
| 742 | return function pipeOnDrainFunctionResult() {
|
---|
| 743 | var state = src._readableState;
|
---|
| 744 | debug('pipeOnDrain', state.awaitDrain);
|
---|
| 745 | if (state.awaitDrain) state.awaitDrain--;
|
---|
| 746 |
|
---|
| 747 | if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
|
---|
| 748 | state.flowing = true;
|
---|
| 749 | flow(src);
|
---|
| 750 | }
|
---|
| 751 | };
|
---|
| 752 | }
|
---|
| 753 |
|
---|
| 754 | Readable.prototype.unpipe = function (dest) {
|
---|
| 755 | var state = this._readableState;
|
---|
| 756 | var unpipeInfo = {
|
---|
| 757 | hasUnpiped: false
|
---|
| 758 | }; // if we're not piping anywhere, then do nothing.
|
---|
| 759 |
|
---|
| 760 | if (state.pipesCount === 0) return this; // just one destination. most common case.
|
---|
| 761 |
|
---|
| 762 | if (state.pipesCount === 1) {
|
---|
| 763 | // passed in one, but it's not the right one.
|
---|
| 764 | if (dest && dest !== state.pipes) return this;
|
---|
| 765 | if (!dest) dest = state.pipes; // got a match.
|
---|
| 766 |
|
---|
| 767 | state.pipes = null;
|
---|
| 768 | state.pipesCount = 0;
|
---|
| 769 | state.flowing = false;
|
---|
| 770 | if (dest) dest.emit('unpipe', this, unpipeInfo);
|
---|
| 771 | return this;
|
---|
| 772 | } // slow case. multiple pipe destinations.
|
---|
| 773 |
|
---|
| 774 |
|
---|
| 775 | if (!dest) {
|
---|
| 776 | // remove all.
|
---|
| 777 | var dests = state.pipes;
|
---|
| 778 | var len = state.pipesCount;
|
---|
| 779 | state.pipes = null;
|
---|
| 780 | state.pipesCount = 0;
|
---|
| 781 | state.flowing = false;
|
---|
| 782 |
|
---|
| 783 | for (var i = 0; i < len; i++) {
|
---|
| 784 | dests[i].emit('unpipe', this, {
|
---|
| 785 | hasUnpiped: false
|
---|
| 786 | });
|
---|
| 787 | }
|
---|
| 788 |
|
---|
| 789 | return this;
|
---|
| 790 | } // try to find the right one.
|
---|
| 791 |
|
---|
| 792 |
|
---|
| 793 | var index = indexOf(state.pipes, dest);
|
---|
| 794 | if (index === -1) return this;
|
---|
| 795 | state.pipes.splice(index, 1);
|
---|
| 796 | state.pipesCount -= 1;
|
---|
| 797 | if (state.pipesCount === 1) state.pipes = state.pipes[0];
|
---|
| 798 | dest.emit('unpipe', this, unpipeInfo);
|
---|
| 799 | return this;
|
---|
| 800 | }; // set up data events if they are asked for
|
---|
| 801 | // Ensure readable listeners eventually get something
|
---|
| 802 |
|
---|
| 803 |
|
---|
| 804 | Readable.prototype.on = function (ev, fn) {
|
---|
| 805 | var res = Stream.prototype.on.call(this, ev, fn);
|
---|
| 806 | var state = this._readableState;
|
---|
| 807 |
|
---|
| 808 | if (ev === 'data') {
|
---|
| 809 | // update readableListening so that resume() may be a no-op
|
---|
| 810 | // a few lines down. This is needed to support once('readable').
|
---|
| 811 | state.readableListening = this.listenerCount('readable') > 0; // Try start flowing on next tick if stream isn't explicitly paused
|
---|
| 812 |
|
---|
| 813 | if (state.flowing !== false) this.resume();
|
---|
| 814 | } else if (ev === 'readable') {
|
---|
| 815 | if (!state.endEmitted && !state.readableListening) {
|
---|
| 816 | state.readableListening = state.needReadable = true;
|
---|
| 817 | state.flowing = false;
|
---|
| 818 | state.emittedReadable = false;
|
---|
| 819 | debug('on readable', state.length, state.reading);
|
---|
| 820 |
|
---|
| 821 | if (state.length) {
|
---|
| 822 | emitReadable(this);
|
---|
| 823 | } else if (!state.reading) {
|
---|
| 824 | process.nextTick(nReadingNextTick, this);
|
---|
| 825 | }
|
---|
| 826 | }
|
---|
| 827 | }
|
---|
| 828 |
|
---|
| 829 | return res;
|
---|
| 830 | };
|
---|
| 831 |
|
---|
| 832 | Readable.prototype.addListener = Readable.prototype.on;
|
---|
| 833 |
|
---|
| 834 | Readable.prototype.removeListener = function (ev, fn) {
|
---|
| 835 | var res = Stream.prototype.removeListener.call(this, ev, fn);
|
---|
| 836 |
|
---|
| 837 | if (ev === 'readable') {
|
---|
| 838 | // We need to check if there is someone still listening to
|
---|
| 839 | // readable and reset the state. However this needs to happen
|
---|
| 840 | // after readable has been emitted but before I/O (nextTick) to
|
---|
| 841 | // support once('readable', fn) cycles. This means that calling
|
---|
| 842 | // resume within the same tick will have no
|
---|
| 843 | // effect.
|
---|
| 844 | process.nextTick(updateReadableListening, this);
|
---|
| 845 | }
|
---|
| 846 |
|
---|
| 847 | return res;
|
---|
| 848 | };
|
---|
| 849 |
|
---|
| 850 | Readable.prototype.removeAllListeners = function (ev) {
|
---|
| 851 | var res = Stream.prototype.removeAllListeners.apply(this, arguments);
|
---|
| 852 |
|
---|
| 853 | if (ev === 'readable' || ev === undefined) {
|
---|
| 854 | // We need to check if there is someone still listening to
|
---|
| 855 | // readable and reset the state. However this needs to happen
|
---|
| 856 | // after readable has been emitted but before I/O (nextTick) to
|
---|
| 857 | // support once('readable', fn) cycles. This means that calling
|
---|
| 858 | // resume within the same tick will have no
|
---|
| 859 | // effect.
|
---|
| 860 | process.nextTick(updateReadableListening, this);
|
---|
| 861 | }
|
---|
| 862 |
|
---|
| 863 | return res;
|
---|
| 864 | };
|
---|
| 865 |
|
---|
| 866 | function updateReadableListening(self) {
|
---|
| 867 | var state = self._readableState;
|
---|
| 868 | state.readableListening = self.listenerCount('readable') > 0;
|
---|
| 869 |
|
---|
| 870 | if (state.resumeScheduled && !state.paused) {
|
---|
| 871 | // flowing needs to be set to true now, otherwise
|
---|
| 872 | // the upcoming resume will not flow.
|
---|
| 873 | state.flowing = true; // crude way to check if we should resume
|
---|
| 874 | } else if (self.listenerCount('data') > 0) {
|
---|
| 875 | self.resume();
|
---|
| 876 | }
|
---|
| 877 | }
|
---|
| 878 |
|
---|
| 879 | function nReadingNextTick(self) {
|
---|
| 880 | debug('readable nexttick read 0');
|
---|
| 881 | self.read(0);
|
---|
| 882 | } // pause() and resume() are remnants of the legacy readable stream API
|
---|
| 883 | // If the user uses them, then switch into old mode.
|
---|
| 884 |
|
---|
| 885 |
|
---|
| 886 | Readable.prototype.resume = function () {
|
---|
| 887 | var state = this._readableState;
|
---|
| 888 |
|
---|
| 889 | if (!state.flowing) {
|
---|
| 890 | debug('resume'); // we flow only if there is no one listening
|
---|
| 891 | // for readable, but we still have to call
|
---|
| 892 | // resume()
|
---|
| 893 |
|
---|
| 894 | state.flowing = !state.readableListening;
|
---|
| 895 | resume(this, state);
|
---|
| 896 | }
|
---|
| 897 |
|
---|
| 898 | state.paused = false;
|
---|
| 899 | return this;
|
---|
| 900 | };
|
---|
| 901 |
|
---|
| 902 | function resume(stream, state) {
|
---|
| 903 | if (!state.resumeScheduled) {
|
---|
| 904 | state.resumeScheduled = true;
|
---|
| 905 | process.nextTick(resume_, stream, state);
|
---|
| 906 | }
|
---|
| 907 | }
|
---|
| 908 |
|
---|
| 909 | function resume_(stream, state) {
|
---|
| 910 | debug('resume', state.reading);
|
---|
| 911 |
|
---|
| 912 | if (!state.reading) {
|
---|
| 913 | stream.read(0);
|
---|
| 914 | }
|
---|
| 915 |
|
---|
| 916 | state.resumeScheduled = false;
|
---|
| 917 | stream.emit('resume');
|
---|
| 918 | flow(stream);
|
---|
| 919 | if (state.flowing && !state.reading) stream.read(0);
|
---|
| 920 | }
|
---|
| 921 |
|
---|
| 922 | Readable.prototype.pause = function () {
|
---|
| 923 | debug('call pause flowing=%j', this._readableState.flowing);
|
---|
| 924 |
|
---|
| 925 | if (this._readableState.flowing !== false) {
|
---|
| 926 | debug('pause');
|
---|
| 927 | this._readableState.flowing = false;
|
---|
| 928 | this.emit('pause');
|
---|
| 929 | }
|
---|
| 930 |
|
---|
| 931 | this._readableState.paused = true;
|
---|
| 932 | return this;
|
---|
| 933 | };
|
---|
| 934 |
|
---|
| 935 | function flow(stream) {
|
---|
| 936 | var state = stream._readableState;
|
---|
| 937 | debug('flow', state.flowing);
|
---|
| 938 |
|
---|
| 939 | while (state.flowing && stream.read() !== null) {
|
---|
| 940 | ;
|
---|
| 941 | }
|
---|
| 942 | } // wrap an old-style stream as the async data source.
|
---|
| 943 | // This is *not* part of the readable stream interface.
|
---|
| 944 | // It is an ugly unfortunate mess of history.
|
---|
| 945 |
|
---|
| 946 |
|
---|
| 947 | Readable.prototype.wrap = function (stream) {
|
---|
| 948 | var _this = this;
|
---|
| 949 |
|
---|
| 950 | var state = this._readableState;
|
---|
| 951 | var paused = false;
|
---|
| 952 | stream.on('end', function () {
|
---|
| 953 | debug('wrapped end');
|
---|
| 954 |
|
---|
| 955 | if (state.decoder && !state.ended) {
|
---|
| 956 | var chunk = state.decoder.end();
|
---|
| 957 | if (chunk && chunk.length) _this.push(chunk);
|
---|
| 958 | }
|
---|
| 959 |
|
---|
| 960 | _this.push(null);
|
---|
| 961 | });
|
---|
| 962 | stream.on('data', function (chunk) {
|
---|
| 963 | debug('wrapped data');
|
---|
| 964 | if (state.decoder) chunk = state.decoder.write(chunk); // don't skip over falsy values in objectMode
|
---|
| 965 |
|
---|
| 966 | if (state.objectMode && (chunk === null || chunk === undefined)) return;else if (!state.objectMode && (!chunk || !chunk.length)) return;
|
---|
| 967 |
|
---|
| 968 | var ret = _this.push(chunk);
|
---|
| 969 |
|
---|
| 970 | if (!ret) {
|
---|
| 971 | paused = true;
|
---|
| 972 | stream.pause();
|
---|
| 973 | }
|
---|
| 974 | }); // proxy all the other methods.
|
---|
| 975 | // important when wrapping filters and duplexes.
|
---|
| 976 |
|
---|
| 977 | for (var i in stream) {
|
---|
| 978 | if (this[i] === undefined && typeof stream[i] === 'function') {
|
---|
| 979 | this[i] = function methodWrap(method) {
|
---|
| 980 | return function methodWrapReturnFunction() {
|
---|
| 981 | return stream[method].apply(stream, arguments);
|
---|
| 982 | };
|
---|
| 983 | }(i);
|
---|
| 984 | }
|
---|
| 985 | } // proxy certain important events.
|
---|
| 986 |
|
---|
| 987 |
|
---|
| 988 | for (var n = 0; n < kProxyEvents.length; n++) {
|
---|
| 989 | stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
|
---|
| 990 | } // when we try to consume some more bytes, simply unpause the
|
---|
| 991 | // underlying stream.
|
---|
| 992 |
|
---|
| 993 |
|
---|
| 994 | this._read = function (n) {
|
---|
| 995 | debug('wrapped _read', n);
|
---|
| 996 |
|
---|
| 997 | if (paused) {
|
---|
| 998 | paused = false;
|
---|
| 999 | stream.resume();
|
---|
| 1000 | }
|
---|
| 1001 | };
|
---|
| 1002 |
|
---|
| 1003 | return this;
|
---|
| 1004 | };
|
---|
| 1005 |
|
---|
| 1006 | if (typeof Symbol === 'function') {
|
---|
| 1007 | Readable.prototype[Symbol.asyncIterator] = function () {
|
---|
| 1008 | if (createReadableStreamAsyncIterator === undefined) {
|
---|
| 1009 | createReadableStreamAsyncIterator = require('./internal/streams/async_iterator');
|
---|
| 1010 | }
|
---|
| 1011 |
|
---|
| 1012 | return createReadableStreamAsyncIterator(this);
|
---|
| 1013 | };
|
---|
| 1014 | }
|
---|
| 1015 |
|
---|
| 1016 | Object.defineProperty(Readable.prototype, 'readableHighWaterMark', {
|
---|
| 1017 | // making it explicit this property is not enumerable
|
---|
| 1018 | // because otherwise some prototype manipulation in
|
---|
| 1019 | // userland will fail
|
---|
| 1020 | enumerable: false,
|
---|
| 1021 | get: function get() {
|
---|
| 1022 | return this._readableState.highWaterMark;
|
---|
| 1023 | }
|
---|
| 1024 | });
|
---|
| 1025 | Object.defineProperty(Readable.prototype, 'readableBuffer', {
|
---|
| 1026 | // making it explicit this property is not enumerable
|
---|
| 1027 | // because otherwise some prototype manipulation in
|
---|
| 1028 | // userland will fail
|
---|
| 1029 | enumerable: false,
|
---|
| 1030 | get: function get() {
|
---|
| 1031 | return this._readableState && this._readableState.buffer;
|
---|
| 1032 | }
|
---|
| 1033 | });
|
---|
| 1034 | Object.defineProperty(Readable.prototype, 'readableFlowing', {
|
---|
| 1035 | // making it explicit this property is not enumerable
|
---|
| 1036 | // because otherwise some prototype manipulation in
|
---|
| 1037 | // userland will fail
|
---|
| 1038 | enumerable: false,
|
---|
| 1039 | get: function get() {
|
---|
| 1040 | return this._readableState.flowing;
|
---|
| 1041 | },
|
---|
| 1042 | set: function set(state) {
|
---|
| 1043 | if (this._readableState) {
|
---|
| 1044 | this._readableState.flowing = state;
|
---|
| 1045 | }
|
---|
| 1046 | }
|
---|
| 1047 | }); // exposed for testing purposes only.
|
---|
| 1048 |
|
---|
| 1049 | Readable._fromList = fromList;
|
---|
| 1050 | Object.defineProperty(Readable.prototype, 'readableLength', {
|
---|
| 1051 | // making it explicit this property is not enumerable
|
---|
| 1052 | // because otherwise some prototype manipulation in
|
---|
| 1053 | // userland will fail
|
---|
| 1054 | enumerable: false,
|
---|
| 1055 | get: function get() {
|
---|
| 1056 | return this._readableState.length;
|
---|
| 1057 | }
|
---|
| 1058 | }); // Pluck off n bytes from an array of buffers.
|
---|
| 1059 | // Length is the combined lengths of all the buffers in the list.
|
---|
| 1060 | // This function is designed to be inlinable, so please take care when making
|
---|
| 1061 | // changes to the function body.
|
---|
| 1062 |
|
---|
| 1063 | function fromList(n, state) {
|
---|
| 1064 | // nothing buffered
|
---|
| 1065 | if (state.length === 0) return null;
|
---|
| 1066 | var ret;
|
---|
| 1067 | if (state.objectMode) ret = state.buffer.shift();else if (!n || n >= state.length) {
|
---|
| 1068 | // read it all, truncate the list
|
---|
| 1069 | if (state.decoder) ret = state.buffer.join('');else if (state.buffer.length === 1) ret = state.buffer.first();else ret = state.buffer.concat(state.length);
|
---|
| 1070 | state.buffer.clear();
|
---|
| 1071 | } else {
|
---|
| 1072 | // read part of list
|
---|
| 1073 | ret = state.buffer.consume(n, state.decoder);
|
---|
| 1074 | }
|
---|
| 1075 | return ret;
|
---|
| 1076 | }
|
---|
| 1077 |
|
---|
| 1078 | function endReadable(stream) {
|
---|
| 1079 | var state = stream._readableState;
|
---|
| 1080 | debug('endReadable', state.endEmitted);
|
---|
| 1081 |
|
---|
| 1082 | if (!state.endEmitted) {
|
---|
| 1083 | state.ended = true;
|
---|
| 1084 | process.nextTick(endReadableNT, state, stream);
|
---|
| 1085 | }
|
---|
| 1086 | }
|
---|
| 1087 |
|
---|
| 1088 | function endReadableNT(state, stream) {
|
---|
| 1089 | debug('endReadableNT', state.endEmitted, state.length); // Check that we didn't get one last unshift.
|
---|
| 1090 |
|
---|
| 1091 | if (!state.endEmitted && state.length === 0) {
|
---|
| 1092 | state.endEmitted = true;
|
---|
| 1093 | stream.readable = false;
|
---|
| 1094 | stream.emit('end');
|
---|
| 1095 |
|
---|
| 1096 | if (state.autoDestroy) {
|
---|
| 1097 | // In case of duplex streams we need a way to detect
|
---|
| 1098 | // if the writable side is ready for autoDestroy as well
|
---|
| 1099 | var wState = stream._writableState;
|
---|
| 1100 |
|
---|
| 1101 | if (!wState || wState.autoDestroy && wState.finished) {
|
---|
| 1102 | stream.destroy();
|
---|
| 1103 | }
|
---|
| 1104 | }
|
---|
| 1105 | }
|
---|
| 1106 | }
|
---|
| 1107 |
|
---|
| 1108 | if (typeof Symbol === 'function') {
|
---|
| 1109 | Readable.from = function (iterable, opts) {
|
---|
| 1110 | if (from === undefined) {
|
---|
| 1111 | from = require('./internal/streams/from');
|
---|
| 1112 | }
|
---|
| 1113 |
|
---|
| 1114 | return from(Readable, iterable, opts);
|
---|
| 1115 | };
|
---|
| 1116 | }
|
---|
| 1117 |
|
---|
| 1118 | function indexOf(xs, x) {
|
---|
| 1119 | for (var i = 0, l = xs.length; i < l; i++) {
|
---|
| 1120 | if (xs[i] === x) return i;
|
---|
| 1121 | }
|
---|
| 1122 |
|
---|
| 1123 | return -1;
|
---|
| 1124 | } |
---|