X-Git-Url: http://www.aleph1.co.uk/gitweb/?p=yaffs-website;a=blobdiff_plain;f=node_modules%2Fbl%2Fnode_modules%2Freadable-stream%2Flib%2F_stream_readable.js;fp=node_modules%2Fbl%2Fnode_modules%2Freadable-stream%2Flib%2F_stream_readable.js;h=54a9d5c553d69e93a4b774f120168d780beb1730;hp=0000000000000000000000000000000000000000;hb=a2bd1bf0c2c1f1a17d188f4dc0726a45494cefae;hpb=57c063afa3f66b07c4bbddc2d6129a96d90f0aad
diff --git a/node_modules/bl/node_modules/readable-stream/lib/_stream_readable.js b/node_modules/bl/node_modules/readable-stream/lib/_stream_readable.js
new file mode 100644
index 000000000..54a9d5c55
--- /dev/null
+++ b/node_modules/bl/node_modules/readable-stream/lib/_stream_readable.js
@@ -0,0 +1,880 @@
+'use strict';
+
+module.exports = Readable;
+
+/**/
+var processNextTick = require('process-nextick-args');
+/**/
+
+/**/
+var isArray = require('isarray');
+/**/
+
+/**/
+var Buffer = require('buffer').Buffer;
+/**/
+
+Readable.ReadableState = ReadableState;
+
+var EE = require('events');
+
+/**/
+var EElistenerCount = function (emitter, type) {
+ return emitter.listeners(type).length;
+};
+/**/
+
+/**/
+var Stream;
+(function () {
+ try {
+ Stream = require('st' + 'ream');
+ } catch (_) {} finally {
+ if (!Stream) Stream = require('events').EventEmitter;
+ }
+})();
+/**/
+
+var Buffer = require('buffer').Buffer;
+
+/**/
+var util = require('core-util-is');
+util.inherits = require('inherits');
+/**/
+
+/**/
+var debugUtil = require('util');
+var debug = undefined;
+if (debugUtil && debugUtil.debuglog) {
+ debug = debugUtil.debuglog('stream');
+} else {
+ debug = function () {};
+}
+/**/
+
+var StringDecoder;
+
+util.inherits(Readable, Stream);
+
+var Duplex;
+function ReadableState(options, stream) {
+ Duplex = Duplex || require('./_stream_duplex');
+
+ options = options || {};
+
+ // 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 (stream instanceof Duplex) 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 defaultHwm = this.objectMode ? 16 : 16 * 1024;
+ this.highWaterMark = hwm || hwm === 0 ? hwm : defaultHwm;
+
+ // cast to ints.
+ this.highWaterMark = ~ ~this.highWaterMark;
+
+ this.buffer = [];
+ 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 onwrite cb is called immediately,
+ // or on a later tick. We set this to true at first, because any
+ // actions that shouldn't happen until "later" should generally also
+ // not happen before the first write call.
+ this.sync = true;
+
+ // 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;
+
+ // 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';
+
+ // when piping, we only care about 'readable' events that happen
+ // after read()ing all the bytes and not getting any pushback.
+ this.ranOut = false;
+
+ // 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;
+ }
+}
+
+var Duplex;
+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 && typeof options.read === 'function') this._read = options.read;
+
+ Stream.call(this);
+}
+
+// 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;
+
+ if (!state.objectMode && typeof chunk === 'string') {
+ encoding = encoding || state.defaultEncoding;
+ if (encoding !== state.encoding) {
+ chunk = new Buffer(chunk, encoding);
+ encoding = '';
+ }
+ }
+
+ return readableAddChunk(this, state, chunk, encoding, false);
+};
+
+// Unshift should *always* be something directly out of read()
+Readable.prototype.unshift = function (chunk) {
+ var state = this._readableState;
+ return readableAddChunk(this, state, chunk, '', true);
+};
+
+Readable.prototype.isPaused = function () {
+ return this._readableState.flowing === false;
+};
+
+function readableAddChunk(stream, state, chunk, encoding, addToFront) {
+ var er = chunkInvalid(state, chunk);
+ if (er) {
+ stream.emit('error', er);
+ } else if (chunk === null) {
+ state.reading = false;
+ onEofChunk(stream, state);
+ } else if (state.objectMode || chunk && chunk.length > 0) {
+ if (state.ended && !addToFront) {
+ var e = new Error('stream.push() after EOF');
+ stream.emit('error', e);
+ } else if (state.endEmitted && addToFront) {
+ var e = new Error('stream.unshift() after end event');
+ stream.emit('error', e);
+ } else {
+ var skipAdd;
+ if (state.decoder && !addToFront && !encoding) {
+ chunk = state.decoder.write(chunk);
+ skipAdd = !state.objectMode && chunk.length === 0;
+ }
+
+ if (!addToFront) state.reading = false;
+
+ // Don't add to the buffer if we've decoded to an empty string chunk and
+ // we're not in object mode
+ if (!skipAdd) {
+ // if we want the data now, just emit it.
+ 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);
+ }
+ } else if (!addToFront) {
+ state.reading = false;
+ }
+
+ return needMoreData(state);
+}
+
+// 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);
+}
+
+// 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
+ n--;
+ n |= n >>> 1;
+ n |= n >>> 2;
+ n |= n >>> 4;
+ n |= n >>> 8;
+ n |= n >>> 16;
+ n++;
+ }
+ return n;
+}
+
+function howMuchToRead(n, state) {
+ if (state.length === 0 && state.ended) return 0;
+
+ if (state.objectMode) return n === 0 ? 0 : 1;
+
+ if (n === null || isNaN(n)) {
+ // only flow one buffer at a time
+ if (state.flowing && state.buffer.length) return state.buffer[0].length;else return state.length;
+ }
+
+ if (n <= 0) return 0;
+
+ // If we're asking for more than the target buffer level,
+ // then raise the water mark. Bump up to the next highest
+ // power of 2, to prevent increasing it excessively in tiny
+ // amounts.
+ if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
+
+ // don't have that much. return null, unless we've ended.
+ if (n > state.length) {
+ if (!state.ended) {
+ state.needReadable = true;
+ return 0;
+ } else {
+ return state.length;
+ }
+ }
+
+ return n;
+}
+
+// you can override either this method, or the async _read(n) below.
+Readable.prototype.read = function (n) {
+ debug('read', n);
+ var state = this._readableState;
+ var nOrig = n;
+
+ if (typeof n !== 'number' || 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);
+ }
+
+ 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 (doRead && !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;
+ }
+
+ state.length -= n;
+
+ // If we have nothing in the buffer, then we want to know
+ // as soon as we *do* get something into the buffer.
+ if (state.length === 0 && !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 && state.length === 0) endReadable(this);
+
+ if (ret !== null) this.emit('data', ret);
+
+ return ret;
+};
+
+function chunkInvalid(state, chunk) {
+ var er = null;
+ if (!Buffer.isBuffer(chunk) && typeof chunk !== 'string' && chunk !== null && chunk !== undefined && !state.objectMode) {
+ er = new TypeError('Invalid non-string/buffer chunk');
+ }
+ return er;
+}
+
+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) processNextTick(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;
+ processNextTick(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('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 : cleanup;
+ if (state.endEmitted) processNextTick(endFn);else src.once('end', endFn);
+
+ dest.on('unpipe', onunpipe);
+ function onunpipe(readable) {
+ debug('onunpipe');
+ if (readable === src) {
+ 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', cleanup);
+ 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();
+ }
+
+ src.on('data', ondata);
+ function ondata(chunk) {
+ debug('ondata');
+ var ret = dest.write(chunk);
+ if (false === ret) {
+ // If the user unpiped during `dest.write()`, it is possible
+ // to get stuck in a permanently paused state if that write
+ // also returned false.
+ if (state.pipesCount === 1 && state.pipes[0] === dest && src.listenerCount('data') === 1 && !cleanedUp) {
+ debug('false write response, pause', src._readableState.awaitDrain);
+ src._readableState.awaitDrain++;
+ }
+ 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);
+ }
+ // This is a brutally ugly hack to make sure that our error handler
+ // is attached before any userland ones. NEVER DO THIS.
+ if (!dest._events || !dest._events.error) dest.on('error', onerror);else if (isArray(dest._events.error)) dest._events.error.unshift(onerror);else dest._events.error = [onerror, dest._events.error];
+
+ // 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;
+
+ // 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);
+ 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);
+ }return this;
+ }
+
+ // try to find the right one.
+ var i = indexOf(state.pipes, dest);
+ if (i === -1) return this;
+
+ state.pipes.splice(i, 1);
+ state.pipesCount -= 1;
+ if (state.pipesCount === 1) state.pipes = state.pipes[0];
+
+ dest.emit('unpipe', this);
+
+ 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 listening to data, and it has not explicitly been paused,
+ // then call resume to start the flow of data on the next tick.
+ if (ev === 'data' && false !== this._readableState.flowing) {
+ this.resume();
+ }
+
+ if (ev === 'readable' && !this._readableState.endEmitted) {
+ var state = this._readableState;
+ if (!state.readableListening) {
+ state.readableListening = true;
+ state.emittedReadable = false;
+ state.needReadable = true;
+ if (!state.reading) {
+ processNextTick(nReadingNextTick, this);
+ } else if (state.length) {
+ emitReadable(this, state);
+ }
+ }
+ }
+
+ 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;
+ processNextTick(resume_, stream, state);
+ }
+}
+
+function resume_(stream, state) {
+ if (!state.reading) {
+ debug('resume read 0');
+ stream.read(0);
+ }
+
+ state.resumeScheduled = false;
+ 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);
+ if (state.flowing) {
+ do {
+ var chunk = stream.read();
+ } while (null !== chunk && state.flowing);
+ }
+}
+
+// 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 state = this._readableState;
+ var paused = false;
+
+ var self = this;
+ stream.on('end', function () {
+ debug('wrapped end');
+ if (state.decoder && !state.ended) {
+ var chunk = state.decoder.end();
+ if (chunk && chunk.length) self.push(chunk);
+ }
+
+ self.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 = self.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.
+ var events = ['error', 'close', 'destroy', 'pause', 'resume'];
+ forEach(events, function (ev) {
+ stream.on(ev, self.emit.bind(self, ev));
+ });
+
+ // when we try to consume some more bytes, simply unpause the
+ // underlying stream.
+ self._read = function (n) {
+ debug('wrapped _read', n);
+ if (paused) {
+ paused = false;
+ stream.resume();
+ }
+ };
+
+ return self;
+};
+
+// 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.
+function fromList(n, state) {
+ var list = state.buffer;
+ var length = state.length;
+ var stringMode = !!state.decoder;
+ var objectMode = !!state.objectMode;
+ var ret;
+
+ // nothing in the list, definitely empty.
+ if (list.length === 0) return null;
+
+ if (length === 0) ret = null;else if (objectMode) ret = list.shift();else if (!n || n >= length) {
+ // read it all, truncate the array.
+ if (stringMode) ret = list.join('');else if (list.length === 1) ret = list[0];else ret = Buffer.concat(list, length);
+ list.length = 0;
+ } else {
+ // read just some of it.
+ if (n < list[0].length) {
+ // just take a part of the first list item.
+ // slice is the same for buffers and strings.
+ var buf = list[0];
+ ret = buf.slice(0, n);
+ list[0] = buf.slice(n);
+ } else if (n === list[0].length) {
+ // first list is a perfect match
+ ret = list.shift();
+ } else {
+ // complex case.
+ // we have enough to cover it, but it spans past the first buffer.
+ if (stringMode) ret = '';else ret = new Buffer(n);
+
+ var c = 0;
+ for (var i = 0, l = list.length; i < l && c < n; i++) {
+ var buf = list[0];
+ var cpy = Math.min(n - c, buf.length);
+
+ if (stringMode) ret += buf.slice(0, cpy);else buf.copy(ret, c, 0, cpy);
+
+ if (cpy < buf.length) list[0] = buf.slice(cpy);else list.shift();
+
+ c += cpy;
+ }
+ }
+ }
+
+ 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;
+ processNextTick(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 forEach(xs, f) {
+ for (var i = 0, l = xs.length; i < l; i++) {
+ f(xs[i], i);
+ }
+}
+
+function indexOf(xs, x) {
+ for (var i = 0, l = xs.length; i < l; i++) {
+ if (xs[i] === x) return i;
+ }
+ return -1;
+}
\ No newline at end of file