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fediversity.eu/node_modules/minipass/dist/esm/index.js

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2024-03-26 16:28:28 +01:00
const proc = typeof process === 'object' && process
? process
: {
stdout: null,
stderr: null,
};
import { EventEmitter } from 'events';
import Stream from 'stream';
import { StringDecoder } from 'string_decoder';
/**
* Return true if the argument is a Minipass stream, Node stream, or something
* else that Minipass can interact with.
*/
export const isStream = (s) => !!s &&
typeof s === 'object' &&
(s instanceof Minipass ||
s instanceof Stream ||
isReadable(s) ||
isWritable(s));
/**
* Return true if the argument is a valid {@link Minipass.Readable}
*/
export const isReadable = (s) => !!s &&
typeof s === 'object' &&
s instanceof EventEmitter &&
typeof s.pipe === 'function' &&
// node core Writable streams have a pipe() method, but it throws
s.pipe !== Stream.Writable.prototype.pipe;
/**
* Return true if the argument is a valid {@link Minipass.Writable}
*/
export const isWritable = (s) => !!s &&
typeof s === 'object' &&
s instanceof EventEmitter &&
typeof s.write === 'function' &&
typeof s.end === 'function';
const EOF = Symbol('EOF');
const MAYBE_EMIT_END = Symbol('maybeEmitEnd');
const EMITTED_END = Symbol('emittedEnd');
const EMITTING_END = Symbol('emittingEnd');
const EMITTED_ERROR = Symbol('emittedError');
const CLOSED = Symbol('closed');
const READ = Symbol('read');
const FLUSH = Symbol('flush');
const FLUSHCHUNK = Symbol('flushChunk');
const ENCODING = Symbol('encoding');
const DECODER = Symbol('decoder');
const FLOWING = Symbol('flowing');
const PAUSED = Symbol('paused');
const RESUME = Symbol('resume');
const BUFFER = Symbol('buffer');
const PIPES = Symbol('pipes');
const BUFFERLENGTH = Symbol('bufferLength');
const BUFFERPUSH = Symbol('bufferPush');
const BUFFERSHIFT = Symbol('bufferShift');
const OBJECTMODE = Symbol('objectMode');
// internal event when stream is destroyed
const DESTROYED = Symbol('destroyed');
// internal event when stream has an error
const ERROR = Symbol('error');
const EMITDATA = Symbol('emitData');
const EMITEND = Symbol('emitEnd');
const EMITEND2 = Symbol('emitEnd2');
const ASYNC = Symbol('async');
const ABORT = Symbol('abort');
const ABORTED = Symbol('aborted');
const SIGNAL = Symbol('signal');
const DATALISTENERS = Symbol('dataListeners');
const DISCARDED = Symbol('discarded');
const defer = (fn) => Promise.resolve().then(fn);
const nodefer = (fn) => fn();
const isEndish = (ev) => ev === 'end' || ev === 'finish' || ev === 'prefinish';
const isArrayBufferLike = (b) => b instanceof ArrayBuffer ||
(!!b &&
typeof b === 'object' &&
b.constructor &&
b.constructor.name === 'ArrayBuffer' &&
b.byteLength >= 0);
const isArrayBufferView = (b) => !Buffer.isBuffer(b) && ArrayBuffer.isView(b);
/**
* Internal class representing a pipe to a destination stream.
*
* @internal
*/
class Pipe {
src;
dest;
opts;
ondrain;
constructor(src, dest, opts) {
this.src = src;
this.dest = dest;
this.opts = opts;
this.ondrain = () => src[RESUME]();
this.dest.on('drain', this.ondrain);
}
unpipe() {
this.dest.removeListener('drain', this.ondrain);
}
// only here for the prototype
/* c8 ignore start */
proxyErrors(_er) { }
/* c8 ignore stop */
end() {
this.unpipe();
if (this.opts.end)
this.dest.end();
}
}
/**
* Internal class representing a pipe to a destination stream where
* errors are proxied.
*
* @internal
*/
class PipeProxyErrors extends Pipe {
unpipe() {
this.src.removeListener('error', this.proxyErrors);
super.unpipe();
}
constructor(src, dest, opts) {
super(src, dest, opts);
this.proxyErrors = er => dest.emit('error', er);
src.on('error', this.proxyErrors);
}
}
const isObjectModeOptions = (o) => !!o.objectMode;
const isEncodingOptions = (o) => !o.objectMode && !!o.encoding && o.encoding !== 'buffer';
/**
* Main export, the Minipass class
*
* `RType` is the type of data emitted, defaults to Buffer
*
* `WType` is the type of data to be written, if RType is buffer or string,
* then any {@link Minipass.ContiguousData} is allowed.
*
* `Events` is the set of event handler signatures that this object
* will emit, see {@link Minipass.Events}
*/
export class Minipass extends EventEmitter {
[FLOWING] = false;
[PAUSED] = false;
[PIPES] = [];
[BUFFER] = [];
[OBJECTMODE];
[ENCODING];
[ASYNC];
[DECODER];
[EOF] = false;
[EMITTED_END] = false;
[EMITTING_END] = false;
[CLOSED] = false;
[EMITTED_ERROR] = null;
[BUFFERLENGTH] = 0;
[DESTROYED] = false;
[SIGNAL];
[ABORTED] = false;
[DATALISTENERS] = 0;
[DISCARDED] = false;
/**
* true if the stream can be written
*/
writable = true;
/**
* true if the stream can be read
*/
readable = true;
/**
* If `RType` is Buffer, then options do not need to be provided.
* Otherwise, an options object must be provided to specify either
* {@link Minipass.SharedOptions.objectMode} or
* {@link Minipass.SharedOptions.encoding}, as appropriate.
*/
constructor(...args) {
const options = (args[0] ||
{});
super();
if (options.objectMode && typeof options.encoding === 'string') {
throw new TypeError('Encoding and objectMode may not be used together');
}
if (isObjectModeOptions(options)) {
this[OBJECTMODE] = true;
this[ENCODING] = null;
}
else if (isEncodingOptions(options)) {
this[ENCODING] = options.encoding;
this[OBJECTMODE] = false;
}
else {
this[OBJECTMODE] = false;
this[ENCODING] = null;
}
this[ASYNC] = !!options.async;
this[DECODER] = this[ENCODING]
? new StringDecoder(this[ENCODING])
: null;
//@ts-ignore - private option for debugging and testing
if (options && options.debugExposeBuffer === true) {
Object.defineProperty(this, 'buffer', { get: () => this[BUFFER] });
}
//@ts-ignore - private option for debugging and testing
if (options && options.debugExposePipes === true) {
Object.defineProperty(this, 'pipes', { get: () => this[PIPES] });
}
const { signal } = options;
if (signal) {
this[SIGNAL] = signal;
if (signal.aborted) {
this[ABORT]();
}
else {
signal.addEventListener('abort', () => this[ABORT]());
}
}
}
/**
* The amount of data stored in the buffer waiting to be read.
*
* For Buffer strings, this will be the total byte length.
* For string encoding streams, this will be the string character length,
* according to JavaScript's `string.length` logic.
* For objectMode streams, this is a count of the items waiting to be
* emitted.
*/
get bufferLength() {
return this[BUFFERLENGTH];
}
/**
* The `BufferEncoding` currently in use, or `null`
*/
get encoding() {
return this[ENCODING];
}
/**
* @deprecated - This is a read only property
*/
set encoding(_enc) {
throw new Error('Encoding must be set at instantiation time');
}
/**
* @deprecated - Encoding may only be set at instantiation time
*/
setEncoding(_enc) {
throw new Error('Encoding must be set at instantiation time');
}
/**
* True if this is an objectMode stream
*/
get objectMode() {
return this[OBJECTMODE];
}
/**
* @deprecated - This is a read-only property
*/
set objectMode(_om) {
throw new Error('objectMode must be set at instantiation time');
}
/**
* true if this is an async stream
*/
get ['async']() {
return this[ASYNC];
}
/**
* Set to true to make this stream async.
*
* Once set, it cannot be unset, as this would potentially cause incorrect
* behavior. Ie, a sync stream can be made async, but an async stream
* cannot be safely made sync.
*/
set ['async'](a) {
this[ASYNC] = this[ASYNC] || !!a;
}
// drop everything and get out of the flow completely
[ABORT]() {
this[ABORTED] = true;
this.emit('abort', this[SIGNAL]?.reason);
this.destroy(this[SIGNAL]?.reason);
}
/**
* True if the stream has been aborted.
*/
get aborted() {
return this[ABORTED];
}
/**
* No-op setter. Stream aborted status is set via the AbortSignal provided
* in the constructor options.
*/
set aborted(_) { }
write(chunk, encoding, cb) {
if (this[ABORTED])
return false;
if (this[EOF])
throw new Error('write after end');
if (this[DESTROYED]) {
this.emit('error', Object.assign(new Error('Cannot call write after a stream was destroyed'), { code: 'ERR_STREAM_DESTROYED' }));
return true;
}
if (typeof encoding === 'function') {
cb = encoding;
encoding = 'utf8';
}
if (!encoding)
encoding = 'utf8';
const fn = this[ASYNC] ? defer : nodefer;
// convert array buffers and typed array views into buffers
// at some point in the future, we may want to do the opposite!
// leave strings and buffers as-is
// anything is only allowed if in object mode, so throw
if (!this[OBJECTMODE] && !Buffer.isBuffer(chunk)) {
if (isArrayBufferView(chunk)) {
//@ts-ignore - sinful unsafe type changing
chunk = Buffer.from(chunk.buffer, chunk.byteOffset, chunk.byteLength);
}
else if (isArrayBufferLike(chunk)) {
//@ts-ignore - sinful unsafe type changing
chunk = Buffer.from(chunk);
}
else if (typeof chunk !== 'string') {
throw new Error('Non-contiguous data written to non-objectMode stream');
}
}
// handle object mode up front, since it's simpler
// this yields better performance, fewer checks later.
if (this[OBJECTMODE]) {
// maybe impossible?
/* c8 ignore start */
if (this[FLOWING] && this[BUFFERLENGTH] !== 0)
this[FLUSH](true);
/* c8 ignore stop */
if (this[FLOWING])
this.emit('data', chunk);
else
this[BUFFERPUSH](chunk);
if (this[BUFFERLENGTH] !== 0)
this.emit('readable');
if (cb)
fn(cb);
return this[FLOWING];
}
// at this point the chunk is a buffer or string
// don't buffer it up or send it to the decoder
if (!chunk.length) {
if (this[BUFFERLENGTH] !== 0)
this.emit('readable');
if (cb)
fn(cb);
return this[FLOWING];
}
// fast-path writing strings of same encoding to a stream with
// an empty buffer, skipping the buffer/decoder dance
if (typeof chunk === 'string' &&
// unless it is a string already ready for us to use
!(encoding === this[ENCODING] && !this[DECODER]?.lastNeed)) {
//@ts-ignore - sinful unsafe type change
chunk = Buffer.from(chunk, encoding);
}
if (Buffer.isBuffer(chunk) && this[ENCODING]) {
//@ts-ignore - sinful unsafe type change
chunk = this[DECODER].write(chunk);
}
// Note: flushing CAN potentially switch us into not-flowing mode
if (this[FLOWING] && this[BUFFERLENGTH] !== 0)
this[FLUSH](true);
if (this[FLOWING])
this.emit('data', chunk);
else
this[BUFFERPUSH](chunk);
if (this[BUFFERLENGTH] !== 0)
this.emit('readable');
if (cb)
fn(cb);
return this[FLOWING];
}
/**
* Low-level explicit read method.
*
* In objectMode, the argument is ignored, and one item is returned if
* available.
*
* `n` is the number of bytes (or in the case of encoding streams,
* characters) to consume. If `n` is not provided, then the entire buffer
* is returned, or `null` is returned if no data is available.
*
* If `n` is greater that the amount of data in the internal buffer,
* then `null` is returned.
*/
read(n) {
if (this[DESTROYED])
return null;
this[DISCARDED] = false;
if (this[BUFFERLENGTH] === 0 ||
n === 0 ||
(n && n > this[BUFFERLENGTH])) {
this[MAYBE_EMIT_END]();
return null;
}
if (this[OBJECTMODE])
n = null;
if (this[BUFFER].length > 1 && !this[OBJECTMODE]) {
// not object mode, so if we have an encoding, then RType is string
// otherwise, must be Buffer
this[BUFFER] = [
(this[ENCODING]
? this[BUFFER].join('')
: Buffer.concat(this[BUFFER], this[BUFFERLENGTH])),
];
}
const ret = this[READ](n || null, this[BUFFER][0]);
this[MAYBE_EMIT_END]();
return ret;
}
[READ](n, chunk) {
if (this[OBJECTMODE])
this[BUFFERSHIFT]();
else {
const c = chunk;
if (n === c.length || n === null)
this[BUFFERSHIFT]();
else if (typeof c === 'string') {
this[BUFFER][0] = c.slice(n);
chunk = c.slice(0, n);
this[BUFFERLENGTH] -= n;
}
else {
this[BUFFER][0] = c.subarray(n);
chunk = c.subarray(0, n);
this[BUFFERLENGTH] -= n;
}
}
this.emit('data', chunk);
if (!this[BUFFER].length && !this[EOF])
this.emit('drain');
return chunk;
}
end(chunk, encoding, cb) {
if (typeof chunk === 'function') {
cb = chunk;
chunk = undefined;
}
if (typeof encoding === 'function') {
cb = encoding;
encoding = 'utf8';
}
if (chunk !== undefined)
this.write(chunk, encoding);
if (cb)
this.once('end', cb);
this[EOF] = true;
this.writable = false;
// if we haven't written anything, then go ahead and emit,
// even if we're not reading.
// we'll re-emit if a new 'end' listener is added anyway.
// This makes MP more suitable to write-only use cases.
if (this[FLOWING] || !this[PAUSED])
this[MAYBE_EMIT_END]();
return this;
}
// don't let the internal resume be overwritten
[RESUME]() {
if (this[DESTROYED])
return;
if (!this[DATALISTENERS] && !this[PIPES].length) {
this[DISCARDED] = true;
}
this[PAUSED] = false;
this[FLOWING] = true;
this.emit('resume');
if (this[BUFFER].length)
this[FLUSH]();
else if (this[EOF])
this[MAYBE_EMIT_END]();
else
this.emit('drain');
}
/**
* Resume the stream if it is currently in a paused state
*
* If called when there are no pipe destinations or `data` event listeners,
* this will place the stream in a "discarded" state, where all data will
* be thrown away. The discarded state is removed if a pipe destination or
* data handler is added, if pause() is called, or if any synchronous or
* asynchronous iteration is started.
*/
resume() {
return this[RESUME]();
}
/**
* Pause the stream
*/
pause() {
this[FLOWING] = false;
this[PAUSED] = true;
this[DISCARDED] = false;
}
/**
* true if the stream has been forcibly destroyed
*/
get destroyed() {
return this[DESTROYED];
}
/**
* true if the stream is currently in a flowing state, meaning that
* any writes will be immediately emitted.
*/
get flowing() {
return this[FLOWING];
}
/**
* true if the stream is currently in a paused state
*/
get paused() {
return this[PAUSED];
}
[BUFFERPUSH](chunk) {
if (this[OBJECTMODE])
this[BUFFERLENGTH] += 1;
else
this[BUFFERLENGTH] += chunk.length;
this[BUFFER].push(chunk);
}
[BUFFERSHIFT]() {
if (this[OBJECTMODE])
this[BUFFERLENGTH] -= 1;
else
this[BUFFERLENGTH] -= this[BUFFER][0].length;
return this[BUFFER].shift();
}
[FLUSH](noDrain = false) {
do { } while (this[FLUSHCHUNK](this[BUFFERSHIFT]()) &&
this[BUFFER].length);
if (!noDrain && !this[BUFFER].length && !this[EOF])
this.emit('drain');
}
[FLUSHCHUNK](chunk) {
this.emit('data', chunk);
return this[FLOWING];
}
/**
* Pipe all data emitted by this stream into the destination provided.
*
* Triggers the flow of data.
*/
pipe(dest, opts) {
if (this[DESTROYED])
return dest;
this[DISCARDED] = false;
const ended = this[EMITTED_END];
opts = opts || {};
if (dest === proc.stdout || dest === proc.stderr)
opts.end = false;
else
opts.end = opts.end !== false;
opts.proxyErrors = !!opts.proxyErrors;
// piping an ended stream ends immediately
if (ended) {
if (opts.end)
dest.end();
}
else {
// "as" here just ignores the WType, which pipes don't care about,
// since they're only consuming from us, and writing to the dest
this[PIPES].push(!opts.proxyErrors
? new Pipe(this, dest, opts)
: new PipeProxyErrors(this, dest, opts));
if (this[ASYNC])
defer(() => this[RESUME]());
else
this[RESUME]();
}
return dest;
}
/**
* Fully unhook a piped destination stream.
*
* If the destination stream was the only consumer of this stream (ie,
* there are no other piped destinations or `'data'` event listeners)
* then the flow of data will stop until there is another consumer or
* {@link Minipass#resume} is explicitly called.
*/
unpipe(dest) {
const p = this[PIPES].find(p => p.dest === dest);
if (p) {
if (this[PIPES].length === 1) {
if (this[FLOWING] && this[DATALISTENERS] === 0) {
this[FLOWING] = false;
}
this[PIPES] = [];
}
else
this[PIPES].splice(this[PIPES].indexOf(p), 1);
p.unpipe();
}
}
/**
* Alias for {@link Minipass#on}
*/
addListener(ev, handler) {
return this.on(ev, handler);
}
/**
* Mostly identical to `EventEmitter.on`, with the following
* behavior differences to prevent data loss and unnecessary hangs:
*
* - Adding a 'data' event handler will trigger the flow of data
*
* - Adding a 'readable' event handler when there is data waiting to be read
* will cause 'readable' to be emitted immediately.
*
* - Adding an 'endish' event handler ('end', 'finish', etc.) which has
* already passed will cause the event to be emitted immediately and all
* handlers removed.
*
* - Adding an 'error' event handler after an error has been emitted will
* cause the event to be re-emitted immediately with the error previously
* raised.
*/
on(ev, handler) {
const ret = super.on(ev, handler);
if (ev === 'data') {
this[DISCARDED] = false;
this[DATALISTENERS]++;
if (!this[PIPES].length && !this[FLOWING]) {
this[RESUME]();
}
}
else if (ev === 'readable' && this[BUFFERLENGTH] !== 0) {
super.emit('readable');
}
else if (isEndish(ev) && this[EMITTED_END]) {
super.emit(ev);
this.removeAllListeners(ev);
}
else if (ev === 'error' && this[EMITTED_ERROR]) {
const h = handler;
if (this[ASYNC])
defer(() => h.call(this, this[EMITTED_ERROR]));
else
h.call(this, this[EMITTED_ERROR]);
}
return ret;
}
/**
* Alias for {@link Minipass#off}
*/
removeListener(ev, handler) {
return this.off(ev, handler);
}
/**
* Mostly identical to `EventEmitter.off`
*
* If a 'data' event handler is removed, and it was the last consumer
* (ie, there are no pipe destinations or other 'data' event listeners),
* then the flow of data will stop until there is another consumer or
* {@link Minipass#resume} is explicitly called.
*/
off(ev, handler) {
const ret = super.off(ev, handler);
// if we previously had listeners, and now we don't, and we don't
// have any pipes, then stop the flow, unless it's been explicitly
// put in a discarded flowing state via stream.resume().
if (ev === 'data') {
this[DATALISTENERS] = this.listeners('data').length;
if (this[DATALISTENERS] === 0 &&
!this[DISCARDED] &&
!this[PIPES].length) {
this[FLOWING] = false;
}
}
return ret;
}
/**
* Mostly identical to `EventEmitter.removeAllListeners`
*
* If all 'data' event handlers are removed, and they were the last consumer
* (ie, there are no pipe destinations), then the flow of data will stop
* until there is another consumer or {@link Minipass#resume} is explicitly
* called.
*/
removeAllListeners(ev) {
const ret = super.removeAllListeners(ev);
if (ev === 'data' || ev === undefined) {
this[DATALISTENERS] = 0;
if (!this[DISCARDED] && !this[PIPES].length) {
this[FLOWING] = false;
}
}
return ret;
}
/**
* true if the 'end' event has been emitted
*/
get emittedEnd() {
return this[EMITTED_END];
}
[MAYBE_EMIT_END]() {
if (!this[EMITTING_END] &&
!this[EMITTED_END] &&
!this[DESTROYED] &&
this[BUFFER].length === 0 &&
this[EOF]) {
this[EMITTING_END] = true;
this.emit('end');
this.emit('prefinish');
this.emit('finish');
if (this[CLOSED])
this.emit('close');
this[EMITTING_END] = false;
}
}
/**
* Mostly identical to `EventEmitter.emit`, with the following
* behavior differences to prevent data loss and unnecessary hangs:
*
* If the stream has been destroyed, and the event is something other
* than 'close' or 'error', then `false` is returned and no handlers
* are called.
*
* If the event is 'end', and has already been emitted, then the event
* is ignored. If the stream is in a paused or non-flowing state, then
* the event will be deferred until data flow resumes. If the stream is
* async, then handlers will be called on the next tick rather than
* immediately.
*
* If the event is 'close', and 'end' has not yet been emitted, then
* the event will be deferred until after 'end' is emitted.
*
* If the event is 'error', and an AbortSignal was provided for the stream,
* and there are no listeners, then the event is ignored, matching the
* behavior of node core streams in the presense of an AbortSignal.
*
* If the event is 'finish' or 'prefinish', then all listeners will be
* removed after emitting the event, to prevent double-firing.
*/
emit(ev, ...args) {
const data = args[0];
// error and close are only events allowed after calling destroy()
if (ev !== 'error' &&
ev !== 'close' &&
ev !== DESTROYED &&
this[DESTROYED]) {
return false;
}
else if (ev === 'data') {
return !this[OBJECTMODE] && !data
? false
: this[ASYNC]
? (defer(() => this[EMITDATA](data)), true)
: this[EMITDATA](data);
}
else if (ev === 'end') {
return this[EMITEND]();
}
else if (ev === 'close') {
this[CLOSED] = true;
// don't emit close before 'end' and 'finish'
if (!this[EMITTED_END] && !this[DESTROYED])
return false;
const ret = super.emit('close');
this.removeAllListeners('close');
return ret;
}
else if (ev === 'error') {
this[EMITTED_ERROR] = data;
super.emit(ERROR, data);
const ret = !this[SIGNAL] || this.listeners('error').length
? super.emit('error', data)
: false;
this[MAYBE_EMIT_END]();
return ret;
}
else if (ev === 'resume') {
const ret = super.emit('resume');
this[MAYBE_EMIT_END]();
return ret;
}
else if (ev === 'finish' || ev === 'prefinish') {
const ret = super.emit(ev);
this.removeAllListeners(ev);
return ret;
}
// Some other unknown event
const ret = super.emit(ev, ...args);
this[MAYBE_EMIT_END]();
return ret;
}
[EMITDATA](data) {
for (const p of this[PIPES]) {
if (p.dest.write(data) === false)
this.pause();
}
const ret = this[DISCARDED] ? false : super.emit('data', data);
this[MAYBE_EMIT_END]();
return ret;
}
[EMITEND]() {
if (this[EMITTED_END])
return false;
this[EMITTED_END] = true;
this.readable = false;
return this[ASYNC]
? (defer(() => this[EMITEND2]()), true)
: this[EMITEND2]();
}
[EMITEND2]() {
if (this[DECODER]) {
const data = this[DECODER].end();
if (data) {
for (const p of this[PIPES]) {
p.dest.write(data);
}
if (!this[DISCARDED])
super.emit('data', data);
}
}
for (const p of this[PIPES]) {
p.end();
}
const ret = super.emit('end');
this.removeAllListeners('end');
return ret;
}
/**
* Return a Promise that resolves to an array of all emitted data once
* the stream ends.
*/
async collect() {
const buf = Object.assign([], {
dataLength: 0,
});
if (!this[OBJECTMODE])
buf.dataLength = 0;
// set the promise first, in case an error is raised
// by triggering the flow here.
const p = this.promise();
this.on('data', c => {
buf.push(c);
if (!this[OBJECTMODE])
buf.dataLength += c.length;
});
await p;
return buf;
}
/**
* Return a Promise that resolves to the concatenation of all emitted data
* once the stream ends.
*
* Not allowed on objectMode streams.
*/
async concat() {
if (this[OBJECTMODE]) {
throw new Error('cannot concat in objectMode');
}
const buf = await this.collect();
return (this[ENCODING]
? buf.join('')
: Buffer.concat(buf, buf.dataLength));
}
/**
* Return a void Promise that resolves once the stream ends.
*/
async promise() {
return new Promise((resolve, reject) => {
this.on(DESTROYED, () => reject(new Error('stream destroyed')));
this.on('error', er => reject(er));
this.on('end', () => resolve());
});
}
/**
* Asynchronous `for await of` iteration.
*
* This will continue emitting all chunks until the stream terminates.
*/
[Symbol.asyncIterator]() {
// set this up front, in case the consumer doesn't call next()
// right away.
this[DISCARDED] = false;
let stopped = false;
const stop = async () => {
this.pause();
stopped = true;
return { value: undefined, done: true };
};
const next = () => {
if (stopped)
return stop();
const res = this.read();
if (res !== null)
return Promise.resolve({ done: false, value: res });
if (this[EOF])
return stop();
let resolve;
let reject;
const onerr = (er) => {
this.off('data', ondata);
this.off('end', onend);
this.off(DESTROYED, ondestroy);
stop();
reject(er);
};
const ondata = (value) => {
this.off('error', onerr);
this.off('end', onend);
this.off(DESTROYED, ondestroy);
this.pause();
resolve({ value, done: !!this[EOF] });
};
const onend = () => {
this.off('error', onerr);
this.off('data', ondata);
this.off(DESTROYED, ondestroy);
stop();
resolve({ done: true, value: undefined });
};
const ondestroy = () => onerr(new Error('stream destroyed'));
return new Promise((res, rej) => {
reject = rej;
resolve = res;
this.once(DESTROYED, ondestroy);
this.once('error', onerr);
this.once('end', onend);
this.once('data', ondata);
});
};
return {
next,
throw: stop,
return: stop,
[Symbol.asyncIterator]() {
return this;
},
};
}
/**
* Synchronous `for of` iteration.
*
* The iteration will terminate when the internal buffer runs out, even
* if the stream has not yet terminated.
*/
[Symbol.iterator]() {
// set this up front, in case the consumer doesn't call next()
// right away.
this[DISCARDED] = false;
let stopped = false;
const stop = () => {
this.pause();
this.off(ERROR, stop);
this.off(DESTROYED, stop);
this.off('end', stop);
stopped = true;
return { done: true, value: undefined };
};
const next = () => {
if (stopped)
return stop();
const value = this.read();
return value === null ? stop() : { done: false, value };
};
this.once('end', stop);
this.once(ERROR, stop);
this.once(DESTROYED, stop);
return {
next,
throw: stop,
return: stop,
[Symbol.iterator]() {
return this;
},
};
}
/**
* Destroy a stream, preventing it from being used for any further purpose.
*
* If the stream has a `close()` method, then it will be called on
* destruction.
*
* After destruction, any attempt to write data, read data, or emit most
* events will be ignored.
*
* If an error argument is provided, then it will be emitted in an
* 'error' event.
*/
destroy(er) {
if (this[DESTROYED]) {
if (er)
this.emit('error', er);
else
this.emit(DESTROYED);
return this;
}
this[DESTROYED] = true;
this[DISCARDED] = true;
// throw away all buffered data, it's never coming out
this[BUFFER].length = 0;
this[BUFFERLENGTH] = 0;
const wc = this;
if (typeof wc.close === 'function' && !this[CLOSED])
wc.close();
if (er)
this.emit('error', er);
// if no error to emit, still reject pending promises
else
this.emit(DESTROYED);
return this;
}
/**
* Alias for {@link isStream}
*
* Former export location, maintained for backwards compatibility.
*
* @deprecated
*/
static get isStream() {
return isStream;
}
}
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