WriteStream

Defined in: src/node/streams.ts:90

A WriteStream implementation that wraps an underlying global WritableStream.

Extends

Writable

Implements

WriteStream

Constructors

Constructor

new WriteStream(opts?, handleOrPromise): WriteStream

Defined in: src/node/streams.ts:97

Parameters

opts?

CreateWriteStreamOptions = {}

handleOrPromise

FileHandle | Promise<FileHandle>

Returns

WriteStream

Overrides

Writable.constructor

Properties

_events

_events: Listeners

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:28

Inherited from

Writable._events

_eventsCount

_eventsCount: number

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:29

Inherited from

Writable._eventsCount

_maxListeners?

optional _maxListeners?: number

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:30

Inherited from

Writable._maxListeners

_readableState?

optional _readableState?: ReadableState

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:126

Present on a Duplex; undefined on a plain Writable.

Inherited from

Writable._readableState

_writableState

_writableState: WritableState

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:124

Inherited from

Writable._writableState

[kCapture]

protected [kCapture]: boolean

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:31

Inherited from

Writable.[kCapture]

pending

pending: boolean = true

Defined in: src/node/streams.ts:91

This property is true if the underlying file has not been opened yet, i.e. before the 'ready' event is emitted.

Since

v11.2.0

Implementation of

fs.WriteStream.pending

captureRejections

static captureRejections: boolean

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:25

The default for the captureRejections option of newly created emitters.

Inherited from

Writable.captureRejections

captureRejectionSymbol

readonly static captureRejectionSymbol: typeof captureRejectionSymbol

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:26

Inherited from

Writable.captureRejectionSymbol

defaultMaxListeners

static defaultMaxListeners: number

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:23

Inherited from

Writable.defaultMaxListeners

errorMonitor

readonly static errorMonitor: typeof errorMonitor

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:27

Inherited from

Writable.errorMonitor

WritableState

readonly static WritableState: typeof WritableState

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:128

Inherited from

Writable.WritableState

Accessors

bytesWritten

Get Signature

get bytesWritten(): number

Defined in: src/node/streams.ts:154

The number of bytes written so far. Does not include data that is still queued for writing.

Since

v0.4.7

Returns

number

Implementation of

fs.WriteStream.bytesWritten

closed

Get Signature

get closed(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:145

Is true after 'close' has been emitted.

Since

v18.0.0

Returns

boolean

Implementation of

fs.WriteStream.closed

Inherited from

Writable.closed

destroyed

Get Signature

get destroyed(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:146

Is true after writable.destroy() has been called.

Since

v8.0.0

Returns

boolean

Set Signature

set destroyed(value): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:147

Is true after writable.destroy() has been called.

Since

v8.0.0

Parameters

value

boolean

Returns

void

Implementation of

fs.WriteStream.destroyed

Inherited from

Writable.destroyed

errored

Get Signature

get errored(): Error | null

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:158

Returns error if the stream has been destroyed with an error.

Since

v18.0.0

Returns

Error | null

Implementation of

fs.WriteStream.errored

Inherited from

Writable.errored

path

Get Signature

get path(): string

Defined in: src/node/streams.ts:150

The path to the file the stream is writing to as specified in the first argument to createWriteStream. If path is passed as a string, thenwriteStream.path will be a string. If path is passed as a Buffer, thenwriteStream.path will be a Buffer.

Since

v0.1.93

Returns

string

Implementation of

fs.WriteStream.path

writable

Get Signature

get writable(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:148

Is true if it is safe to call writable.write(), which means the stream has not been destroyed, errored, or ended.

Since

v11.4.0

Returns

boolean

Set Signature

set writable(value): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:149

Is true if it is safe to call writable.write(), which means the stream has not been destroyed, errored, or ended.

Since

v11.4.0

Parameters

value

boolean

Returns

void

Implementation of

fs.WriteStream.writable

Inherited from

Writable.writable

writableAborted

Get Signature

get writableAborted(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:159

Returns whether the stream was destroyed or errored before emitting 'finish'.

Since

v18.0.0, v16.17.0

Returns

boolean

Implementation of

fs.WriteStream.writableAborted

Inherited from

Writable.writableAborted

writableBuffer

Get Signature

get writableBuffer(): BufferedWrite[] | undefined

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:152

Returns

BufferedWrite[] | undefined

Inherited from

Writable.writableBuffer

writableCorked

Get Signature

get writableCorked(): number

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:156

Number of times writable.uncork() needs to be called in order to fully uncork the stream.

Since

v13.2.0, v12.16.0

Returns

number

Implementation of

fs.WriteStream.writableCorked

Inherited from

Writable.writableCorked

writableEnded

Get Signature

get writableEnded(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:153

Is true after writable.end() has been called. This property does not indicate whether the data has been flushed, for this use writable.writableFinished instead.

Since

v12.9.0

Returns

boolean

Implementation of

fs.WriteStream.writableEnded

Inherited from

Writable.writableEnded

writableFinished

Get Signature

get writableFinished(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:150

Is set to true immediately before the 'finish' event is emitted.

Since

v12.6.0

Returns

boolean

Implementation of

fs.WriteStream.writableFinished

Inherited from

Writable.writableFinished

writableHighWaterMark

Get Signature

get writableHighWaterMark(): number

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:155

Return the value of highWaterMark passed when creating this Writable.

Since

v9.3.0

Returns

number

Implementation of

fs.WriteStream.writableHighWaterMark

Inherited from

Writable.writableHighWaterMark

writableLength

Get Signature

get writableLength(): number

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:157

This property contains the number of bytes (or objects) in the queue ready to be written. The value provides introspection data regarding the status of the highWaterMark.

Since

v9.4.0

Returns

number

Implementation of

fs.WriteStream.writableLength

Inherited from

Writable.writableLength

writableNeedDrain

Get Signature

get writableNeedDrain(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:154

Is true if the stream’s buffer has been full and stream will emit 'drain'.

Since

v15.2.0, v14.17.0

Returns

boolean

Implementation of

fs.WriteStream.writableNeedDrain

Inherited from

Writable.writableNeedDrain

writableObjectMode

Get Signature

get writableObjectMode(): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:151

Getter for the property objectMode of a given Writable stream.

Since

v12.3.0

Returns

boolean

Implementation of

fs.WriteStream.writableObjectMode

Inherited from

Writable.writableObjectMode

Methods

_construct()?

optional _construct(callback): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:141

Parameters

callback

Callback

Returns

void

Implementation of

fs.WriteStream._construct

Inherited from

Writable._construct

_destroy()

_destroy(error, callback): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:162

Parameters

error

Error | null

callback

Callback

Returns

void

Implementation of

fs.WriteStream._destroy

Inherited from

Writable._destroy

_final()

_final(callback): Promise<void>

Defined in: src/node/streams.ts:127

Parameters

callback

(error?) => void

Returns

Promise<void>

Implementation of

fs.WriteStream._final

Overrides

Writable._final

_undestroy()

_undestroy(): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:161

Returns

void

Inherited from

Writable._undestroy

_write()

_write(chunk, encoding, callback): Promise<void>

Defined in: src/node/streams.ts:110

Parameters

chunk

any

encoding

"buffer" | BufferEncoding

callback

(error?) => void

Returns

Promise<void>

Implementation of

fs.WriteStream._write

Overrides

Writable._write

_writev()?

optional _writev(chunks, callback): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:140

Parameters

chunks

WriteRequest[]

callback

Callback

Returns

void

Implementation of

fs.WriteStream._writev

Inherited from

Writable._writev

[asyncDispose]()

[asyncDispose](): Promise<void>

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:168

Returns

Promise<void>

Implementation of

fs.WriteStream.[asyncDispose]

Inherited from

Writable.[asyncDispose]

[captureRejectionSymbol]()

[captureRejectionSymbol](err): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:163

Parameters

err

Error

Returns

void

Inherited from

Writable.[captureRejectionSymbol]

addListener()

addListener(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:36

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.addListener

Inherited from

Writable.addListener

close()

close(callback?): void

Defined in: src/node/streams.ts:140

Closes writeStream. Optionally accepts a callback that will be executed once the writeStreamis closed.

Parameters

callback?

Callback<[void]> = ...

Returns

void

Since

v0.9.4

Implementation of

fs.WriteStream.close

cork()

cork(): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:136

Buffers writes until a matching number of uncork() calls.

Returns

void

Implementation of

fs.WriteStream.cork

Inherited from

Writable.cork

destroy()

destroy(error?, callback?): this

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:160

Parameters

error?

Error | null

callback?

Callback

Returns

this

Implementation of

fs.WriteStream.destroy

Inherited from

Writable.destroy

emit()

emit(type, …args): boolean

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:35

Parameters

type

EventKey

args

…any[]

Returns

boolean

Implementation of

fs.WriteStream.emit

Inherited from

Writable.emit

end()

Call Signature

end(callback?): this

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:142

Calling the writable.end() method signals that no more data will be written to the Writable. The optional chunk and encoding arguments allow one final additional chunk of data to be written immediately before closing the stream.

Calling the write method after calling end will raise an error.

// Write 'hello, ' and then end with 'world!'.
import fs from 'node:fs';
const file = fs.createWriteStream('example.txt');
file.write('hello, ');
file.end('world!');
// Writing more now is not allowed!

Parameters

callback?

Callback

Returns

this

Since

v0.9.4

Implementation of

fs.WriteStream.end

Inherited from

Writable.end

Call Signature

end(chunk, callback?): this

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:143

Signals that no more data will be written, with one final chunk of data.

Parameters

chunk

any

Optional data to write. For streams not operating in object mode, chunk must be a {string}, {Buffer}, {TypedArray} or {DataView}. For object mode streams, chunk may be any JavaScript value other than null.

callback?

Callback

Returns

this

See

Writable.end for full details.

Since

v0.9.4

Implementation of

fs.WriteStream.end

Inherited from

Writable.end

Call Signature

end(chunk, encoding?, callback?): this

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:144

Signals that no more data will be written, with one final chunk of data.

Parameters

chunk

any

encoding?

BufferEncoding | null

The encoding if chunk is a string

callback?

Callback

Returns

this

See

Writable.end for full details.

Since

v0.9.4

Implementation of

fs.WriteStream.end

Inherited from

Writable.end

eventNames()

eventNames(): EventKey[]

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:47

Returns

EventKey[]

Implementation of

fs.WriteStream.eventNames

Inherited from

Writable.eventNames

getMaxListeners()

getMaxListeners(): number

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:34

Returns

number

Implementation of

fs.WriteStream.getMaxListeners

Inherited from

Writable.getMaxListeners

listenerCount()

listenerCount(type, listener?): number

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:46

Parameters

type

EventKey

listener?

Listener

Returns

number

Implementation of

fs.WriteStream.listenerCount

Inherited from

Writable.listenerCount

listeners()

listeners(type): Listener[]

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:44

Parameters

type

EventKey

Returns

Listener[]

Implementation of

fs.WriteStream.listeners

Inherited from

Writable.listeners

off()

off(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:42

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.off

Inherited from

Writable.off

on()

on(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:37

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.on

Inherited from

Writable.on

once()

once(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:39

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.once

Inherited from

Writable.once

pipe()

pipe<T>(dest): T

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:132

Writables are not readable, so piping from one is always an error.

Type Parameters

T

T extends PipeDestination

Parameters

dest

T

Returns

T

Implementation of

fs.WriteStream.pipe

Inherited from

Writable.pipe

prependListener()

prependListener(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:38

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.prependListener

Inherited from

Writable.prependListener

prependOnceListener()

prependOnceListener(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:40

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.prependOnceListener

Inherited from

Writable.prependOnceListener

rawListeners()

rawListeners(type): Listener[]

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:45

Parameters

type

EventKey

Returns

Listener[]

Implementation of

fs.WriteStream.rawListeners

Inherited from

Writable.rawListeners

removeAllListeners()

removeAllListeners(type?): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:43

Parameters

type?

EventKey

Returns

this

Implementation of

fs.WriteStream.removeAllListeners

Inherited from

Writable.removeAllListeners

removeListener()

removeListener(type, listener): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:41

Parameters

type

EventKey

listener

Listener

Returns

this

Implementation of

fs.WriteStream.removeListener

Inherited from

Writable.removeListener

setDefaultEncoding()

setDefaultEncoding(encoding): this

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:138

The writable.setDefaultEncoding() method sets the default encoding for a Writable stream.

Parameters

encoding

BufferEncoding

The new default encoding

Returns

this

Since

v0.11.15

Implementation of

fs.WriteStream.setDefaultEncoding

Inherited from

Writable.setDefaultEncoding

setMaxListeners()

setMaxListeners(n): this

Defined in: node_modules/@zenfs/streams/dist/events.d.ts:33

Parameters

n

number

Returns

this

Implementation of

fs.WriteStream.setMaxListeners

Inherited from

Writable.setMaxListeners

uncork()

uncork(): void

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:137

The writable.uncork() method flushes all data buffered since cork was called.

When using writable.cork() and writable.uncork() to manage the buffering of writes to a stream, defer calls to writable.uncork() using process.nextTick(). Doing so allows batching of all writable.write() calls that occur within a given Node.js event loop phase.

stream.cork();
stream.write('some ');
stream.write('data ');
process.nextTick(() => stream.uncork());

If the writable.cork() method is called multiple times on a stream, the same number of calls to writable.uncork() must be called to flush the buffered data.

stream.cork();
stream.write('some ');
stream.cork();
stream.write('data ');
process.nextTick(() => {
  stream.uncork();
  // The data will not be flushed until uncork() is called a second time.
  stream.uncork();
});

Returns

void

Since

v0.11.2

Implementation of

fs.WriteStream.uncork

Inherited from

Writable.uncork

write()

Call Signature

write(chunk, encoding?, callback?): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:133

The writable.write() method writes some data to the stream, and calls the supplied callback once the data has been fully handled. If an error occurs, the callback will be called with the error as its first argument. The callback is called asynchronously and before 'error' is emitted.

The return value is true if the internal buffer is less than the highWaterMark configured when the stream was created after admitting chunk. If false is returned, further attempts to write data to the stream should stop until the 'drain' event is emitted.

While a stream is not draining, calls to write() will buffer chunk, and return false. Once all currently buffered chunks are drained (accepted for delivery by the operating system), the 'drain' event will be emitted. Once write() returns false, do not write more chunks until the 'drain' event is emitted. While calling write() on a stream that is not draining is allowed, Node.js will buffer all written chunks until maximum memory usage occurs, at which point it will abort unconditionally. Even before it aborts, high memory usage will cause poor garbage collector performance and high RSS (which is not typically released back to the system, even after the memory is no longer required). Since TCP sockets may never drain if the remote peer does not read the data, writing a socket that is not draining may lead to a remotely exploitable vulnerability.

Writing data while the stream is not draining is particularly problematic for a Transform, because the Transform streams are paused by default until they are piped or a 'data' or 'readable' event handler is added.

If the data to be written can be generated or fetched on demand, it is recommended to encapsulate the logic into a Readable and use pipe. However, if calling write() is preferred, it is possible to respect backpressure and avoid memory issues using the 'drain' event:

function write(data, cb) {
  if (!stream.write(data)) {
    stream.once('drain', cb);
  } else {
    process.nextTick(cb);
  }
}

// Wait for cb to be called before doing any other write.
write('hello', () => {
  console.log('Write completed, do more writes now.');
});

A Writable stream in object mode will always ignore the encoding argument.

Parameters

chunk

any

encoding?

BufferEncoding | null

callback?

Callback

Callback for when this chunk of data is flushed.

Returns

boolean

false if the stream wishes for the calling code to wait for the 'drain' event to be emitted before continuing to write additional data; otherwise true.

Since

v0.9.4

Implementation of

fs.WriteStream.write

Inherited from

Writable.write

Call Signature

write(chunk, callback?): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:134

Writes data to the stream, with an explicit encoding for string data.

Parameters

chunk

any

callback?

Callback

Callback for when this chunk of data is flushed.

Returns

boolean

false if the stream wishes for the calling code to wait for the 'drain' event to be emitted before continuing to write additional data; otherwise true.

See

Writable.write for full details.

Since

v0.9.4

Implementation of

fs.WriteStream.write

Inherited from

Writable.write

[hasInstance]()

static [hasInstance](instance): boolean

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:130

Recognizes a Duplex, which inherits from Readable and so is not a structural subclass.

Parameters

instance

unknown

Returns

boolean

Inherited from

Writable.[hasInstance]

fromWeb()

static fromWeb(writableStream, options?): Writable

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:165

Wraps a WHATWG WritableStream.

Parameters

writableStream

WritableStream

options?

WritableOptions<Writable>

Returns

Writable

Inherited from

Writable.fromWeb

toWeb()

static toWeb(streamWritable): WritableStream

Defined in: node_modules/@zenfs/streams/dist/writable.d.ts:167

Exposes this stream as a WHATWG WritableStream.

Parameters

streamWritable

Writable

Returns

WritableStream

Inherited from

Writable.toWeb

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