| Current File : //proc/self/root/kunden/usr/share/doc/nodejs-docs/doc/api/webstreams.json |
{
"type": "module",
"source": "doc/api/webstreams.md",
"modules": [
{
"textRaw": "Web Streams API",
"name": "web_streams_api",
"introduced_in": "v16.5.0",
"stability": 1,
"stabilityText": "Experimental",
"desc": "<p>An implementation of the <a href=\"https://streams.spec.whatwg.org/\">WHATWG Streams Standard</a>.</p>\n<pre><code class=\"language-mjs\">import {\n ReadableStream,\n WritableStream,\n TransformStream,\n} from 'node:stream/web';\n</code></pre>\n<pre><code class=\"language-cjs\">const {\n ReadableStream,\n WritableStream,\n TransformStream,\n} = require('stream/web');\n</code></pre>",
"modules": [
{
"textRaw": "Overview",
"name": "overview",
"desc": "<p>The <a href=\"https://streams.spec.whatwg.org/\">WHATWG Streams Standard</a> (or \"web streams\") defines an API for handling\nstreaming data. It is similar to the Node.js <a href=\"stream.html\">Streams</a> API but emerged later\nand has become the \"standard\" API for streaming data across many JavaScript\nenvironments.</p>\n<p>There are three primary types of objects:</p>\n<ul>\n<li><code>ReadableStream</code> - Represents a source of streaming data.</li>\n<li><code>WritableStream</code> - Represents a destination for streaming data.</li>\n<li><code>TransformStream</code> - Represents an algorithm for transforming streaming data.</li>\n</ul>\n<h3>Example <code>ReadableStream</code></h3>\n<p>This example creates a simple <code>ReadableStream</code> that pushes the current\n<code>performance.now()</code> timestamp once every second forever. An async iterable\nis used to read the data from the stream.</p>\n<pre><code class=\"language-mjs\">import {\n ReadableStream\n} from 'node:stream/web';\n\nimport {\n setInterval as every\n} from 'node:timers/promises';\n\nimport {\n performance\n} from 'node:perf_hooks';\n\nconst SECOND = 1000;\n\nconst stream = new ReadableStream({\n async start(controller) {\n for await (const _ of every(SECOND))\n controller.enqueue(performance.now());\n }\n});\n\nfor await (const value of stream)\n console.log(value);\n</code></pre>\n<pre><code class=\"language-cjs\">const {\n ReadableStream\n} = require('node:stream/web');\n\nconst {\n setInterval: every\n} = require('node:timers/promises');\n\nconst {\n performance\n} = require('node:perf_hooks');\n\nconst SECOND = 1000;\n\nconst stream = new ReadableStream({\n async start(controller) {\n for await (const _ of every(SECOND))\n controller.enqueue(performance.now());\n }\n});\n\n(async () => {\n for await (const value of stream)\n console.log(value);\n})();\n</code></pre>",
"type": "module",
"displayName": "Overview"
},
{
"textRaw": "API",
"name": "api",
"classes": [
{
"textRaw": "Class: `ReadableStream`",
"type": "class",
"name": "ReadableStream",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"properties": [
{
"textRaw": "`locked` Type: {boolean} Set to `true` if there is an active reader for this {ReadableStream}.",
"type": "boolean",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The <code>readableStream.locked</code> property is <code>false</code> by default, and is\nswitched to <code>true</code> while there is an active reader consuming the\nstream's data.</p>",
"shortDesc": "Set to `true` if there is an active reader for this {ReadableStream}."
}
],
"methods": [
{
"textRaw": "`readableStream.cancel([reason])`",
"type": "method",
"name": "cancel",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined` once cancelation has been completed.",
"name": "return",
"desc": "A promise fulfilled with `undefined` once cancelation has been completed."
},
"params": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
}
]
}
]
},
{
"textRaw": "`readableStream.getReader([options])`",
"type": "method",
"name": "getReader",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {ReadableStreamDefaultReader|ReadableStreamBYOBReader}",
"name": "return",
"type": "ReadableStreamDefaultReader|ReadableStreamBYOBReader"
},
"params": [
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`mode` {string} `'byob'` or `undefined`",
"name": "mode",
"type": "string",
"desc": "`'byob'` or `undefined`"
}
]
}
]
}
],
"desc": "<pre><code class=\"language-mjs\">import { ReadableStream } from 'node:stream/web';\n\nconst stream = new ReadableStream();\n\nconst reader = stream.getReader();\n\nconsole.log(await reader.read());\n</code></pre>\n<pre><code class=\"language-cjs\">const { ReadableStream } = require('node:stream/web');\n\nconst stream = new ReadableStream();\n\nconst reader = stream.getReader();\n\nreader.read().then(console.log);\n</code></pre>\n<p>Causes the <code>readableStream.locked</code> to be <code>true</code>.</p>"
},
{
"textRaw": "`readableStream.pipeThrough(transform[, options])`",
"type": "method",
"name": "pipeThrough",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {ReadableStream} From `transform.readable`.",
"name": "return",
"type": "ReadableStream",
"desc": "From `transform.readable`."
},
"params": [
{
"textRaw": "`transform` {Object}",
"name": "transform",
"type": "Object",
"options": [
{
"textRaw": "`readable` {ReadableStream} The `ReadableStream` to which `transform.writable` will push the potentially modified data is receives from this `ReadableStream`.",
"name": "readable",
"type": "ReadableStream",
"desc": "The `ReadableStream` to which `transform.writable` will push the potentially modified data is receives from this `ReadableStream`."
},
{
"textRaw": "`writable` {WritableStream} The `WritableStream` to which this `ReadableStream`'s data will be written.",
"name": "writable",
"type": "WritableStream",
"desc": "The `WritableStream` to which this `ReadableStream`'s data will be written."
}
]
},
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`preventAbort` {boolean} When `true`, errors in this `ReadableStream` will not cause `transform.writable` to be aborted.",
"name": "preventAbort",
"type": "boolean",
"desc": "When `true`, errors in this `ReadableStream` will not cause `transform.writable` to be aborted."
},
{
"textRaw": "`preventCancel` {boolean} When `true`, errors in the destination `transform.writable` do not cause this `ReadableStream` to be canceled.",
"name": "preventCancel",
"type": "boolean",
"desc": "When `true`, errors in the destination `transform.writable` do not cause this `ReadableStream` to be canceled."
},
{
"textRaw": "`preventClose` {boolean} When `true`, closing this `ReadableStream` does not cause `transform.writable` to be closed.",
"name": "preventClose",
"type": "boolean",
"desc": "When `true`, closing this `ReadableStream` does not cause `transform.writable` to be closed."
},
{
"textRaw": "`signal` {AbortSignal} Allows the transfer of data to be canceled using an {AbortController}.",
"name": "signal",
"type": "AbortSignal",
"desc": "Allows the transfer of data to be canceled using an {AbortController}."
}
]
}
]
}
],
"desc": "<p>Connects this <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> to the pair of <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> and\n<a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a> provided in the <code>transform</code> argument such that the\ndata from this <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> is written in to <code>transform.writable</code>,\npossibly transformed, then pushed to <code>transform.readable</code>. Once the\npipeline is configured, <code>transform.readable</code> is returned.</p>\n<p>Causes the <code>readableStream.locked</code> to be <code>true</code> while the pipe operation\nis active.</p>\n<pre><code class=\"language-mjs\">import {\n ReadableStream,\n TransformStream,\n} from 'node:stream/web';\n\nconst stream = new ReadableStream({\n start(controller) {\n controller.enqueue('a');\n },\n});\n\nconst transform = new TransformStream({\n transform(chunk, controller) {\n controller.enqueue(chunk.toUpperCase());\n }\n});\n\nconst transformedStream = stream.pipeThrough(transform);\n\nfor await (const chunk of transformedStream)\n console.log(chunk);\n</code></pre>\n<pre><code class=\"language-cjs\">const {\n ReadableStream,\n TransformStream,\n} = require('node:stream/web');\n\nconst stream = new ReadableStream({\n start(controller) {\n controller.enqueue('a');\n },\n});\n\nconst transform = new TransformStream({\n transform(chunk, controller) {\n controller.enqueue(chunk.toUpperCase());\n }\n});\n\nconst transformedStream = stream.pipeThrough(transform);\n\n(async () => {\n for await (const chunk of transformedStream)\n console.log(chunk);\n})();\n</code></pre>"
},
{
"textRaw": "`readableStream.pipeTo(destination, options)`",
"type": "method",
"name": "pipeTo",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`",
"name": "return",
"desc": "A promise fulfilled with `undefined`"
},
"params": [
{
"textRaw": "`destination` {WritableStream} A {WritableStream} to which this `ReadableStream`'s data will be written.",
"name": "destination",
"type": "WritableStream",
"desc": "A {WritableStream} to which this `ReadableStream`'s data will be written."
},
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`preventAbort` {boolean} When `true`, errors in this `ReadableStream` will not cause `destination` to be aborted.",
"name": "preventAbort",
"type": "boolean",
"desc": "When `true`, errors in this `ReadableStream` will not cause `destination` to be aborted."
},
{
"textRaw": "`preventCancel` {boolean} When `true`, errors in the `destination` will not cause this `ReadableStream` to be canceled.",
"name": "preventCancel",
"type": "boolean",
"desc": "When `true`, errors in the `destination` will not cause this `ReadableStream` to be canceled."
},
{
"textRaw": "`preventClose` {boolean} When `true`, closing this `ReadableStream` does not cause `destination` to be closed.",
"name": "preventClose",
"type": "boolean",
"desc": "When `true`, closing this `ReadableStream` does not cause `destination` to be closed."
},
{
"textRaw": "`signal` {AbortSignal} Allows the transfer of data to be canceled using an {AbortController}.",
"name": "signal",
"type": "AbortSignal",
"desc": "Allows the transfer of data to be canceled using an {AbortController}."
}
]
}
]
}
],
"desc": "<p>Causes the <code>readableStream.locked</code> to be <code>true</code> while the pipe operation\nis active.</p>"
},
{
"textRaw": "`readableStream.tee()`",
"type": "method",
"name": "tee",
"meta": {
"added": [
"v16.5.0"
],
"changes": [
{
"version": "v16.18.0",
"pr-url": "https://github.com/nodejs/node/pull/44505",
"description": "Support teeing a readable byte stream."
}
]
},
"signatures": [
{
"return": {
"textRaw": "Returns: {ReadableStream\\[]}",
"name": "return",
"type": "ReadableStream\\[]"
},
"params": []
}
],
"desc": "<p>Returns a pair of new <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> instances to which this\n<code>ReadableStream</code>'s data will be forwarded. Each will receive the\nsame data.</p>\n<p>Causes the <code>readableStream.locked</code> to be <code>true</code>.</p>"
},
{
"textRaw": "`readableStream.values([options])`",
"type": "method",
"name": "values",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`preventCancel` {boolean} When `true`, prevents the {ReadableStream} from being closed when the async iterator abruptly terminates. **Default**: `false`.",
"name": "preventCancel",
"type": "boolean",
"desc": "When `true`, prevents the {ReadableStream} from being closed when the async iterator abruptly terminates. **Default**: `false`."
}
]
}
]
}
],
"desc": "<p>Creates and returns an async iterator usable for consuming this\n<code>ReadableStream</code>'s data.</p>\n<p>Causes the <code>readableStream.locked</code> to be <code>true</code> while the async iterator\nis active.</p>\n<pre><code class=\"language-mjs\">import { Buffer } from 'node:buffer';\n\nconst stream = new ReadableStream(getSomeSource());\n\nfor await (const chunk of stream.values({ preventCancel: true }))\n console.log(Buffer.from(chunk).toString());\n</code></pre>"
}
],
"modules": [
{
"textRaw": "Async Iteration",
"name": "async_iteration",
"desc": "<p>The <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> object supports the async iterator protocol using\n<code>for await</code> syntax.</p>\n<pre><code class=\"language-mjs\">import { Buffer } from 'node:buffer';\n\nconst stream = new ReadableStream(getSomeSource());\n\nfor await (const chunk of stream)\n console.log(Buffer.from(chunk).toString());\n</code></pre>\n<p>The async iterator will consume the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> until it terminates.</p>\n<p>By default, if the async iterator exits early (via either a <code>break</code>,\n<code>return</code>, or a <code>throw</code>), the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> will be closed. To prevent\nautomatic closing of the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>, use the <code>readableStream.values()</code>\nmethod to acquire the async iterator and set the <code>preventCancel</code> option to\n<code>true</code>.</p>\n<p>The <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> must not be locked (that is, it must not have an existing\nactive reader). During the async iteration, the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> will be locked.</p>",
"type": "module",
"displayName": "Async Iteration"
},
{
"textRaw": "Transferring with `postMessage()`",
"name": "transferring_with_`postmessage()`",
"desc": "<p>A <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> instance can be transferred using a <a href=\"worker_threads.html#class-messageport\" class=\"type\"><MessagePort></a>.</p>\n<pre><code class=\"language-js\">const stream = new ReadableStream(getReadableSourceSomehow());\n\nconst { port1, port2 } = new MessageChannel();\n\nport1.onmessage = ({ data }) => {\n data.getReader().read().then((chunk) => {\n console.log(chunk);\n });\n};\n\nport2.postMessage(stream, [stream]);\n</code></pre>",
"type": "module",
"displayName": "Transferring with `postMessage()`"
}
],
"signatures": [
{
"params": [],
"desc": "<!--lint disable maximum-line-length remark-lint-->\n<ul>\n<li><code>underlyingSource</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object\" class=\"type\"><Object></a>\n<ul>\n<li><code>start</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function\" class=\"type\"><Function></a> A user-defined function that is invoked immediately when\nthe <code>ReadableStream</code> is created.\n<ul>\n<li><code>controller</code> <a href=\"webstreams.html#class-readablestreamdefaultcontroller\" class=\"type\"><ReadableStreamDefaultController></a> | <a href=\"webstreams.html#class-readablebytestreamcontroller\" class=\"type\"><ReadableByteStreamController></a></li>\n<li>Returns: <code>undefined</code> or a promise fulfilled with <code>undefined</code>.</li>\n</ul>\n</li>\n<li><code>pull</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function\" class=\"type\"><Function></a> A user-defined function that is called repeatedly when the\n<code>ReadableStream</code> internal queue is not full. The operation may be sync or\nasync. If async, the function will not be called again until the previously\nreturned promise is fulfilled.\n<ul>\n<li><code>controller</code> <a href=\"webstreams.html#class-readablestreamdefaultcontroller\" class=\"type\"><ReadableStreamDefaultController></a> | <a href=\"webstreams.html#class-readablebytestreamcontroller\" class=\"type\"><ReadableByteStreamController></a></li>\n<li>Returns: A promise fulfilled with <code>undefined</code>.</li>\n</ul>\n</li>\n<li><code>cancel</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function\" class=\"type\"><Function></a> A user-defined function that is called when the\n<code>ReadableStream</code> is canceled.\n<ul>\n<li><code>reason</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types\" class=\"type\"><any></a></li>\n<li>Returns: A promise fulfilled with <code>undefined</code>.</li>\n</ul>\n</li>\n<li><code>type</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type\" class=\"type\"><string></a> Must be <code>'bytes'</code> or <code>undefined</code>.</li>\n<li><code>autoAllocateChunkSize</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\"><number></a> Used only when <code>type</code> is equal to\n<code>'bytes'</code>.</li>\n</ul>\n</li>\n<li><code>strategy</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object\" class=\"type\"><Object></a>\n<ul>\n<li><code>highWaterMark</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\"><number></a> The maximum internal queue size before backpressure\nis applied.</li>\n<li><code>size</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function\" class=\"type\"><Function></a> A user-defined function used to identify the size of each\nchunk of data.\n<ul>\n<li><code>chunk</code> <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Data_types\" class=\"type\"><any></a></li>\n<li>Returns: <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Number_type\" class=\"type\"><number></a></li>\n</ul>\n</li>\n</ul>\n</li>\n</ul>\n<!--lint enable maximum-line-length remark-lint-->"
}
]
},
{
"textRaw": "Class: `ReadableStreamDefaultReader`",
"type": "class",
"name": "ReadableStreamDefaultReader",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>By default, calling <code>readableStream.getReader()</code> with no arguments\nwill return an instance of <code>ReadableStreamDefaultReader</code>. The default\nreader treats the chunks of data passed through the stream as opaque\nvalues, which allows the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> to work with generally any\nJavaScript value.</p>",
"methods": [
{
"textRaw": "`readableStreamDefaultReader.cancel([reason])`",
"type": "method",
"name": "cancel",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
}
]
}
],
"desc": "<p>Cancels the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> and returns a promise that is fulfilled\nwhen the underlying stream has been canceled.</p>"
},
{
"textRaw": "`readableStreamDefaultReader.read()`",
"type": "method",
"name": "read",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with an object:",
"name": "return",
"desc": "A promise fulfilled with an object:",
"options": [
{
"textRaw": "`value` {ArrayBuffer}",
"name": "value",
"type": "ArrayBuffer"
},
{
"textRaw": "`done` {boolean}",
"name": "done",
"type": "boolean"
}
]
},
"params": []
}
],
"desc": "<p>Requests the next chunk of data from the underlying <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>\nand returns a promise that is fulfilled with the data once it is\navailable.</p>"
},
{
"textRaw": "`readableStreamDefaultReader.releaseLock()`",
"type": "method",
"name": "releaseLock",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": []
}
],
"desc": "<p>Releases this reader's lock on the underlying <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>.</p>"
}
],
"properties": [
{
"textRaw": "`closed` Type: {Promise} Fulfilled with `undefined` when the associated {ReadableStream} is closed or rejected if the stream errors or the reader's lock is released before the stream finishes closing.",
"type": "Promise",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "Fulfilled with `undefined` when the associated {ReadableStream} is closed or rejected if the stream errors or the reader's lock is released before the stream finishes closing."
}
],
"signatures": [
{
"params": [
{
"textRaw": "`stream` {ReadableStream}",
"name": "stream",
"type": "ReadableStream"
}
],
"desc": "<p>Creates a new <a href=\"webstreams.html#class-readablestreamdefaultreader\" class=\"type\"><ReadableStreamDefaultReader></a> that is locked to the\ngiven <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>.</p>"
}
]
},
{
"textRaw": "Class: `ReadableStreamBYOBReader`",
"type": "class",
"name": "ReadableStreamBYOBReader",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The <code>ReadableStreamBYOBReader</code> is an alternative consumer for\nbyte-oriented <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>s (those that are created with\n<code>underlyingSource.type</code> set equal to <code>'bytes'</code> when the\n<code>ReadableStream</code> was created).</p>\n<p>The <code>BYOB</code> is short for \"bring your own buffer\". This is a\npattern that allows for more efficient reading of byte-oriented\ndata that avoids extraneous copying.</p>\n<pre><code class=\"language-mjs\">import {\n open\n} from 'node:fs/promises';\n\nimport {\n ReadableStream\n} from 'node:stream/web';\n\nimport { Buffer } from 'node:buffer';\n\nclass Source {\n type = 'bytes';\n autoAllocateChunkSize = 1024;\n\n async start(controller) {\n this.file = await open(new URL(import.meta.url));\n this.controller = controller;\n }\n\n async pull(controller) {\n const view = controller.byobRequest?.view;\n const {\n bytesRead,\n } = await this.file.read({\n buffer: view,\n offset: view.byteOffset,\n length: view.byteLength\n });\n\n if (bytesRead === 0) {\n await this.file.close();\n this.controller.close();\n }\n controller.byobRequest.respond(bytesRead);\n }\n}\n\nconst stream = new ReadableStream(new Source());\n\nasync function read(stream) {\n const reader = stream.getReader({ mode: 'byob' });\n\n const chunks = [];\n let result;\n do {\n result = await reader.read(Buffer.alloc(100));\n if (result.value !== undefined)\n chunks.push(Buffer.from(result.value));\n } while (!result.done);\n\n return Buffer.concat(chunks);\n}\n\nconst data = await read(stream);\nconsole.log(Buffer.from(data).toString());\n</code></pre>",
"methods": [
{
"textRaw": "`readableStreamBYOBReader.cancel([reason])`",
"type": "method",
"name": "cancel",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
}
]
}
],
"desc": "<p>Cancels the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> and returns a promise that is fulfilled\nwhen the underlying stream has been canceled.</p>"
},
{
"textRaw": "`readableStreamBYOBReader.read(view)`",
"type": "method",
"name": "read",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with an object:",
"name": "return",
"desc": "A promise fulfilled with an object:",
"options": [
{
"textRaw": "`value` {ArrayBuffer}",
"name": "value",
"type": "ArrayBuffer"
},
{
"textRaw": "`done` {boolean}",
"name": "done",
"type": "boolean"
}
]
},
"params": [
{
"textRaw": "`view` {Buffer|TypedArray|DataView}",
"name": "view",
"type": "Buffer|TypedArray|DataView"
}
]
}
],
"desc": "<p>Requests the next chunk of data from the underlying <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>\nand returns a promise that is fulfilled with the data once it is\navailable.</p>\n<p>Do not pass a pooled <a href=\"buffer.html#class-buffer\" class=\"type\"><Buffer></a> object instance in to this method.\nPooled <code>Buffer</code> objects are created using <code>Buffer.allocUnsafe()</code>,\nor <code>Buffer.from()</code>, or are often returned by various <code>node:fs</code> module\ncallbacks. These types of <code>Buffer</code>s use a shared underlying\n<a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer\" class=\"type\"><ArrayBuffer></a> object that contains all of the data from all of\nthe pooled <code>Buffer</code> instances. When a <code>Buffer</code>, <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray\" class=\"type\"><TypedArray></a>,\nor <a href=\"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView\" class=\"type\"><DataView></a> is passed in to <code>readableStreamBYOBReader.read()</code>,\nthe view's underlying <code>ArrayBuffer</code> is <em>detached</em>, invalidating\nall existing views that may exist on that <code>ArrayBuffer</code>. This\ncan have disastrous consequences for your application.</p>"
},
{
"textRaw": "`readableStreamBYOBReader.releaseLock()`",
"type": "method",
"name": "releaseLock",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": []
}
],
"desc": "<p>Releases this reader's lock on the underlying <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>.</p>"
}
],
"properties": [
{
"textRaw": "`closed` Type: {Promise} Fulfilled with `undefined` when the associated {ReadableStream} is closed or rejected if the stream errors or the reader's lock is released before the stream finishes closing.",
"type": "Promise",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "Fulfilled with `undefined` when the associated {ReadableStream} is closed or rejected if the stream errors or the reader's lock is released before the stream finishes closing."
}
],
"signatures": [
{
"params": [
{
"textRaw": "`stream` {ReadableStream}",
"name": "stream",
"type": "ReadableStream"
}
],
"desc": "<p>Creates a new <code>ReadableStreamBYOBReader</code> that is locked to the\ngiven <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>.</p>"
}
]
},
{
"textRaw": "Class: `ReadableStreamDefaultController`",
"type": "class",
"name": "ReadableStreamDefaultController",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>Every <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> has a controller that is responsible for\nthe internal state and management of the stream's queue. The\n<code>ReadableStreamDefaultController</code> is the default controller\nimplementation for <code>ReadableStream</code>s that are not byte-oriented.</p>",
"methods": [
{
"textRaw": "`readableStreamDefaultController.close()`",
"type": "method",
"name": "close",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": []
}
],
"desc": "<p>Closes the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> to which this controller is associated.</p>"
},
{
"textRaw": "`readableStreamDefaultController.enqueue(chunk)`",
"type": "method",
"name": "enqueue",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
}
]
}
],
"desc": "<p>Appends a new chunk of data to the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>'s queue.</p>"
},
{
"textRaw": "`readableStreamDefaultController.error(error)`",
"type": "method",
"name": "error",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`error` {any}",
"name": "error",
"type": "any"
}
]
}
],
"desc": "<p>Signals an error that causes the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> to error and close.</p>"
}
],
"properties": [
{
"textRaw": "`desiredSize` Type: {number}",
"type": "number",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>Returns the amount of data remaining to fill the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>'s\nqueue.</p>"
}
]
},
{
"textRaw": "Class: `ReadableByteStreamController`",
"type": "class",
"name": "ReadableByteStreamController",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>Every <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> has a controller that is responsible for\nthe internal state and management of the stream's queue. The\n<code>ReadableByteStreamController</code> is for byte-oriented <code>ReadableStream</code>s.</p>",
"properties": [
{
"textRaw": "`byobRequest` Type: {ReadableStreamBYOBRequest}",
"type": "ReadableStreamBYOBRequest",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>Returns the amount of data remaining to fill the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>'s\nqueue.</p>"
},
{
"textRaw": "`desiredSize` Type: {number}",
"type": "number",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>Returns the amount of data remaining to fill the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>'s\nqueue.</p>"
}
],
"methods": [
{
"textRaw": "`readableByteStreamController.close()`",
"type": "method",
"name": "close",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": []
}
],
"desc": "<p>Closes the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> to which this controller is associated.</p>"
},
{
"textRaw": "`readableByteStreamController.enqueue(chunk)`",
"type": "method",
"name": "enqueue",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`chunk`: {Buffer|TypedArray|DataView}",
"name": "chunk",
"type": "Buffer|TypedArray|DataView"
}
]
}
],
"desc": "<p>Appends a new chunk of data to the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>'s queue.</p>"
},
{
"textRaw": "`readableByteStreamController.error(error)`",
"type": "method",
"name": "error",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`error` {any}",
"name": "error",
"type": "any"
}
]
}
],
"desc": "<p>Signals an error that causes the <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> to error and close.</p>"
}
]
},
{
"textRaw": "Class: `ReadableStreamBYOBRequest`",
"type": "class",
"name": "ReadableStreamBYOBRequest",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>When using <code>ReadableByteStreamController</code> in byte-oriented\nstreams, and when using the <code>ReadableStreamBYOBReader</code>,\nthe <code>readableByteStreamController.byobRequest</code> property\nprovides access to a <code>ReadableStreamBYOBRequest</code> instance\nthat represents the current read request. The object\nis used to gain access to the <code>ArrayBuffer</code>/<code>TypedArray</code>\nthat has been provided for the read request to fill,\nand provides methods for signaling that the data has\nbeen provided.</p>",
"methods": [
{
"textRaw": "`readableStreamBYOBRequest.respond(bytesWritten)`",
"type": "method",
"name": "respond",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`bytesWritten` {number}",
"name": "bytesWritten",
"type": "number"
}
]
}
],
"desc": "<p>Signals that a <code>bytesWritten</code> number of bytes have been written\nto <code>readableStreamBYOBRequest.view</code>.</p>"
},
{
"textRaw": "`readableStreamBYOBRequest.respondWithNewView(view)`",
"type": "method",
"name": "respondWithNewView",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`view` {Buffer|TypedArray|DataView}",
"name": "view",
"type": "Buffer|TypedArray|DataView"
}
]
}
],
"desc": "<p>Signals that the request has been fulfilled with bytes written\nto a new <code>Buffer</code>, <code>TypedArray</code>, or <code>DataView</code>.</p>"
}
],
"properties": [
{
"textRaw": "`view` Type: {Buffer|TypedArray|DataView}",
"type": "Buffer|TypedArray|DataView",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
}
}
]
},
{
"textRaw": "Class: `WritableStream`",
"type": "class",
"name": "WritableStream",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The <code>WritableStream</code> is a destination to which stream data is sent.</p>\n<pre><code class=\"language-mjs\">import {\n WritableStream\n} from 'node:stream/web';\n\nconst stream = new WritableStream({\n write(chunk) {\n console.log(chunk);\n }\n});\n\nawait stream.getWriter().write('Hello World');\n</code></pre>",
"methods": [
{
"textRaw": "`writableStream.abort([reason])`",
"type": "method",
"name": "abort",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
}
]
}
],
"desc": "<p>Abruptly terminates the <code>WritableStream</code>. All queued writes will be\ncanceled with their associated promises rejected.</p>"
},
{
"textRaw": "`writableStream.close()`",
"type": "method",
"name": "close",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": []
}
],
"desc": "<p>Closes the <code>WritableStream</code> when no additional writes are expected.</p>"
},
{
"textRaw": "`writableStream.getWriter()`",
"type": "method",
"name": "getWriter",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {WritableStreamDefaultWriter}",
"name": "return",
"type": "WritableStreamDefaultWriter"
},
"params": []
}
],
"desc": "<p>Creates and creates a new writer instance that can be used to write\ndata into the <code>WritableStream</code>.</p>"
}
],
"properties": [
{
"textRaw": "`locked` Type: {boolean}",
"type": "boolean",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The <code>writableStream.locked</code> property is <code>false</code> by default, and is\nswitched to <code>true</code> while there is an active writer attached to this\n<code>WritableStream</code>.</p>"
}
],
"modules": [
{
"textRaw": "Transferring with postMessage()",
"name": "transferring_with_postmessage()",
"desc": "<p>A <a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a> instance can be transferred using a <a href=\"worker_threads.html#class-messageport\" class=\"type\"><MessagePort></a>.</p>\n<pre><code class=\"language-js\">const stream = new WritableStream(getWritableSinkSomehow());\n\nconst { port1, port2 } = new MessageChannel();\n\nport1.onmessage = ({ data }) => {\n data.getWriter().write('hello');\n};\n\nport2.postMessage(stream, [stream]);\n</code></pre>",
"type": "module",
"displayName": "Transferring with postMessage()"
}
],
"signatures": [
{
"params": [
{
"textRaw": "`underlyingSink` {Object}",
"name": "underlyingSink",
"type": "Object",
"options": [
{
"textRaw": "`start` {Function} A user-defined function that is invoked immediately when the `WritableStream` is created.",
"name": "start",
"type": "Function",
"desc": "A user-defined function that is invoked immediately when the `WritableStream` is created.",
"options": [
{
"textRaw": "`controller` {WritableStreamDefaultController}",
"name": "controller",
"type": "WritableStreamDefaultController"
},
{
"textRaw": "Returns: `undefined` or a promise fulfilled with `undefined`.",
"name": "return",
"desc": "`undefined` or a promise fulfilled with `undefined`."
}
]
},
{
"textRaw": "`write` {Function} A user-defined function that is invoked when a chunk of data has been written to the `WritableStream`.",
"name": "write",
"type": "Function",
"desc": "A user-defined function that is invoked when a chunk of data has been written to the `WritableStream`.",
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "`controller` {WritableStreamDefaultController}",
"name": "controller",
"type": "WritableStreamDefaultController"
},
{
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
}
]
},
{
"textRaw": "`close` {Function} A user-defined function that is called when the `WritableStream` is closed.",
"name": "close",
"type": "Function",
"desc": "A user-defined function that is called when the `WritableStream` is closed.",
"options": [
{
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
}
]
},
{
"textRaw": "`abort` {Function} A user-defined function that is called to abruptly close the `WritableStream`.",
"name": "abort",
"type": "Function",
"desc": "A user-defined function that is called to abruptly close the `WritableStream`.",
"options": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
},
{
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
}
]
},
{
"textRaw": "`type` {any} The `type` option is reserved for future use and _must_ be undefined.",
"name": "type",
"type": "any",
"desc": "The `type` option is reserved for future use and _must_ be undefined."
}
]
},
{
"textRaw": "`strategy` {Object}",
"name": "strategy",
"type": "Object",
"options": [
{
"textRaw": "`highWaterMark` {number} The maximum internal queue size before backpressure is applied.",
"name": "highWaterMark",
"type": "number",
"desc": "The maximum internal queue size before backpressure is applied."
},
{
"textRaw": "`size` {Function} A user-defined function used to identify the size of each chunk of data.",
"name": "size",
"type": "Function",
"desc": "A user-defined function used to identify the size of each chunk of data.",
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "Returns: {number}",
"name": "return",
"type": "number"
}
]
}
]
}
]
}
]
},
{
"textRaw": "Class: `WritableStreamDefaultWriter`",
"type": "class",
"name": "WritableStreamDefaultWriter",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"methods": [
{
"textRaw": "`writableStreamDefaultWriter.abort([reason])`",
"type": "method",
"name": "abort",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
}
]
}
],
"desc": "<p>Abruptly terminates the <code>WritableStream</code>. All queued writes will be\ncanceled with their associated promises rejected.</p>"
},
{
"textRaw": "`writableStreamDefaultWriter.close()`",
"type": "method",
"name": "close",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": []
}
],
"desc": "<p>Closes the <code>WritableStream</code> when no additional writes are expected.</p>"
},
{
"textRaw": "`writableStreamDefaultWriter.releaseLock()`",
"type": "method",
"name": "releaseLock",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": []
}
],
"desc": "<p>Releases this writer's lock on the underlying <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a>.</p>"
},
{
"textRaw": "`writableStreamDefaultWriter.write([chunk])`",
"type": "method",
"name": "write",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
},
"params": [
{
"textRaw": "`chunk`: {any}",
"name": "chunk",
"type": "any"
}
]
}
],
"desc": "<p>Appends a new chunk of data to the <a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a>'s queue.</p>"
}
],
"properties": [
{
"textRaw": "`closed` Type: {Promise} Fulfilled with `undefined` when the associated {WritableStream} is closed or rejected if the stream errors or the writer's lock is released before the stream finishes closing.",
"type": "Promise",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "Fulfilled with `undefined` when the associated {WritableStream} is closed or rejected if the stream errors or the writer's lock is released before the stream finishes closing."
},
{
"textRaw": "`desiredSize` Type: {number}",
"type": "number",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The amount of data required to fill the <a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a>'s queue.</p>"
},
{
"textRaw": "`ready` type: A promise that is fulfilled with `undefined` when the writer is ready to be used.",
"name": "type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "A promise that is fulfilled with `undefined` when the writer is ready to be used."
}
],
"signatures": [
{
"params": [
{
"textRaw": "`stream` {WritableStream}",
"name": "stream",
"type": "WritableStream"
}
],
"desc": "<p>Creates a new <code>WritableStreamDefaultWriter</code> that is locked to the given\n<code>WritableStream</code>.</p>"
}
]
},
{
"textRaw": "Class: `WritableStreamDefaultController`",
"type": "class",
"name": "WritableStreamDefaultController",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The <code>WritableStreamDefaultController</code> manage's the <a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a>'s\ninternal state.</p>",
"properties": [
{
"textRaw": "`abortReason` Type: {any} The `reason` value passed to `writableStream.abort()`.",
"type": "any",
"name": "Type",
"desc": "The `reason` value passed to `writableStream.abort()`."
},
{
"textRaw": "`signal` Type: {AbortSignal} An `AbortSignal` that can be used to cancel pending write or close operations when a {WritableStream} is aborted.",
"type": "AbortSignal",
"name": "Type",
"desc": "An `AbortSignal` that can be used to cancel pending write or close operations when a {WritableStream} is aborted."
}
],
"methods": [
{
"textRaw": "`writableStreamDefaultController.error(error)`",
"type": "method",
"name": "error",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`error` {any}",
"name": "error",
"type": "any"
}
]
}
],
"desc": "<p>Called by user-code to signal that an error has occurred while processing\nthe <code>WritableStream</code> data. When called, the <a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a> will be aborted,\nwith currently pending writes canceled.</p>"
}
]
},
{
"textRaw": "Class: `TransformStream`",
"type": "class",
"name": "TransformStream",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>A <code>TransformStream</code> consists of a <a href=\"webstreams.html#class-readablestream\" class=\"type\"><ReadableStream></a> and a <a href=\"webstreams.html#class-writablestream\" class=\"type\"><WritableStream></a> that\nare connected such that the data written to the <code>WritableStream</code> is received,\nand potentially transformed, before being pushed into the <code>ReadableStream</code>'s\nqueue.</p>\n<pre><code class=\"language-mjs\">import {\n TransformStream\n} from 'node:stream/web';\n\nconst transform = new TransformStream({\n transform(chunk, controller) {\n controller.enqueue(chunk.toUpperCase());\n }\n});\n\nawait Promise.all([\n transform.writable.getWriter().write('A'),\n transform.readable.getReader().read(),\n]);\n</code></pre>",
"properties": [
{
"textRaw": "`readable` Type: {ReadableStream}",
"type": "ReadableStream",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
}
},
{
"textRaw": "`writable` Type: {WritableStream}",
"type": "WritableStream",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
}
}
],
"modules": [
{
"textRaw": "Transferring with postMessage()",
"name": "transferring_with_postmessage()",
"desc": "<p>A <a href=\"webstreams.html#class-transformstream\" class=\"type\"><TransformStream></a> instance can be transferred using a <a href=\"worker_threads.html#class-messageport\" class=\"type\"><MessagePort></a>.</p>\n<pre><code class=\"language-js\">const stream = new TransformStream();\n\nconst { port1, port2 } = new MessageChannel();\n\nport1.onmessage = ({ data }) => {\n const { writable, readable } = data;\n // ...\n};\n\nport2.postMessage(stream, [stream]);\n</code></pre>",
"type": "module",
"displayName": "Transferring with postMessage()"
}
],
"signatures": [
{
"params": [
{
"textRaw": "`transformer` {Object}",
"name": "transformer",
"type": "Object",
"options": [
{
"textRaw": "`start` {Function} A user-defined function that is invoked immediately when the `TransformStream` is created.",
"name": "start",
"type": "Function",
"desc": "A user-defined function that is invoked immediately when the `TransformStream` is created.",
"options": [
{
"textRaw": "`controller` {TransformStreamDefaultController}",
"name": "controller",
"type": "TransformStreamDefaultController"
},
{
"textRaw": "Returns: `undefined` or a promise fulfilled with `undefined`",
"name": "return",
"desc": "`undefined` or a promise fulfilled with `undefined`"
}
]
},
{
"textRaw": "`transform` {Function} A user-defined function that receives, and potentially modifies, a chunk of data written to `transformStream.writable`, before forwarding that on to `transformStream.readable`.",
"name": "transform",
"type": "Function",
"desc": "A user-defined function that receives, and potentially modifies, a chunk of data written to `transformStream.writable`, before forwarding that on to `transformStream.readable`.",
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "`controller` {TransformStreamDefaultController}",
"name": "controller",
"type": "TransformStreamDefaultController"
},
{
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
}
]
},
{
"textRaw": "`flush` {Function} A user-defined function that is called immediately before the writable side of the `TransformStream` is closed, signaling the end of the transformation process.",
"name": "flush",
"type": "Function",
"desc": "A user-defined function that is called immediately before the writable side of the `TransformStream` is closed, signaling the end of the transformation process.",
"options": [
{
"textRaw": "`controller` {TransformStreamDefaultController}",
"name": "controller",
"type": "TransformStreamDefaultController"
},
{
"textRaw": "Returns: A promise fulfilled with `undefined`.",
"name": "return",
"desc": "A promise fulfilled with `undefined`."
}
]
},
{
"textRaw": "`readableType` {any} the `readableType` option is reserved for future use and _must_ be `undefined`.",
"name": "readableType",
"type": "any",
"desc": "the `readableType` option is reserved for future use and _must_ be `undefined`."
},
{
"textRaw": "`writableType` {any} the `writableType` option is reserved for future use and _must_ be `undefined`.",
"name": "writableType",
"type": "any",
"desc": "the `writableType` option is reserved for future use and _must_ be `undefined`."
}
]
},
{
"textRaw": "`writableStrategy` {Object}",
"name": "writableStrategy",
"type": "Object",
"options": [
{
"textRaw": "`highWaterMark` {number} The maximum internal queue size before backpressure is applied.",
"name": "highWaterMark",
"type": "number",
"desc": "The maximum internal queue size before backpressure is applied."
},
{
"textRaw": "`size` {Function} A user-defined function used to identify the size of each chunk of data.",
"name": "size",
"type": "Function",
"desc": "A user-defined function used to identify the size of each chunk of data.",
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "Returns: {number}",
"name": "return",
"type": "number"
}
]
}
]
},
{
"textRaw": "`readableStrategy` {Object}",
"name": "readableStrategy",
"type": "Object",
"options": [
{
"textRaw": "`highWaterMark` {number} The maximum internal queue size before backpressure is applied.",
"name": "highWaterMark",
"type": "number",
"desc": "The maximum internal queue size before backpressure is applied."
},
{
"textRaw": "`size` {Function} A user-defined function used to identify the size of each chunk of data.",
"name": "size",
"type": "Function",
"desc": "A user-defined function used to identify the size of each chunk of data.",
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "Returns: {number}",
"name": "return",
"type": "number"
}
]
}
]
}
]
}
]
},
{
"textRaw": "Class: `TransformStreamDefaultController`",
"type": "class",
"name": "TransformStreamDefaultController",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The <code>TransformStreamDefaultController</code> manages the internal state\nof the <code>TransformStream</code>.</p>",
"properties": [
{
"textRaw": "`desiredSize` Type: {number}",
"type": "number",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"desc": "<p>The amount of data required to fill the readable side's queue.</p>"
}
],
"methods": [
{
"textRaw": "`transformStreamDefaultController.enqueue([chunk])`",
"type": "method",
"name": "enqueue",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
}
]
}
],
"desc": "<p>Appends a chunk of data to the readable side's queue.</p>"
},
{
"textRaw": "`transformStreamDefaultController.error([reason])`",
"type": "method",
"name": "error",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": [
{
"textRaw": "`reason` {any}",
"name": "reason",
"type": "any"
}
]
}
],
"desc": "<p>Signals to both the readable and writable side that an error has occurred\nwhile processing the transform data, causing both sides to be abruptly\nclosed.</p>"
},
{
"textRaw": "`transformStreamDefaultController.terminate()`",
"type": "method",
"name": "terminate",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"signatures": [
{
"params": []
}
],
"desc": "<p>Closes the readable side of the transport and causes the writable side\nto be abruptly closed with an error.</p>"
}
]
},
{
"textRaw": "Class: `ByteLengthQueuingStrategy`",
"type": "class",
"name": "ByteLengthQueuingStrategy",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"properties": [
{
"textRaw": "`highWaterMark` Type: {number}",
"type": "number",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
}
},
{
"textRaw": "`size` Type: {Function}",
"type": "Function",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "Returns: {number}",
"name": "return",
"type": "number"
}
]
}
],
"signatures": [
{
"params": [
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`highWaterMark` {number}",
"name": "highWaterMark",
"type": "number"
}
]
}
]
}
]
},
{
"textRaw": "Class: `CountQueuingStrategy`",
"type": "class",
"name": "CountQueuingStrategy",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"properties": [
{
"textRaw": "`highWaterMark` Type: {number}",
"type": "number",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
}
},
{
"textRaw": "`size` Type: {Function}",
"type": "Function",
"name": "Type",
"meta": {
"added": [
"v16.5.0"
],
"changes": []
},
"options": [
{
"textRaw": "`chunk` {any}",
"name": "chunk",
"type": "any"
},
{
"textRaw": "Returns: {number}",
"name": "return",
"type": "number"
}
]
}
],
"signatures": [
{
"params": [
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`highWaterMark` {number}",
"name": "highWaterMark",
"type": "number"
}
]
}
]
}
]
},
{
"textRaw": "Class: `TextEncoderStream`",
"type": "class",
"name": "TextEncoderStream",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
},
"properties": [
{
"textRaw": "`encoding` Type: {string}",
"type": "string",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
},
"desc": "<p>The encoding supported by the <code>TextEncoderStream</code> instance.</p>"
},
{
"textRaw": "`readable` Type: {ReadableStream}",
"type": "ReadableStream",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
}
},
{
"textRaw": "`writable` Type: {WritableStream}",
"type": "WritableStream",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
}
}
],
"signatures": [
{
"params": [],
"desc": "<p>Creates a new <code>TextEncoderStream</code> instance.</p>"
}
]
},
{
"textRaw": "Class: `TextDecoderStream`",
"type": "class",
"name": "TextDecoderStream",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
},
"properties": [
{
"textRaw": "`encoding` Type: {string}",
"type": "string",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
},
"desc": "<p>The encoding supported by the <code>TextDecoderStream</code> instance.</p>"
},
{
"textRaw": "`fatal` Type: {boolean}",
"type": "boolean",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
},
"desc": "<p>The value will be <code>true</code> if decoding errors result in a <code>TypeError</code> being\nthrown.</p>"
},
{
"textRaw": "`ignoreBOM` Type: {boolean}",
"type": "boolean",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
},
"desc": "<p>The value will be <code>true</code> if the decoding result will include the byte order\nmark.</p>"
},
{
"textRaw": "`readable` Type: {ReadableStream}",
"type": "ReadableStream",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
}
},
{
"textRaw": "`writable` Type: {WritableStream}",
"type": "WritableStream",
"name": "Type",
"meta": {
"added": [
"v16.6.0"
],
"changes": []
}
}
],
"signatures": [
{
"params": [
{
"textRaw": "`encoding` {string} Identifies the `encoding` that this `TextDecoder` instance supports. **Default:** `'utf-8'`.",
"name": "encoding",
"type": "string",
"default": "`'utf-8'`",
"desc": "Identifies the `encoding` that this `TextDecoder` instance supports."
},
{
"textRaw": "`options` {Object}",
"name": "options",
"type": "Object",
"options": [
{
"textRaw": "`fatal` {boolean} `true` if decoding failures are fatal.",
"name": "fatal",
"type": "boolean",
"desc": "`true` if decoding failures are fatal."
},
{
"textRaw": "`ignoreBOM` {boolean} When `true`, the `TextDecoderStream` will include the byte order mark in the decoded result. When `false`, the byte order mark will be removed from the output. This option is only used when `encoding` is `'utf-8'`, `'utf-16be'`, or `'utf-16le'`. **Default:** `false`.",
"name": "ignoreBOM",
"type": "boolean",
"default": "`false`",
"desc": "When `true`, the `TextDecoderStream` will include the byte order mark in the decoded result. When `false`, the byte order mark will be removed from the output. This option is only used when `encoding` is `'utf-8'`, `'utf-16be'`, or `'utf-16le'`."
}
]
}
],
"desc": "<p>Creates a new <code>TextDecoderStream</code> instance.</p>"
}
]
}
],
"modules": [
{
"textRaw": "Utility Consumers",
"name": "utility_consumers",
"meta": {
"added": [
"v16.7.0"
],
"changes": []
},
"desc": "<p>The utility consumer functions provide common options for consuming\nstreams.</p>\n<p>They are accessed using:</p>\n<pre><code class=\"language-mjs\">import {\n arrayBuffer,\n blob,\n buffer,\n json,\n text,\n} from 'node:stream/consumers';\n</code></pre>\n<pre><code class=\"language-cjs\">const {\n arrayBuffer,\n blob,\n buffer,\n json,\n text,\n} = require('node:stream/consumers');\n</code></pre>",
"methods": [
{
"textRaw": "`streamConsumers.arrayBuffer(stream)`",
"type": "method",
"name": "arrayBuffer",
"meta": {
"added": [
"v16.7.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {Promise} Fulfills with an `ArrayBuffer` containing the full contents of the stream.",
"name": "return",
"type": "Promise",
"desc": "Fulfills with an `ArrayBuffer` containing the full contents of the stream."
},
"params": [
{
"textRaw": "`stream` {ReadableStream|stream.Readable|AsyncIterator}",
"name": "stream",
"type": "ReadableStream|stream.Readable|AsyncIterator"
}
]
}
],
"desc": "<pre><code class=\"language-mjs\">import { buffer as arrayBuffer } from 'node:stream/consumers';\nimport { Readable } from 'node:stream';\nimport { TextEncoder } from 'node:util';\n\nconst encoder = new TextEncoder();\nconst dataArray = encoder.encode('hello world from consumers!');\n\nconst readable = Readable.from(dataArray);\nconst data = await arrayBuffer(readable);\nconsole.log(`from readable: ${data.byteLength}`);\n</code></pre>\n<pre><code class=\"language-cjs\">const { arrayBuffer } = require('node:stream/consumers');\nconst { Readable } = require('stream');\nconst { TextEncoder } = require('util');\n\nconst encoder = new TextEncoder();\nconst dataArray = encoder.encode(['hello world from consumers!']);\nconst readable = Readable.from(dataArray);\narrayBuffer(readable).then((data) => {\n console.log(`from readable: ${data.byteLength}`);\n});\n</code></pre>"
},
{
"textRaw": "`streamConsumers.blob(stream)`",
"type": "method",
"name": "blob",
"meta": {
"added": [
"v16.7.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {Promise} Fulfills with a {Blob} containing the full contents of the stream.",
"name": "return",
"type": "Promise",
"desc": "Fulfills with a {Blob} containing the full contents of the stream."
},
"params": [
{
"textRaw": "`stream` {ReadableStream|stream.Readable|AsyncIterator}",
"name": "stream",
"type": "ReadableStream|stream.Readable|AsyncIterator"
}
]
}
],
"desc": "<pre><code class=\"language-mjs\">import { blob } from 'node:stream/consumers';\n\nconst dataBlob = new Blob(['hello world from consumers!']);\n\nconst readable = dataBlob.stream();\nconst data = await blob(readable);\nconsole.log(`from readable: ${data.size}`);\n</code></pre>\n<pre><code class=\"language-cjs\">const { blob } = require('node:stream/consumers');\n\nconst dataBlob = new Blob(['hello world from consumers!']);\n\nconst readable = dataBlob.stream();\nblob(readable).then((data) => {\n console.log(`from readable: ${data.size}`);\n});\n</code></pre>"
},
{
"textRaw": "`streamConsumers.buffer(stream)`",
"type": "method",
"name": "buffer",
"meta": {
"added": [
"v16.7.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {Promise} Fulfills with a {Buffer} containing the full contents of the stream.",
"name": "return",
"type": "Promise",
"desc": "Fulfills with a {Buffer} containing the full contents of the stream."
},
"params": [
{
"textRaw": "`stream` {ReadableStream|stream.Readable|AsyncIterator}",
"name": "stream",
"type": "ReadableStream|stream.Readable|AsyncIterator"
}
]
}
],
"desc": "<pre><code class=\"language-mjs\">import { buffer } from 'node:stream/consumers';\nimport { Readable } from 'node:stream';\nimport { Buffer } from 'node:buffer';\n\nconst dataBuffer = Buffer.from('hello world from consumers!');\n\nconst readable = Readable.from(dataBuffer);\nconst data = await buffer(readable);\nconsole.log(`from readable: ${data.length}`);\n</code></pre>\n<pre><code class=\"language-cjs\">const { buffer } = require('node:stream/consumers');\nconst { Readable } = require('node:stream');\nconst { Buffer } = require('node:buffer');\n\nconst dataBuffer = Buffer.from('hello world from consumers!');\n\nconst readable = Readable.from(dataBuffer);\nbuffer(readable).then((data) => {\n console.log(`from readable: ${data.length}`);\n});\n</code></pre>"
},
{
"textRaw": "`streamConsumers.json(stream)`",
"type": "method",
"name": "json",
"meta": {
"added": [
"v16.7.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {Promise} Fulfills with the contents of the stream parsed as a UTF-8 encoded string that is then passed through `JSON.parse()`.",
"name": "return",
"type": "Promise",
"desc": "Fulfills with the contents of the stream parsed as a UTF-8 encoded string that is then passed through `JSON.parse()`."
},
"params": [
{
"textRaw": "`stream` {ReadableStream|stream.Readable|AsyncIterator}",
"name": "stream",
"type": "ReadableStream|stream.Readable|AsyncIterator"
}
]
}
],
"desc": "<pre><code class=\"language-mjs\">import { json } from 'node:stream/consumers';\nimport { Readable } from 'node:stream';\n\nconst items = Array.from(\n {\n length: 100\n },\n () => ({\n message: 'hello world from consumers!'\n })\n);\n\nconst readable = Readable.from(JSON.stringify(items));\nconst data = await json(readable);\nconsole.log(`from readable: ${data.length}`);\n</code></pre>\n<pre><code class=\"language-cjs\">const { json } = require('node:stream/consumers');\nconst { Readable } = require('node:stream');\n\nconst items = Array.from(\n {\n length: 100\n },\n () => ({\n message: 'hello world from consumers!'\n })\n);\n\nconst readable = Readable.from(JSON.stringify(items));\njson(readable).then((data) => {\n console.log(`from readable: ${data.length}`);\n});\n</code></pre>"
},
{
"textRaw": "`streamConsumers.text(stream)`",
"type": "method",
"name": "text",
"meta": {
"added": [
"v16.7.0"
],
"changes": []
},
"signatures": [
{
"return": {
"textRaw": "Returns: {Promise} Fulfills with the contents of the stream parsed as a UTF-8 encoded string.",
"name": "return",
"type": "Promise",
"desc": "Fulfills with the contents of the stream parsed as a UTF-8 encoded string."
},
"params": [
{
"textRaw": "`stream` {ReadableStream|stream.Readable|AsyncIterator}",
"name": "stream",
"type": "ReadableStream|stream.Readable|AsyncIterator"
}
]
}
],
"desc": "<pre><code class=\"language-mjs\">import { json, text, blob, buffer } from 'node:stream/consumers';\nimport { Readable } from 'node:stream';\n\nconst readable = Readable.from('Hello world from consumers!');\nconst data = await text(readable);\nconsole.log(`from readable: ${data.length}`);\n</code></pre>\n<pre><code class=\"language-cjs\">const { text } = require('node:stream/consumers');\nconst { Readable } = require('node:stream');\n\nconst readable = Readable.from('Hello world from consumers!');\ntext(readable).then((data) => {\n console.log(`from readable: ${data.length}`);\n});\n</code></pre>"
}
],
"type": "module",
"displayName": "Utility Consumers"
}
],
"type": "module",
"displayName": "API"
}
],
"type": "module",
"displayName": "Web Streams API"
}
]
}