new stream.Writable([options])

• options <Object>

  • highWaterMark <number> stream.write() 开始返回 false 时的缓冲级别。默认值:65536 (64 KiB),或 16 用于 objectMode 流。

    \highWaterMark <number> Buffer level when stream.write() starts returning false. Default: 65536 (64 KiB), or 16 for objectMode streams.

  • decodeStrings <boolean> 是否将传递给 stream.write() 的 string 编码为 Buffer(使用 stream.write() 调用中指定的编码),然后再将它们传递给 stream._write()。不转换其他类型的数据(即 Buffer 不解码为 string)。设置为 false 将阻止 string 被转换。默认值:true。

    \decodeStrings <boolean> Whether to encode strings passed to stream.write() to Buffers (with the encoding specified in the stream.write() call) before passing them to stream._write(). Other types of data are not converted (i.e. Buffers are not decoded into strings). Setting to false will prevent strings from being converted. Default: true.

  • defaultEncoding <string> 当没有将编码指定为 stream.write() 的参数时使用的默认编码。默认值:'utf8'。

    \defaultEncoding <string> The default encoding that is used when no encoding is specified as an argument to stream.write(). Default: 'utf8'.

  • objectMode <boolean> stream.write(anyObj) 是否为有效操作。设置后,如果流实现支持,则可以写入除字符串、<Buffer>、<TypedArray> 或 <DataView> 之外的 JavaScript 值。默认值:false。

    \objectMode <boolean> Whether or not the stream.write(anyObj) is a valid operation. When set, it becomes possible to write JavaScript values other than string, <Buffer>, <TypedArray> or <DataView> if supported by the stream implementation. Default: false.

  • emitClose <boolean> 流被销毁后是否应该触发 'close'。默认值:true。

    \emitClose <boolean> Whether or not the stream should emit 'close' after it has been destroyed. Default: true.

  • write <Function> stream._write() 方法的实现。

    \write <Function> Implementation for the stream._write() method.

  • writev <Function> stream._writev() 方法的实现。

    \writev <Function> Implementation for the stream._writev() method.

  • destroy <Function> stream._destroy() 方法的实现。

    \destroy <Function> Implementation for the stream._destroy() method.

  • final <Function> stream._final() 方法的实现。

    \final <Function> Implementation for the stream._final() method.

  • construct <Function> stream._construct() 方法的实现。

    \construct <Function> Implementation for the stream._construct() method.

  • autoDestroy <boolean> 此流是否应在结束后自动调用自身的 .destroy()。默认值:true。

    \autoDestroy <boolean> Whether this stream should automatically call .destroy() on itself after ending. Default: true.

  • signal <AbortSignal> 表示可能取消的信号。

    \signal <AbortSignal> A signal representing possible cancellation.

const { Writable } = require('node:stream');
class MyWritable extends Writable {
 constructor(options) {
 // Calls the stream.Writable() constructor.
 super(options);
 // ...
 }
} 拷贝

或者,当使用 ES6 之前的样式构造函数时:

\Or, when using pre-ES6 style constructors:

const { Writable } = require('node:stream');
const util = require('node:util');
function MyWritable(options) {
 if (!(this instanceof MyWritable))
 return new MyWritable(options);
 Writable.call(this, options);
}
util.inherits(MyWritable, Writable); 拷贝

或者,使用简化的构造函数方法:

\Or, using the simplified constructor approach:

const { Writable } = require('node:stream');
const myWritable = new Writable({
 write(chunk, encoding, callback) {
 // ...
 },
 writev(chunks, callback) {
 // ...
 },
}); 拷贝

在对应于传递的 AbortSignal 的 AbortController 上调用 abort 的行为方式与在可写流上调用 .destroy(new AbortError()) 的方式相同。

\Calling abort on the AbortController corresponding to the passed AbortSignal will behave the same way as calling .destroy(new AbortError()) on the writeable stream.

const { Writable } = require('node:stream');
const controller = new AbortController();
const myWritable = new Writable({
 write(chunk, encoding, callback) {
 // ...
 },
 writev(chunks, callback) {
 // ...
 },
 signal: controller.signal,
});
// Later, abort the operation closing the stream
controller.abort(); 拷贝