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