Stream.shareSyncProtocol

• 值：Symbol.for('Stream.shareSyncProtocol')

该值必须是一个函数。当被 SyncShare.fromSync() 调用时，它会接收到传递给 SyncShare.fromSync() 的选项，并且必须返回一个符合 SyncShare 接口的对象。实现完全自定义——它可以按照自己的方式管理共享源、消费者和缓冲。

🌐 The value must be a function. When called by SyncShare.fromSync(), it receives the options passed to SyncShare.fromSync() and must return an object conforming to the SyncShare interface. The implementation is fully custom -- it can manage the shared source, consumers, and buffering however it wants.

import { shareSync, SyncShare, textSync } from 'node:stream/iter';

// This example defers to the built-in shareSync(), but a custom
// implementation could use any mechanism.
class SyncDataPool {
  #share;

  constructor(source) {
    this.#share = shareSync(source);
  }

  [Symbol.for('Stream.shareSyncProtocol')](options) {
    return this.#share;
  }
}

const encoder = new TextEncoder();
const pool = new SyncDataPool(
  function* () {
    yield [encoder.encode('hello')];
  }(),
);

const shared = SyncShare.fromSync(pool);
const consumer = shared.pull();
console.log(textSync(consumer)); // 'hello'const { shareSync, SyncShare, textSync } = require('node:stream/iter');

// This example defers to the built-in shareSync(), but a custom
// implementation could use any mechanism.
class SyncDataPool {
  #share;

  constructor(source) {
    this.#share = shareSync(source);
  }

  [Symbol.for('Stream.shareSyncProtocol')](options) {
    return this.#share;
  }
}

const encoder = new TextEncoder();
const pool = new SyncDataPool(
  function* () {
    yield [encoder.encode('hello')];
  }(),
);

const shared = SyncShare.fromSync(pool);
const consumer = shared.pull();
console.log(textSync(consumer)); // 'hello'拷贝