SseWriter

SUPPORT · interface · 类型合同

Destination that reports backpressure instead of buffering without bound.

导入

TypeScript

import type { SseWriter } from '@jangts/agent-core/sse';

JavaScript

/** @typedef {import('@jangts/agent-core/sse').SseWriter} SseWriter */

其他公开入口：@jangts/agent-core、@jangts/agent-core/types、@jangts/agent-core/structs、@jangts/agent-core/sse、@jangts/agent-core/support。

定义

interface SseWriter

字段结构

字段	类型	必需	说明
write	(frame: string) => boolean	必需	Writes one encoded frame; returns false when the consumer needs a drain wait.
waitForDrain	(signal?: AbortSignal) => Promise<unknown>	必需	Resolves once the destination can accept more data, or rejects when signal aborts.

成员目录

成员	用途
write	Writes one encoded frame; returns false when the consumer needs a drain wait.
waitForDrain	Resolves once the destination can accept more data, or rejects when signal aborts.

成员详情

write

Writes one encoded frame; returns false when the consumer needs a drain wait.

SseWriter.write(frame: string): boolean

Writes one encoded frame; returns false when the consumer needs a drain wait.

参数	类型	传递	说明
frame	string	必需	—

返回： boolean。

waitForDrain

Resolves once the destination can accept more data, or rejects when signal aborts.

SseWriter.waitForDrain(signal?: AbortSignal): Promise<unknown>

Resolves once the destination can accept more data, or rejects when signal aborts.

参数	类型	传递	说明
signal	AbortSignal | undefined	可省略	—

返回： Promise<unknown>。

等待后的值： unknown。

使用示例

• SSE、JSON 帧与有界事件流：复用传输机制，保持取消和背压；协议解析与业务校验仍各自负责。

在本地解析一帧 SSE

入门 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
const frame = Support.encodeSseEvent({ event: 'status', data: JSON.stringify({ phase: 'thinking' }) });
const body = new Response(frame).body!;
for await (const event of Support.readSse(body)) console.log(event.event, event.data);

JavaScript

import { Support } from '@jangts/agent-core';
const frame = Support.encodeSseEvent({ event: 'status', data: JSON.stringify({ phase: 'thinking' }) });
const body = new Response(frame).body;
for await (const event of Support.readSse(body))
    console.log(event.event, event.data);

生产者等待每一次事件交付

配置 · Node.js

TypeScript

import { Support } from '@jangts/agent-core';
const signal = new AbortController().signal;
const stream = Support.streamEvents<{ phase: string }>(async emit => {
  await emit({ phase: 'preparing' });
  await emit({ phase: 'complete' });
}, { signal });
for await (const event of stream) console.log(event.phase);

JavaScript

import { Support } from '@jangts/agent-core';
const signal = new AbortController().signal;
const stream = Support.streamEvents(async (emit) => {
    await emit({ phase: 'preparing' });
    await emit({ phase: 'complete' });
}, { signal });
for await (const event of stream)
    console.log(event.phase);

相关策略源码

• 事件流单槽交接与背压