36 lines
1.5 KiB
TypeScript
36 lines
1.5 KiB
TypeScript
// 不自动运行（Next.js 路由处理器，npm run dev 后 POST /api/chat）
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// 服务端调用大模型并以流的形式返回；模型密钥只在服务端，浏览器拿不到。
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export const runtime = "nodejs";
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async function* fakeLLM(question: string, signal: AbortSignal): AsyncGenerator<string> {
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// 真实项目：调用模型 SDK 的流式接口，并把 signal 传进去
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const words = `关于“${question}”：签收 7 天内可以无理由退货。`.split("");
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for (const w of words) {
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if (signal.aborted) return; // 用户停止或断开：不再继续生成（节省费用）
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await new Promise((r) => setTimeout(r, 30));
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yield w;
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}
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}
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export async function POST(request: Request): Promise<Response> {
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const { question } = (await request.json()) as { question?: unknown };
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if (typeof question !== "string" || question.length === 0 || question.length > 500) {
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return Response.json({ error: "question 必须是 1~500 字的字符串" }, { status: 400 });
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}
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const encoder = new TextEncoder();
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const stream = new ReadableStream<Uint8Array>({
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async start(controller) {
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try {
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for await (const token of fakeLLM(question, request.signal)) {
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controller.enqueue(encoder.encode(token));
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}
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} finally {
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controller.close();
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}
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},
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});
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return new Response(stream, {
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headers: { "Content-Type": "text/plain; charset=utf-8", "Cache-Control": "no-cache", "X-Accel-Buffering": "no" },
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});
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}
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