121 lines
4.3 KiB
JavaScript
121 lines
4.3 KiB
JavaScript
// 以流式方式请求LLM大模型接口，并打印流式返回内容
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async function requestLLMStream({ apiKey, model, messages, onSegment }) {
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const response = await fetch('https://ark.cn-beijing.volces.com/api/v3/bots/chat/completions', {
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method: 'POST',
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headers: {
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'Authorization': `Bearer ${apiKey}`,
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'Content-Type': 'application/json',
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'Accept': 'text/event-stream',
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'Cache-Control': 'no-cache',
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},
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body: JSON.stringify({
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model,
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stream: true,
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stream_options: { include_usage: true },
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messages,
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}),
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});
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if (!response.ok) {
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throw new Error(`HTTP error! status: ${response.status}`);
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}
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const reader = response.body.getReader();
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const decoder = new TextDecoder('utf-8');
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let done = false;
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let buffer = '';
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let content = '';
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let pendingText = ''; // 待处理的文本片段
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// 分段分隔符
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const segmentDelimiters = /[，。：；！？,.:;!?]/;
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while (!done) {
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const { value, done: doneReading } = await reader.read();
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done = doneReading;
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if (value) {
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const chunk = decoder.decode(value, { stream: true });
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buffer += chunk;
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// 处理SSE格式的数据
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const lines = buffer.split('\n');
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buffer = lines.pop(); // 最后一行可能是不完整的，留到下次
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for (const line of lines) {
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if (!line.trim()) continue;
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// 检查是否是SSE格式的数据行
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if (line.startsWith('data:')) {
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const jsonStr = line.substring(5).trim(); // 移除 'data:' 前缀
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if (jsonStr === '[DONE]') {
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console.log('LLM SSE流结束');
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// 处理最后的待处理文本（无论长度是否大于5个字）
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if (pendingText.trim() && onSegment) {
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console.log('处理最后的待处理文本:', pendingText.trim());
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await onSegment(pendingText.trim(), true);
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}
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continue;
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}
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try {
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const obj = JSON.parse(jsonStr);
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if (obj.choices && obj.choices[0] && obj.choices[0].delta && obj.choices[0].delta.content) {
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const deltaContent = obj.choices[0].delta.content;
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content += deltaContent;
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pendingText += deltaContent;
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console.log('LLM内容片段:', deltaContent);
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// 检查是否包含分段分隔符
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if (segmentDelimiters.test(pendingText)) {
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// 按分隔符分割文本
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const segments = pendingText.split(segmentDelimiters);
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// 重新组合处理：只处理足够长的完整段落
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let accumulatedText = '';
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let hasProcessed = false;
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for (let i = 0; i < segments.length - 1; i++) {
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const segment = segments[i].trim();
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if (segment) {
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accumulatedText += segment;
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// 找到分隔符
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const delimiterMatch = pendingText.match(segmentDelimiters);
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if (delimiterMatch) {
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accumulatedText += delimiterMatch[0];
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}
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// 如果累积文本长度大于5个字，处理它
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if (accumulatedText.length > 6 && onSegment) {
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console.log('检测到完整段落:', accumulatedText);
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await onSegment(accumulatedText, false);
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hasProcessed = true;
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accumulatedText = ''; // 重置
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}
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}
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}
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// 更新pendingText
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if (hasProcessed) {
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// 保留未处理的累积文本和最后一个不完整段落
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pendingText = accumulatedText + (segments[segments.length - 1] || '');
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}
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}
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}
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} catch (e) {
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console.error('解析LLM SSE数据失败:', e, '原始数据:', jsonStr);
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}
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} else if (line.startsWith('event: ') || line.startsWith('id: ') || line.startsWith('retry: ')) {
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// 忽略SSE的其他字段
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continue;
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}
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}
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}
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}
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// 返回完整内容
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return content;
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}
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export { requestLLMStream }; |