autosnippet
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Extract code patterns into a knowledge base for AI coding assistants
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JavaScript
/**
* ConversationStore — 对话持久化 + 上下文窗口管理
*
* 设计:
* - 每个对话一个 JSONL 文件: .autosnippet/conversations/{id}.jsonl
* - 索引文件: .autosnippet/conversations/index.json
* - 按 category 隔离: 'user'(Dashboard) / 'system'(SignalCollector)
* - Token 预算: 超限时自动生成摘要压缩旧轮次
* - 静默降级: 持久化失败不影响核心功能
*
* Token 计算策略:
* 采用字符数近似估算 (1 token ≈ 3.5 字符中文 / ≈ 4 字符英文)
* 简单高效，无需额外依赖
*
* 文件结构:
* .autosnippet/conversations/
* index.json — 对话元数据索引
* {id}.jsonl — 每行一条消息 {role, content, ts}
*/
import crypto from 'node:crypto';
import fs from 'node:fs';
import path from 'node:path';
import Logger from '#infra/logging/Logger.js';
import pathGuard from '#shared/PathGuard.js';
import { estimateTokens as _estimateTokens } from '#shared/token-utils.js';
const DEFAULT_TOKEN_BUDGET = 12000; // ~12K tokens 留给历史, 其余给系统提示词和当前消息
const MAX_CONVERSATIONS = 100; // 索引最多保留 100 个对话
const _SUMMARY_TARGET_TOKENS = 500; // 压缩后的摘要目标 token 数
export class ConversationStore {
#dir;
#indexPath;
#logger;
/** @param projectRoot 用户项目根目录 */
constructor(projectRoot) {
this.#dir = path.join(projectRoot, '.autosnippet', 'conversations');
this.#indexPath = path.join(this.#dir, 'index.json');
this.#logger = Logger.getInstance();
// 路径安全检查
pathGuard.assertProjectWriteSafe(this.#dir);
}
// ═══════════════════════════════════════════════════════
// 公共 API
// ═══════════════════════════════════════════════════════
/**
* 创建新对话
* @param opts.category 对话类别
* @param [opts.title] 对话标题
* @returns conversationId
*/
create({ category = 'user', title = '' } = {}) {
const id = crypto.randomUUID();
const entry = {
id,
category,
title,
createdAt: new Date().toISOString(),
updatedAt: new Date().toISOString(),
messageCount: 0,
hasSummary: false,
};
const index = this.#loadIndex();
index.unshift(entry);
// 限制索引大小
if (index.length > MAX_CONVERSATIONS) {
const removed = index.splice(MAX_CONVERSATIONS);
// 清理旧对话文件
for (const old of removed) {
this.#deleteConversationFile(old.id);
}
}
this.#saveIndex(index);
return id;
}
/**
* 追加消息到对话
* @param message
*/
append(conversationId, message) {
try {
fs.mkdirSync(this.#dir, { recursive: true });
const filePath = this.#conversationPath(conversationId);
const line = JSON.stringify({
role: message.role,
content: message.content,
ts: new Date().toISOString(),
});
fs.appendFileSync(filePath, `${line}\n`, 'utf-8');
// 更新索引
const index = this.#loadIndex();
const entry = index.find((e) => e.id === conversationId);
if (entry) {
entry.updatedAt = new Date().toISOString();
entry.messageCount = (entry.messageCount || 0) + 1;
// 用首条用户消息作为标题
if (!entry.title && message.role === 'user') {
entry.title = message.content.substring(0, 60);
}
this.#saveIndex(index);
}
}
catch (err) {
this.#logger.warn(`[ConversationStore] append failed: ${err.message}`);
}
}
/**
* 加载对话历史（带 token 预算控制）
*
* 如果历史超出 tokenBudget:
* - 保留开头的摘要（如有）
* - 截断中间的旧消息
* - 保留最新的消息
*
* @param [opts.tokenBudget] token 预算
* @returns []}
*/
load(conversationId, { tokenBudget = DEFAULT_TOKEN_BUDGET } = {}) {
try {
const filePath = this.#conversationPath(conversationId);
if (!fs.existsSync(filePath)) {
return [];
}
const raw = fs.readFileSync(filePath, 'utf-8').trim();
if (!raw) {
return [];
}
const messages = raw
.split('\n')
.filter(Boolean)
.map((line) => {
try {
const parsed = JSON.parse(line);
return { role: parsed.role, content: parsed.content };
}
catch {
return null;
}
})
.filter((m) => m !== null);
return this.#fitWithinBudget(messages, tokenBudget);
}
catch {
return [];
}
}
/**
* 对话列表
* @param [opts.category] 按类别过滤
*/
list({ category, limit = 20 } = {}) {
const index = this.#loadIndex();
let results = index;
if (category) {
results = results.filter((e) => e.category === category);
}
return results.slice(0, limit);
}
/** 删除对话 */
delete(conversationId) {
this.#deleteConversationFile(conversationId);
const index = this.#loadIndex();
const filtered = index.filter((e) => e.id !== conversationId);
this.#saveIndex(filtered);
}
/**
* 为对话生成压缩摘要（需要 AI）
* 将旧消息替换为一条 system 摘要消息
*
* @param opts.aiProvider AI Provider 实例
* @returns 是否成功压缩
*/
async summarize(conversationId, { aiProvider }) {
if (!aiProvider) {
return false;
}
try {
const filePath = this.#conversationPath(conversationId);
if (!fs.existsSync(filePath)) {
return false;
}
const raw = fs.readFileSync(filePath, 'utf-8').trim();
if (!raw) {
return false;
}
const messages = raw
.split('\n')
.filter(Boolean)
.map((line) => {
try {
return JSON.parse(line);
}
catch {
return null;
}
})
.filter(Boolean);
if (messages.length < 6) {
return false; // 太短不需要压缩
}
// 保留最近 4 条消息，压缩其余
const toSummarize = messages.slice(0, -4);
const toKeep = messages.slice(-4);
const summaryPrompt = `请用 2-3 句话总结以下对话的要点（保留关键决策、用户偏好、操作结果）：\n\n${toSummarize
.map((m) => `[${m.role}] ${m.content}`)
.join('\n')
.substring(0, 4000)}`;
const summary = await aiProvider.chat(summaryPrompt, {
temperature: 0.3,
maxTokens: 300,
});
if (!summary) {
return false;
}
// 重写对话文件: 摘要 + 最近消息
const newMessages = [
{ role: 'system', content: `[对话摘要] ${summary.trim()}`, ts: new Date().toISOString() },
...toKeep,
];
fs.writeFileSync(filePath, `${newMessages.map((m) => JSON.stringify(m)).join('\n')}\n`, 'utf-8');
// 更新索引
const index = this.#loadIndex();
const entry = index.find((e) => e.id === conversationId);
if (entry) {
entry.hasSummary = true;
entry.messageCount = newMessages.length;
this.#saveIndex(index);
}
this.#logger.info(`[ConversationStore] summarized conversation ${conversationId}: ${messages.length} → ${newMessages.length} messages`);
return true;
}
catch (err) {
this.#logger.warn(`[ConversationStore] summarize failed: ${err.message}`);
return false;
}
}
/**
* 清理过期对话
* @param [opts.maxAgeDays=30] 超过此天数的对话将被删除
* @param [opts.category] 只清理特定类别
* @returns }
*/
cleanup({ maxAgeDays = 30, category, } = {}) {
const index = this.#loadIndex();
const cutoff = Date.now() - maxAgeDays * 86400000;
let deleted = 0;
const kept = index.filter((entry) => {
if (category && entry.category !== category) {
return true;
}
const updatedAt = new Date(entry.updatedAt).getTime();
if (updatedAt < cutoff) {
this.#deleteConversationFile(entry.id);
deleted++;
return false;
}
return true;
});
if (deleted > 0) {
this.#saveIndex(kept);
this.#logger.info(`[ConversationStore] cleaned up ${deleted} old conversations`);
}
return { deleted };
}
/** 估算 token 数 — 委托给共享 token-utils（CJK 感知） */
estimateTokens(text) {
return _estimateTokens(text);
}
// ═══════════════════════════════════════════════════════
// 内部方法
// ═══════════════════════════════════════════════════════
/**
* 将消息列表裁剪到 token 预算内
* 策略: 保留首条摘要(如有) + 最新消息，丢弃中间旧消息
*/
#fitWithinBudget(messages, tokenBudget) {
if (messages.length === 0) {
return [];
}
// 计算总 token
let totalTokens = 0;
const tokenCounts = messages.map((m) => {
const tokens = this.estimateTokens(m.content);
totalTokens += tokens;
return tokens;
});
if (totalTokens <= tokenBudget) {
return messages;
}
// 超预算 — 保留首条(摘要) + 从末尾往前取
const result = [];
let used = 0;
// 如果首条是 system 摘要，优先保留
if (messages[0].role === 'system' && messages[0].content.startsWith('[对话摘要]')) {
result.push(messages[0]);
used += tokenCounts[0];
}
// 从末尾往前填充
const tail = [];
for (let i = messages.length - 1; i >= (result.length > 0 ? 1 : 0); i--) {
if (used + tokenCounts[i] > tokenBudget) {
break;
}
tail.unshift(messages[i]);
used += tokenCounts[i];
}
// 如果丢弃了消息，插入提示
const keptFromStart = result.length;
const keptFromEnd = tail.length;
const dropped = messages.length - keptFromStart - keptFromEnd;
if (dropped > 0) {
result.push({
role: 'system',
content: `[上下文截断] 省略了 ${dropped} 条较早的消息以适应上下文窗口。`,
});
}
result.push(...tail);
return result;
}
#conversationPath(id) {
return path.join(this.#dir, `${id}.jsonl`);
}
#deleteConversationFile(id) {
try {
const filePath = this.#conversationPath(id);
if (fs.existsSync(filePath)) {
fs.unlinkSync(filePath);
}
}
catch {
/* ignore */
}
}
#loadIndex() {
try {
if (fs.existsSync(this.#indexPath)) {
return JSON.parse(fs.readFileSync(this.#indexPath, 'utf-8'));
}
}
catch {
/* corrupt — reset */
}
return [];
}
#saveIndex(index) {
try {
fs.mkdirSync(this.#dir, { recursive: true });
fs.writeFileSync(this.#indexPath, JSON.stringify(index, null, 2), 'utf-8');
}
catch (err) {
this.#logger.warn(`[ConversationStore] index save failed: ${err.message}`);
}
}
}
export default ConversationStore;