nsgm-cli
Version:
A CLI tool to run Next/Style-components and Graphql/Mysql fullstack project
222 lines (197 loc) • 7.09 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.DataLoaderGenerator = void 0;
const base_generator_1 = require("./base-generator");
/**
* DataLoader生成器
* 自动生成对应的 DataLoader 文件
*/
class DataLoaderGenerator extends base_generator_1.BaseGenerator {
generate() {
const capitalizedController = this.getCapitalizedController();
const selectFields = this.fields.map((f) => f.name).join(", ");
// const searchableFields = this.getSearchableFields(); // 暂时注释掉未使用的变量
return `import DataLoader from 'dataloader';
import { executeQuery } from '../utils/common';
/**
* ${capitalizedController} DataLoader
* 针对 ${this.controller} 表的批量数据加载器，解决 N+1 查询问题
*/
export class ${capitalizedController}DataLoader {
// 按 ID 批量加载 ${this.controller}
public readonly byId: DataLoader<number, any>;
// 按名称批量加载 ${this.controller}
public readonly byName: DataLoader<string, any>;
// 按名称模糊搜索 ${this.controller}
public readonly searchByName: DataLoader<string, any[]>;
constructor() {
// 按 ID 批量加载
this.byId = new DataLoader(
async (ids: readonly number[]) => {
try {
console.log(\`🔍 DataLoader: 批量加载 \${ids.length} 个 ${this.controller} by ID\`);
const placeholders = ids.map(() => '?').join(',');
const sql = \`SELECT ${selectFields} FROM ${this.controller} WHERE id IN (\${placeholders})\`;
const results = await executeQuery(sql, [...ids]);
// 确保返回顺序与输入 keys 一致，未找到的返回 null
return ids.map(id =>
results.find((row: any) => row.id === id) || null
);
} catch (error) {
console.error('DataLoader byId 批量加载失败:', error);
throw error;
}
},
{
cache: true,
maxBatchSize: 100,
batchScheduleFn: callback => setTimeout(callback, 10), // 10ms 内的请求合并
}
);
// 按名称批量加载
this.byName = new DataLoader(
async (names: readonly string[]) => {
try {
console.log(\`🔍 DataLoader: 批量加载 \${names.length} 个 ${this.controller} by name\`);
const placeholders = names.map(() => '?').join(',');
const sql = \`SELECT ${selectFields} FROM ${this.controller} WHERE name IN (\${placeholders})\`;
const results = await executeQuery(sql, [...names]);
// 确保返回顺序与输入 keys 一致
return names.map(name =>
results.find((row: any) => row.name === name) || null
);
} catch (error) {
console.error('DataLoader byName 批量加载失败:', error);
throw error;
}
},
{
cache: true,
maxBatchSize: 50,
batchScheduleFn: callback => setTimeout(callback, 10),
}
);
// 按名称模糊搜索（返回数组）
this.searchByName = new DataLoader(
async (searchTerms: readonly string[]) => {
try {
console.log(\`🔍 DataLoader: 批量搜索 \${searchTerms.length} 个关键词\`);
// 对于搜索，我们需要为每个搜索词执行独立的查询
const results = await Promise.all(
searchTerms.map(async (term) => {
const sql = 'SELECT ${selectFields} FROM ${this.controller} WHERE name LIKE ?';
return executeQuery(sql, [\`%\${term}%\`]);
})
);
return results;
} catch (error) {
console.error('DataLoader searchByName 批量搜索失败:', error);
throw error;
}
},
{
cache: true,
maxBatchSize: 20, // 搜索请求较少，降低批量大小
batchScheduleFn: callback => setTimeout(callback, 20), // 稍长的等待时间
}
);
${this.generateForeignKeyLoaders()}
}
/**
* 清除所有缓存
*/
clearAll(): void {
this.byId.clearAll();
this.byName.clearAll();
this.searchByName.clearAll();
console.log('🧹 ${capitalizedController} DataLoader 缓存已清空');
}
/**
* 清除特定 ID 的缓存
*/
clearById(id: number): void {
this.byId.clear(id);
}
/**
* 清除特定名称的缓存
*/
clearByName(name: string): void {
this.byName.clear(name);
}
/**
* 预加载数据到缓存
*/
prime(id: number, data: any): void {
this.byId.prime(id, data);
if (data && data.name) {
this.byName.prime(data.name, data);
}
}
/**
* 获取缓存统计信息
*/
getStats() {
return {
byId: {
cacheMap: this.byId.cacheMap?.size || 0,
name: '${capitalizedController}.byId'
},
byName: {
cacheMap: this.byName.cacheMap?.size || 0,
name: '${capitalizedController}.byName'
},
searchByName: {
cacheMap: this.searchByName.cacheMap?.size || 0,
name: '${capitalizedController}.searchByName'
}
};
}
}
/**
* 创建 ${capitalizedController} DataLoader 实例
*/
export function create${capitalizedController}DataLoader(): ${capitalizedController}DataLoader {
return new ${capitalizedController}DataLoader();
}`;
}
/**
* 生成外键 DataLoader
*/
generateForeignKeyLoaders() {
const foreignKeys = this.fields.filter((f) => f.name.endsWith("_id") && f.name !== "id");
if (foreignKeys.length === 0) {
return "";
}
return foreignKeys
.map((fk) => {
const relatedTable = fk.name.replace("_id", "");
const capitalizedRelated = relatedTable.charAt(0).toUpperCase() + relatedTable.slice(1);
return `
// 按 ${fk.name} 批量加载相关的 ${this.controller}
this.by${capitalizedRelated}Id = new DataLoader(
async (${fk.name}s: readonly number[]) => {
try {
console.log(\`🔍 DataLoader: 批量加载 \${${fk.name}s.length} 个 ${this.controller} by ${fk.name}\`);
const placeholders = ${fk.name}s.map(() => '?').join(',');
const sql = \`SELECT ${this.fields.map((f) => f.name).join(", ")} FROM ${this.controller} WHERE ${fk.name} IN (\${placeholders})\`;
const results = await executeQuery(sql, [...${fk.name}s]);
// 按外键分组
return ${fk.name}s.map(${fk.name} =>
results.filter((row: any) => row.${fk.name} === ${fk.name})
);
} catch (error) {
console.error('DataLoader by${capitalizedRelated}Id 批量加载失败:', error);
throw error;
}
},
{
cache: true,
maxBatchSize: 50,
batchScheduleFn: callback => setTimeout(callback, 10),
}
);`;
})
.join("\n");
}
}
exports.DataLoaderGenerator = DataLoaderGenerator;