怎么获取应用已使用的缓存大小，如何使用api清理缓存

import fs from ‘@ohos.file.fs’; 
let cacheDir = context.cacheDir; 
@Entry 
@Component 
struct Clear_cache { 
clearCache() { 
// let cacheDir = getContext(this).cacheDir 
// fs.rmdirSync(cacheDir) 
// console.log(“delete !!!”) 
  
fs.listFile(cacheDir).then((filenames) => { 
for (let i = 0;i < filenames.length; i++) { 
// let dirPath = cacheDir+filenames[i] 
let dirPath = ${cacheDir}/${filenames[i]} 
// 判断是否文件夹 
let isDirectory 
try { 
isDirectory = fs.statSync(dirPath).isDirectory() 
} 
catch (e) { 
console.log(e) 
} 
  
if (isDirectory) { 
fs.rmdirSync(dirPath) 
} else { 
fs.unlink(dirPath).then(() => { 
console.info(“remove file succeed”); 
}).catch((err) => { 
console.info("remove file failed with error message: " + err.message + ", error code: " + err.code); 
}); 
} 
} 
  
}) 
} 
}