js storage 存储大小测试

 1 function env(strategy) {
 2     const _strategy = window[strategy];
 3     function getStr(size) {
 4         return Array(size + 1).join("1");
 5     }
 6 
 7     function test(pieces, size) {
 8         let count = 0,
 9             piece = pieces.shift(),
10             trySize = size;
11         if (pieces.length) {
12             try {
13                 while (true) {
14                     trySize = size + (count + 1) * piece;
15                     _strategy.setItem(`${strategy}:test`, getStr(trySize));
16                     count++;
17                 }
18             } catch (err) {
19                 return test(pieces, trySize - piece);
20             }
21         } else {
22             let K = size / 2 ** 10,
23                 M = K / 2 ** 10;
24             return { K, M };
25         }
26     }
27 
28     _strategy.clear();
29 
30     const { K, M } = test(
31         [20, 18, 16, 13, 10].map((level) => 2 ** level), // 预估一个存储梯度
32         0,
33     );
34 
35     _strategy.clear();
36 
37     console.log(`${strategy}大致可存储 ${K}K，合约 ${M}M`);
38 }
39 
40 env("localStorage");
41 env("sessionStorage");