如何使用 javascript 将 base64 转换为压缩文件？

Question

我有这种格式，我想将其转换为压缩文件并使用 javascript 解压缩该文件。当我转换这个https://base64.guru/converter/decode/file?fbclid=IwAR3X1qwrnSLTw9cHT9iKl5HxiCRmKG5l0tForN3Odraz_4pYsYApoVprEJE 时，它会给出一个压缩文件，我必须解压缩文件以增加数据

{
    "awslogs": {
        "data": "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"
    }
}

Answer 1

我们可以使用 node 的 zlib 和 buffer 模块来解析为 base64 和 gunzip：

const zlib = require("zlib");
function unzip(str) {
    return new Promise((res, rej) => {
        // we read in the base64
        const data = Buffer.from(str, "base64");
        // we create a transform string to gunzip it
        const gzip = zlib.createGunzip();
        // initialize ret with an empty buffer
        let ret = Buffer.alloc(0);
        gzip.on("data", function(dat) {
            // concatenate the data to ret
            ret = Buffer.concat([ret, dat], res.length + dat.length);
        });
        gzip.on("error", function(err) {
            rej(err);
        });
        gzip.on("end", function() {
            // we're done, resolve the promise
            res(ret);
        });
        // send the data to the gunzip stream
        gzip.end(data);
    });
}

const data = "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";
// this uses promises for asynchronous execution
unzip(data).then(v => console.log(v.toString("utf8")));