yyzone/src/components/business/security-upload/utils.js

yyzone vue components and utils

import SparkMD5 from 'spark-md5';


const chunkSize = 1048576;


export function calcFileMd5(file) {
    return new Promise((resolve, reject) => {
        const blobSlice = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice;
        const spark = new SparkMD5();
        const fileReader = new FileReader();
        const chunkTotal = Math.ceil(file.size / chunkSize);
        let currentChunk = 0;

        fileReader.onload = e => {
            spark.append(e.target.result);
            currentChunk ++;
            if (currentChunk < chunkTotal) readNext();
            else {
                resolve(spark.end())
            }
        }

        fileReader.onerror = err => reject(err);

        function readNext() {
            const start = currentChunk * chunkSize;
            const end = ((start + chunkSize) >= file.size) ? file.size : start + chunkSize;

            fileReader.readAsArrayBuffer(blobSlice.call(file, start, end))
        }

        readNext();
    })
}