计算文件的md5值

作者: 菜鸟的平凡之路 | 来源:发表于2020-07-03 16:11 被阅读0次

            export function getFileMd5(file) {
                let chunkSize = 2097152, // 2M
                    chunks = Math.ceil(file.size / chunkSize),
                    currentChunk = 0,
                    spark = new SparkMD5.ArrayBuffer(),
                    fileReader = new FileReader(),
                    blobSlice = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice
                fileReader.onload = function (e) {
                    spark.append(e.target.result)
                    currentChunk++
                    if (currentChunk < chunks) {
                    loadNext()
                    } else {
                    console.log('fileMd5', spark.end())
                    }
                }
                fileReader.onerror = function (e) {
                    // 出错
                }

                function loadNext() {
                    let start = currentChunk * chunkSize
                    let end = ((start + chunkSize) >= file.size) ? file.size : start + chunkSize
                    fileReader.readAsArrayBuffer(blobSlice.call(file, start, end))
                }
                loadNext()
            }