ts-md5/dist/esm/md5_file_hasher.js

TypeScript MD5 implementation

import { Md5 } from './md5';
// Hashes any blob
export class Md5FileHasher {
    constructor(_callback, // Callback to return the result
    _async = true, // Async version is not always available in a web worker
    _partSize = 1048576) {
        this._callback = _callback;
        this._async = _async;
        this._partSize = _partSize;
        this._configureReader();
    }
    /**
     * Hash a blob of data in the worker
     * @param blob Data to hash
     */
    hash(blob) {
        const self = this;
        self._blob = blob;
        // self._length = Math.ceil(blob.size / self._partSize);
        self._part = 0;
        self._md5 = new Md5();
        self._processPart();
    }
    _fail() {
        this._callback({
            success: false,
            result: 'data read failed'
        });
    }
    _hashData(e) {
        let self = this;
        self._md5.appendByteArray(new Uint8Array(e.target.result));
        if (self._part * self._partSize >= self._blob.size) {
            self._callback({
                success: true,
                result: self._md5.end()
            });
        }
        else {
            self._processPart();
        }
    }
    _processPart() {
        const self = this;
        let endbyte = 0;
        let current_part;
        self._part += 1;
        if (self._blob.size > self._partSize) { // If blob bigger then part_size we will slice it up
            endbyte = self._part * self._partSize;
            if (endbyte > self._blob.size) {
                endbyte = self._blob.size;
            }
            current_part = self._blob.slice((self._part - 1) * self._partSize, endbyte);
        }
        else {
            current_part = self._blob;
        }
        if (self._async) {
            self._reader.readAsArrayBuffer(current_part);
        }
        else {
            setTimeout(() => {
                try {
                    self._hashData({
                        target: {
                            result: self._reader.readAsArrayBuffer(current_part)
                        },
                    });
                }
                catch (e) {
                    self._fail();
                }
            }, 0);
        }
    }
    _configureReader() {
        const self = this;
        if (self._async) {
            self._reader = new FileReader();
            self._reader.onload = self._hashData.bind(self);
            self._reader.onerror = self._fail.bind(self);
            self._reader.onabort = self._fail.bind(self);
        }
        else {
            self._reader = new FileReaderSync();
        }
    }
}
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