Method readFile

src/core/Utils.mjs:1183–1217

* Reads a File and returns the data as a Uint8Array. * * @param {File | for node: array|arrayBuffer|buffer|string} file * @returns {Uint8Array} * * @example * // returns Uint8Array(5) [104, 101, 108, 108, 111] * await Utils.readFile(new File(["hello"], "test"))

(file)

     * await Utils.readFile(new File(["hello"], "test"))
     */
    static readFile(file) {

        if (isNodeEnvironment()) {
            return Buffer.from(file).buffer;

        } else {
            return new Promise((resolve, reject) => {
                const reader = new FileReader();
                const data = new Uint8Array(file.size);
                let offset = 0;
                const CHUNK_SIZE = 10485760; // 10MiB

                const seek = function() {
                    if (offset >= file.size) {
                        resolve(data);
                        return;
                    }
                    const slice = file.slice(offset, offset + CHUNK_SIZE);
                    reader.readAsArrayBuffer(slice);
                };

                reader.onload = function(e) {
                    data.set(new Uint8Array(reader.result), offset);
                    offset += CHUNK_SIZE;
                    seek();
                };

                reader.onerror = function(e) {
                    reject(reader.error.message);
                };

                seek();
            });
        }
    }

    /**
     * Synchronously read the raw data from a File object.