file-box/dist/esm/src/pure-functions/sized-chunk-transformer.js

Pack a File into Box for easy move/transfer between servers no matter of where it is.(local path, remote url, or cloud storage)

/**
 * ChunkerTransformStream, a transform stream to take arbitrary chunk sizes and make them consistent
 * https://codereview.stackexchange.com/q/57492/185709
 */
import stream from 'stream';
/**
 * TCP streaming workload tuning
 *  https://www.ibm.com/docs/en/aix/7.2?topic=tuning-tcp-streaming-workload
 */
const DEFAULT_CHUNK_BYTE = 256 * 1024; // 256 KB
/**
 * @param chunkByte The size of the chunks to be created
 * @returns
 */
function sizedChunkTransformer(chunkByte = DEFAULT_CHUNK_BYTE) {
    let buffer = Buffer.from([]);
    const transform = function (chunk, _, done) {
        buffer = Buffer.concat([buffer, chunk]);
        while (buffer.length >= chunkByte) {
            this.push(buffer.slice(0, chunkByte));
            buffer = buffer.slice(chunkByte);
        }
        done();
    };
    const flush = function (done) {
        if (buffer.length) {
            this.push(buffer);
        }
        done();
    };
    const chunker = new stream.Transform({
        flush,
        objectMode: true,
        transform,
    });
    return chunker;
}
export { sizedChunkTransformer, };
//# sourceMappingURL=sized-chunk-transformer.js.map